Department of Animal Science, University of Nebraska, Lincoln 68583.
Department of Animal Science, University of Nebraska, Lincoln 68583.
J Dairy Sci. 2020 May;103(5):4206-4217. doi: 10.3168/jds.2019-17762. Epub 2020 Mar 18.
A study using indirect calorimetry and 12 lactating multiparous Jersey cows (53 ± 23 d in milk at the beginning of the experiment; mean ± standard deviation) was conducted to evaluate the utilization of energy in cattle consuming diets containing increasing hydrolyzed feather meal (HFM). A triplicated 4 × 4 Latin square design with 35-d periods (28-d adaption and 4-d collections) was used to compare 4 different dietary treatments. Treatments contained (DM basis) HFM at 0% (0HFM), 3.3% (3.3HFM), 6.7% (6.7MFM), and 10.0% (10HFM). Diets were formulated such that HFM replaced blood meal and nonenzymatically browned soybean meal. With increasing HFM, linear increases were observed for dietary NE content (1.61, 1.64, 1.69, and 1.70 ± 0.042 Mcal/kg of DM for 0HFM, 3.3HFM, 6.7MFM, and 10HFM, respectively), and the efficiency of converting ME to NE (0.708, 0.711, 0.717, and 0.719). Apparent total-tract digestibility of CP linearly decreased with increasing HFM (63.4, 61.1, 59.9, and 58.6 ± 1.46% for 0HFM, 3.3HFM, 6.7MFM, and 10HFM, respectively), whereas long-chain fatty acid digestibility increased with increasing HFM (77.2, 77.7, 78.5, and 80.6 ± 1.30%). With increased inclusion of HFM, fecal N excretion increased (199, 230, 239, 237 ± 12.1 g/d for 0HFM, 3.3HFM, 6.7MFM, and 10HFM, respectively), whereas urinary N excretion decreased (166, 151, 155, and 119 ± 14.8 g/d). Increasing the concentration of HFM resulted in a quadratic effect on DMI (19.6, 20.2, 20.3, and 19.1 ± 0.79 kg/d for 0HFM, 3.3HFM, 6.7MFM, and 10HFM, respectively) and milk yield (31.7, 32.0, 31.9, and 29.7 ± 1.32 kg/d). Increasing HFM linearly decreased the milk protein concentration (3.34, 3.29, 3.23, and 3.23 ± 0.158 for 0HFM, 3.3HFM, 6.7MFM, and 10HFM, respectively) and yield (1.05, 1.05, 1.02, and 0.96 ± 0.040 kg). The inclusion of HFM did not affect energy-correct milk yield (average of 39.3 ± 1.54). Results of this study suggest that HFM can increase dietary NE content compared with blood meal and nonenzymatically browned soybean meal and maintained energy-corrected milk yield; however, feeding HFM at greater than 6.7% of diet DM decreased DMI, and protein availability may have been reduced with increased HFM, leading to a linear decrease in milk protein concentration and yield.
本研究采用间接测热法和 12 头泌乳期的荷斯坦奶牛（试验开始时泌乳天数为 53±23 天；平均值±标准差），评估了采食含有不同水解羽毛粉（HFM）日粮的奶牛的能量利用情况。采用三重复 4×4 拉丁方设计，共 35 天的试验期（28 天适应期和 4 天收集期），比较了 4 种不同的日粮处理。处理组日粮含有 0%（0HFM）、3.3%（3.3HFM）、6.7%（6.7MFM）和 10.0%（10HFM）的 HFM。日粮配方中，HFM 替代了血粉和非酶褐变大豆粉。随着 HFM 含量的增加，日粮的非纤维性碳水化合物（NFC）含量（0HFM、3.3HFM、6.7MFM 和 10HFM 组分别为 1.61、1.64、1.69 和 1.70±0.042 Mcal/kg 干物质）和 ME 转化为 NE 的效率（0.708、0.711、0.717 和 0.719）线性增加。随着 HFM 含量的增加，CP 的表观全肠道消化率线性下降（0HFM、3.3HFM、6.7MFM 和 10HFM 组分别为 63.4、61.1、59.9 和 58.6±1.46%），而长链脂肪酸的消化率增加（77.2、77.7、78.5 和 80.6±1.30%）。随着 HFM 含量的增加，粪便氮排泄量增加（0HFM、3.3HFM、6.7MFM 和 10HFM 组分别为 199、230、239 和 237±12.1 g/d），而尿液氮排泄量减少（166、151、155 和 119±14.8 g/d）。HFM 浓度的增加对 DMI 有二次效应（0HFM、3.3HFM、6.7MFM 和 10HFM 组分别为 19.6、20.2、20.3 和 19.1±0.79 kg/d）和产奶量（31.7、32.0、31.9 和 29.7±1.32 kg/d）。随着 HFM 含量的增加，牛奶蛋白浓度（0HFM、3.3HFM、6.7MFM 和 10HFM 组分别为 3.34、3.29、3.23 和 3.23±0.158）和产量（1.05、1.05、1.02 和 0.96±0.040 kg）线性下降。HFM 的添加不影响能量校正奶产量（平均值为 39.3±1.54）。本研究结果表明，与血粉和非酶褐变大豆粉相比，HFM 可以增加日粮的 NE 含量，并维持能量校正奶产量；然而，当 HFM 添加量超过日粮 DM 的 6.7%时，DMI 降低，随着 HFM 的增加，蛋白质的可用性可能降低，导致牛奶蛋白浓度和产量线性下降。
