Garnsworthy P C, Saunders N, Goodman J R, Algherair I H, Ambrose J D
School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
Animal. 2025 Jan;19(1):101379. doi: 10.1016/j.animal.2024.101379. Epub 2024 Nov 22.
Live yeast (Saccharomyces cerevisiae) products have the potential to increase milk yield of dairy cows in early lactation by improving rumen fermentation. Greater milk yields, however, are sometimes associated with poorer reproductive performance. This study aimed to assess the effect of a live yeast supplement on milk yield, methane emissions and reproduction indicators in high-yielding dairy cows. Fifty Holstein cows were paired according to month of calving, parity and predicted milk yield, and allocated at random to either a Control diet or a diet containing live Yeast (Actisaf® Sc 47, 1 × 10 cfu/g, Phileo by Lesaffre) supplying 1 × 10 cfu/cow per day (10 g). Diets were fed to cows from 7 to 128 days in milk. Live yeast resulted in higher yields of milk (50.1 vs 47.5 kg/day), energy-corrected milk (ECM; 50.5 vs 47.7 kg/day), fat-corrected milk (49.2 vs 46.3 kg/day) and milk fat (1 945 vs 1 823 g/day), compared with Control. There was no effect of treatment on DM intake (DMI), so cows fed on Yeast had greater feed efficiency (2.11 vs 1.98 kg ECM/kg DMI). Enhanced milk yield and feed efficiency were attributed to higher digestibility coefficients for DM (0.80 vs 0.77), NDF (0.66 vs 0.62) and gross energy (0.81 vs 0.78) in cows fed on Yeast compared with Control. Rumen pH, redox potential and volatile fatty acid concentrations, methane emissions, plasma metabolites and immunity indicators, and health events were not affected by treatment. There was no effect of treatment on days from calving to first milk progesterone rise above 3 ng/ml, days to first insemination, days to conception, conception rate, number of inseminations or incidence of atypical ovarian cycles. It was concluded that live yeast enhanced digestibility, milk yield and feed efficiency in high-yielding dairy cows, and that despite increased milk yield, methane emissions, reproduction and health indicators were maintained at the same levels as control cows.
活酵母（酿酒酵母）产品有可能通过改善瘤胃发酵来提高泌乳早期奶牛的产奶量。然而，更高的产奶量有时与较差的繁殖性能相关。本研究旨在评估添加活酵母对高产奶牛产奶量、甲烷排放和繁殖指标的影响。根据产犊月份、胎次和预测产奶量将50头荷斯坦奶牛配对，随机分配到对照日粮组或含活酵母（Actisaf® Sc 47，1×10 cfu/g，乐斯福公司生产）的日粮组，每天每头奶牛供应1×10 cfu（10克）。从产奶第7天至128天给奶牛饲喂日粮。与对照组相比，活酵母使牛奶产量（50.1对47.5千克/天）、能量校正乳（ECM；50.5对47.7千克/天）、脂肪校正乳（49.2对46.3千克/天）和乳脂（1945对1823克/天）更高。处理对干物质采食量（DMI）没有影响，因此饲喂酵母的奶牛具有更高的饲料效率（2.11对1.98千克ECM/千克DMI）。与对照组相比，饲喂酵母的奶牛干物质（0.80对0.77）、中性洗涤纤维（0.66对0.62）和总能（0.81对0.78）的消化率系数更高，这归因于产奶量和饲料效率的提高。瘤胃pH值、氧化还原电位和挥发性脂肪酸浓度、甲烷排放、血浆代谢物和免疫指标以及健康事件均不受处理影响。处理对从产犊到首次乳孕酮升至3纳克/毫升以上的天数、首次输精天数、受孕天数、受孕率、输精次数或非典型卵巢发生率没有影响。得出的结论是，活酵母提高了高产奶牛的消化率、产奶量和饲料效率，并且尽管产奶量增加，但甲烷排放、繁殖和健康指标维持在与对照奶牛相同的水平。
