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PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON LIVESTOCK PRODUCTION THROUGH ANIMAL BREEDING AND GENETICS University of Zimbabwe Department of Animal Science Edited by K. Dzama, F.N. Ngwerume and E. Bhebhe UNIVERSITY OF ZIMBABWE DEPARTMENT OF ANIMAL SCIENCE Proceedings of the International Symposium on Livestock Production through Animal Breeding and Genetics May 10–11, 1995 Sheraton Hotel, Harare, Zimbabwe International Symposium on Livestock Production through Animal Breeding and Genetics Organised by The University of Zimbabwe, Department of Animal Science in conjunction with The Zimbabwe Society for Animal Production Coordinator – Dr K Dzama Organising Committee – Editors Dr K Dzama> – Dr K Dzama Dr F Ngwerume> – Dr F Ngwerume Dr E Bhebhe> – Dr E Bhebhe Ms S Moyo> – Dr N Mpofu To obtain the proceedings call University of Zimbabwe Telephone 303211 Ext 1409 Copyright 1995: Organising Committee, International Symposium on Livestock Production through Animal Breeding and Genetics, Harare, Zimbabwe I.S.B.N. 0–86924–112–5 SUPPORT FOR THE SYMPOSIUM WAS PROVIDED BY GTZ CATTLE PRODUCERS ASSOCIATION DICK ELLIOT MEMORIAL TRUST NESTLE ZIMBABWE SOCIETY FOR ANIMAL PRODUCTION RAINBOW TOURS IRVINE'S DAY OLD CHICKS COOPERS COLCOM NATIONAL ASSOCIATION OF DAIRY FARMERS PIG INDUSTRY BOARD AIR ZIMBABWE DAIRIBOARD FINHOLD THE OSTRICH PRODUCERS ASSOCIATION OF ZIMBABWE Table of Contents Acknowledgement Opening Address Dairy herd improvement programmes in Zimbabwe Future prospects in pig improvement in Zimbabwe Lactation effects in Zimbabwean Holstein Herds Environmental factors affecting milk production of Holstein-Friesian cows in Southern Malawi Utilising test-day information to monitor individual cow performance Application of biotechnology in genetic improvement, characterisation and conservation of livestock Conservation strategies for endangered livestock species The conservation and selection of indigenous beef cattle in Zimbabwe Poultry Improvement programmes in Zimbabwe Ostrich production in Zimbabwe Appendix 1 Some aspects on current and future livestock breeding strategies in livestock in Southern Africa Pig Improvement Programmes in Zimbabwe Future prospects in pig improvement in Zimbabwe A study of the productivity of pigs at the pig industry board farm at ARCTURUS Crossbreeding for weaner production in pigs Evaluation of indigenous pigs in Zimbabwe Goat breeding research and development activities Zimbabwe Use of molecular genetic techniques in livestock: A case example in goats Phenotypic differences in digestive parameters between indigenous Malawian and Dorper males The role of indigenous cattle breeds: Adaptive and production traits. LINE X environment interaction for fertility in Afrikaner cattle Selection for improved reproductive efficiency in beef cattle under tropical and subtropical environments Evaluation of beef breeds for production in Zimbabwe Livestock improvement in South Africa: Performance driven Beef performance recording in Zimbabwe: the way ahead Recent developments in livestock breeding in South Africa Closing Remarks ACKNOWLEDGEMENTS The organising committee would like to thank everybody who contributed in making this symposium a success. We are especially grateful to the sponsors without whose kind support this gathering would not have been possible. The Chairman of the Department of Animal Science, Dr Simbarashe Sibanda and members of his department provided invaluable support to the symposium. Special thanks to Dr Stanley Makuza and Mr Irvin Mpofu for reading through the manuscript and making very helpful comments. INTERNATIONAL SYMPOSIUM ON LIVESTOCK PRODUCTION THROUGH ANIMAL BREEDING AND GENETICS: OPENING ADDRESS P. Nyathi Department of Research and Specialist Services, Ministry of Agriculture, P O Box 8108, Causeway, Harare, Zimbabwe. Ladies and gentlemen, I want to thank the organisers of this important event for inviting me to come and open this two-day symposium. To all scientists from Kenya, Zambia, Malawi and the Republic of South Africa and to our Zimbabwean scientists representing various institutions and organisations in the livestock industry, I congratulate you all for having been able to support this symposium with papers to be presented in the two days. I hope that the diversity of the subjects under consideration is sufficient to cause the desired discussion to take place. Let me on behalf of the Department of Research and Speciality Services, the Ministry of Agriculture and the Government of Zimbabwe welcome all present, and in particular extend our gratitude to all our visitors for having taken all the trouble to travel to be with us during this symposium. This symposium on livestock production through animal breeding and genetics has come at the right time when there is an international call for conservation of natural resources. Livestock are an important component of national economies in those countries in which livestock by-products (meat, milk, hides. mohair, tallow etc) are consumed by local industry and are also exported. These products are however, derived from animals whose genetic constitution has been little studied and their potential to survive in the ever changing ecosystems is not well understood. In Zimbabwe, animal breeders have concentrated on accounting for non-genetic factors as a prerequisite for the assessment of the genetic potential of individual animals. A literature search indicates that factors such as age at weaning, year of calving, feeding regime, age of darn at calving, lactation status etc have been taken into account in animal breeding experiments in Zimbabwe. In addition, the performance (reproductive, growth and carcass attributes) of a wide range of pure bred and crossbred genotypes from representative Bos taurus (Charolais, Sussex, Simmental, Holstein - Friesian, Hereford) Zebu and Sanga cattle (Mashona, Nkone, Tull) has for several years received attention locally and regionally. The body of research results is impressive, although it can be argued that all effort was directed to the improvement of livestock productivity and production with conservation of genetics being incidental. This trend of experimentation has probably led to a loss of important genes necessary for adaptation to changes in the environment. Animals and the environment in which they survive are both evolving as human intervention aimed at the supply of human needs is intensified. This raises the question whether we have the institutional capacity to develop genetic engineering techniques (such as restriction fragment length polymorphism analysis and Mitochondrial DNA sequencing for differentiating cattle breeds). This form of analysis provides high resolution information with good efficiency and data readily amenable to phytogenetic analysis. The existence of unplanned crossbreeding and crossbreeding for short-term gains when the economics of producing a particular animal type or genotype is favourable, has meant that our livestock populations are now a mixed bag rather than breeds. In the past few decades, there has been interest in the crossing of cattle breeds (Bos indicus x Bos taunts) to exploit interbreed dominance variation, otherwise known as heterosis. However, the selection of suitable breeds and crossbreeding strategies tends to be based on historical records of the breed and information gleaned from existing crossbreeding programmes. Consequently, an estimate of intrabreed and interbreed variation may help in the formulation of rational breeding policies. To that end, the analysis of mitochondrial DNA and Microsatellite markers can contribute information to this form of study and help in the decision making process. Pedigree records are kept in Zimbabwe by a few breed societies and the Zimbabwe Herdbook and these need to be consulted to ensure that animals which we may want to use in cross- breeding work are unrelated and representative of the desired breeds. There is need to characterise the gene pool of cattle kept in rural areas where no records are kept. In those areas, there could be important genes, relevant to fitness and therefore warranting a concerted effort to harness these genes in order to meet future requirements for survival, particularly because these cattle, and indeed goats and other livestock have evolved with very limited management. The ever-increasing costs of production in commercial livestock enterprises and the frequent droughts that decimate the grazing resource base both indicate the relevance of the need to develop livestock types that can perpetuate the species under conditions of reduced available grazing and feed resources. The question is whether we should change the environment. This requires that careful thought be given to the kind of manipulation needed to achieve the long-term goal of sustainability in the productivity of individual breeds, that of their crosses with other breeds and that of the environment on which livestock production is based. Animal breeding geared towards the satisfaction of short-term gains may be costly in future as it may unintentionally lead to loss of some important genes and this equates to genetic erosion of the livestock resource base. Technologies to facilitate animal breeding are in place in the world, ie Artificial insemination (AI) Embryo transfer (ET), gene cloning, DNA marker assisted selection and many other newly developed techniques. This symposium is the correct forum for discussion of the relevance of methods that are adoptable in this region. I therefore leave it to you as professionals

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