Get reliable rangeland science

Livestock farming is one of the main sources of global greenhouse gas emissions, particularly methane produced during the digestion process of cattle and sheep, which not only harms the environment but also results in feed energy loss. Therefore, it is essential to understand the patterns and influencing factors of livestock greenhouse gas emissions to improve feed energy efficiency and protect the environment. By feeding different combinations of roughage, production efficiency can be increased and polluti on reduced. Different forage compositions lead to varying greenhouse gas emissions in lambs. Understanding the response of productivity and greenhouse gas emissions to dietary combinations, exploring green regulation methods, and focusing on low-carbon emission reduction technologies are crucial for reducing methane pollution, improving feed utilization, ensuring animal health and product safety, and promoting sustainable livestock farming. This study selected 24 healthy lambs of similar weight, randomly divided into four groups of six, and fed different combinations of diets: natural hay, oat hay + natural hay, alfalfa hay + natural hay, and alfalfa hay + oat hay. Feed intake, weight changes, and greenhouse gas emissions were measured during the experiment. The results showed: (1) Under ad libitum feeding conditions, the dry matter intake of the alfalfa hay + oat hay group and the natural hay group was significantly higher than that of the other two groups (P<0.05); the protein intake of the oat hay + natural hay group was significantly lower than that of the other three groups (P<0.05). (2) The average daily weight gain of lambs in the alfalfa hay + natural hay group was significantly higher than that in the oat hay + natural hay group (P<0.05). (3) The trend of CH4 emissions in lambs was similar to that of CO2, with the natural hay group significantly higher than the other three groups, and the emissions in the alfalfa hay + oat hay group being the lowest; the N2O emissions in the alfalfa hay + oat hay group were also significantly lower than those in the oat hay + natural hay group. This indicates that feeding natural hay significantly increases the greenhouse gas emissions of lambs.