Background: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 u...Background: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_(4))and carbon dioxide(CO_(2))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_(4) and CO_(2) emissions.Results: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_(4) production(expressed in CO_(2) equivalent,CO_(2)-eq)was found to be 8304 g/d,CH_(4)_(CO_(2)−eq)/DMI was 359 g/kg,CH_(4)_(CO_(2)−eq)/energy-corrected milk(ECM)was 229.5 g/kg,total CO_(2) production(CH_(4) production plus CO_(2) production)was 19,201 g/d,total CO_(2)/DMI was 831 g/kg,and total CO_(2)/ECM was 531 g/kg.The parity and metabolic weight of cows had no significant effect on total CO_(2) emissions(P>0.05).Cows with high milk yield,milk fat yield,milk protein yield,and total milk solids yield produced more total CO_(2)(P<0.05),but their total CO_(2) production per kg of ECM was low(P<0.05).The total CO_(2)/ECM of the medium and high milk yield groups was 17%and 27%lower than that of the low milk yield group,respectively.Conclusions:The parity and body condition had no effect on total CO_(2) emissions,while the total CO_(2)/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_(2) 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.展开更多
Introduction of solid feeds in the ration of calves has<span style="font-family:Verdana;"> been</span><span style="font-family:""><span style="font-family:Verdana;&qu...Introduction of solid feeds in the ration of calves has<span style="font-family:Verdana;"> been</span><span style="font-family:""><span style="font-family:Verdana;"> shown to increase rumen size and stimulate rumen fermentation. With the initiation of bacterial fermentation in the rumen, the intermediary metabolism moves from a glucose-based to a volatile fatty acid-based metabolism, which releases methane. Mootral<sup>TM</sup> has been identified as a promising plant-derived feed supplement to reduce methane emission in dairy and beef cattle. Therefore, the present study aimed at quantifying and mitigating the methane emissions in calves until the slaughtering age of 28 weeks. The study consisted of 20 Holstein bull calves at a commercial farm, assigned randomly into 2 groups (control n = 10;treatment n = 10), for 2 weeks of adaptation and 8 weeks of sample collection. The calves were fed an increasing amount of milk replacer and </span><i><span style="font-family:Verdana;">ad libitum</span></i><span style="font-family:Verdana;"> wheat straw. Mootral was fed once a day to the treatment calves. Methane was measured using GreenFeed units where concentrate feed was offered as bait. The calves were weighed at the start and every four weeks during the experiment. The calves in the treatment group had lower methane emissions (54 g/d) compared to the control group (70 g/d), a reduction of 22.8%. In contrast, carbon dioxide emission and dry matter intake did not differ significantly between the study groups. Moreover, no negative impact on the average daily weight gain and carcass weight was observed in Mootral fed calves. Although the methane emission (g/kg body weight) was lower in treatment than in the control group, the absolute difference between the groups narrowed with increasing age of the calves. The results suggest a need to increase the dose in line with the increased body weight and intake of the calves. In conclusion, Mootral effectively reduced methane in calves. Further trials to determine the optimal dose for calves are warranted, and as well studies to investigate if interventions (such as Mootral) applied at an earlier life cycle stage would have an impact on methane emissions at later stages of cattle’s life, would be of scientific interest.</span></span>展开更多
基金funded by the Central Public-interest Scientific Institution Basal Research Fund of Chinese Academy of Agricultural Sciences(No.Y2022GH12)the Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2017-FRI-04).
文摘Background: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_(4))and carbon dioxide(CO_(2))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_(4) and CO_(2) emissions.Results: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_(4) production(expressed in CO_(2) equivalent,CO_(2)-eq)was found to be 8304 g/d,CH_(4)_(CO_(2)−eq)/DMI was 359 g/kg,CH_(4)_(CO_(2)−eq)/energy-corrected milk(ECM)was 229.5 g/kg,total CO_(2) production(CH_(4) production plus CO_(2) production)was 19,201 g/d,total CO_(2)/DMI was 831 g/kg,and total CO_(2)/ECM was 531 g/kg.The parity and metabolic weight of cows had no significant effect on total CO_(2) emissions(P>0.05).Cows with high milk yield,milk fat yield,milk protein yield,and total milk solids yield produced more total CO_(2)(P<0.05),but their total CO_(2) production per kg of ECM was low(P<0.05).The total CO_(2)/ECM of the medium and high milk yield groups was 17%and 27%lower than that of the low milk yield group,respectively.Conclusions:The parity and body condition had no effect on total CO_(2) emissions,while the total CO_(2)/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_(2) 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.
文摘Introduction of solid feeds in the ration of calves has<span style="font-family:Verdana;"> been</span><span style="font-family:""><span style="font-family:Verdana;"> shown to increase rumen size and stimulate rumen fermentation. With the initiation of bacterial fermentation in the rumen, the intermediary metabolism moves from a glucose-based to a volatile fatty acid-based metabolism, which releases methane. Mootral<sup>TM</sup> has been identified as a promising plant-derived feed supplement to reduce methane emission in dairy and beef cattle. Therefore, the present study aimed at quantifying and mitigating the methane emissions in calves until the slaughtering age of 28 weeks. The study consisted of 20 Holstein bull calves at a commercial farm, assigned randomly into 2 groups (control n = 10;treatment n = 10), for 2 weeks of adaptation and 8 weeks of sample collection. The calves were fed an increasing amount of milk replacer and </span><i><span style="font-family:Verdana;">ad libitum</span></i><span style="font-family:Verdana;"> wheat straw. Mootral was fed once a day to the treatment calves. Methane was measured using GreenFeed units where concentrate feed was offered as bait. The calves were weighed at the start and every four weeks during the experiment. The calves in the treatment group had lower methane emissions (54 g/d) compared to the control group (70 g/d), a reduction of 22.8%. In contrast, carbon dioxide emission and dry matter intake did not differ significantly between the study groups. Moreover, no negative impact on the average daily weight gain and carcass weight was observed in Mootral fed calves. Although the methane emission (g/kg body weight) was lower in treatment than in the control group, the absolute difference between the groups narrowed with increasing age of the calves. The results suggest a need to increase the dose in line with the increased body weight and intake of the calves. In conclusion, Mootral effectively reduced methane in calves. Further trials to determine the optimal dose for calves are warranted, and as well studies to investigate if interventions (such as Mootral) applied at an earlier life cycle stage would have an impact on methane emissions at later stages of cattle’s life, would be of scientific interest.</span></span>
