Economic evaluation of heterosis and culling policies for lifetime productivity in Hereford, Angus, Shorthorn, and crossbred cows
Article Abstract:
The effect of heterosis on economic efficiency was evaluated under three culling strategies and different terminal ages (TA) for removal of cows from the herd. For both purebreds and crossbreds, the ratio of input cost to output value decreased with TA to a minimum at 9 years, rising after. Output from calves sold rose with TA up to 9 or 10 years then declined therafter, regardless of culling policy or lineage. Due to positive heterosis, the overall efficiency of the crossbred herd was higher, the higher costs being offset by a larger increase in output.
Publication Name: Journal of Animal Science
Subject: Zoology and wildlife conservation
ISSN: 0021-8812
Year: 1992
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Genetic analysis of bovine respiratory disease in beef calves during the first year of life
Article Abstract:
The prevalence of bovine respiratory disease (BRD) in beef calves during the first year of life was investigated. The study protocol involved assessing 10,142 beef calves from nine pure breeds and three composite populations born from 1983 to 1988. The results showed that 24% of calves experienced a BRD episode in the first year of life. Heritability estimates during the first year of a calf's life did not differ significantly from zero. The results indicate that response to selection for BRD resistance will not be significant.
Publication Name: Journal of Animal Science
Subject: Zoology and wildlife conservation
ISSN: 0021-8812
Year: 1992
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Heterosis for lifetime production in Hereford, Angus, Shorthorn, and crossbred cows
Article Abstract:
Heterosis effects on survival and growth of crossbred calves and maternal heterosis effects on reproductive rate, weaning weights of progeny and longevity resulted in an increase of 36% in the lifetime production of crossbred herds. Type of cross did not significantly affect results. Heterosis effects on reproductive performance were consistent up to 8 years of age. Cumulative calf production was greater in crossbreeds and crossbred calves were generally heavier at weaning.
Publication Name: Journal of Animal Science
Subject: Zoology and wildlife conservation
ISSN: 0021-8812
Year: 1992
User Contributions:
Comment about this article or add new information about this topic:
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