feeding of sheep

8/7/2019 feeding of sheep

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An introduction to feeding small

ruminants

Feed is the single largest cost associated with raising small ruminants, typicallyaccounting for 60% or more of total production costs. It goes without saying thatnutrition exerts a very large influence on flock reproduction, milk production,and lamb and kid growth.

Late-gestation and lactation are the mostcritical periods for ewe and doe nutrition,with lactation placing the highest nutritionaldemands on ewes/does. Nutrition level

largely determines growth rate in lambs andkids. Lambs and kids with higher growthpotential have higher nutritional needs,especially with regards to protein. Animalsreceiving inadequate diets are more prone todisease and will fail to reach their genetic potential.

Small ruminants require energy, protein, vitamins, minerals, fiber, and water.Energy (calories) is usually the most limiting nutrient, whereas protein is themost expensive. Deficiencies, excesses, and imbalances of vitamins and mineralscan limit animal performance and lead to various health problems. Fiber (bulk) isnecessary to maintain a healthy rumen environment and prevent digestiveupsets. Water is the cheapest feed ingredient, yet often the most neglected.

Many factors affect the nutritional requirements of small ruminants:maintenance, growth, pregnancy, lactation, fiber production, activity, andenvironment. As a general rule of thumb, sheep and goats will consume 2 to 4percent of their body weight on a dry matter basis in feed. The exact percentagevaries according to the size (weight) of the animal, with smaller animals needinga higher intake (percentage-wise) to maintain their weight.

Maintenance requirements increase as the level of the animals' activity increases.For example, a sheep or goat that has to travel a farther distance for feed and

water will have a higher maintenance requirements than animals in a feed lot.Environmental conditions also affect maintenance requirements. In cold andsevere weather, sheep and goats require more feed to maintain body heat. Theadded stresses of pregnancy, lactation, and growth further increase nutrientrequirements.

The following chart gives the nutritional requirements for various classes ofsheep and goats:


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Sheep Percent Protein (CP) Percent Energy (TDN)

Maintenance (154 lb.mature ewe)

9.6 57.6

Late Gestation180-225% lamb crop

expected11.2 66.7

LactationNursing Twins

14.8 64.5

Early Weaned Lambs(66 lbs.)

Moderate growthHigh Growth

14.5 75.8

Lamb Finishing88 lbs., 4-7 mos of age

11.7 77.1

Yearlings (110 lbs.) 9.1 57.6

Source: Sixth Revised Edition, National Research Council, 1985.

Goats Percent Protein (CP) Percent Energy (TDN)

Bucks 11 60

Dry Doe 10 55

Late Gestation 11 60

LactationAvg. Milk

High Milk

1114

6065

Weanling 14 68

Yearlings 12 65

The next chart gives typical "book values" or "ballpark" figures for the nutritionalcontent of various feedstuffs commonly fed to sheep and goats.

Feed Stuff Percent Protein (CP) Percent Energy (TDN)

Mature Pasture 8 50

Clover Pasture 25 69

Orchardgrass Pasture 18 65

Browse (Honeysuckle) 16 72

Soybean Meal 44 88

Complete Pellets 12 78

Barley Grain 13.5 84


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Corn Grain 10 89

Poor Hay 8 50

Grass Hay 12 58

Mixed Hay 15 50

Legume Hay 18 62

A sheep or goat's nutritional requirements can be met by feeding a variety of feedstuffs. Feed ingredients can substitute for one another so long as the animalsnutritional requirements are being met. Small ruminant feeding programs shouldtake into account animal requirements, feed availability, and costs of nutrients.

Pasture, forbs, and browsePasture, forbs, and browse are usually theprimary and most economical source of

nutrients for sheep and goats, and in somecases, pasture is all small ruminants need tomeet their nutritional requirements. Pasturetends to be high in energy and protein when itis in a vegetative state. However, it can have ahigh moisture content, and sometimes it maybe difficult for high-producing animals to eatenough grass to meet their nutrientrequirements.

As pasture plants mature, palatability and digestibility decline, thus it is

important to rotate pastures to keep plants in a vegetative state. During the earlypart of the grazing season, browse (woody plants, vines and brush) and forbs(weeds) tend to be higher in protein and energy than ordinary pasture. Sheep areexcellent weed eaters. Goats are natural browsers and have the unique ability toselect plants when they are at their most nutritious state. Sheep and goats thatbrowse have fewer problems with internal parasites.

HayHay is the primary source of nutrients for small ruminants during the winter ornon-grazing season. Hay varies tremendously in quality, and the only way to

know the nutritional content is to have the hay analyzed by a forage testinglaboratory. Hay tends to be a moderate source of protein and energy for sheepand goats. Legume hays --alfalfa, clover, lespedeza -- tend to be higher in protein,vitamins and minerals, especially calcium, than grass hays. The energy, as well asprotein content of hay depends upon the maturity of the forage when it washarvested for forage. Proper curing and storage is also necessary to maintainnutritional quality of hay.


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SilageSilage made from forage or grain crops has been successfully fed to both sheepand goats; however, special attention must be paid to quality, as moldy silage cancause listeriosis or "circling disease" in small ruminants. As with fresh forage, thehigh-producing animal often cannot consume enough high moisture silage to

meet its nutritional needs. Silage is typically fed on large farms, due to the needfor storage and automated feeding equipment.

ConcentratesIt is oftentimes necessary to feed concentrates to provide the nutrients thatforage alone cannot provide. This is particularly true in the case of high-producing animals. There are also times and situations where concentrates are amore economical source of nutrients. Creep feeding and supplemental feeding oflambs and kids has been shown to increase growth weight, but should only bedone to the extent that it increases profit.

There are two types of concentrate feeds: carbonaceous and proteinaceous.Carbonaceous concentrates or "energy" feeds tend to be low in protein (8-11%).They include the cereal grains --corn, barley, wheat, oats, milo, and rye. It is notnecessary to process grains for sheep and goats unless the animals are less thansix weeks of age and lack a functioning rumen.

One of the problems with feeding a lot ofcereal grains is that they are high inphosphorus content, but low in calcium.Feeding a diet that is high in phosphorus andlow in calcium can cause urinary calculi

(kidney stones) in wethers and intact males.Inadequate calcium can lead to milk fever(hypocalcemia) in pregnant or lactatingewes/does.

Proteinaceous concentrates or "proteinsupplements" contain high levels of protein (>15%) and may be of animal or plantorigin. They include soybean meal, cottonseed meal, and fish meal. Ruminant-derived meat and bone meal cannot (by law) be fed to other ruminants, includingas sheep and goats. Protein quantity is generally more important than proteinquality (amino acid content) in ruminant livestock since the microorganisms in

the rumen manufacture their own body protein.

Livestock do not store excess protein; it is burned as energy or eliminated (asnitrogen) by the kidneys. Since parasites often cause blood loss in smallruminants, higher levels of protein in the diet may enable the animal to mount agreater immune response to parasites.
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By-products feeds, such as fat, soy hulls, wheat middlings, and broiler litter maycontain high levels of various nutrients and can be incorporated into smallruminant diets if they are cost effective. Due to its copper content, it is notrecommended that sheep be fed broiler litter for sustained periods of time.

Many feed companies offer "complete" sheep and/or goat feeds -- pelleted ortextured -- which are balanced for the needs of the animals in a particularproduction class. Pelleted rations have an advantage in that the animals cannotsort feed ingredients. While complete sheep feeds have been available for manyyears, it has only been in recent years, that meat goat rations have beenintroduced to the market place. Complete feeds come in 50 or 100 lb. sacks andtend to be much more expensive than home-made concentrate rations.

Vitamins and mineralsMany minerals are required by small ruminants. The most important are salt,calcium, and phosphorus. The ratio of calcium to phosphorus should be keptaround 2:1 to prevent urinary calculi. Vitamins are need in small amounts. Smallruminants require vitamins A, D and E, whereas vitamin K and all the B vitaminsare manufactured in the rumen.

A free choice salt-vitamin-mineral premixshould be made available to small ruminantsat all times, unless a premix has beenincorporated into the grain ration or TMR(total mixed ration). In the very least, ewesand does should be fed pre-choice mineralduring late gestation and lactation. Either a

loose mineral or mineral block may beoffered. Force-feeding minerals and vitaminsis actually better than offering it free choicesince animals will not consume mineralsaccording to their needs.

Mid-Atlantic soils are typically deficient in selenium, thus the premix should befortified with selenium to preventwhite muscle diseasein lambs and kids andreproductive problems in females. Supplementing selenium via the feed ormineral is preferred to giving selenium injections.

Goats appear to have a much higher tolerance for copper in their diets ascompared to sheep, thus it is recommended that feeds and/or premixes containcopper, unless the goats are co-mingled with sheep. Sheep should be fed mineralmixes that have been specifically formulated for sheep.

It is possible to get pelleted supplements that contain vitamins and minerals, aswell as high levels of protein (34-40%). These supplements can easily becombined with whole grains or by-product feeds to create a balanced concentrate
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ration. Coccidiostats and antibiotics can also be added to the mineral mix orsupplement. Bovatec (lasalocid) is FDA- approved to coccidiosis in lambs.Rumensin (monensin) is FDA approved for goats. Deccox is approved as acoccidiostat for both species.

WaterSmall ruminants should have ad libitumaccess to clean, fresh water at all times. Amature animal will consume between to 1 gallons of water per day. Waterrequirements and intake increase greatlyduring late gestation and during lactation.Water requirements increase substantiallywhen environmental temperatures rise above70?F and decline with very cold

environmental temperatures.

An animals nutrient requirements will increase if it has to consume cold waterduring cold weather. Rain, dew, and snowfall may dramatically decrease freewater intake. Inadequate water intake can cause various health problems. Inaddition water and feed intake are positively correlated.

Introduction

Nutrition plays a major role in the overall productivity, health, and well-being of thesheep flock. Because feed costs account for approximately two-thirds of the total cost of

production on most Virginia sheep farms, it is important that producers consider nutritionmanagement a top priority. Nutrient requirements of sheep vary with differences in age,body weight, and stage of production. The five major categories of nutrients required bysheep are: 1) water; 2) energy; 3) protein; 4) vitamins; and 5) minerals. During thegrazing season, sheep are able to meet their nutrient requirements from pasture and a saltand mineral supplement. Hay is provided to the flock when forages are limited, and grainmay be added to the diet at certain stages of production when additional nutrientsupplementation is required. Small grain pastures or stockpiled fescue can supply up toone-half of the feed requirements of the ewe flock during the winter. For winter-bornlambs, creep diets and diets for early-weaned lambs are formulated from high energy feedgrains and protein supplements to promote accelerated growth. During the grazing

season, pastures of mixed grass and clover, alfalfa, small grain, and turnip serve asexcellent sources of nutrition for growing lambs. A source of clean, fresh water isprovided to sheep at all times.

Return to Table of Contents
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Feeding the Ewe Flock

Ewe body weight does not remain constant throughout the year, but changes with stage ofproduction. Nutrient requirements are lowest for ewes during maintenance, increasegradually from early to late gestation, and are highest during lactation. Decisions

affecting feeding management are improved significantly by knowing ewe body weightand condition score at three distinct stages of production: 1) three weeks before breeding;2) mid-gestation; and 3) weaning. Condition score is a subjective measure of body fatthat is most easily determined by handling ewes down their back. It is the best methodavailable to monitor nutritional status and overall well-being of the sheep flock.Condition scores range from 0 to 5, with 0 being extremely thin and 5 being very fat.Condition scores at either end of the scale are undesirable. Ideally, ewes should rangefrom a condition score of 2.5 at weaning to a 3.5 at lambing. When necessary, thin ewesare separated and fed additional energy to increase body condition. Conversely, obeseewes are separated and fed a lower energy diet at a stage of production when body weightloss is acceptable. It should be noted that problems with overfat ewes are far fewer than

those associated with ewes that are too thin.

Starting two weeks before breeding and continuing two weeks into the breeding period,ewes should be placed on high-quality pasture or supplemented daily with .75 to 1 poundwhole shelled corn or barley. This management practice is called flushing and has beenshown to improve lambing percentage by 10 to 20 percent. Flushing works best withmature ewes that are in moderate body condition, and has been shown to be moreeffective for early- and out-of-season breeding than at the seasonal peak of ovulationduring the fall. Most prenatal deaths occur within the first 25 days after breeding and areusually associated with poor nutrition. Therefore, it is important not to make dramaticreductions in nutrient supplies during the breeding season. Pastures with more than 50

percent clover or other legumes should be avoided during breeding because legumes maycontain estrogenic compounds that reduce conception rates. From breeding to six weeksbefore lambing, the ewe flock can be maintained on permanent pastures, small grainpastures, stockpiled fescue, aftermath crop fields, or hay. Fetal growth is minimal, andthe total feed requirement of the ewe is not significantly different from a maintenancediet.

The developing fetus acquires approximately two-thirds of its weight during the last sixweeks of pregnancy. Rumen capacity may be limited with ewes carrying multiple fetuses.Therefore, it is important to supplement ewes with .75 to 1 pound of corn or barley inaddition to their normal diet starting six weeks before lambing, to prevent pregnancy

toxemia, low birth weights, weak lambs at birth, and low milk production. Producersshould be careful not to overfeed grain during late gestation, which could result inlambing difficulty caused by large lambs.

After lambing, the energy and protein requirements of the ewe increase by 30 and 55percent, respectively. Failure to supplement ewes accordingly results in excessive bodyweight loss, low milk production, mismothering, and poor lamb gains. Proteinsupplementation is especially critical for ewe flocks with a high percentage of multiple


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births. Unless high quality legume hays are fed, protein supplementation will benecessary as a part of the grain portion of the diet. A general rule of thumb forconcentrate feeding of lactating ewes is 1 pound of grain for each lamb nursing the ewe.Ewes should be sorted into feeding groups based on type of rearing (single, twin, etc.) tomake sure grain supplements are neither over- or underfed. Table 1 gives the TDN and

crude protein requirements of ewes based on body weight and stage of production. Byknowing the nutrient requirements of the ewe and the nutrient content of the feed, dietscan be properly formulated to meet the nutritional needs of the ewe. Shown in Table 2 arethe estimated quantities of hay, corn and soybean meal that would be fed to a 175 poundewe at different stages of production and with different crude protein values for the hay.To successfully use this table, hay samples should be submitted to a testing lab todetermine its crude protein content.

Table 1. Changes in the Daily Total Digestible Nutrients (TDN) and Protein

Requirements of a Ewe from Maintenance Through Early Lactation.

Stage of

production

Ewe weight

130 lba 155 lba 175 lba 200 lba

TDN Protein TDN Protein TDN Protein TDN Protein

lb

Maintenance 1.30 0.23 1.50 0.25 1.60 0.27 1.70 0.29

Earlypregnancy

1.60 0.27 1.70 0.29 1.80 0.31 1.90 0.33

Latepregnancyb

2.60 0.45 2.80 0.47 2.90 0.49 3.00 0.51

Earlylactation,

single

3.30 0.70 3.60 0.73 3.70 0.76 3.80 0.78

Earlylactation,twins

3.70 0.89 4.00 0.92 4.30 0.96 4.60 0.99

Earlylactation,tripletsc

3.90 0.99 4.20 1.02 4.60 1.06 5.00 1.10

aBased on ewe weight at breeding time.bNational Research Council recommendations for ewes expected to have a 180-to 225-percent lamb crop. If130-to 150-percent lamb crop is expected, then you can reduce total digestible nutrients by 0.4 pound andprotein by 0.05 pound.

cEstimates made by adding on one-half of the difference between ewes nursing singles and twins to theamount indicated for ewes nursing twins.

Table 2. The Amount of Hay, Shelled Corn (SC), and Soybean Meal (SBM) Required

to Meet the Total Digestible Nutrients (TDN) and Crude Protein (CP) Requirements

of a 175-lb Ewe When the Hay Contains Different Protein Levels.

Stage of

production

Percent protein in hay*

16.5 15.0 12.5 10.0


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lb

Maintenance Hay 3.25 3.25 3.25 3.25

Earlypregnancy

Hay 3.75 3.75 3.75 3.75

Latepregnancy

Hay 4.20 4.20 4.20 4.20

SC 1.00 1.00 1.00 1.00

SBM 0.10

Early lactation(single)

Hay 5.00 5.00 5.00 5.00

SC 1.50 1.50 1.40 1.15

SBM 0.10 0.40

Early lactation(twins)

Hay 5.00 5.00 5.00 5.00

SC 2.25 2.10 1.90 1.15

SBM 0.10 0.40 0.75

Early lactation

(triplets)

Hay 3.50 3.50 3.50 3.50

SC 3.15 2.95 2.70 2.45

SBM 0.45 0.65 0.90 1.15

Note: Adjusted from dry matter values: Corn - 80 percent TDN and 8.8 percent CP, SBM -80 percent TDNand 44 percent CP, Hay - 50 percent TDN. TDN of hay increases as hay quality increases, but is leftconstant here for ease of discussion and diet calculations.*Percentages are figured on an as-fed basis, as are the pounds of feed.


Feeding Lambs

Feeding programs in Virginia for growing and finishing lambs are different for winter-and spring-lambing production systems. Lambs born from November through earlyFebruary will likely be grown and finished on high concentrate feeds. Lambs born afterthe middle of February are placed on pasture with their dams where they remainthroughout the spring and summer. If necessary, spring-born lambs are weaned andfinished to market weight in the fall, using a grain on grass feeding program or placed ina feedlot for an abbreviated period of high concentrate feeding.

Lambs on a winter-lambing program should have access to a high quality creep feed by

the time they are seven days old. Creep feeds should contain 18 to 20 percent crudeprotein and be low in fiber (high in energy). The source of protein in commerciallyprepared lamb creep pellets should be all natural protein. Because the rumen of younglambs is not fully developed, urea should not be used as a partial source of protein in thediet. A 2:1 calcium to phosphorous ratio is maintained in on-farm feed mixes by addingfeed grade limestone at 1 percent of the diet. Calcium to phosphorous ratios of less than2:1 may lead to urinary calculi (water belly), which most often results in the death of thelamb. If the addition of limestone to the diet fails to control urinary calculi, ammonium
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chloride should be added at .5 percent of the diet. When constructing a creep area, keepthe following points in mind: 1) place the creep in a convenient location close to an areawhere the ewe flock congregates; 2) have openings on at least two sides of the creep andseveral openings per side; 3) keep the creep area clean and well bedded; 4) place a lightover the creep to help attract the lambs to the feed or arrange the creep in such a way that

the sun shines into the area during the day; 5) provide fresh water in the creep area; and6) construct the creep feeder so that lambs cannot stand and play in it. Allow 2 inches oftrough space per lamb.

Winter-born lambs should be weaned and adjusted to a growing diet by the time they aretwo months of age. A growing diet for lambs weighing 40 to 70 pounds should containapproximately 78 percent TDN and 16 percent crude protein. At body weights of 70pounds and up, the level of crude protein in the diet can be lowered to 14 percent. Feedefficiency values range from 2 pounds of feed per pound of gain for light weight young,growing lambs on up to 3.5 to 4 pounds of feed per pound of gain as winter-born lambsapproach their optimum market weight. Feed efficiency values for old-crop (spring born)

feeder lambs weighing 75 pounds and up in the fall average 5 to 5.5 pounds of feed perpound of gain when a whole-grain feeding program is used. Whole-grain feedingimproves feed efficiency, increases rate of gain, and lowers the feed cost per pound oflamb gain. Whole-grain diets consist of whole (unprocessed) grains, such as shelled cornor barley, mixed with a pelleted protein-mineral supplement. No roughage is contained inthe feed or supplemented on the side. Consequently, the diet is high in energy andpromotes accelerated lamb gains.

Ground ear corn, silage, and urea should not be fed until lambs are weighing 65 poundsand up. Creep diets should be ground or pelleted. Weaned lamb growing and finishingdiets may be ground, pelleted, or consist of a mixture of whole grain and a pelleted

supplement.


Ram Feeding

Rams should have a body condition score of 3.5 to 4 before the beginning of the breedingseason. Once turned in with the ewes for breeding, rams spend very little time eating.They can lose up to 12 percent of their body weight during a 45-day breeding period.

That equates to 30 pounds for a 250 pound ram. Poor nutrition is a major cause of rammortality. As the sheep industry has moved away from smaller framed, earlier maturingtypes of sheep to larger framed, later maturing types of sheep, they have increased therams' mature body weight. In many cases, forage alone is not adequate nutrition forplacing rams in proper body condition for the breeding season. At the very least, ramsshould be evaluated for body condition six weeks before breeding. Thin rams shouldreceive grain supplementation as a means to increase body weight and condition. It takes50 days and approximately 2.5 pounds of corn per day in addition to a ram's normal diet


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to move him from a weight of 225 pounds to 250 pounds. Mature rams, not in breeding,can be maintained on pasture or wintered on good quality hay. Six to eight pounds ofmixed grass and clover hay is sufficient to meet the daily energy requirements of a 250pound ram. A free choice source of water, salt, and minerals should be available at alltimes.


Feeds for Sheep

Pasture

Permanent pasture should be the predominant source of nutrition for the sheep flock.Intensive sheep production systems where the sheep are housed and fed harvested feeds

are not as profitable as more extensive production systems where they harvest their ownfeed. When a sufficient quantity of forage is available, sheep are able to meet theirnutrient requirements from forage alone along with a supplemental source of salt andminerals. Clover should be overseeded on permanent pastures in the winter to improvethe quantity and quality of forage produced during the grazing season. Sheep prefer tograze leafy, vegetative growth that is 2 to 6 inches tall rather than stemmy, more matureforages. Pasture growth is not distributed evenly throughout the year. Approximately 60percent of the annual dry matter production of most species of cool season grasses occursin the spring. When pastures are not stocked heavily enough to utilize the spring flush ofgrowth, sheep graze and regraze certain areas while other areas are left to mature and goto seed. This type of grazing behavior weakens those plants that are grazed more

frequently and gives the less desirable plants a competitive advantage. Approximatelyone-third of spring pasture should be fenced for hay production. After a hay cutting,pasture should be given a three- to four-week recovery period before making it availablefor grazing the remainder of the year. Rotational grazing programs designed for themovement of sheep every 10 to 14 days are instituted in late June and early July toimprove both pasture and lamb production. More intensive rotational grazing systemswhere higher stocking rates are used help to promote more complete forage utilization,but also require greater input costs in the form of fence and water and may result inhigher levels of internal parasitism, increased risk of coccidiosis, and impaired lambperformance.


Hay

Average or poor quality hay should be fed during gestation, leaving the higher qualityhay to be fed during lactation. Because protein requirements of the ewe increase
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dramatically after lambing, less protein supplementation from concentrate feeds isrequired when higher quality hay is used. Second-cutting, mixed grass-clover hay may bemore economical to feed to the ewe flock than alfalfa hay. This is especially true if alfalfahay must be purchased from off the farm. Alfalfa hay is an excellent feed for sheep and isbest used during lactation when ewes require more protein to promote higher levels of

milk production. Many producers have fed alfalfa hay to gestating ewes with goodresults. However, some producers feeding alfalfa hay to gestating ewes have experiencedproblems with vaginal prolapses, late term abortions, and milk fever. If alfalfa hay isbeing fed during late gestation, it should be limit fed and be free of must and mold.Because of its high quality and palatability, ewes consume more alfalfa hay than isneeded. The bulkiness of the hay in the rumen may place pressure on the reproductivetract, resulting in a vaginal prolapse before lambing. Ewes receiving alfalfa hay duringgestation are more prone to milk fever than ewes fed grass hay. Because alfalfa is high incalcium, ewes are able to meet their calcium requirements without mobilizing body storesof calcium. However, after lambing, ewes not accustomed to mobilizing bone calciummay experience milk fever because of their inability to meet the additional calcium

requirements associated with lactation. Regardless of the type of hay fed, producersshould submit hay samples to a forage testing lab to determine its nutrient content. Byknowing the nutrient content of the hay, diets can be more accurately and economicallyformulated for the sheep flock.

In general, there is less waste and more flexibility when feeding hay harvested as squarebales. However, round bales can provide quality feed for sheep when stored and fedproperly. To minimize dry matter and nutrient losses, which can approach 40 to 50percent, round bales should be covered with plastic for outside storage or placed undershelter. Bales should be stored on pallets or tires to prevent ground contact. Feedinground bales without a feeder may result in as much as 30 percent of the hay being wasted,

and poses a hazard to the sheep should the bales roll over. A variety of round bale feedersare commercially available. Feeders designed in the shape of a cradle hold the bales upoff the ground, are maintenance free, and appear to work best for minimizing waste.


Silage

High quality, finely chopped (1/4 to 1/2 inch) corn, grass, or small grain silage is

acceptable feed for sheep. Care must be taken to properly harvest, store, and feed silage.Poorly packed silage may contain harmful molds, which causes listeriosis (circlingdisease) in sheep. Moldy or frozen silage should be discarded and troughs should becleaned daily.

Corn silage is low in protein and calcium. Studies have shown that the addition of 20pounds of urea, 10 pounds of ground limestone, 4 pounds of dicalcium phosphate, and 5pounds of calcium sulfate per ton of silage at the time of ensiling makes a complete feed


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for the ewe flock by increasing its crude protein and calcium content. Alternatively, extraprotein, calcium, phosphorous, and vitamins can be supplied through a grain mixtopdressed on the silage at the time of feeding.

Because of its high moisture content, 3 pounds of silage is required to supply the TDN

furnished by 1.5 pounds of hay. The bulkiness of silage prevents adequate dry matterintake and its use as the sole source of feed for ewes in late gestation. A typical diet fed toewes during the last four weeks of pregnancy on an as fed basis would contain: 6 poundsof corn silage (35 percent dry matter), 2 pounds of hay, 0.5 pound of corn, and 0.25pound of soybean meal.


Grain

When additional energy and protein are required, corn and soybean meal commonly formthe basis of the grain portion of the diet. However, when justified by supply or price,other grains may replace all or part of the corn and soybean meal in a diet. The energyvalue of other common grains compared to corn and the maximum amounts to use in eweand lamb diets are given in Table 3. Because of its high fiber content, the replacementvalue of oats ranges from 50 to 100 percent. The higher replacement rate is used forbreeding sheep, while the lower rate is used in creep feeds and finishing diets for lambs.Alternative sources of protein to soybean meal include cottonseed and peanut meal.

Table 3. Value of Grain Substitutes for Corn.

Ingredient Energy Value of Corn % Maximum Replacement forCorn (%)

Corn 100 100

Barley 90 100

Oats 80 50-100

Wheat 100 50

Sorghum 90 100


Differences in Value

To determine if other feeds are a better value than corn or soybean meal, comparisons canbe made based on the cost per unit of nutrient. If corn is selling for $0.06 per pound andbarley is selling for $0.05 per pound, which is the better buy for TDN? Divide $0.06 perpound by 92 percent TDN for corn to get $0.065 per pound of TDN. Divide $0.05 per


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pound by 85 percent TDN for barley to get $0.059 per pound of TDN. In this example,even though barley has a lower TDN value than corn, it is still a better buy than corn. Ifalfalfa hay is selling for $120 a ton and soybean meal is selling for $250 a ton, which isthe better buy for crude protein? Divide $0.06 per pound by 15 percent crude protein foralfalfa hay to get $0.40 per pound of crude protein. Divide $0.125 per pound by 44

percent crude protein for soybean meal to get $0.284 per pound of crude protein. In thisexample, even though alfalfa hay is selling for less than half the price of soybean meal,soybean meal is still a better buy than alfalfa hay.


Alternative Feeds

Table 4 provides a list of some of the by-products of grain milling and processing and

certain nontraditional feeds that are commonly available in Virginia. They are consideredto have more value and less risk when fed to the ewe flock than to lambs. Caution shouldbe used when substituting alternative feeds for corn and soybean meal when they appearto be a better value. Although these feeds may be comparable in terms of nutrientanalysis, the animals may not perform similarly. Therefore, it is important to know ifthere are problems with certain alternative feeds, and to monitor the performance of thesheep flock once changes have been made.

Table 4. Potential Alternative Feeds for Sheep in Virginia.

IngredientaAverage Nutrient

ValueLimitations Remarks

Corn Gluten Feed 80% TDN 24% CrudeProtein

No Limitations Best used as a sourceof protein to go withcorn or barley

Dry Distillers Grains 87% TDN 27% CrudeProtein

No Limitations Can be substituted for up to one half of thesoybean meal in thediet without losing thebenefits of all soybeanmeal

Hominy Feed 92% TDN 11% Crude

Protein

Limit to 1 lb per day Feed within one month

of purchaseSoybean Hulls 77% TDN 14% CrudeProtein

No Limitations Works well as asupplement to hay

Wheat Midds 18%Crude Protein

82% TDN Limit to 1 lb per day Pelleted form is easier to handle and feed

Whole Cottonseed23% Crude Protein

94% TDN Limit to l lb per day Contains Gossypol andshould not be fed toyoung lambs


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aWith the exception of soy hulls, all of these feeds are low in calcium and high in phosphorous. Therefore,calcium supplementation is necessary when these feeds are used.


Urea

Urea is not a protein supplement, but a source of nonprotein nitrogen (NPN) for proteinsynthesis by rumen bacteria. It should be used only in conjunction with high-energy feedssuch as corn. Urea, which is 45 percent nitrogen and has a crude protein equivalent of281 percent, should not supply over one-third of the total nitrogen in a diet. To determinethe pounds of nitrogen in a diet, multiply the total pounds of crude protein in the diet by16 percent. Other general rules for the use of urea are: 1) should not be more than 1percent of the diet or 3 percent of the concentrate mix; and 2) should not be more than 5

percent of a supplement to be used with low grade roughages.


Minerals

Salt and mineral supplementation is required on a free choice, year-round basis. Failureto supplement salt and minerals results in low fertility, weak lambs at birth, lowered milkproduction, impaired immunity, and numerous metabolic disorders. A variety of salt and

mineral supplements specifically formulated for sheep are commercially available. Thesesupplements range from trace mineralized salt (TMS) fortified with selenium to completemineral mixes containing all of the macro and micro minerals required by sheep. Ingeneral, TMS fortified with selenium is all that is needed during the spring and summerwhen sheep are grazing high quality pastures containing more than 20 percent clover.Complete mineral mixes are recommended when grazing low quality roughages, startingfour weeks before breeding, during breeding, and during late gestation and earlylactation. Virginia is a selenium deficient state. Studies have clearly shown that seleniumsupplementation for pregnant ewes via a mineral mix is superior to selenium injections inlate gestation. Mineral supplements formulated for cattle and horses should not be usedfor sheep because they are high in copper, which is toxic to sheep. Mineral concentration

is oftentimes expressed in parts per million (ppm). Equivalent expressions for 1 ppm are1 milligram per kilogram or .0001 percent. When high grain diets, certain alternativefeeds, or silage are fed to sheep, additional calcium is required in the diet. This can besupplied by adding feed grade limestone to the feed. A general rule is to add limestone at1 percent of the diet.

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Pearson Square

Protein is often the major limiting nutrient in a sheep diet. The Pearson Square is used toformulate simple diets on the basis of protein.

Problem: Using Table 1, assume a 155 lb ewe needs .92 lb crude protein per day to meether nutrient requirements in early lactation. Four pounds of mixed grass-clover hay (13%crude protein) will be fed per day along with 2 lb of a mixture of barley and soybeanmeal. What proportion of barley and soybean meal should be used in the mix?

1. Determine the percentage of crude protein (CP) contributed by the hay.a. 4 lb x .88% Dry Matter = 3.52 lb Dry Matter

b. 3.52 lb Dry Matter x 13% CP = .46 lb CP

2. Determine the amount of additional CP needed from the barley and soybean mealmix.

a. .92 lb CP Required - .46 lb CP from the Hay = .46 lb additional CPneeded

3. Determine the percentage of crude protein needed in the barley and soybean meal

mix.a. 2 lb x .90% Dry Matter = 1.8 lb Dry Matterb. .46 lb additional CP needed 1.8 lb Dry Matter = 25.5% CP in the grain

mix

4. Use a Pearson Square to determine the proportion of barley and soybean meal inthe mix.


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a. Subtract diagonally across the square, the smaller number from the largernumber without regard to the sign and record the difference at the rightcorners.

b. The parts of each feed can be expressed as a percentage of the total. 18.5 33.0 (100) = 56% Barley

14.5 33.0 (100) = 44% Soybean Mealc. Check the math to make sure that .46 lb CP is coming from the barley andsoybean meal mix.

1.8 lb Dry Matter from Grain Mix x 56% Barley x 11% CP = .11lb CP

1.8 lb Dry Matter from Grain Mix x 44% Soybean Meal x 44% CP= .35 lb CP

.11 lb CP from Barley + .35 lb CP from Soybean Meal = .46 lb CPfrom the 2 lb Grain Mix

Table 5. Sample Diets for Creep Feeding, Growing Lambs, and Finishing Lambs.

Feed Ingredient 18% Crude Protein* (Percent Ingredient in the Diet)

Cracked Corn 54 59 54 68

Whole Oats 20 10 - -

Whole Barley - - 20 -

Soybean Meal 25 25 25 26

Feed GradeLimestone

1 1 1 1

Molasses - 5 - 5

Vitamin Premix + + + +

Antibiotic orIonophore

+ + + +

*To be fed with free choice source of high quality alfalfa hay.

Feed Ingredient 16% Crude Protein (Percent Ingredient in the Diet)

Cracked Corn 59 59

Alfalfa Pellets(17% CP)

25 -

Ground LegumeHay (15% CP)

- 23

Soybean Meal 15 17

Feed GradeLimestone

1 1

Vitamin Premix + +


+ +



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Shelled Corn - - 85

Cracked Corn 64 - -

Corn and CobMeal

- 59 -

Ground LegumeHay (15% CP) 28 26 -

Soybean Meal 7 9 -

PelletedSupplement (36%CP)*

- - 15

Feed GradeLimestone

1 1 -

Vitamin Premix + + +


+ + +

*Vitamins and minerals are included in the pelleted protein supplement.

Table 6. Feeder Space Requirements - Inches Per Head.

Hay Rack Grain Trough Creep Feeder

Ewes - Limit Fed 18-24 16-20 -

Ewes - Self Fed 6-8 4-6 -

Baby Lambs - - 2

Feeder Lambs - LimitFed - 9-12 -

Feeder Lambs - SelfFed

- 1-2 -

Additional Recommended Reading

Virginia Cooperative Extension Publication 410-024,Finishing Lambs With WholeGrain.

Virginia Cooperative Extension Publication 410-366, Sheep Grazing Management.

Acknowledgment

Tables 1 and 2 were adapted from Management Guidelines for Efficient SheepProduction. North Central Regional Extension Publication 240.


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Disclaimer

Commercial products are named in this publication forinformational purposes only. Virginia CooperativeExtension does not endorse these products and does not

intend discrimination against other products Introduction

Nutrition plays a major role in the overall productivity, health, and well-being of thesheep flock. Because feed costs account for approximately two-thirds of the total cost ofproduction on most Virginia sheep farms, it is important that producers consider nutritionmanagement a top priority. Nutrient requirements of sheep vary with differences in age,body weight, and stage of production. The five major categories of nutrients required bysheep are: 1) water; 2) energy; 3) protein; 4) vitamins; and 5) minerals. During thegrazing season, sheep are able to meet their nutrient requirements from pasture and a saltand mineral supplement. Hay is provided to the flock when forages are limited, and grainmay be added to the diet at certain stages of production when additional nutrient

supplementation is required. Small grain pastures or stockpiled fescue can supply up toone-half of the feed requirements of the ewe flock during the winter. For winter-bornlambs, creep diets and diets for early-weaned lambs are formulated from high energy feedgrains and protein supplements to promote accelerated growth. During the grazingseason, pastures of mixed grass and clover, alfalfa, small grain, and turnip serve asexcellent sources of nutrition for growing lambs. A source of clean, fresh water isprovided to sheep at all times.



Ewe body weight does not remain constant throughout the year, but changes with stage ofproduction. Nutrient requirements are lowest for ewes during maintenance, increasegradually from early to late gestation, and are highest during lactation. Decisionsaffecting feeding management are improved significantly by knowing ewe body weightand condition score at three distinct stages of production: 1) three weeks before breeding;2) mid-gestation; and 3) weaning. Condition score is a subjective measure of body fatthat is most easily determined by handling ewes down their back. It is the best methodavailable to monitor nutritional status and overall well-being of the sheep flock.

Condition scores range from 0 to 5, with 0 being extremely thin and 5 being very fat.Condition scores at either end of the scale are undesirable. Ideally, ewes should rangefrom a condition score of 2.5 at weaning to a 3.5 at lambing. When necessary, thin ewesare separated and fed additional energy to increase body condition. Conversely, obeseewes are separated and fed a lower energy diet at a stage of production when body weightloss is acceptable. It should be noted that problems with overfat ewes are far fewer thanthose associated with ewes that are too thin.


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Starting two weeks before breeding and continuing two weeks into the breeding period,ewes should be placed on high-quality pasture or supplemented daily with .75 to 1 poundwhole shelled corn or barley. This management practice is called flushing and has beenshown to improve lambing percentage by 10 to 20 percent. Flushing works best withmature ewes that are in moderate body condition, and has been shown to be more

effective for early- and out-of-season breeding than at the seasonal peak of ovulationduring the fall. Most prenatal deaths occur within the first 25 days after breeding and areusually associated with poor nutrition. Therefore, it is important not to make dramaticreductions in nutrient supplies during the breeding season. Pastures with more than 50percent clover or other legumes should be avoided during breeding because legumes maycontain estrogenic compounds that reduce conception rates. From breeding to six weeksbefore lambing, the ewe flock can be maintained on permanent pastures, small grainpastures, stockpiled fescue, aftermath crop fields, or hay. Fetal growth is minimal, andthe total feed requirement of the ewe is not significantly different from a maintenancediet.

The developing fetus acquires approximately two-thirds of its weight during the last sixweeks of pregnancy. Rumen capacity may be limited with ewes carrying multiple fetuses.Therefore, it is important to supplement ewes with .75 to 1 pound of corn or barley inaddition to their normal diet starting six weeks before lambing, to prevent pregnancytoxemia, low birth weights, weak lambs at birth, and low milk production. Producersshould be careful not to overfeed grain during late gestation, which could result inlambing difficulty caused by large lambs.

After lambing, the energy and protein requirements of the ewe increase by 30 and 55percent, respectively. Failure to supplement ewes accordingly results in excessive bodyweight loss, low milk production, mismothering, and poor lamb gains. Protein

supplementation is especially critical for ewe flocks with a high percentage of multiplebirths. Unless high quality legume hays are fed, protein supplementation will benecessary as a part of the grain portion of the diet. A general rule of thumb forconcentrate feeding of lactating ewes is 1 pound of grain for each lamb nursing the ewe.Ewes should be sorted into feeding groups based on type of rearing (single, twin, etc.) tomake sure grain supplements are neither over- or underfed. Table 1 gives the TDN andcrude protein requirements of ewes based on body weight and stage of production. Byknowing the nutrient requirements of the ewe and the nutrient content of the feed, dietscan be properly formulated to meet the nutritional needs of the ewe. Shown in Table 2 arethe estimated quantities of hay, corn and soybean meal that would be fed to a 175 poundewe at different stages of production and with different crude protein values for the hay.To successfully use this table, hay samples should be submitted to a testing lab todetermine its crude protein content.



Stage of

production

Ewe weight

130 lba 155 lba 175 lba 200 lba


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lb

Maintenance 1.30 0.23 1.50 0.25 1.60 0.27 1.70 0.29

Earlypregnancy

1.60 0.27 1.70 0.29 1.80 0.31 1.90 0.33

Latepregnancyb

2.60 0.45 2.80 0.47 2.90 0.49 3.00 0.51

Earlylactation,single

3.30 0.70 3.60 0.73 3.70 0.76 3.80 0.78


3.70 0.89 4.00 0.92 4.30 0.96 4.60 0.99

Earlylactation,

tripletsc3.90 0.99 4.20 1.02 4.60 1.06 5.00 1.10

aBased on ewe weight at breeding time.bNational Research Council recommendations for ewes expected to have a 180-to 225-percent lamb crop. If130-to 150-percent lamb crop is expected, then you can reduce total digestible nutrients by 0.4 pound andprotein by 0.05 pound.cEstimates made by adding on one-half of the difference between ewes nursing singles and twins to theamount indicated for ewes nursing twins.




Stage ofproduction


16.5 15.0 12.5 10.0lb


Earlypregnancy

Hay 3.75 3.75 3.75 3.75

Latepregnancy

Hay 4.20 4.20 4.20 4.20

SC 1.00 1.00 1.00 1.00

SBM 0.10


Hay 5.00 5.00 5.00 5.00

SC 1.50 1.50 1.40 1.15

SBM 0.10 0.40


Hay 5.00 5.00 5.00 5.00

SC 2.25 2.10 1.90 1.15

SBM 0.10 0.40 0.75

Early lactation(triplets)

Hay 3.50 3.50 3.50 3.50

SC 3.15 2.95 2.70 2.45


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SBM 0.45 0.65 0.90 1.15



Feeding Lambs

Feeding programs in Virginia for growing and finishing lambs are different for winter-and spring-lambing production systems. Lambs born from November through earlyFebruary will likely be grown and finished on high concentrate feeds. Lambs born afterthe middle of February are placed on pasture with their dams where they remain

throughout the spring and summer. If necessary, spring-born lambs are weaned andfinished to market weight in the fall, using a grain on grass feeding program or placed ina feedlot for an abbreviated period of high concentrate feeding.

Lambs on a winter-lambing program should have access to a high quality creep feed bythe time they are seven days old. Creep feeds should contain 18 to 20 percent crudeprotein and be low in fiber (high in energy). The source of protein in commerciallyprepared lamb creep pellets should be all natural protein. Because the rumen of younglambs is not fully developed, urea should not be used as a partial source of protein in thediet. A 2:1 calcium to phosphorous ratio is maintained in on-farm feed mixes by addingfeed grade limestone at 1 percent of the diet. Calcium to phosphorous ratios of less than

2:1 may lead to urinary calculi (water belly), which most often results in the death of thelamb. If the addition of limestone to the diet fails to control urinary calculi, ammoniumchloride should be added at .5 percent of the diet. When constructing a creep area, keepthe following points in mind: 1) place the creep in a convenient location close to an areawhere the ewe flock congregates; 2) have openings on at least two sides of the creep andseveral openings per side; 3) keep the creep area clean and well bedded; 4) place a lightover the creep to help attract the lambs to the feed or arrange the creep in such a way thatthe sun shines into the area during the day; 5) provide fresh water in the creep area; and6) construct the creep feeder so that lambs cannot stand and play in it. Allow 2 inches oftrough space per lamb.

Winter-born lambs should be weaned and adjusted to a growing diet by the time they aretwo months of age. A growing diet for lambs weighing 40 to 70 pounds should containapproximately 78 percent TDN and 16 percent crude protein. At body weights of 70pounds and up, the level of crude protein in the diet can be lowered to 14 percent. Feedefficiency values range from 2 pounds of feed per pound of gain for light weight young,growing lambs on up to 3.5 to 4 pounds of feed per pound of gain as winter-born lambsapproach their optimum market weight. Feed efficiency values for old-crop (spring born)feeder lambs weighing 75 pounds and up in the fall average 5 to 5.5 pounds of feed per


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pound of gain when a whole-grain feeding program is used. Whole-grain feedingimproves feed efficiency, increases rate of gain, and lowers the feed cost per pound oflamb gain. Whole-grain diets consist of whole (unprocessed) grains, such as shelled cornor barley, mixed with a pelleted protein-mineral supplement. No roughage is contained inthe feed or supplemented on the side. Consequently, the diet is high in energy and

promotes accelerated lamb gains.

Ground ear corn, silage, and urea should not be fed until lambs are weighing 65 poundsand up. Creep diets should be ground or pelleted. Weaned lamb growing and finishingdiets may be ground, pelleted, or consist of a mixture of whole grain and a pelletedsupplement.


Ram Feeding

Rams should have a body condition score of 3.5 to 4 before the beginning of the breedingseason. Once turned in with the ewes for breeding, rams spend very little time eating.They can lose up to 12 percent of their body weight during a 45-day breeding period.That equates to 30 pounds for a 250 pound ram. Poor nutrition is a major cause of rammortality. As the sheep industry has moved away from smaller framed, earlier maturingtypes of sheep to larger framed, later maturing types of sheep, they have increased therams' mature body weight. In many cases, forage alone is not adequate nutrition forplacing rams in proper body condition for the breeding season. At the very least, ramsshould be evaluated for body condition six weeks before breeding. Thin rams should

receive grain supplementation as a means to increase body weight and condition. It takes50 days and approximately 2.5 pounds of corn per day in addition to a ram's normal dietto move him from a weight of 225 pounds to 250 pounds. Mature rams, not in breeding,can be maintained on pasture or wintered on good quality hay. Six to eight pounds ofmixed grass and clover hay is sufficient to meet the daily energy requirements of a 250pound ram. A free choice source of water, salt, and minerals should be available at alltimes.


Feeds for Sheep

Pasture

Permanent pasture should be the predominant source of nutrition for the sheep flock.Intensive sheep production systems where the sheep are housed and fed harvested feedsare not as profitable as more extensive production systems where they harvest their own


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feed. When a sufficient quantity of forage is available, sheep are able to meet theirnutrient requirements from forage alone along with a supplemental source of salt andminerals. Clover should be overseeded on permanent pastures in the winter to improvethe quantity and quality of forage produced during the grazing season. Sheep prefer tograze leafy, vegetative growth that is 2 to 6 inches tall rather than stemmy, more mature

forages. Pasture growth is not distributed evenly throughout the year. Approximately 60percent of the annual dry matter production of most species of cool season grasses occursin the spring. When pastures are not stocked heavily enough to utilize the spring flush ofgrowth, sheep graze and regraze certain areas while other areas are left to mature and goto seed. This type of grazing behavior weakens those plants that are grazed morefrequently and gives the less desirable plants a competitive advantage. Approximatelyone-third of spring pasture should be fenced for hay production. After a hay cutting,pasture should be given a three- to four-week recovery period before making it availablefor grazing the remainder of the year. Rotational grazing programs designed for themovement of sheep every 10 to 14 days are instituted in late June and early July toimprove both pasture and lamb production. More intensive rotational grazing systems

where higher stocking rates are used help to promote more complete forage utilization,but also require greater input costs in the form of fence and water and may result inhigher levels of internal parasitism, increased risk of coccidiosis, and impaired lambperformance.


Hay

Average or poor quality hay should be fed during gestation, leaving the higher qualityhay to be fed during lactation. Because protein requirements of the ewe increasedramatically after lambing, less protein supplementation from concentrate feeds isrequired when higher quality hay is used. Second-cutting, mixed grass-clover hay may bemore economical to feed to the ewe flock than alfalfa hay. This is especially true if alfalfahay must be purchased from off the farm. Alfalfa hay is an excellent feed for sheep and isbest used during lactation when ewes require more protein to promote higher levels ofmilk production. Many producers have fed alfalfa hay to gestating ewes with goodresults. However, some producers feeding alfalfa hay to gestating ewes have experiencedproblems with vaginal prolapses, late term abortions, and milk fever. If alfalfa hay isbeing fed during late gestation, it should be limit fed and be free of must and mold.

Because of its high quality and palatability, ewes consume more alfalfa hay than isneeded. The bulkiness of the hay in the rumen may place pressure on the reproductivetract, resulting in a vaginal prolapse before lambing. Ewes receiving alfalfa hay duringgestation are more prone to milk fever than ewes fed grass hay. Because alfalfa is high incalcium, ewes are able to meet their calcium requirements without mobilizing body storesof calcium. However, after lambing, ewes not accustomed to mobilizing bone calciummay experience milk fever because of their inability to meet the additional calciumrequirements associated with lactation. Regardless of the type of hay fed, producers


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should submit hay samples to a forage testing lab to determine its nutrient content. Byknowing the nutrient content of the hay, diets can be more accurately and economicallyformulated for the sheep flock.

In general, there is less waste and more flexibility when feeding hay harvested as square

bales. However, round bales can provide quality feed for sheep when stored and fedproperly. To minimize dry matter and nutrient losses, which can approach 40 to 50percent, round bales should be covered with plastic for outside storage or placed undershelter. Bales should be stored on pallets or tires to prevent ground contact. Feedinground bales without a feeder may result in as much as 30 percent of the hay being wasted,and poses a hazard to the sheep should the bales roll over. A variety of round bale feedersare commercially available. Feeders designed in the shape of a cradle hold the bales upoff the ground, are maintenance free, and appear to work best for minimizing waste.


Silage

High quality, finely chopped (1/4 to 1/2 inch) corn, grass, or small grain silage isacceptable feed for sheep. Care must be taken to properly harvest, store, and feed silage.Poorly packed silage may contain harmful molds, which causes listeriosis (circlingdisease) in sheep. Moldy or frozen silage should be discarded and troughs should becleaned daily.

Corn silage is low in protein and calcium. Studies have shown that the addition of 20

pounds of urea, 10 pounds of ground limestone, 4 pounds of dicalcium phosphate, and 5pounds of calcium sulfate per ton of silage at the time of ensiling makes a complete feedfor the ewe flock by increasing its crude protein and calcium content. Alternatively, extraprotein, calcium, phosphorous, and vitamins can be supplied through a grain mixtopdressed on the silage at the time of feeding.

Because of its high moisture content, 3 pounds of silage is required to supply the TDNfurnished by 1.5 pounds of hay. The bulkiness of silage prevents adequate dry matterintake and its use as the sole source of feed for ewes in late gestation. A typical diet fed toewes during the last four weeks of pregnancy on an as fed basis would contain: 6 poundsof corn silage (35 percent dry matter), 2 pounds of hay, 0.5 pound of corn, and 0.25

pound of soybean meal.



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the pounds of nitrogen in a diet, multiply the total pounds of crude protein in the diet by16 percent. Other general rules for the use of urea are: 1) should not be more than 1percent of the diet or 3 percent of the concentrate mix; and 2) should not be more than 5percent of a supplement to be used with low grade roughages.


Minerals

Salt and mineral supplementation is required on a free choice, year-round basis. Failureto supplement salt and minerals results in low fertility, weak lambs at birth, lowered milkproduction, impaired immunity, and numerous metabolic disorders. A variety of salt andmineral supplements specifically formulated for sheep are commercially available. Thesesupplements range from trace mineralized salt (TMS) fortified with selenium to complete

mineral mixes containing all of the macro and micro minerals required by sheep. Ingeneral, TMS fortified with selenium is all that is needed during the spring and summerwhen sheep are grazing high quality pastures containing more than 20 percent clover.Complete mineral mixes are recommended when grazing low quality roughages, startingfour weeks before breeding, during breeding, and during late gestation and earlylactation. Virginia is a selenium deficient state. Studies have clearly shown that seleniumsupplementation for pregnant ewes via a mineral mix is superior to selenium injections inlate gestation. Mineral supplements formulated for cattle and horses should not be usedfor sheep because they are high in copper, which is toxic to sheep. Mineral concentrationis oftentimes expressed in parts per million (ppm). Equivalent expressions for 1 ppm are1 milligram per kilogram or .0001 percent. When high grain diets, certain alternative

feeds, or silage are fed to sheep, additional calcium is required in the diet. This can besupplied by adding feed grade limestone to the feed. A general rule is to add limestone at1 percent of the diet.


Vitamins

Pasture or high-quality hay provides the vitamins required by most classes of sheep.

However, after a drought, or when low-quality hay or silage is fed, a supplementsupplying vitamins A, D, and E may be needed. Estimated daily vitamin requirements forewes during late pregnancy and lactation are: 6,500 international units (IU) Vitamin A,400 IU Vitamin D, and 40 IU Vitamin E. To assure an adequate supply of vitamins, avitamin supplement containing 3,000,000 IU Vitamin A, 200,000 IU Vitamin D, and25,000 IU Vitamin E may be added to each ton of feed for ewes and lambs.

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Feed Additives

Antibiotics or ionophores are often added to the diet to improve animal performance.

Antibiotics are fed to reduce the incidence of subclinical bacterial infections of thedigestive and respiratory tracts. Ionophores are used to control coccidiosis in lambs fedunder confinement. The use of antibiotics and ionophores has been shown to improvelamb average daily gain and feed efficiency. To date, the combined use of antibiotics andionophores in the same feed is not approved. Chlortetracycline (Aureomycin), anantibiotic, is added at the rate of 20 to 30 grams per ton of feed for lambs to improvelamb performance. Supplementing pregnant ewes with 65 mg of Chlortetracycline dailystarting six weeks before lambing and continuing six weeks into lactation has been shownto cause a significant reduction in baby lamb mortality. Lasalocid (Bovatec), anionophore, is added at the rate of 30 grams per ton of feed for lambs fed in confinement.The use of lasalocid has been shown to improve lamb gain and feed efficiency by

approximately 10 percent.


Water

Sheep must have a free-choice supply of clean, fresh water. If adequate fresh water isavailable and convenient, a lactating ewe will consume approximately 2 to 3 gallons aday. Frozen water supplies, muddy conditions where sheep have to drink, and long

distances to water reduce water intake and have a negative impact on production. Heatedwater bowls should be used during the winter to encourage adequate consumption ofwater by lactating ewes and lambs. Water bowls should be checked and cleaned on adaily basis.


Pearson Square

Protein is often the major limiting nutrient in a sheep diet. The Pearson Square is used toformulate simple diets on the basis of protein.

Problem: Using Table 1, assume a 155 lb ewe needs .92 lb crude protein per day to meether nutrient requirements in early lactation. Four pounds of mixed grass-clover hay (13%crude protein) will be fed per day along with 2 lb of a mixture of barley and soybeanmeal. What proportion of barley and soybean meal should be used in the mix?


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1. Determine the percentage of crude protein (CP) contributed by the hay.a. 4 lb x .88% Dry Matter = 3.52 lb Dry Matterb. 3.52 lb Dry Matter x 13% CP = .46 lb CP

2. Determine the amount of additional CP needed from the barley and soybean mealmix.

a. .92 lb CP Required - .46 lb CP from the Hay = .46 lb additional CPneeded

3. Determine the percentage of crude protein needed in the barley and soybean mealmix.

a. 2 lb x .90% Dry Matter = 1.8 lb Dry Matterb. .46 lb additional CP needed 1.8 lb Dry Matter = 25.5% CP in the grain

mix4. Use a Pearson Square to determine the proportion of barley and soybean meal inthe mix.

a. Subtract diagonally across the square, the smaller number from the largernumber without regard to the sign and record the difference at the rightcorners.

b. The parts of each feed can be expressed as a percentage of the total. 18.5 33.0 (100) = 56% Barley 14.5 33.0 (100) = 44% Soybean Meal

c. Check the math to make sure that .46 lb CP is coming from the barley andsoybean meal mix.

1.8 lb Dry Matter from Grain Mix x 56% Barley x 11% CP = .11lb CP 1.8 lb Dry Matter from Grain Mix x 44% Soybean Meal x 44% CP

= .35 lb CP .11 lb CP from Barley + .35 lb CP from Soybean Meal = .46 lb CP

from the 2 lb Grain Mix


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Table 5. Sample Diets for Creep Feeding, Growing Lambs, and Finishing Lambs.

Feed Ingredient 18% Crude Protein* (Percent Ingredient in the Diet)

Cracked Corn 54 59 54 68

Whole Oats 20 10 - -

Whole Barley - - 20 -Soybean Meal 25 25 25 26

Feed GradeLimestone

1 1 1 1

Molasses - 5 - 5

Vitamin Premix + + + +


+ + + +

*To be fed with free choice source of high quality alfalfa hay.


Cracked Corn 59 59Alfalfa Pellets(17% CP)

25 -


- 23

Soybean Meal 15 17

Feed GradeLimestone

1 1

Vitamin Premix + +

Antibiotic or

Ionophore+ +


Shelled Corn - - 85

Cracked Corn 64 - -

Corn and CobMeal

- 59 -


28 26 -

Soybean Meal 7 9 -

Pelleted

Supplement (36%CP)*

- - 15

Feed GradeLimestone

1 1 -

Vitamin Premix + + +


+ + +


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*Vitamins and minerals are included in the pelleted protein supplement.

Table 6. Feeder Space Requirements - Inches Per Head.

Hay Rack Grain Trough Creep Feeder

Ewes - Limit Fed 18-24 16-20 -

Ewes - Self Fed 6-8 4-6 -

Baby Lambs - - 2

Feeder Lambs - LimitFed

- 9-12 -

Feeder Lambs - SelfFed

- 1-2 -

Additional Recommended Reading

Virginia Cooperative Extension Publication 410-024,Finishing Lambs With WholeGrain.

Virginia Cooperative Extension Publication 410-366, Sheep Grazing Management.

Acknowledgment

Tables 1 and 2 were adapted from Management Guidelines for Efficient SheepProduction. North Central Regional Extension Publication 240.

Disclaimer

Commercial products are named in this publication for informational purposes only.Virginia Cooperative Extension does not endorse these products and does not intenddiscrimination against other products which also may be suitable.

Introduction

Nutrition plays a major role in the overall productivity, health, and well-being of the

sheep flock. Because feed costs account for approximately two-thirds of the total cost ofproduction on most Virginia sheep farms, it is important that producers consider nutritionmanagement a top priority. Nutrient requirements of sheep vary with differences in age,body weight, and stage of production. The five major categories of nutrients required bysheep are: 1) water; 2) energy; 3) protein; 4) vitamins; and 5) minerals. During thegrazing season, sheep are able to meet their nutrient requirements from pasture and a saltand mineral supplement. Hay is provided to the flock when forages are limited, and grainmay be added to the diet at certain stages of production when additional nutrient


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supplementation is required. Small grain pastures or stockpiled fescue can supply up toone-half of the feed requirements of the ewe flock during the winter. For winter-bornlambs, creep diets and diets for early-weaned lambs are formulated from high energy feedgrains and protein supplements to promote accelerated growth. During the grazingseason, pastures of mixed grass and clover, alfalfa, small grain, and turnip serve as

excellent sources of nutrition for growing lambs. A source of clean, fresh water isprovided to sheep at all times.



Ewe body weight does not remain constant throughout the year, but changes with stage ofproduction. Nutrient requirements are lowest for ewes during maintenance, increase

gradually from early to late gestation, and are highest during lactation. Decisionsaffecting feeding management are improved significantly by knowing ewe body weightand condition score at three distinct stages of production: 1) three weeks before breeding;2) mid-gestation; and 3) weaning. Condition score is a subjective measure of body fatthat is most easily determined by handling ewes down their back. It is the best methodavailable to monitor nutritional status and overall well-being of the sheep flock.Condition scores range from 0 to 5, with 0 being extremely thin and 5 being very fat.Condition scores at either end of the scale are undesirable. Ideally, ewes should rangefrom a condition score of 2.5 at weaning to a 3.5 at lambing. When necessary, thin ewesare separated and fed additional energy to increase body condition. Conversely, obeseewes are separated and fed a lower energy diet at a stage of production when body weight

loss is acceptable. It should be noted that problems with overfat ewes are far fewer thanthose associated with ewes that are too thin.

Starting two weeks before breeding and continuing two weeks into the breeding period,ewes should be placed on high-quality pasture or supplemented daily with .75 to 1 poundwhole shelled corn or barley. This management practice is called flushing and has beenshown to improve lambing percentage by 10 to 20 percent. Flushing works best withmature ewes that are in moderate body condition, and has been shown to be moreeffective for early- and out-of-season breeding than at the seasonal peak of ovulationduring the fall. Most prenatal deaths occur within the first 25 days after breeding and areusually associated with poor nutrition. Therefore, it is important not to make dramatic

reductions in nutrient supplies during the breeding season. Pastures with more than 50percent clover or other legumes should be avoided during breeding because legumes maycontain estrogenic compounds that reduce conception rates. From breeding to six weeksbefore lambing, the ewe flock can be maintained on permanent pastures, small grainpastures, stockpiled fescue, aftermath crop fields, or hay. Fetal growth is minimal, andthe total feed requirement of the ewe is not significantly different from a maintenancediet.


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The developing fetus acquires approximately two-thirds of its weight during the last sixweeks of pregnancy. Rumen capacity may be limited with ewes carrying multiple fetuses.Therefore, it is important to supplement ewes with .75 to 1 pound of corn or barley inaddition to their normal diet starting six weeks before lambing, to prevent pregnancytoxemia, low birth weights, weak lambs at birth, and low milk production. Producers

should be careful not to overfeed grain during late gestation, which could result inlambing difficulty caused by large lambs.

After lambing, the energy and protein requirements of the ewe increase by 30 and 55percent, respectively. Failure to supplement ewes accordingly results in excessive bodyweight loss, low milk production, mismothering, and poor lamb gains. Proteinsupplementation is especially critical for ewe flocks with a high percentage of multiplebirths. Unless high quality legume hays are fed, protein supplementation will benecessary as a part of the grain portion of the diet. A general rule of thumb forconcentrate feeding of lactating ewes is 1 pound of grain for each lamb nursing the ewe.Ewes should be sorted into feeding groups based on type of rearing (single, twin, etc.) to

make sure grain supplements are neither over- or underfed. Table 1 gives the TDN andcrude protein requirements of ewes based on body weight and stage of production. Byknowing the nutrient requirements of the ewe and the nutrient content of the feed, dietscan be properly formulated to meet the nutritional needs of the ewe. Shown in Table 2 arethe estimated quantities of hay, corn and soybean meal that would be fed to a 175 poundewe at different stages of production and with different crude protein values for the hay.To successfully use this table, hay samples should be submitted to a testing lab todetermine its crude protein content.



Stage of

production

Ewe weight130 lba 155 lba 175 lba 200 lba


lb

Maintenance 1.30 0.23 1.50 0.25 1.60 0.27 1.70 0.29

Earlypregnancy

1.60 0.27 1.70 0.29 1.80 0.31 1.90 0.33

Latepregnancyb

2.60 0.45 2.80 0.47 2.90 0.49 3.00 0.51

Early

lactation,single

3.30 0.70 3.60 0.73 3.70 0.76 3.80 0.78


3.70 0.89 4.00 0.92 4.30 0.96 4.60 0.99

Earlylactation,

3.90 0.99 4.20 1.02 4.60 1.06 5.00 1.10


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tripletsc

aBased on ewe weight at breeding time.bNational Research Council recommendations for ewes expected to have a 180-to 225-percent lamb crop. If130-to 150-percent lamb crop is expected, then you can reduce total digestible nutrients by 0.4 pound andprotein by 0.05 pound.cEstimates made by adding on one-half of the difference between ewes nursing singles and twins to the

amount indicated for ewes nursing twins.




Stage of

production


16.5 15.0 12.5 10.0

lb


Earlypregnancy

Hay 3.75 3.75 3.75 3.75

Latepregnancy

Hay 4.20 4.20 4.20 4.20

SC 1.00 1.00 1.00 1.00

SBM 0.10


Hay 5.00 5.00 5.00 5.00

SC 1.50 1.50 1.40 1.15

SBM 0.10 0.40


Hay 5.00 5.00 5.00 5.00

SC 2.25 2.10 1.90 1.15

SBM 0.10 0.40 0.75

Early lactation(triplets)

Hay 3.50 3.50 3.50 3.50SC 3.15 2.95 2.70 2.45

SBM 0.45 0.65 0.90 1.15



Feeding Lambs

Feeding programs in Virginia for growing and finishing lambs are different for winter-and spring-lambing production systems. Lambs born from November through earlyFebruary will likely be grown and finished on high concentrate feeds. Lambs born afterthe middle of February are placed on pasture with their dams where they remainthroughout the spring and summer. If necessary, spring-born lambs are weaned and


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finished to market weight in the fall, using a grain on grass feeding program or placed ina feedlot for an abbreviated period of high concentrate feeding.

Lambs on a winter-lambing program should have access to a high quality creep feed bythe time they are seven days old. Creep feeds should contain 18 to 20 percent crude

protein and be low in fiber (high in energy). The source of protein in commerciallyprepared lamb creep pellets should be all natural protein. Because the rumen of younglambs is not fully developed, urea should not be used as a partial source of protein in thediet. A 2:1 calcium to phosphorous ratio is maintained in on-farm feed mixes by addingfeed grade limestone at 1 percent of the diet. Calcium to phosphorous ratios of less than2:1 may lead to urinary calculi (water belly), which most often results in the death of thelamb. If the addition of limestone to the diet fails to control urinary calculi, ammoniumchloride should be added at .5 percent of the diet. When constructing a creep area, keepthe following points in mind: 1) place the creep in a convenient location close to an areawhere the ewe flock congregates; 2) have openings on at least two sides of the creep andseveral openings per side; 3) keep the creep area clean and well bedded; 4) place a light

over the creep to help attract the lambs to the feed or arrange the creep in such a way thatthe sun shines into the area during the day; 5) provide fresh water in the creep area; and6) construct the creep feeder so that lambs cannot stand and play in it. Allow 2 inches oftrough space per lamb.

Winter-born lambs should be weaned and adjusted to a growing diet by the time they aretwo months of age. A growing diet for lambs weighing 40 to 70 pounds should containapproximately 78 percent TDN and 16 percent crude protein. At body weights of 70pounds and up, the level of crude protein in the diet can be lowered to 14 percent. Feedefficiency values range from 2 pounds of feed per pound of gain for light weight young,growing lambs on up to 3.5 to 4 pounds of feed per pound of gain as winter-born lambs

approach their optimum market weight. Feed efficiency values for old-crop (spring born)feeder lambs weighing 75 pounds and up in the fall average 5 to 5.5 pounds of feed perpound of gain when a whole-grain feeding program is used. Whole-grain feedingimproves feed efficiency, increases rate of gain, and lowers the feed cost per pound oflamb gain. Whole-grain diets consist of whole (unprocessed) grains, such as shelled cornor barley, mixed with a pelleted protein-mineral supplement. No roughage is contained inthe feed or supplemented on the side. Consequently, the diet is high in energy andpromotes accelerated lamb gains.

Ground ear corn, silage, and urea should not be fed until lambs are weighing 65 poundsand up. Creep diets should be ground or pelleted. Weaned lamb growing and finishingdiets may be ground, pelleted, or consist of a mixture of whole grain and a pelletedsupplement.



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Ram Feeding

Rams should have a body condition score of 3.5 to 4 before the beginning of the breedingseason. Once turned in with the ewes for breeding, rams spend very little time eating.They can lose up to 12 percent of their body weight during a 45-day breeding period.

That equates to 30 pounds for a 250 pound ram. Poor nutrition is a major cause of rammortality. As the sheep industry has moved away from smaller framed, earlier maturingtypes of sheep to larger framed, later maturing types of sheep, they have increased therams' mature body weight. In many cases, forage alone is not adequate nutrition forplacing rams in proper body condition for the breeding season. At the very least, ramsshould be evaluated for body condition six weeks before breeding. Thin rams shouldreceive grain supplementation as a means to increase body weight and condition. It takes50 days and approximately 2.5 pounds of corn per day in addition to a ram's normal dietto move him from a weight of 225 pounds to 250 pounds. Mature rams, not in breeding,can be maintained on pasture or wintered on good quality hay. Six to eight pounds ofmixed grass and clover hay is sufficient to meet the daily energy requirements of a 250

pound ram. A free choice source of water, salt, and minerals should be available at alltimes.


Feeds for Sheep

Pasture

Permanent pasture should be the predominant source of nutrition for the sheep flock.Intensive sheep production systems where the sheep are housed and fed harvested feedsare not as profitable as more extensive production systems where they harvest their ownfeed. When a sufficient quantity of forage is available, sheep are able to meet theirnutrient requirements from forage alone along with a supplemental source of salt andminerals. Clover should be overseeded on permanent pastures in the winter to improvethe quantity and quality of forage produced during the grazing season. Sheep prefer tograze leafy, vegetative growth that is 2 to 6 inches tall rather than stemmy, more matureforages. Pasture growth is not distributed evenly throughout the year. Approximately 60percent of the annual dry matter production of most species of cool season grasses occursin the spring. When pastures are not stocked heavily enough to utilize the spring flush of

growth, sheep graze and regraze certain areas while other areas are left to mature and goto seed. This type of grazing behavior weakens those plants that are grazed morefrequently and gives the less desirable plants a competitive advantage. Approximatelyone-third of spring pasture should be fenced for hay production. After a hay cutting,pasture should be given a three- to four-week recovery period before making it availablefor grazing the remainder of the year. Rotational grazing programs designed for themovement of sheep every 10 to 14 days are instituted in late June and early July toimprove both pasture and lamb production. More intensive rotational grazing systems


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where higher stocking rates are used help to promote more complete forage utilization,but also require greater input costs in the form of fence and water and may result inhigher levels of internal parasitism, increased risk of coccidiosis, and impaired lambperformance.


Hay

Average or poor quality hay should be fed during gestation, leaving the higher qualityhay to be fed during lactation. Because protein requirements of the ewe increasedramatically after lambing, less protein supplementation from concentrate feeds isrequired when higher quality hay is used. Second-cutting, mixed grass-clover hay may bemore economical to feed to the ewe flock than alfalfa hay. This is especially true if alfalfa

hay must be purchased from off the farm. Alfalfa hay is an excellent feed for sheep and isbest used during lactation when ewes require more protein to promote higher levels ofmilk production. Many producers have fed alfalfa hay to gestating ewes with goodresults. However, some producers feeding alfalfa hay to gestating ewes have experiencedproblems with vaginal prolapses, late term abortions, and milk fever. If alfalfa hay isbeing fed during late gestation, it should be limit fed and be free of must and mold.Because of its high quality and palatability, ewes consume more alfalfa hay than isneeded. The bulkiness of the hay in the rumen may place pressure on the reproductivetract, resulting in a vaginal prolapse before

feeding of sheep

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