Colin Reba L, Sperber Jessica L, Buse Kassidy K, Kononoff Paul J, Watson Andrea K, Erickson Galen E
Department of Animal Science, University of Nebraska, Lincoln, NE 68583-0908, USA.
Transl Anim Sci. 2024 Aug 1;8:txae109. doi: 10.1093/tas/txae109. eCollection 2024.
Alga 1.0, a product containing bromoform, was fed to cattle to evaluate its effects on methane ( ) and carbon dioxide ( ) emissions and diet digestibility. Twelve nonlactating, nonpregnant Jersey cows (490 ± 19 kg body weight) were used in four replicated 3 × 3 Latin squares with three periods, each consisting of 21 d. Cows were blocked by feed intake (averaged intakes over 4 wk prior to trial) and assigned randomly to one of three treatments. Treatments included Alga 1.0 fed at 0, 69, and 103 g/d in a 0.454 kg/d dry matter () top-dress daily in a modified distillers grains plus solubles () carrier. Diet consisted of 60% dry-rolled corn, 20% corn silage, 15% modified distillers grains, and 5% supplement (DM basis). Headbox-style indirect calorimeters were utilized to evaluate gas production from individual cows with two nonconsecutive 23-h collections in each period. Data were analyzed using the GLIMMIX procedure of SAS with cow within square as experimental unit and as a random effect, and treatment and period as fixed effects. Linear and quadratic contrasts were used to compare treatments. Feeding Alga 1.0 linearly reduced dry matter intake (, < 0.01) by 10.1% for 69 g/d inclusion and 13.3% for 103 g/d inclusion compared to the control. Nutrient intakes decreased linearly ( < 0.01) due to lower DMI, but nutrient digestibility was not impacted ( ≥ 0.28). Inclusion of Alga 1.0 did not impact gross energy or digestible energy concentration of the diets expressed as Mcal/kg DM ( ≥ 0.22) but did linearly reduce energy intake (Mcal/d; < 0.01). Feeding Alga 1.0 linearly reduced enteric CH emissions measured as g/kg DMI ( < 0.01) by 39 and 64% for 69 g/d and 103 g/d inclusion, respectively. Linear reductions ( < 0.01) of 64% to 65% were also observed in enteric CH emissions when expressed per kilogram of DM or organic matter digested. Respired CO as g/d linearly decreased ( = 0.03) for cattle fed Alga 1.0 but did not differ when expressed as g/kg of DMI ( ≥ 0.23). Oxygen consumption did not differ between treatments for g/d and g/kg DMI (≥ 0.19). In conclusion, feeding Alga 1.0 reduced DMI up to 13.3%, did not impact digestibility, and significantly reduced CH emissions up to 63%.
藻类1.0是一种含有溴仿的产品，将其喂给奶牛以评估其对甲烷（ ）和二氧化碳（ ）排放以及日粮消化率的影响。选用12头非泌乳、未怀孕的泽西奶牛（体重490±19千克），采用4个重复的3×3拉丁方设计，共3个阶段，每个阶段持续21天。奶牛按采食量（试验前4周的平均采食量）进行分组，并随机分配到三种处理之一。处理包括以0、69和103克/天的剂量投喂藻类1.0，以0.454千克/天的干物质（ ）形式每日在改良酒糟加可溶物（ ）载体上进行顶层投喂。日粮由60%干碾压玉米、20%玉米青贮、15%改良酒糟和5%补充料（干物质基础）组成。采用头箱式间接测热法，在每个阶段对每头奶牛进行两次不连续的23小时气体收集，以评估气体产生情况。数据采用SAS的GLIMMIX程序进行分析，以方内奶牛作为实验单位并作为随机效应，处理和阶段作为固定效应。采用线性和二次对比来比较处理。与对照组相比，投喂藻类1.0使干物质摄入量呈线性下降（ ， ＜0.01），69克/天添加量时下降10.1%，103克/天添加量时下降13.3%。由于干物质摄入量降低，养分摄入量呈线性下降（ ＜0.01），但养分消化率未受影响（ ≥0.28）。添加藻类1.0对日粮以兆卡/千克干物质表示的总能或可消化能浓度没有影响（ ≥0.22），但使能量摄入量呈线性下降（兆卡/天； ＜0.01）。投喂藻类1.0使以克/千克干物质摄入量衡量的肠道甲烷排放量呈线性下降（ ＜0.01），69克/天和103克/天添加量时分别下降39%和64%。当以每千克干物质或消化的有机物表示时，肠道甲烷排放量也呈线性下降（ ＜0.01），下降幅度为64%至65%。对于投喂藻类1.0的奶牛，呼出的二氧化碳以克/天表示呈线性下降（ =0.03），但以克/千克干物质摄入量表示时无差异（ ≥0.23）。不同处理之间，氧气消耗量以克/天和克/千克干物质摄入量表示时无差异（ ≥0.19）。总之，投喂藻类1.0使干物质摄入量降低高达13.3%，不影响消化率，并显著降低甲烷排放量高达63%。
