Evaluating Breed Complementarity and Sexed Semen with Maternal Use of Afrikaner Germplasm
Autor: | Razie Khorshidi, Michael D. MacNeil, Annette Theunissen, Graham Plastow, J. J. Crowley, Michiel M. Scholtz |
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Rok vydání: | 2017 |
Předmět: |
0301 basic medicine
Germplasm business.industry Sire biology.animal_breed 0402 animal and dairy science Semen 04 agricultural and veterinary sciences General Medicine Biology 040201 dairy & animal science Breed Biotechnology 03 medical and health sciences 030104 developmental biology Animal science Herd Livestock business Purebred Afrikaner cattle |
Zdroj: | Agricultural Sciences. :507-517 |
ISSN: | 2156-8561 2156-8553 |
DOI: | 10.4236/as.2017.87038 |
Popis: | Livestock production impacts food security of developing countries, especially where efficiency of production is compromised by environmental stressors. In South Africa, breeding with indigenous Afrikaner cattle that are genetically well adapted to subtropical environments is considered an essential strategy for sustainable beef production. Today, there is a potential for farmers to participate in commercial systems that join adapted Afrikaner germplasm, used in a specialized maternal role, with exotic terminal sires to optimize production. The objective of this study was to assess productivity of five simulated production systems: 1) straightbred Afrikaner mated naturally, 2) a straight-bred Afrikaner cow herd with two sections; one section to produce replacement females and the other to cross with Charolais terminal sires, both using natural mating, 3) similar to 2, but applying sexed semen to produce replacement females, 4) similar to 2, but using a multi-breed composite dam line with a breed combination of 50% Afrikaner, 25% Hereford and 25% Simmental, and 5) similar to 4, but again applying sexed semen to produce replacement females. Parameter estimates needed to compare these systems were extracted from the scientific literature. Relative to straightbred Afrikaner dams, the simulated composite dams were more fit producing 7.8% more calves and their progeny performance was improved by reducing feed intake (-24.4%) and increasing meat production (+11.7%). The potential benefit of allocating more cows to the terminal sire was insufficient to offset the reduction in pregnancy rate that results with the use of sexed semen. Thus, system 4 had the greatest productivity (+23.1%) while requiring 22.8% less feed for finishing the progeny to be harvested relative to the purebred Afrikaner system. The combination of increased productivity and reduced feed requirement made use of a Charolais terminal sire in conjunction with multi-breed composite females bred by natural service the most efficient system among those studied. |
Databáze: | OpenAIRE |
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