Cappellozza Bruno I, Sousa Dannylo O, Alveblad Christine, Queiroz Oscar, Joergensen Jens N, Rustas Bengt-Ove
Chr. Hansen Animal and Plant Health & Nutrition, Commercial Development, Hørsholm 2970, Denmark.
Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Skara 532-23, Sweden.
JDS Commun. 2023 Nov 17;5(2):107-112. doi: 10.3168/jdsc.2023-0439. eCollection 2024 Mar.
This experiment was conducted to evaluate the effects of feeding a -based direct-fed microbial (DFM) on performance, nutrient digestibility, rumen fermentation, and metabolic response of lactating dairy cows. Sixty-eight lactating (50 ± 6 d in milk) Holstein-Friesian (n = 20) and Swedish Red (n = 48) cows were enrolled to a 15-wk experiment. Cows were blocked by breed, lactation number, and days in milk and, within blocks, assigned to 1 of the 2 treatments: (1) basal partial mixed ration (PMR) without DFM (n = 34; CON) or (2) basal PMR with the addition of 3 g/head per day of a DFM containing and (n = 34; DFM). The DFM was mixed in a protein pellet, whereas the CON group was fed the same pellet without DFM (1 kg/cow per day). The PMR contained 53% clover grass silage and 47% compound feed plus 3 kg of a concentrate (dry matter basis) offered during milking. Milk yield and production efficiency were recorded daily, whereas milk samples were collected for 24 h every second week of the study for milk composition. During the experimental period, fecal, rumen fluid, and blood samples were collected from each cow for apparent nutrient digestibility, rumen fermentation, and metabolic responses, respectively. All data were analyzed using the MIXED procedure of SAS. No treatment effects were observed on cows final body weight and daily dry matter intake. However, cows fed DFM had a greater milk yield, milk production efficiency, lactose and total solids yield, and also tended to have a greater energy-corrected milk production efficiency and milk protein yield. No significant differences were observed on nutrient digestibility and total volatile fatty acids, but molar proportion of acetate was greater for cows fed DFM. In contrast, molar proportion of propionate was greater and butyrate tended to be greater for CON. Cows fed DFM had greater mean plasma insulin-like growth factor-I (IGF-I), but no differences were observed for plasma glucose and insulin. In summary, supplementing a -based DFM benefited productive responses of lactating dairy cows, while also modulating rumen fermentation and serum IGF-I.
本试验旨在评估饲喂基于α-的直接投喂微生物（DFM）对泌乳奶牛生产性能、养分消化率、瘤胃发酵和代谢反应的影响。68头泌乳（产奶50±6天）的荷斯坦-弗里生奶牛（n = 20）和瑞典红牛（n = 48）被纳入一项为期15周的试验。奶牛按品种、泌乳次数和产奶天数进行分组，在每组内，分配到2种处理中的1种：（1）不添加DFM的基础部分混合日粮（PMR）（n = 34；对照组）或（2）添加每天每头3 g含α-和β-的DFM的基础PMR（n = 34；DFM组）。DFM混入蛋白质颗粒中，而对照组饲喂不含DFM的相同颗粒（每天每头1 kg）。PMR包含53%的三叶草青贮和47%的配合饲料，外加挤奶期间提供的3 kg精料（干物质基础）。每天记录产奶量和生产效率，而在研究的每第二周收集24小时的牛奶样本用于分析牛奶成分。在试验期内，从每头奶牛采集粪便、瘤胃液和血液样本，分别用于表观养分消化率、瘤胃发酵和代谢反应的测定。所有数据使用SAS的MIXED程序进行分析。在奶牛最终体重和每日干物质采食量上未观察到处理效应。然而，饲喂DFM的奶牛产奶量、产奶效率、乳糖和总固体产量更高，并且能量校正产奶效率和乳蛋白产量也有增加的趋势。在养分消化率和总挥发性脂肪酸方面未观察到显著差异，但饲喂DFM的奶牛乙酸摩尔比例更高。相反，对照组丙酸摩尔比例更高，丁酸有更高的趋势。饲喂DFM的奶牛平均血浆胰岛素样生长因子-I（IGF-I）更高，但血浆葡萄糖和胰岛素未观察到差异。总之，添加基于α-的DFM有利于泌乳奶牛的生产反应，同时也调节瘤胃发酵和血清IGF-I。
