goat theriogenology - Kasetsart University

GOAT THERIOGENOLOGY

Theera RukkwamsukDept. of Large Animal and Wildlife Clinical Science

Faculty of Veterinary MedicineKasetsart University

Toggenburg : Dairy goat

Saanan : Dairy goatAlpine (French) : Dairy goat

Angora : Fiber goat

Boer : meat goat

GOAT• Short-day breeders, with breeding season.• From late August or September to late

January or February in Northern Hemisphere.

• The Nubian dairy goat generally has longer breeding season than dairy breeding originating in Europe.

GOAT• In regions near the equator where day

length varies little during the year, the breeding seasons are correlated more with rain and improved nutrition than simply with season of the year.

• In region far from the equator, breeding season may be restricted to a few months(Oct - Dec)

TERMS USED IN GOATKEEPING

• BILLY : ADULT MALE• BUCK : ADULT MALE (DAIRY GOAT)• DOE : ADULT FEMALE • NANNY : ADULT FEMALE • DOELING : YOUNG FEMALE FROM BIRTH

UNTIL FIRST FRESHENING

TERMS USED IN GOATKEEPING

• FIRST FRESHENER : female that has had one set of offspring

• FRESHENING : parturition• GOATING : young goat from birth until

puberty• KID : young goat from birth until puberty• KIDDING : parturition• WETHER : castrated male

PUBERTY• ANY TIME AFTER 4 MONTHS OF AGE

DEPENDING ON• : SIZE ( approximate 65% of their adult body

weight)• : SEASON OF THE YEAR ( born early or late

in the kidding season)

PUBERTY• Undersized doe kids may breed and

conceive only to undergo stress abortion in mild to late gestation.• Yong Angora nannies are often not

exposed to males until the second breeding after they are born.

MANAGEMENT OF BREEDING GOAT

• Detection of estrous : presence of buck or teaser buck• The male effect : the sudden

introduction of a male to females that have not been to exposed to a male at least 30 days will induce ovulation within 3 days in female if they are transitional.

TRANSITION

• Refers to the reproductive state in which female are not cycling, but are approaching the breeding season and so are more easily induced to cycle than during deep anestrous.


• Flushing : the technique of supplementing nutrition for several weeks prior to the breeding season to increase in ovulation rate.


•Male : female ratio- with natural service, one fertile buck per 50does.- Buck are capable of serving as many as 20time / day.- Young bucks in their first year of breeding : 1 : 25 does- Buck should be good body condition when turned in with the female (deworm, foot trim)


• Timing of routine procedures :deworm and foot trimming• Breeding record.• Breeding to an outside bucks.

PLANNING A BREEDING PROGRAME

USING THE MALE EFFECT

• Would be separate the bucks from the does at least 1 month prior to breeding season• begin flushing the females 2 weeks

prior to introduction of the male.• Introduce the male suddenly at the

desired onset the breeding season.

USING THE MALE EFFECT

• Infertile teaser animal can be used for this purpose.• This should result in most females

ovulating during the 10-day period after introduces of the male.• The male effect is reduced as the

breeding season progress.

SHORT ESTROUS CYCLES

• Due to lack of progesterone priming.• Many of first estrous cycles observed (up

to 75%) during breeding season are short (4-7 days).• The first ovulation will not result in

conception because the CL formed is short-lived.

SHORT ESTROUS CYCLES• Management technique is to used infertile

teaser with the females for the first week and then turn in the desired sires.

• One group of bucks can be turned in at the beginning of season and replaced with a rested group of bucks after the length of one estrous cycle.

• AI might also best be postponed until the second observed estrous.

OUT-OF-SEASON BREEDING

• Healthy animals that are proper size and condition.

• Does that are less than 60 days postpartum are not good candidates for successful out-of-season breeding.

• Bucks should either be placed under lights ahead of time, or should have been continuously used since the previous breeding season.


• Continued use can help maintain libido in buck during the none breeding season, but dose not prevent the seasonal decline in semen quality.

• A lower female : male ratio should be considered during non breeding season(10:1) .


• Light : exposed to 19-20 hour days for two months at which time the extra light are tuned off.

• Decrease in day length will stimulate the goat to start cycling approximately 7-10 week later.


• Melatonin : exogenous melatonin signal the body that darkness is present, thus indicating that day are suddenly shorter.

• Hormone : progestin and equine chrionicgonadotrophin.

ESTROUS CYCLE IN GOAT

The Estrous Cycle

• Usually 21 days unless in transition• Standing heat for 24 (to 72+) hours• Estrogen dominant for 2-4 days• Progesterone dominant during luteal phase (12-

14 days)• Phases: Estrus (day 0-1), metestrus (day 1-5),

diestrus (day 6-17) and proestrus (day 18-20)

Control of Estrous Cycle

• Doe’s hormones• Day length (season or

artificial light)• Presence or absence of

bucks

Breeding Options• Doelings: 60-70% of mature weight, or by 10-12

months old maximum• Does: Two-three months after kidding (for three

kid crops in two years)• Every Fall, as does cycle naturally• When she stands for buck• AI: 12-18 hours after start of estrus

Out-of-season breeding techniquesAssess body condition score before breeding

Early re-breeding means early weaning

POSTPARTUM PERIOD

• Goat usually breed during the autumn and kid 5 month later.• This is the anestrous season, so the

animals do not resume cyclicity postpartum until the subsequent autumn.

POSTPARTUM PERIOD

• Animals that kid during the breeding season and have a postpartum period similar to that observed in cattle.

• Normal goat will begin estrous cycles 30-40 days after kidding during breeding season. Uterine involution is complete at this time.

DETECTION OF ESTROUS

Does in estrous will : seek the male : flag their tail vigorously: vulvar hyperemia : present of mucus: increased vocalization : frequent urination.

DETECTION OF ESTROUS

• Heat detection is not reliable without the presence of buck.• Homosexual activity is not as

prevalent in does as it in cows.• Teaser animals can used.• Buck rags are the rags that are

saturated with buck odor.

Signs of heat are:• Unusual restlessness and bleating• Continuous twitching of the tail• Decreased milk production• Decreased appetite• Redness and swollen around the vulva• Mucous discharge that wets the hair around the tail• Attempts to fight molest and annoy other goats• Rubbing against other animals• Mounting other animals or standing to be mounted.

SYNCONIZATION OF ESTROUS

THE MALE EFFECTHORMONE: PROSTAGLANDIN: PMSG: PROGESTERONE

PROSTAGLANDIN

• Two injection (11 days apart).• Show sign of estrous 36-60 hour after

injection.• Functional CL are present from day 4 to

day 16 of the 20-day estrous cycle.

PROGESTERONE+PMSG

• Use in non breeding season.• P4 can administered by vaginal implants, ear

implants or daily injection for 9-15 day.• Administered 300-600 iu of PMSG 48 hour prior

P4 removal.• Standing estrous starting 12-36 hours after

removal P4.

PROPER TIME OF BREED

• Goat ovulate 30-36 hours after the onset of standing estrous.• Typically bred 12-24 hour after they are

first observed in standing heat.• Goat may remain in standing estrous for

24-36 hours.

MATING SUPERVISION

• HAND-MATING• PEN-MATING• PASTURE MATING• ARTIFICIAL INSEMINATION

PREGNANCY

Pregnancy Detection• Lack of heat• Lack of interest in/by

buck• Hormonal assays (milk,

serum)• Ultrasound• Doppler• Hulet’s Rod• Ballottement• X-rays

EARLY DEVELOPMENT OF THE CONCEPTUS

• Embryo enter the uterus on the third to fourth day after estrous.• 11 day after fertilization, the blatocyst is

about 1 mm diameter.• Attachment of the chorioallantois to the

endometrium is cotyledonary, beginning in the caruncular areas at about 17-20day.

EARLY DEVELOPMENT OF THE CONCEPTUS

• Tranuterine migration of embryo is common.• Approximately 10-20% of embryo from

double ovulation on one ovary migrating to contralateral uterine horn .

ESTIMATEING THE STAGE OF GESTATION

• 1.78 * ( BIPARIETAL DIAMETER(MM) +1.46)• CROWN-RUMP MEASUREMENT• = (fetal length (inched)/ 0.149) + 30

LENGTH OF GESTATION

• Breed average for gestation length vary from 143 days(Black Bengal) to 153 days (Murciana breed).• Most average fall in the range of 146-150

day.• The genotype of the fetus influences

variation in gestation more than genotype of dam.

LENGTH OF GESTATION

• There is a tendency for does carrying female kids, does carrying multiple kids and does kidding during the breeding season to have shorter gestation.

NUTRITION DURING THE LATE GESTATION

• Close attention should be paid to the nutrition of goats during the last 4-6 weeks of gestation because of their susceptibility to pregnancy toxemia.

• Animals in confinement may be gradually introduce to 0.5-0.7 kg of concentrate per head per day.

BOOSTING COLOSTRAL IMMUNOGLOBULINS

• Pregnant does should be vaccinated approximately 1 month prior to expected parturition.• These disease include

enterotoxemia(overeating disease cause by Clostidium perfringens) and tetanus.

TERMINATION OF PREGNANCY

• Because goats are dependent on corpus luteum as a source of progesterone throughout gestation,pregnancy can be terminated at any time through the administration of prostaglandin.

PREGNANCY DIAGNOSIS

• NON RETURN TO ESTROUS• PROGESTERONE TEST• ULTRASONOGRAPHY ( 30 DAY)• OESTRONE SULPHATE (50 DAY)• RADIOGRAPHY (75-80)• MISCELLANEOUS METHOD ; BALLOTTMENT

PRENATAL LOSSES

• Environmental factor such as temperature and nutrition play an important role in ovulation rate and very likely in embryo survival rate.• Fertilization failure and EED are

higher during the early part of breeding season.

PRENATAL LOSSES

• Heat stress and selenium-vitamin E deficiency may also be associated with infertile and EED in small ruminant.• Infectious causes of abortion can

cause significant losses in goat.

PARTURITION

SIGNS OF IMPENDING PARTURITION

• Development of mammary gland.• Relax of the sacral ligament in the

last days of gestations.

Normal Kidding

• Phase 1 = Prepatory period (ligaments relax, udder fills, fetus repositions, cervix dilates, cervical plug discharged) ; lasts 12-36 hours

• Phase 2 = Labor and delivery of kid(s); lasts 5-60 minutes

• Phase 3 = Passage of fetal membranes and placenta; lasts 0-12 hours

Phase 1• Pacing• Vocalizing• Off by self• Gets up and down often• Looks at abdomen• Doesn’t eat• Paws ground• May leak milk• Tailhead ligaments very loose• Fetus is being presented to cervix,

causing dilation• Vulva swollen

Phase 1

Phase 2

• Doe usually lies down• Fetal membranes appear• Abdominal presses evident• Nose and/or feet appear• 5 to 60 minutes between kids

Phase 2

Phase 2Presentation of fetal nose

Phase 2Delivery of fetal head

Phase 2

Phase 2

Note angle of lamb’s body with respect to ewe’s pelvis and mimic this when helping to deliver kid/lamb/calf/foal.

Completion of Phase 2: Delivery of Lamb

Completion of Phase 2:Delivery of Kid

Beginning of Phase 3: Expulsion of Fetal Membranes and Placenta

Lochia: Normal for up to three weeks post-kidding. Dark red, no foul smell.

INDUCTION OF PARTURITION

• Injected with 10-20 mg of prostaglandin F2α after 140 days of gestation.• Goats will usually kid 27-50 hours

(mean 31 hour) after being injected with prostaglandin or one of its analogues.

Dystocia = difficulty with delivery

• Fetal-maternal relative size mismatch• Uterine inertia (fatigue, low calcium)• Maternal factors: ringwomb, hernias,

pelvic fracture...• Malpresentation of fetus• Fetal monsters or malformation

Causes:

Malpresentations

• Head back• Leg(s) back• Jumbled-up twins/triplets• Transverse• True breech (rump and tail presented)• Posterior presentation (hind feet

presented)• Poll presented

Keys to Assisting:• Be clean• Be gentle• Be patient• Use lubricant• Small hands help• Twins can be very confusing • Take time to figure out what you feel• Look for key landmarks you can identify• Have assistant retract does’ vulva• Be willing to be “repulsive” (retropulse kid

back into doe)

Questions• Is she dilated enough?• Does she just need a tincture of

time?• Front leg or hind leg?• One or more kids? Which parts

are which?!• Should I check for another kid?

When to Assist:

1. Malpresentation

2. No progress after one hour of active labor (doeling) or one half hour (doe)

Head Back• Very common• Could confuse with breech

presentation• Won’t feel tail or anus• Check for ear, eye, teeth.• Angle of mouth is a good

handle• Can be difficult to correct if

kid dead a while• Head snare can help

Leg Back

• Also very common• ID front leg vs. back• ID twins, single or triplets• Follow leg to chest to other

shoulder; follow leg to knee, bend knee tightly closed, cup hoof in hand, lift up and forward while pushing shoulder back; hoof must be delivered first

• Must protect uterus from hoof

Reproductive Problems• Dystocia• Pregnancy toxemia• Milk fever• Abortions• Retained placentas• False pregnancy• Nymphomania (cystic ovaries, Copper def.)• Prolapsed uterus

Retained Placenta• Retained beyond 12 hours• Causes: infections, premature, abortion,

selenium deficiency, calcium deficiency• DON’T PULL!• Treatment: call your vet– Oxytocin– Perhaps Lutalyse®– Antibiotics (intrauterine vs. systemic)– NSAIDs help with fever, inflammation,

toxins– Tetanus booster

Prolapsed Uterus• Associated with lack of exercise,

nutritional deficiencies and/or dystocia• Treatment: call your vet– Clean, clean, clean (use HOT soapy

water)– Elevate hind quarters– Use gentle fists, not fingers– Antibiotics, oxytocin, tetanus booster– No need to stitch vulva if uterus

replaced properly– “Bit” or bite block prevents doe from

straining against prolapse reduction efforts

Causes of Abortions

• Spontaneous regression of CL• Toxins• Exogenous hormones• Fetal malformation/genetic error• Trauma• Maternal illness (fever,

starvation)• Too many feti for uterus to

support• Campylobacteriosis • Selenium deficiency

• Listeriosis• Salmonella• Steroids• Molds/fungi• Toxoplasmosis• Leptospirosis • Immune factors• Chlamydiosis (last

2-8 weeks); treatment and

vaccination available

Neonatal Kid Care• COLOSTRUM! When in doubt: tube feed• Dip navel with 7% iodine; clip to 1-2”• Check doe’s udder; strip out teats• Vitamin E/Selenium injection• Tag, tattoo or other ID• +/- anti-toxins, depending on doe’s vaccination

history• Keep warm• May need enema in 1-2 days.• Beware of Floppy Kid Syndrome...

Record Keeping • Birth weight• Animal ID• Dam and sire• Number of kids• Kidding ease• Treatments,

medications• Weaning weight• Dates of routine

procedures• Illnesses• Birth date• Number of kids

weaned• Pounds of kids weaned

Kidding Supplies

• See handout• ESSENTIAL:– tube feeder– Bo-Se®– Iodine– Thermometer– Epinephrine– Disinfectant soap

Synchronizing Estrus• Why??• Methods

1. Progesterone sponges, implants or feed additive for at least 14 days, +/- FSH; heat in 3-5 days.

2. Prostaglandin (Lutalyse ®or Estrumate®) injections for herd; repeat in 10-11 days; most in heat 2 days later. Goat must have CL for treatment to be effective

• You will need to have enough bucks or straws to service all does!NOTE: none of these products are approved for use in goats

Superovulation and Embryo Transfer

• Cost prohibitive for most herds• Being used by purebred Boer breeders and

breeders of other rare or high-value breeds or individuals

• Steps: synchronize donor and recipient; superovulate donor; breed/inseminate donor; flush embryos; implant embryos in recipients

• Nutritional flushing two weeks pre/post-breeding associated with increased number of ovulations

Artificial Insemination

• Reasons• Growing in availability, practicality and

popularity• Steps: semen collection, processing,

storage, insemination• Inseminate 12-18 hours after estrus starts• Methods: cervical, trans-cervical and

laparoscopic

Breeding Out-of-Season

• Reasons• Remember: most breeds respond to

decreasing day length and start cyclinginAugust or later.

• Methods: (combination is best)Melatonin orally, injection or implantArtificial Light: 16 hours of lightMale effect (new buck => greater

effect)

Artificial Day Length

• Two months of 16-19-20 hour days, or 1-2 hr. of bright light 16 hours after

dawn; holds off cycling• After two months, return to short day length;

does start cycling in about 6 weeks• Add buck for added male effect• Consider electricity bill...

Hormonal Manipulation of Out-of-Season Breeding(during anestrous period)

• Progesterone source for 11 days (d. 0-11)• Give prostaglandin and PMSG on day 9• Estrus 36-48 hr. later

Influences on Buck Fertility

• Temperature• Season• Health• Nutrition• Genetics

Selecting Bucks

• Positive traits of buck and progeny! (weaning weights, dressing percent, rate

of gain, conformation, etc.)• Fertile! (Re-assess each year)

Normal external genitaliaLibidoNormal ejaculate (microscopic exam)

• Healthy and sound

SUMMARY• The best reproduction program is part of an

entire herd health program• Nutrition plays a very important role• Colostrum, colostrum, colostrum!• Know due dates for best management!!!• Not every animal should pass its genes on• Plan breeding to hit best market dates with

kids• To turn a profit, you must learn how to do most

treatments and interventions yourself

goat theriogenology - Kasetsart University

Documents