Feed Management - Aquafeed in Tanzania

March | April 2010

Feature title: Feed Management - Aquafeed in Tanzania

The International magazine for the aquaculture feed industry

International Aquafeed is published five times a year by Perendale Publishers Ltd of the United Kingdom.All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies, the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis of information published. ©Copyright 2009 Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any form or by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1464-0058

Aquaculture in Tanzania is still minimal and is prac-ticed in both freshwater and marine environments.

Freshwater species are tilapia (Nile tilapia, Oreochromis niloticus, Mozambique tilapia, O. mossambicus and Zanzibar tilapia, Tilapia hornorum) which are cultured by small scale fish farmers, and rainbow trout, Oncorhynchus mykiss which is cultured commercially.

Marine species include seaweeds of the red algal species (Eucheuma denticula-tum and Kappaphycus alvarezii) (Bryceson, 2002), prawns, Penaeus monodon (Bryceson, 2002), rabbitfish, Siganus can-naliculatus (Bwathondi, 1982) and milkfish, Chanos chanos (Mwangamilo and Jiddawi,

2003); clams, ark clam, Anadara antiquate and giant clam, Tridacna maxima; oysters, pearl oysters Pinctada margaritifera and mangrove oysters, Saccostrea cucullata and mud crab, Scylla serrata (Rice et al. 2006).

The bulk of fish production comes from tilapias which are kept mostly by subsist-ence farmers who regard fish farming as a secondary activity to provide protein to the household and little surplus for cash or barter.

The fish are cultured in extensive to semi–intensive earthen ponds with sizes varying from 150–500m2 (Bjoneseth, 1992). The ponds are usually fertilised with animal droppings or tender leaves as compost manure.

Supplementary feeds commonly used are rice and maize bran, kitchen leftovers and garden remains. The use of formulated aquafeeds is almost non-existent.

Fish are partially or totally harvested after six to 12 months with an average yield of 2089kg ha-1 year-1 (Wetengere et al. 1998; Kaliba et al. 2006). The yield is low compared to the 10,000kg ha-1 year-1 which can be achieved if properly formu-lated supplementary aquafeeds were used (Jauncey, 1998).

There are several potential feedstuffs that

can be incorporated in fish diets as shown in the table below.

A few studies have been conducted to a evaluate suitability of some of the locally available ingredients in tilapia diets.

Cotton seed cake and soybean meal were shown to be suitable as a main source of protein sources (Shoko, 2002). Pigeon peas processed by either sprouting or roasting could replace up 40 percent of fish-meal without causing a significant reduction in growth performance (Mnembuka, 2003).

Moringa and cassava leaf meals could pro-vide less than 15 percent of dietary protein while their composite could provide up to 20 percent (Madalla, 2009). Cassava root meal could replace up 75 percent of the wheat meal without significantly reducing performance (Madalla, 2009).

Adoption of these findings by farmers has been poor mostly due to the subsist-ence nature of fish farming which does not encourage investment in formulated feeds.

Feed formulation has a cost implica-tion in terms of ingredients as well as the feed formulation knowledge. Even if such knowledge is availed, it will still be difficult to put it into practice due to the relatively high cost of ingredients relative to the returns due to the subsistence nature of aquaculture.

ReferencesBjoneseth, R. (1992) A survey of freshwater fish farming in Tanzania, Unpublished M.Sc Thesis, Agricultural University of Norway.

Bryceson, I. (2002) Coastal aquaculture developments in Tanzania: sustainable and non-sustainable experience. Western Indian Ocean Journal of Marine Science 1 (1):1-10.

Bwathondi, P.O.J. (1982) Preliminary investigations

table: feed ingredients locally available in tanzania

Feed resource Biochemical composition in DM (%)

DM Ash CP Cl CF

Green foragesGliricidia NA 11.7 20.0 3.8 16.7

Leucaena  92.6 9.4 24.6 3.4 17.1

Sesbania  NA 9.3 22.1 3.3 17.3

Cassava  83.0  17 21.7 4.7 11.9

Mulbery Morus alba 89.0 14.5 19.6 2.2 12.9

Cereal grains & by-productsMaize meal 89.9 1.55 10.6 3.5 2.5

Maize bran 89.5 2.8 10.5 10.6 7.1

Maize hominy 90.5 5.2 13.6 12.7 7.6

Rice polishing 91.8 13.7 11.0 5.2 11.3

Rice bran 91.1 15.8 9.3 4.3 27.9

Wheat bran 89.9 5.43 18.6 2.5 10.5

Wheat pollard 89.4 3.26 17.9 4.1 5.7

NA: not available | Source: Laswai et al. (2002)

TanzaniaAquafeeds in

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on rabbitfish, Siganus canalicullatus, cultivation in Tanzania. Aquaculture 27(3):205-210.

Jauncey, K. (1998) Tilapia feeds and feeding. Scotland: Pisces Press Limited.

Kaliba, A.R., Osewe, K.O., Senkondo, E.M., Mnembuka, B.V. and Quagrainie, K.K. (2006) Economic Analysis of Nile Tilapia (Oreochromis niloticus) Production in Tanzania. Journal of the World Aquaculture Society 37 (4):464-473.

Laswai, G.H., Mutayoba, S. K., Temu, A. A. and Kusolwa P. M (2002) Feed Table: Chemical composition of poultry feedstuffs in Tanzania. Sokoine University of Agriculture and ASARECA/FOODNET project

Madalla, N. (2009) Novel feed ingredients for Nile tilapia (Oreochromis niloticus L.). Unpublished PhD Thesis, University of Stirling, United Kingdom.

Mnembuka, B. V. (2003) Studies on the use of pigeon peas (Cajanus cajan) as a protein supplement for Nile tilapia. Unpublished PhD Thesis, University of Dar es salaam, Tanzania.

Mwangamilo, J.J. and Jiddawi, N.S. (2003) Nutritional studies and development of a practical feed for milkfish (Chanos chanos) culture in Zanzibar, Tanzania. Western Indian Ocean Journal of Marine Science 2 (2):137-146.

Rice, M.A., Mmochi, A.J., Zuberi, L. and Savoie, R.M. (2006) Aquaculture in Tanzania. World Aquaculture 37 (4):50-57

Shoko, A. P. (2002) The effects of different diets and stocking density on the growth performance of Oreochromis variabilis (Boulenger, 1906) under aquaculture conditions. Unpublished M.sc Thesis, University of Dar es salaam, Tanzania.

Wetengere, K., Osewe, K. and Herwaarden, H. (1998) Development of semi-intensive fish farming in Morogoro region, Tanzania . ALCOM working paper no. 22. FAO/SIDA.

table: feed ingredients locally available in tanzania

Feed resource Biochemical composition in DM (%)

DM Ash CP Cl CF

oil Seed Cake and legumesCotton seed meal (Undecorticated) 92.6 13.2 38.1 7.4 20.3

Cotton seed meal (Decorticated) 90.8 5.6 33.8 7.0 15.2

Sunflower seed meal (Decorticated) 94.4 5.5 32.9 17.7 32.7

Sunflower seed meal (Undecorticated) 94.3 4.9 25.8 12.3 43.2

Copra cake 86.9 6.1 22.3 8.4 12.0

Soybean (Boiled) 95.5 6.2 41.5 9.9 5.9

Soybean (Toasted) 88.9 7.0 48.7 3.1 7.2

Pigeon peas  92.6 4.5 20.9 1.8 1.0

Animal ProductsSardine “dagaa” 

fishmeal 92.4 22.09 60.6 4.15 2.5

Nile Perch Body Frame Meal 93.5 36.7 41.5 7.7 10.5

Fish Waste  90.6 33.6 42.5 NA 8.6

Blood meals 97.3 9.1 85.1 0.9 NA

Bone meals 91.3 69.1 26.9 NA 2.17

Tubers

Cassava 87.4 5.7 2.8 2.5 3.6

NA: not available | Source: Laswai et al. (2002)

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