Journal ArticleDOI
Optimum postweaning test for measurement of growth rate, feed intake, and feed efficiency in British breed cattle
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TLDR
A 70-d test with cattle weighed every 2 wk seems to be optimal for measuring these traits in British breed cattle.Abstract:
The optimum duration of test for measurement of growth rate, feed intake, feed conver- sion, and residual feed intake was examined using postweaning feed intake and weight data from 760 Angus, Hereford, Polled Hereford, and Shorthorn heifer and Angus bull progeny from 78 sires. Variance components, heritability, phenotypic and genetic correlations, and the efficiency of selection using shortened tests compared with a 119-d test were used as criteria to assess the optimum test length. The results indicated that a 35-d test was sufficient for measurement of feed intake, whereas a 70-d test was required to measure growth rate, feed conversion, and residual feed intake without compromising the ac- curacy of measurement. When a 70-d test is used to measure growth rate, feed conversion, and residual feed intake there is minimal loss in accuracy when weights are collected every 2 wk instead of weekly, but a further increase in the interval between weights to 5 wk caused a decline in the accuracy of the test. Therefore a 70-d test with cattle weighed every 2 wk seems to be optimal for measuring these traits in British breed cattle.read more
Citations
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Journal ArticleDOI
Genetic and phenotypic variance and covariance components for feed intake, feed efficiency, and other postweaning traits in Angus cattle
TL;DR: Results indicate that genetic improvement in feed efficiency can be achieved through selection and, in general, correlated responses in growth and the other postweaning traits will be minimal.
Journal ArticleDOI
Residual feed intake and body composition in young growing cattle
TL;DR: Crossbred steers from the five BeefBooster strains were used to determine the relationships between residual feed intake and growth rate, body composition and heat production, and to quantify differences in RFI independent of differences in body composition.
Journal ArticleDOI
Cattle selected for lower residual feed intake have reduced daily methane production.
TL;DR: Although the opportunity to abate livestock MPR by selection against RFI seems great, RFI explained only a small proportion of the observed variation in MPR, and the MPR:RFI(EBV) relationship will need to be defined over a range of diet types to account for this.
Journal ArticleDOI
Genetic and phenotypic relationships among different measures of growth and feed efficiency in young Charolais bulls
TL;DR: Performance and progeny test data on young Charolais bulls in France were used to estimate genetic and phenotypic variation, and correlations among postweaning growth and feed efficiency traits, highlighting the fact that genetic improvement can potentially be made in any of these traits.
Journal ArticleDOI
Ruminant enteric methane mitigation: a review
TL;DR: In this paper, a review of strategies for reducing ruminant methane output are considered in relation to rumen ecology and biochemistry, animal breeding and management options at an animal, farm, or national level.
References
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Book
Introduction to quantitative genetics
TL;DR: The genetic constitution of a population: Hardy-Weinberg equilibrium and changes in gene frequency: migration mutation, changes of variance, and heritability are studied.
Net feed conversion efficiency and its relationship with other traits in beef cattle
TL;DR: The Net FCE trait was not significantly correlated with any of the production traits measured, except actual feed intake, feed conversion ratio and measures of fat depth, with correlation coefficients being 0.49, 0.47 and 0.24.
Journal ArticleDOI
Factors influencing growth performance of beef bulls in a test station
M F Liu,M. Makarechian +1 more
TL;DR: The effect of herd of origin on periodic and cumulative ADG decreased as the test advanced but showed an increasing trend and a 56-d adjustment period followed by an 84-d test period for accurate evaluation of beef bulls for growth potential seems appropriate.
Journal ArticleDOI
Effects of 84-, 112- and 140-day postweaning feedlot performance tests for beef bulls.
TL;DR: If the primary objective of central station testing is to evaluate ADG during the linear phase of growth, and if testing procedures are those currently recommended by the Beef Improvement Federation, then feeding bulls beyond 112 d has no advantage because the information upon which selection decisions are made is similar at both 112 and 140 d.
Journal Article
Relationships among test length and absolute and relative growth rate in central bull tests.
TL;DR: The Wisconsin central bull test data representing 4 yr, 401 bulls, three breeds, 158 sires and 72 herds were analyzed to establish relationships between absolute growth rate (AGR) and relative growth rates (RGR) for different test lengths.