摘要
The objective of this project was to investigate the effects of selecting sires for residual feed intake (RFI) on the performance of their daughters. Bulls with low or high estimated breeding values (EBV) for RFI were selected from the Angus Society of Australia sire summary and mated to Angus cross commercial cows at the Kansas State University Cow-Calf Unit in 2005 and 2006. The average EBV of low- and high-RFI bulls were −0.55 and 0.27 kg DM, respectively. Heifers born in 2006 were tested for feed intake in 2 groups (n = 24, n = 26), and heifers born in 2007 (n = 42) were sent to a commercial bull test facility for feed intake and BW gain tests. Body weights were collected every 14 d and used to calculate midtest BW and ADG. Actual feed intake was regressed on midtest metabolic BW and ADG to calculate an expected feed intake for each heifer. Residual feed intake was calculated by subtracting the expected intake from the actual intake. There were no significant differences between heifers sired by lowor high-RFI EBV bulls in RFI, feed intake, G:F, or BW gain (P > 0.05). Heifers in this study were being developed on a less energy-dense diet than the diet used to rank their sires. Genetic differences in RFI calculated in growing bulls may not have been expressed on the lower plane of nutrition of these developing heifers.
摘要译文
该项目的目的是调查选择公牛残余采食量（RFI）对其女儿表现的影响。RFI的育种值（EBV）选自澳大利亚Angus Society of sire摘要，并于2005年和2006年与堪萨斯州立大学Cow-Calf小组的Angus交叉商业奶牛交配。低RFI和高RFI公牛的平均EBV分别为-0.55和0.27 kg DM。 2006年出生的小母牛在两组中测试了采食量（n \x3d 24，n \x3d 26），2007年出生的小母牛（n \x3d 42）被送到商业牛测试设施进行采食和BW增益测试。每14天收集体重并用于计算中期BW和ADG。实际采食量在中期代谢BW和ADG上回归，以计算每个小母牛的预期采食量。通过从实际摄入量中减去预期摄入量来计算剩余采食量。 RFI中由低RFI EBV公牛引发的小母牛之间没有显着差异，采食量，G：F或BW增加（P 0.05）。这项研究中的小母牛正在开发的能量密度低于用于对其公牛进行排名的饮食。在生长的公牛中计算的RFI的遗传差异可能没有在这些发育中的小母牛的营养的较低平面上表达。
J. MinickBormannPAS;D.W.Moser;T.T.MarstonPAS[3];. CASE STUDY: Feed Intake and Performance of Heifers Sired by High- or Low-Residual Feed Intake Angus Bulls1[J]. The Professional Animal Scientist, 2010,26(3): 328-331