Department of Animal Science, University of Minnesota, St. Paul 55108; West Central Research and Outreach Center, University of Minnesota, Morris 56267.
Department of Animal Science, University of Minnesota, St. Paul 55108.
J Dairy Sci. 2022 Nov;105(11):8989-9000. doi: 10.3168/jds.2022-21783. Epub 2022 Aug 31.
The objective of this study was to compare 3-breed rotational crossbred (CB) cows of the Montbéliarde, Viking Red, and Holstein (HO) breeds with HO cows fed 2 alternative diets for dry matter intake (DMI), fat plus protein production (CFP), body weight (BW), body condition score (BCS), feed efficiency, and residual feed intake (RFI) from 46 to 150 days in milk (DIM) during first lactation. The CB cows (n = 17) and HO cows (n = 19) calved from September 2019 to March 2020. Cows were fed either a traditional total mixed ration diet (TRAD) or a higher fiber, lower starch total mixed ration diet (HFLS). The HFLS had 21% more corn silage, 47% more alfalfa hay, 44% less corn grain, and 43% less corn gluten feed than the TRAD. The 2 diets were analyzed for dry matter content, crude protein, forage digestibility, starch, and net energy for lactation. The BW and BCS were recorded once weekly. Daily milk, fat, and protein production were estimated from twice monthly milk recording with random regression. Measures of efficiency were CFP per kilogram of DMI and DMI per kilogram of BW. The RFI from 46 to 150 DIM was the residual error from regression of DMI on milk energy, metabolic BW, and the energy required for change in BW. Statistical analysis of all variables included the fixed effects of diet, breed group, and the interaction of diet and breed group. The CB cows fed HFLS had less DMI (-12%) and lower DMI/BW (-14%) compared with the HO cows fed TRAD. For CFP, CB and HO cows were not different when fed TRAD or HFLS. Furthermore, the CB cows fed HFLS had higher BW (+50 kg) compared with HO cows fed HFLS. The CB cows fed TRAD had higher BCS than HO cows fed TRAD and HO cows fed HFLS (+0.46 and +0.62, respectively). The HO cows fed TRAD had more DMI (+14%) and lower CFP per kilogram of DMI (-12%) compared with the HO cows fed HFLS. In addition, mean RFI from 46 to 150 DIM was lower and more desirable for CB cows fed HFLS (-120.0 kg) compared with HO cows fed TRAD (85.3 kg). Dairy producers may feed either TRAD or HFLS to CB cows without loss of CFP.
本研究旨在比较 3 品种轮作杂交（CB）奶牛（蒙贝利亚德、Viking Red 和荷斯坦品种）与荷斯坦奶牛，在干物质采食量（DMI）、脂肪加蛋白质产量（CFP）、体重（BW）、体况评分（BCS）、饲料效率和剩余采食量（RFI）方面的差异。在第一次泌乳期间，从泌乳第 46 天到 150 天，CB 奶牛（n = 17）和荷斯坦奶牛（n = 19）分别接受两种替代日粮（TRAD 和 HFLS）。CB 奶牛采食传统全混合日粮（TRAD），而荷斯坦奶牛采食高纤维、低淀粉全混合日粮（HFLS）。HFLS 比 TRAD 多 21%的青贮玉米、47%的苜蓿干草、44%的玉米谷物和 43%的玉米蛋白粉。对这两种日粮的干物质含量、粗蛋白、饲草消化率、淀粉和泌乳净能进行了分析。每周记录一次 BW 和 BCS。每月两次通过随机回归法进行产奶量记录，估算日奶、脂肪和蛋白质产量。从泌乳第 46 天到 150 天的 RFI 是 DMI 对奶能、代谢 BW 和 BW 变化所需能量回归的残差。所有变量的统计分析包括日粮、品种组和日粮与品种组相互作用的固定效应。与荷斯坦奶牛采食 TRAD 相比，采食 HFLS 的 CB 奶牛的 DMI 减少（-12%），DMI/BW 降低（-14%）。对于 CFP，采食 TRAD 或 HFLS 的 CB 和荷斯坦奶牛没有差异。此外，采食 HFLS 的 CB 奶牛 BW 高于采食 HFLS 的荷斯坦奶牛（+50kg）。采食 TRAD 的 CB 奶牛的 BCS 高于采食 TRAD 的荷斯坦奶牛和采食 HFLS 的荷斯坦奶牛（+0.46 和+0.62）。采食 TRAD 的荷斯坦奶牛的 DMI 高于采食 HFLS 的荷斯坦奶牛（+14%），每千克 DMI 的 CFP 减少（-12%）。此外，从泌乳第 46 天到 150 天的平均 RFI 较低，采食 HFLS 的 CB 奶牛（-120.0kg）比采食 TRAD 的荷斯坦奶牛（85.3kg）更可取。奶农可以给 CB 奶牛饲喂 TRAD 或 HFLS，而不会降低 CFP。
