NSW Department of Primary Industries, Agricultural Research Centre, Trangie, NSW, Australia.
NSW Department of Primary Industries, Livestock Industry Centre, Armidale, NSW, Australia.
J Anim Sci. 2020 Sep 1;98(9). doi: 10.1093/jas/skaa253.
This experiment investigated phenotypic and genetic relationships between carbon dioxide production, methane emission, feed intake, and postweaning traits in Angus cattle. Respiration chamber data on 1096 young bulls and heifers from 2 performance recording research herds of Angus cattle were analyzed to provide phenotypic and genetic parameters for carbon dioxide production rate (CPR; n = 425, mean 3,010 ± SD 589 g/d) and methane production rate (MPR; n = 1,096, mean 132.8 ± SD 25.2 g/d) and their relationships with dry matter intake (DMI; n = 1,096, mean 6.15 ± SD 1.33 kg/d), body weight (BW) and body composition traits. Heritability estimates were moderate to high for CPR (0.53 [SE 0.17]), MPR (0.31 [SE 0.07]), DMI (0.49 [SE 0.08]), yearling BW (0.46 [SE 0.08]), and scanned rib fat depth (0.42 [SE 0.07]). There was a strong phenotypic (0.83 [SE 0.02]) and genetic (0.75 [SE 0.10]) correlation between CPR and MPR. The correlations obtained for DMI with CPR and with MPR were high, both phenotypically (rp) and genetically (rg) (rp: 0.85 [SE 0.01] and 0.71 [SE 0.02]; rg (0.95 [SE 0.03] and 0.83 [SE 0.05], respectively). Yearling BW was strongly correlated phenotypically (rp ≥ 0.60) and genetically (rg > 0.80) with CPR, MPR, and DMI, whereas scanned rib fat was weakly correlated phenotypically (rp < 0.20) and genetically (rg ≤ 0.20) with CPR, MPR, and DMI. The strong correlation between both CPR and MPR with DMI confirms their potential use as proxies for DMI in situations where direct DMI recording is not possible such as on pasture.
本实验研究了安格斯牛的二氧化碳生成率（CPR）、甲烷排放量、采食量和断奶后性状之间的表型和遗传关系。对来自安格斯牛 2 个性能记录研究牛群的 1096 头公牛和小母牛的呼吸室数据进行了分析，为二氧化碳生成率（CPR；n=425，平均值 3010±SD589g/d）和甲烷生成率（MPR；n=1096，平均值 132.8±SD25.2g/d）及其与干物质采食量（DMI；n=1096，平均值 6.15±SD1.33kg/d）、体重（BW）和身体成分性状的关系提供了表型和遗传参数。CPR（0.53[SE0.17]）、MPR（0.31[SE0.07]）、DMI（0.49[SE0.08]）、育成牛 BW（0.46[SE0.08]）和扫描肋骨脂肪深度（0.42[SE0.07]）的遗传力估计值为中等至高度。CPR 和 MPR 之间存在很强的表型（0.83[SE0.02]）和遗传（0.75[SE0.10]）相关性。DMI 与 CPR 和 MPR 的相关性很高，表型（rp）和遗传（rg）（rp：0.85[SE0.01]和 0.71[SE0.02]；rg：0.95[SE0.03]和 0.83[SE0.05]）。育成牛 BW 与 CPR、MPR 和 DMI 之间存在很强的表型相关性（rp≥0.60）和遗传相关性（rg>0.80），而扫描肋骨脂肪与 CPR、MPR 和 DMI 之间的表型相关性较弱（rp<0.20）和遗传相关性（rg≤0.20）。CPR 和 MPR 与 DMI 之间的强相关性证实了它们在直接 DMI 记录不可行的情况下（例如在牧场上）作为 DMI 替代指标的潜力。
