Submitted to: World Wide Web
Publication Type: Popular Publication
Publication Acceptance Date: 12/28/2018
Publication Date: 1/4/2018
Citation: Thallman, R.M. 2018. Selection for improved feed efficiency: Comparison of different indices. World Wide Web. 2018-1 p. 1-2. Available: http://www.eBEEF.org.
Technical Abstract: Feed efficiency is one of the most economically important traits in beef production and is sufficiently heritable to respond to genetic selection. However, selection for feed efficiency requires measuring the amount of feed consumed by individual animals. Currently, this is done in both research and industry settings in special facilities with electronic equipment designed specifically for this purpose. The high cost of measuring feed intake is due primarily to facility and labor costs and severely limits the number of animals measured both in research projects and by cattle breeders. It has been proposed that the cost per animal could be reduced by shortening the period of time the animals are in the facility. Previous research has shown that the feeding period could be considerably shorter without significantly reducing the accuracy of measuring feed intake, but that the shorter period is not sufficient to obtain an accurate measurement of the animals’ weight gain that coincides with the feed intake. Therefore, it has been further proposed to use feed intake measured over a short period along with weight gain over a much longer period together in an index to estimate feed efficiency. Individual feed intake and weight gain data on 6,331 beef cattle to retrospectively evaluate this proposal. The analysis confirmed that feed intake measured over a shorter period is nearly as accurate as when measured over a longer time. However, the analysis included weight gains over both the same period as the feed intake was recorded and over a much longer time period. The best predictions resulted from using both the short and long measures of weight gain together with feed intake to predict feed efficiency. It is recommended to include gain over the period coinciding with intake recording and gain over a much longer period of time simultaneously in a genetic evaluation and to use all three traits in a selection index for feed efficiency. Breed effects from the USMARC germplasm evaluation program are also presented.