W.N.M. MwenyaDepartment of Animal Science, University of Zambia
Box 32379, Lusaka, Zambia
Abstract
Introduction
Breeding in production sectors
Breeding in research
Breeding in extension
Future breeding work
References
Sheep breeding in Zambia is reviewed, particularly the use of evaluation, selection and mating systems to improve the economic traits of sheep.
Programmes to improve sheep production by evaluating and selecting the best animals should concentrate on the traditional sector. Open national nucleus flocks should be established for the Fat-tailed indigenous sheep which are widespread throughout the country. The improved genotype would be disseminated by the extensive use of rams from the national nucleus flock.
Production ovine en Zambie: étude de la reproduction et de la sélection des moutons
Résumé
Cet article passe en revue les programmes de reproduction et de sélection des ovins en Zambie, et particulièrement les systèmes d'évaluation, de sélection et de lutte utilisés pour améliorer les paramètres de production des ovins.
Les programmes d'amélioration de la production ovine par l'évaluation et la sélection des meilleurs animaux devraient être axés sur le secteur traditionnel et des troupeaux reproducteurs nationaux ouverts de moutons indigènes à queue grasse devraient être constitués. Le génotype amélioré de ce type de mouton, qui se rencontre sur l'ensemble du territoire, serait disséminé par le recours à grande échelle à des béliers issus de ce troupeau reproducteur national.
Sheep in Zambia are produced by two farming sectors. The commercial sector has income generation as the main priority of sheep farming. The traditional sector places less emphasis on income and more on nutrition and subsistence. The traditional sector owns 64% of Zambia's 59,720 sheep. In this sector the sheep are mainly of the Fat-tailed and Thin-tailed types, which are indigenous. Traditional sheep production is concentrated in the Southern, Eastern and Luapula Provinces, accounting for 63% of the traditional sheep population found in Zambia. The sheep found in the commercial sector are the exotic type, namely, Blackhead Persian, Dorset Horn, Dorper and Suffolk. The commercial sheep flocks are concentrated in Lusaka and Central Provinces, near the main consumption centres for marketed sheep.
The sheep are kept for meat. Off-take in the commercial sector is 25% while in the traditional sector it is unknown. Most of the mutton consumed in urban areas is supplied by the commercial sector. The annual per capita consumption of mutton is estimated at 0.7 kg of which the rural areas account for 80%. The marketed supply of meat from sheep is relatively small as it accounts for less than one per cent of the total meat supply. There is therefore a need to improve sheep production in order to increase annual per capita consumption of mutton. Better breeding, nutrition, management, disease control and marketing can all contribute to this. This study reviews improving sheep production through breeding.
Traditional sector
Flock sizes in the traditional sector vary from a few to about 50 animals. This sector keeps the two indigenous breeds, Fat-tailed and Thin-tailed sheep. The more widespread of these is the Fat-tailed sheep, which accounts for 63% of the indigenous sheep. Formal animal breeding practices such as evaluation and selection of individual animals for performance are not practised. All ages and sexes of sheep are left to run together at all times and mating is at random within the flock.
Commercial sector
Commercial sheep production started in 1979 (Productive Farming, 1981). Commercial farmers keep Blackhead Persian, Dorset Horn, Dorper and Suffolk. The Dorper is the most common breed because it has good characteristics such as a long breeding season, high milk yield in the ewe and a good quality carcass (Productive Farming, 1983). Suffolk rams are used in two-and three-breed crosses as the terminal sire to improve lamb growth rate and carcass weight. Commercial farmers have claimed that slaughter weights for Suffolk x Dorper crosses are 30% higher than those for pure Dorper (Productive Farming, 1981). There is no evaluation and selection taking place on these farms to accompany crossbreeding.
In 1970 breeding work started at the Mazabuka Regional Research Station, situated in the southern part of Zambia. Its purpose was to evaluate pure Dorper and Blackhead Persian as meat animals. Traits considered were birth weight, pre-weaning mortality rate, weaning weight (at four months) and post-weaning weight gain of male castrates up to the age of three years (MAWD, 1970). Dorper lambs were heavier at birth (4.2 kg) than Blackhead Persian lambs (3.1 kg). However, the pre-weaning mortality rate was better for the Blackhead Persian (10%) than for the Dorper (24.5%). The average weaning weight of single and twin Blackhead Persian lambs was 18.9 kg for females and 20.9 kg for males. At 3.5 years of age the Dorper castrates were about 58% heavier than the Blackhead Persian and the carcass weight was about 49% heavier (MAWD, 1972-73).
In May 1972 another sheep project was initiated at the Mansa Research Station, situated in the northern part of Zambia. The aim of this project was to evaluate the meat production potential of indigenous sheep as purebred and as crossbreds to Dorper and Blackhead Persian sheep. The project was abandoned the same year because of high mortality rates, the reasons for which were unknown.
In 1969 the Government established a National Stud Farm of Dorper and Blackhead Persian near Lusaka in the central part of the country. Breeding stock from the Stud Farm were sold to farmers to establish small sheep units in different parts of the country. Due to high mortality rates and lack of expert management, the Farm was abandoned in 1977.
In 1985, the Government drafted a proposal to set up a ranch to keep indigenous breeds. The animals were to be evaluated and selected for growth and hardiness to survive village conditions. Sires from the ranch were to be used on village ewes to improve the quality of village flocks. This proposal has not been implemented.
The Government's main development objectives for sheep are: to increase substantially the commercial production of sheep; to upgrade the standards and the efficiency of operation of both commercial and traditional producers; and significantly expand the average size of off-take from traditional flocks (MAWD, 1986). The production targets are to increase sheep population by an annual rate of 3.3% and to increase slaughtering by an annual rate of 7%.
The strategy for achieving these objectives includes the improvement of marketing facilities and price incentives, improving extension and animal health services, strengthening applied research activities and establishing strategically located sheep multiplication units for distributing improved genotypes.
In Zambia, material, money and personnel resources are very limited. Improvement through breeding should concentrate on the traditional sector which has the largest population of unimproved sheep. Improvement could therefore make the largest impact. Commercial farmers already have unlimited access to improved genotypes through the import of proven rams, although they do not evaluate and select individual ewes for performance.
Breeding work in the traditional sector should concentrate on establishing an open nucleus flock for Fat-tailed sheep in each of Southern, Eastern and Luapula Provinces. In these flocks evaluation and selection should concentrate on fertility, growth and viability traits. The improved genotypes would be disseminated by the extensive use of rams from the open nucleus flocks.
To improve carcass weights of marketed sheep from the traditional sector, on-farm assessments of the best breed of sire in the terminal cross of indigenous ewes with exotic breed should be carried out concurrently with the establishment of open nucleus flocks. Possible sire breeds to be assessed would be Dorper and Blackhead Persian.
MAWD (Ministry of Agriculture and Water Development), Fourth National Development Plan. 1986. Agricultural Sector: Sheep and Goats. pp. 50-52.
MAWD (Ministry of Agriculture and Water Development). 1970. Animal Husbandry Section. Annual Report. pp. 100-114.
MAWD (Ministry of Agriculture and Water Development). Annual Report. 1972/73. Animal Husbandry Section. pp. 110-111.
Productive Farming. 1981. Sheep Field Day. 10 pp.
Productive Farming. 1983. Dorper Field Day. 17 pp.
