Tanzania Livestock Research Institute (TALIRI), Mpwapwa, Tanzania.
Scotland's Rural College (SRUC) Research, Edinburgh, UK.
J Anim Breed Genet. 2021 Nov;138(6):668-687. doi: 10.1111/jbg.12556. Epub 2021 Jun 2.
Breeding strategies for smallholder dairy farming systems in Sub-Saharan Africa (SSA) were simulated and evaluated considering cow traits identified as priorities by farmers in different agro-ecological zones. These traits were related to cow milk yield, fertility, temperament, feed intake and disease resistance. The first breeding strategy was based on continuous importation of genetically superior exotic dairy sire semen to SSA and crossing with local females leading to a gradual upgrade of the indigenous population. The second strategy assumed that semen from elite exotic bulls would be imported to SSA and used on indigenous cows to produce F1 animals. Thereafter, elite animals would be selected from within the F1 and each subsequent generation to establish a new synthetic breed. The third strategy was to improve the indigenous population by genetically selecting the best sires available domestically. Results showed positive genetic progress for all breeding goal traits. After 15 generations of selection, the genetic response of the importation strategy exceeded the corresponding genetic response of the synthetic breed strategy by 20%-60%. The former also exceeded the genetic response of the indigenous breed improvement strategy by 43%-75%. Potentially there is an opportunity for breeders to choose an appropriate breeding strategy that fits a specific need of smallholder dairy farmers.
针对撒哈拉以南非洲（SSA）小农户奶牛养殖系统的繁殖策略进行了模拟和评估，这些策略考虑了农民在不同农业生态区确定的优先奶牛特征。这些特征与奶牛产奶量、繁殖力、气质、采食量和抗病能力有关。第一种繁殖策略是基于持续从外部进口遗传优良的外来奶牛精液，并与当地母畜杂交，从而逐步提升本地种群。第二种策略假设从优秀的外来公牛精液进口到 SSA 并用于本地奶牛，以生产 F1 动物。此后，从 F1 及后续各代中选择优秀的动物，建立新的合成品种。第三种策略是通过在国内选择最好的种畜来改良本地品种。结果表明，所有繁殖目标特征都有正向遗传进展。经过 15 代的选择，进口策略的遗传反应超过了合成品种策略的相应遗传反应 20%-60%。前者也超过了本地品种改良策略的遗传反应 43%-75%。潜在地，饲养员有机会选择适合小农户特定需求的适当繁殖策略。
