摘要
The cow herd consumes approximately 70% of the annual feed resources. To date, most genetic evaluations of feed intake in beef cattle have been made in growing animals and little information is available for mature cows. Genetic evaluations in mature cows have predominately been confined to lactating dairy cows and the relationship between feed intake as growing heifers and mature cows has not been addressed. It was the purpose of this study to estimate the heritability of feed intake when measured as growing heifers and mature cows and determine the genetic correlation between these measurements. Individual feed intake and BW gain were measured on 687 heifers and 622 5-yr-old cows. The heritability of average daily DMI (ADDMI) estimated in heifers was 0.84 ± 0.12 and 0.53 ± 0.12 in cows. The heritability of ADG estimated in heifers was 0.53 ± 0.12 and 0.34 ± 0.11 in cows. The genetic correlation between heifer and cow ADDMI was 0.84 ± 0.09. The genetic correlation between heifer and cow ADG was 0.73 ± 019. Heritability of residual feed intake in heifers was 0.25 ± 0.11 and 0.16 ± 0.10 in cows. Heritability for residual gain in heifers was 0.21 ± 0.11 and 0.14 ± 0.10 in cows. Feed intake and ADG are heritable and genetically correlated between heifers and cows. Selection for decreased feed intake and ADG in growing animals will probably have the same directional effects on mature cows.
摘要译文
牛群消耗大约每年饲料资源的70％。迄今为止，对肉牛采食量的大多数遗传学评估都是在生长的动物中进行的，很少有关于成年牛的信息。对成年母牛的遗传评估主要限于泌乳奶牛，由于未成熟的母牛和成年母牛的采食量之间的关系尚未得到解决。这项研究的目的是评估以小母牛和成年母牛的身高进行测量时采食量的遗传力，并确定这些测量值之间的遗传相关性。在687头小母牛和622头5岁的母牛上测量了个体采食量和体重增加。母牛的平均日DMI（ADDMI）遗传力在母牛中为0.84±0.12和0.53±0.12。母牛的ADG的遗传力估计为0.53±0.12和0.34±0.11。小母牛与母牛ADDMI之间的遗传相关性为0.84±0.09。小母牛与母牛ADG的遗传相关性为0.73±0.119，小母牛剩余采食量的遗传力为0.25±0.11和0.16±0.10。母牛的小母牛剩余增益的遗传力为0.21±0.11和0.14±0.10。母牛和母牛之间的采食量和日增重是可遗传的，并且具有遗传相关性。在生长中的动物中减少采食量和ADG的选择可能会对成年母牛产生相同的方向性影响。
Harvey C Freetly [1]; Larry A Kuehn [1]; Richard M Thallman [1]; Warren M Snelling [1]. Heritability and genetic correlations of feed intake, body weight gain, residual gain, and residual feed intake of beef cattle as heifers and cows[J]. Journal of Animal Science, 2020,98(1)