本试验旨在通过析因法获得泌乳前期水牛能量需要量。选用30头体况良好、上一泌乳期泌乳量相近、产犊胎次(2、3胎)接近、健康的泌乳前期水牛，随机分为3组，每组10头，采用等粗蛋白质(13.3%)、3种能量水平的精饲料，产乳净能分别为6.0、6.6和7.2 MJ/kg。预试期15 d，正试期30 d。于正试期第24、28天分别从每组选取3头进行为期7 d的消化代谢试验和3 d的气体代谢试验。结果表明，通过进食能量与畜体产热获得的维持净能（NEm）=263.40 kJ/(W0.75·d)×120%=316.10 kJ/(W0.75·d)；通过直接测热获得的水牛乳乳能值为4.4 MJ/kg，在消化代谢期间水牛常乳转换为标准乳的转换系数为1.51，因此每生产1 kg水牛标准乳需要的净能为2.915 MJ。根据析因法原理，水牛泌乳前期净能需要量可表示为：NE(MJ/d)=0.316W0.75＋0.290 7ΔW×W0.75＋2.915FCM（式中NE为净能、W0.75为代谢体重，ΔW为日均体重变化，FCM为标准乳产量）。

 The objective of this study was to obtain the energy requirement of water buffalo in early lactation by factorial method. Thirty healthy water buffalo in early lactation with similar milk yield in the last lactation period and parities (2 or 3) were randomly divided into 3 groups with 10 heads in each group. Water buffalo in the 3 groups were fed concentrates with 3 energy levels and an equal crude protein level (13.5%), in which the net energy values for lactation were 6.0, 6.6 and 7.2 MJ/kg, respectively. The preliminary trial period lasted for 15 d, and the trial period lasted for 30 d. Three heads in each group were selected for a 7-day digestive metabolism test and a 3-day gaseous metabolism test on the 24th and 28th day of the trial period, respectively. The results showed as follows: the net energy for maintenance (NEm) was calculated by energy intake and heat production, NEm=263.40 kJ/(W0.75·d)×120%=316.10 kJ/(W0.75·d); the milk energy was 4.4 MJ/kg, the transfer coefficient of normal milk and fat corrected milk (FCM) was 1.51 during the digestive test. Thus, the production of 1 kg FCM required 2.915 MJ of net energy. According to the principle of factorial method, the requirement for net energy of water buffalo in early lactation can be estimated by the following equation: NE (MJ/d)=0.316W0.75＋0.290 7ΔW×W0.75＋2.915FCM (NE is the net energy, W0.75 is the metabolic weight,ΔW is the daily changing of body weight, and FCM is the fat corrected milk yield).［Chinese Journal of Animal Nutrition， 2011， 23（6）：950 -955］