Methane (CH₄) production of ruminants typically increases with increased dry matter intake (DMI). However, few studies have observed the effects of feeding multiple times a day and its effects on diurnal variation in CH₄ production and energy balance in late-lactation dairy cattle. A study using headbox-style indirect calorimetry and 12 multiparous (225 ± 16.2 d in milk; mean ± SD) lactating Jersey cows was conducted to determine the effects of feeding twice daily on diurnal variation in CH₄ production and total energy balance. A crossover design with 14-d periods (10 d of adaption and 4 d of collection) was used to compare 2 treatments. Treatments consisted of either once a day feeding (1×; 100% of feed given at 1000 h) or twice a day feeding (2×; 50% of feed given at 1000 h and the final 50% at 2000 h) with a common diet fed in both treatments. Dry matter intake was not different between treatments, with a mean of 16.9 ± 0.88 kg/d. Once a day feeding tended to have greater milk yield compared with twice a day feeding (21.2 vs. 20.4 ± 1.59 kg/d, respectively). Milk fat and milk protein percentage were not different, with means of 6.18 ± 0.20% and 3.98 ± 0.08%, respectively. Total CH₄ production did not differ between treatments, with a mean of 402.1 ± 20.8 L/d. Similarly, CH₄ per unit of milk yield and DMI was not different between treatments, with means of 20.5 ± 1.81 and 23.8 ± 1.21 L/kg, respectively. Feeding frequency did not affect diurnal variation of hourly CH₄ production, with a mean of 17.1 ± 0.74 L/h. A trend was observed for a treatment × hour interaction. Methane production per hour increased after the second feeding for cattle fed twice versus once daily. Gross energy, digestible energy, metabolizable energy, and balance (milk plus tissue) per kilogram of DMI did not differ by feeding frequency, with means of 4.41 ± 0.01, 3.05 ± 0.03, 2.63 ± 0.03, and 1.32 ± 0.08 Mcal/kg of DM, respectively. Metabolizable energy for maintenance was 146 kcal/kg of metabolic body weight, with an efficiency of converting metabolizable energy to net energy balance (milk plus tissue) of 76%. Nitrogen balance did not differ among treatments, with a mean balance of 17.3 ± 13.0 g/d. Therefore, total CH₄ production and energy maintenance were not affected by feeding frequency. However, CH₄ was variable throughout the day, and caution should be exercised when collecting CH₄ samples at a limited number of time points because this may under- or overestimate total production.

反刍动物的甲烷（CH ₄）产量通常随干物质摄入量（DMI）的增加而增加。但是，很少有研究观察到每天多次饲喂的影响及其对泌乳后期奶牛CH ₄产量昼夜变化和能量平衡的影响。进行了一项使用流浆箱式间接量热法和12头泌乳的泽西奶牛（产奶量为225±16.2 d；均值±SD）的研究，以确定每日两次饲喂对CH ₄日变化的影响生产和总能源平衡。使用14天周期（适应10天和收集4天）的交叉设计来比较2种治疗。处理方法包括每天喂一次（1x；在1000 h时喂100％的饲料）或一天两次喂食（2x； 1000 h时喂50％的饲料，最后2000％时50％的饲料），两种治疗均需饮食控制。不同处理之间干物质摄入量没有差异，平均为16.9±0.88 kg / d。与每天两次饲喂相比，每天一次饲喂往往具有更高的产奶量（分别为21.2 vs. 20.4±1.59 kg / d）。乳脂和乳蛋白百分比没有差异，平均值分别为6.18±0.20％和3.98±0.08％。不同处理之间的CH ₄总产量没有差异，平均值为402.1±20.8 L / d。同样，CH ₄处理之间的每单位产奶量和DMI无差异，分别为20.5±1.81和23.8±1.21 L / kg。进食频率不影响每小时CH _4的昼夜变化平均产量为17.1±0.74 L / h。观察到治疗×小时相互作用的趋势。第二次喂牛两次后，每小时甲烷产量增加，而每天喂一次。每千克DMI的总能量，消化能，代谢能和平衡（牛奶加组织）随进食频率的不同而不同，平均值为4.41±0.01、3.05±0.03、2.63±0.03和1.32±0.08 Mcal / kg。 DM，分别。用于维持的代谢能为146 kcal / kg代谢体重，将代谢能转化为净能量平衡（牛奶加组织）的效率为76％。各处理之间的氮平衡没有差异，平均平衡为17.3±13.0 g / d。因此，总CH ₄生产和能源维护不受喂食频率的影响。但是，CH ₄在一天中都是可变的，因此在有限的时间点收集CH ₄样品时应格外小心，因为这可能会低估或高估总产量。