Red Angus heifers [n = 19; body weight (BW) = 370 ± 8.1 kg) and their paired offspring (BW = 283 ± 4.2 kg; 18 heifers, 1 steer) were used to compare the respiration gas parameters between dams and their progeny over 2 calving cycles (8 pairs in the 1st cycle, 11 in the 2nd). The methane (CH4), carbon dioxide (CO2) emissions and oxygen (O2) consumption of the dams were measured at 14 mo of age over a 70-d period using an automated head-chamber system (AHCS) that measured the flux of these 3 gases. Dams grazed native mixed-grass prairie and were offered a daily supplement of alfalfa (Medicago sativa L.) pellets (1.0 kg) via the AHCS. Dams were artificially inseminated using sexed semen (female) from a single Black Angus sire. The gas fluxes of the progeny were measured, beginning at 11 mo of age, over a 70-d period. Like the dams, during their measurement period, the progeny grazed native mixed-grass prairie and were offered a daily supplement (1.0 kg) of alfalfa pellets via the AHCS. Pearson correlations were developed between the 70-d means of daily CH4 and CO2 emissions, O2 consumption, CH4:CO2 ratio, respiratory quotient (RQ), and heat of production estimates for the dams and their progeny by regressing maternal parameters on the parameters of the progeny, using beginning dam and progeny BW as covariates, and year as an indicator variable. A dam’s CH4 emission was very strongly correlated with that of their offspring (ρ = 0.86). The CO2 emission and O2 consumption of the dams were both also very strongly (ρ = 0.92 and ρ = 0.97, respectively) correlated, with that of their progeny. The heat production and CH4:CO2 ratio of the dams were very strongly (ρ = 0.96) and fairly (ρ = 0.50) correlated, respectively, with that of their progeny. Lastly, the RQ of the dam was also very strongly correlated (ρ = 0.87) with the RQ of the progeny. These results indicate that CH4 and CO2 emissions, O2 consumption, CH4:CO2 ratio, and heat of production of the dam are fairly to very strongly correlated to the gas flux parameters of their progeny. Hence, even with this small dataset, there is evidence that beef cattle traits related to greenhouse gas emissions are somewhat heritable and could potentially be selected in breeding animals to decrease greenhouse gas emission intensity.

中文翻译：

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PSIX-22 母体甲烷、二氧化碳和氧通量与子代气体通量的比较


红安格斯小母牛 [n = 19;体重 （BW） = 370 ± 8.1 公斤）及其配对后代（体重 = 283 ± 4.2 公斤;18 头小母牛，1 头公牛）用于比较母牛及其后代在 2 个产犊周期（第 1 个周期 8 对，第 2 个周期 11 对）中的呼吸气体参数。使用自动头室系统 （AHCS） 测量这 3 种气体的通量，在 70 天的时间里，在 14 个月大时测量大坝的甲烷 （CH4）、二氧化碳 （CO2） 排放和氧气 （O2） 消耗量。水坝放牧本地混合草原，并通过 AHCS 每天补充紫花苜蓿 （Medicago sativa L.） 颗粒 （1.0 kg）。母猪使用来自单个黑安格斯公牛的性别精液（雌性）进行人工授精。从 11 个月大开始，在 70 天的时间里测量后代的气体通量。与水坝一样，在测量期间，后代放牧本地混合草原，并通过 AHCS 每天补充 （1.0 kg） 苜蓿颗粒。通过对母体参数进行后代参数回归，使用起始母体和后代 BW 作为协变量，以年份为指示变量，在母体及其后代的每日 CH4 和 CO2 排放量、O2 消耗量、CH4：CO2 比率、呼吸商 （RQ） 和生产热量估计之间的 70 d 均值之间建立了 Pearson 相关性。母猪的 CH4 排放与其后代的 CH4 排放非常密切相关 （ρ = 0.86）。大坝的 CO2 排放和 O2 消耗量与其后代的排放和 O2 消耗量也非常相关（分别为 ρ = 0.92 和 ρ = 0.97）。大坝的产热和 CH4：CO2 比分别与其后代的产热和 CH4：CO2 比值非常强 （ρ = 0.96） 和相当 （ρ = 0.50） 相关。 最后，母系的 RQ 与后代的 RQ 也非常相关 （ρ = 0.87）。这些结果表明，CH4 和 CO2 排放、O2 消耗、CH4：CO2 比率和大坝的生产热量与其后代的气体通量参数相当强到非常密切相关。因此，即使数据集很小，也有证据表明，与温室气体排放相关的肉牛性状在某种程度上是可遗传的，并且有可能在种猪中选择以降低温室气体排放强度。