Jia Peng, Tu Yan, Liu Zhihao, Lai Qi, Li Fadi, Dong Lifeng, Diao Qiyu
State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, People's Republic of China.
Institute of Feed Research, Chinese Academy of Agricultural Sciences/Sino-US Joint Lab on Nutrition and Metabolism of Ruminant, Beijing, 100081, People's Republic of China.
J Anim Sci Biotechnol. 2022 Jun 30;13(1):88. doi: 10.1186/s40104-022-00721-3.
This study investigated greenhouse gas (GHG) emission characteristics of lactating Holstein dairy cows in East China and provided a basis for formulating GHG emission reduction measures. GreenFeed system was used to measure the amount of methane (CH) and carbon dioxide (CO) emitted by the cows through respiration. Data from a commercial cow farm were used to observe the effects of parity, body weight, milk yield, and milk component yield on CH and CO emissions.
Mean herd responses throughout the study were as follows: 111 cows completed all experimental processes, while 42 cows were rejected because they were sick or had not visited the GreenFeed system 20 times. On average, lactating days of cows was 138 ± 19.04 d, metabolic weight was 136.5 ± 9.5 kg, parity was 2.8 ± 1.0, dry matter intake (DMI) was 23.1 ± 2.6 kg/d, and milk yield was 38.1 ± 6.9 kg/d. The GreenFeed system revealed that CH production (expressed in CO equivalent, CO-eq) was found to be 8304 g/d, [Formula: see text]/DMI was 359 g/kg, [Formula: see text]/energy-corrected milk (ECM) was 229.5 g/kg, total CO production (CH production plus CO production) was 19,201 g/d, total CO/DMI was 831 g/kg, and total CO/ECM was 531 g/kg. The parity and metabolic weight of cows had no significant effect on total CO emissions (P > 0.05). Cows with high milk yield, milk fat yield, milk protein yield, and total milk solids yield produced more total CO (P < 0.05), but their total CO production per kg of ECM was low (P < 0.05). The total CO/ECM of the medium and high milk yield groups was 17% and 27% lower than that of the low milk yield group, respectively.
The parity and body condition had no effect on total CO emissions, while the total CO/ECM was negatively correlated with milk yield, milk fat yield, milk protein yield, and total milk solids yield in lactating Holstein dairy cows. Measurement of total CO emissions of dairy cows in the Chinese production system will help establish regional or national GHG inventories and develop mitigation approaches to dairy production regimes.
本研究调查了中国东部泌乳期荷斯坦奶牛的温室气体（GHG）排放特征，为制定温室气体减排措施提供依据。采用GreenFeed系统测量奶牛通过呼吸排放的甲烷（CH）和二氧化碳（CO）量。利用某商业奶牛场的数据观察胎次、体重、产奶量和乳成分产量对CH和CO排放的影响。
整个研究期间牛群的平均反应如下：111头奶牛完成了所有实验过程，42头奶牛因生病或未到访GreenFeed系统20次而被排除。奶牛的平均泌乳天数为138±19.04天，代谢体重为136.5±9.5千克，胎次为2.8±1.0，干物质摄入量（DMI）为23.1±2.6千克/天，产奶量为38.1±6.9千克/天。GreenFeed系统显示，CH产量（以CO当量，即CO-eq表示）为8304克/天，CH/DMI为359克/千克，CH/能量校正乳（ECM）为229.5克/千克，总CO产量（CH产量加CO产量）为19201克/天，总CO/DMI为831克/千克，总CO/ECM为531克/千克。奶牛的胎次和代谢体重对总CO排放无显著影响（P>0.05）。产奶量、乳脂产量、乳蛋白产量和总乳固体产量高的奶牛产生的总CO更多（P<0.05），但每千克ECM的总CO产量较低（P<0.05）。中产奶量组和高产奶量组的总CO/ECM分别比低产奶量组低17%和27%。
胎次和体况对总CO排放无影响，而泌乳期荷斯坦奶牛的总CO/ECM与产奶量、乳脂产量、乳蛋白产量和总乳固体产量呈负相关。测量中国生产系统中奶牛的总CO排放将有助于建立区域或国家温室气体清单，并制定奶牛生产体系的减排方法。
