Dairy Health and Management Services, Lowville, NY 13367.
Dairy Health and Management Services, Lowville, NY 13367.
J Dairy Sci. 2023 Jul;106(7):4650-4665. doi: 10.3168/jds.2022-22516. Epub 2023 Jun 1.
The objective of this study was to evaluate the effect of feeding a Saccharomyces cerevisiae fermentation product (SCFP) on milk production efficiency of Holstein cows naturally exposed to high temperature and humidity conditions. The study was conducted in 2 commercial farms in Mexico from July to October 2020 and included 1 wk covariate period, 3 wk adaptation, and 12 wk data collection. Cows [n = 1,843; ≥21 d in milk (DIM) and <100 d carried calf] were enrolled and assigned to the study pens (n = 10) balanced for parity, milk yield, and DIM. Pens were fed a total mixed ration diet either without (CTRL) or with SCFP (19 g/d, NutriTek, Diamond V). Milk yield, energy-corrected milk (ECM), milk components, linear somatic cell score, dry matter intake (DMI), feed efficiency (FE; Milk/DMI and ECM/DMI), body condition score, and the incidence of clinical mastitis, pneumonia, and culling were monitored. Statistical analyses included mixed linear and logistic models accounting for repeated measures (when applicable; multiple measurements per cow within treated pens) with pen as the experimental unit and treatment, time (week of study), parity (1 vs. 2+), and their interactions as fixed and pen nested within farm and treatment as random effect. Parity 2+ cows within pens fed SCFP produced more milk than cows within CTRL pens (42.1 vs. 41.2 kg/d); there were no production differences between groups of primiparous groups. Cows within SCFP pens had lower DMI (25.2 vs. 26.0 kg/d) and greater FE (1.59 vs. 1.53) and ECM FE (1.73 vs. 1.68) than cows within CTRL pens. Milk components, linear somatic cell score, health events, and culling were not different between groups. At the end of the study (245 ± 54 DIM), SCFP cows had greater body condition score than CTRL (3.33 vs. 3.23 in the first parity; 3.11 vs. 3.04 in 2+ parity cows). Feeding Saccharomyces cerevisiae fermentation products to lactating cows exposed to high temperature and humidity conditions improved FE.
本研究旨在评估在高温高湿环境下自然暴露的荷斯坦奶牛饲喂酿酒酵母发酵产物（SCFP）对产奶效率的影响。该研究于 2020 年 7 月至 10 月在墨西哥的 2 个商业农场进行，包括 1 周协变量期、3 周适应期和 12 周数据收集期。入选的奶牛[n=1843；泌乳天数（DIM）≥21 天且<100 天带犊]被分配到研究围栏（n=10）中，按胎次、产奶量和 DIM 平衡。围栏中要么饲喂不添加（CTRL）要么添加 SCFP（19 g/d，NutriTek，Diamond V）的全混合日粮。监测产奶量、能量校正奶（ECM）、乳成分、线性体细胞评分、干物质采食量（DMI）、饲料效率（Milk/DMI 和 ECM/DMI）、体况评分以及临床乳腺炎、肺炎和淘汰的发生率。统计分析包括混合线性和逻辑模型，考虑到重复测量（适用时；每头奶牛在处理围栏内的多次测量），以围栏为实验单位，以处理、时间（研究周）、胎次（1 次与 2+次）及其交互作用作为固定因素，以围栏嵌套在农场内和处理作为随机因素。饲喂 SCFP 的围栏内的 2+胎次奶牛比 CTRL 围栏内的奶牛产奶量多（42.1 比 41.2 kg/d）；初产组和经产组之间没有产奶量差异。SCFP 围栏内的奶牛的 DMI 较低（25.2 比 26.0 kg/d），饲料效率（1.59 比 1.53）和 ECM 饲料效率（1.73 比 1.68）较高。两组之间的乳成分、线性体细胞评分、健康事件和淘汰率没有差异。在研究结束时（245±54 DIM），SCFP 奶牛的体况评分高于 CTRL（初产组为 3.33 比 3.23；2+胎次组为 3.11 比 3.04）。在高温高湿环境下，给泌乳奶牛饲喂酿酒酵母发酵产物可提高饲料效率。
