As the hemp industry continues to develop in the US, there is interest in feeding byproducts of industrial hemp production to livestock. A completely randomized design experiment using crossbred finishing heifers [initial body weight (BW) ± SE = 494 ± 10 kg] was conducted to determine the effects of feeding hempseed cake in a corn-based finishing diet (10% forage) formulated to meet or exceed ruminally degradable and metabolizable protein requirements on growth performance, carcass characteristics, feeding behavior, and plasma parameters. Dietary treatments were inclusion of 20% [dry matter (DM) basis] of: dried corn distillers grains plus solubles (DDGS, n = 16), or hempseed cake (HEMP, n = 15). Cattle were housed in two pens, had ad-libitum access to feed and water, and individual intakes and feeding behavior were monitored using the Insentec feeding system. Cattle were fed treatment diets for 111 days, and every 14 days BW were measured, and blood samples collected. Blood plasma was analyzed for glucose, urea nitrogen, and individual amino acids and results analyzed using repeated measures analysis in SAS. Final BW, average daily gain, gain:feed, and hot carcass weight decreased (P ≤ 0.05) by 2.3%, 7.7%, 7.7%, and 2.6% respectively in heifers fed the HEMP diet than in heifers fed the DDGS diet. Net energy for maintenance and gain (Mcal/kg of feed, DM basis), estimated based on heifer intake and performance, were greater (P = 0.02) for the DDGS diet than the HEMP diet. All other performance and carcass characteristics were not different (P ≥ 0.20) between treatments. Heifers fed the HEMP diet had greater (P < 0.05) plasma urea nitrogen concentration in samples from each collection day compared to heifers fed the DDGS diet, although there was a treatment by day interaction (P < 0.01) because of variability in the magnitude of treatment differences over time. Plasma glucose concentration was not influenced (P = 0.17) by dietary treatment. Plasma concentrations of total amino acids, non-essential amino acids, and essential amino acids were not different between treatments (P ≥ 0.09), although there were several interactions between treatment and day (P ≤ 0.04) for individual amino acids. These data suggest that hempseed cake has a lower NEm and NEg relative to dried corn distillers grains plus solubles when adequate metabolizable protein is supplied, while still providing adequate nutrition to support acceptable performance of finishing cattle.

中文翻译：

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大麻籽饼添加物对肥育小母牛生长性能、胴体特性、采食行为和血液参数的影响

随着大麻产业在美国的持续发展，人们对将工业大麻生产的副产品喂养给牲畜产生了兴趣。使用杂交肥育小母牛 [初始体重 (BW) ± SE = 494 ± 10 kg] 进行完全随机设计实验，以确定在配制的基于玉米的肥育日粮（10% 草料）中饲喂大麻籽饼的效果以满足或超过瘤胃可降解和可代谢蛋白质对生长性能、胴体特性、摄食行为和血浆参数的要求。日粮处理包含 20% [干物质 (DM) 基础]：干玉米酒糟加可溶物（DDGS，n = 16）或大麻籽饼（HEMP，n = 15）。牛被圈养在两个围栏中，可以随意获取饲料和水，使用 Insentec 喂养系统监测个体摄入量和喂养行为。给牛喂食处理日粮 111 天，每 14 天测量一次 BW，并采集血样。分析血浆中的葡萄糖、尿素氮和单个氨基酸，并使用 SAS 中的重复测量分析对结果进行分析。饲喂 HEMP 日粮的小母牛比饲喂 DDGS 日粮的小母牛最终体重、平均日增重、增重：饲料和热胴体重量分别降低 (P ≤ 0.05) 2.3%、7.7%、7.7% 和 2.6%。根据小母牛采食量和生产性能估算的维持和增重净能（Mcal/kg 饲料，干物质基础），DDGS 日粮比 HEMP 日粮高 (P = 0.02)。所有其他性能和胴体特征在处理之间没有差异 (P ≥ 0.20)。与饲喂 DDGS 饮食的小母牛相比，饲喂 HEMP 饮食的小母牛在每个收集日的样品中具有更高的 (P < 0.05) 血浆尿素氮浓度，尽管由于日间的差异性，存在按日治疗的交互作用 (P < 0.01)随着时间的推移治疗差异的大小。血浆葡萄糖浓度不受饮食治疗的影响 (P = 0.17)。总氨基酸、非必需氨基酸和必需氨基酸的血浆浓度在治疗之间没有差异 (P ≥ 0.09)，尽管治疗和日间​​个别氨基酸之间存在一些相互作用 (P ≤ 0.04)。这些数据表明，当提供足够的可代谢蛋白质时，相对于干玉米酒糟加可溶物，大麻籽饼的 NEm 和 NEg 较低，