Abstract Integrating dairy and beef production offers opportunities to reduce greenhouse gas (GHG) emissions of beef production, which is dominated by emissions related to maintenance of the breeding cow. This study aims to quantify the GHG reduction potential of the New Zealand (NZ) beef sector when replacing beef breeding cows and their calves with dairy beef animals. To this end, we combined a cattle herd model of NZ beef and dairy production with GHG emission calculations of beef production. We computed GHG emissions (to farm-gate stage) of the current amount of beef produced, while increasing the number of dairy beef calves at the expense of the number of suckler-beef calves. GHG emissions were 29% lower per kg carcass weight for dairy beef animals compared to suckler-beef animals. The average emission intensity decreased from 21.3 to 16.7 kg CO2e per kg carcass weight (−22%) as the number of suckler-beef animals declined to zero and dairy beef animals increased. Integrating dairy and beef production would enable the NZ beef sector to reduce annual GHG emissions by nearly 2000 kt CO2e (i.e. 22% of the total sector's emissions), while the dairy sector would improve their social licence to operate by reducing the number of surplus dairy calves slaughtered from 4-days old.

中文翻译：

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通过更好地整合乳制品和牛肉生产，减少新西兰牛肉的温室气体排放

摘要 乳制品和牛肉生产的整合为减少牛肉生产的温室气体 (GHG) 排放提供了机会，其中主要是与种牛维护相关的排放。本研究旨在量化新西兰 (NZ) 牛肉行业在用奶牛替代肉牛及其小牛时的温室气体减排潜力。为此，我们将新西兰牛肉和奶制品生产的牛群模型与牛肉生产的温室气体排放计算相结合。我们计算了当前牛肉产量的 GHG 排放量（到农场关口阶段），同时以牺牲乳牛犊数量为代价增加奶牛犊的数量。与乳牛肉动物相比，乳牛肉动物每公斤胴体重量的温室气体排放量低 29%。平均排放强度从 21.3 下降到 16。7 公斤二氧化碳当量每公斤屠体重量 (-22%)，因为乳牛肉动物的数量下降到零，而奶牛动物的数量增加。整合乳制品和牛肉生产将使新西兰牛肉行业的年温室气体排放量减少近 2000 千吨二氧化碳当量（即占行业总排放量的 22%），同时乳制品行业将通过减少剩余乳制品的数量来提高其社会经营许可从 4 天大开始屠宰的小牛。