这项研究的目的是评估饲喂酿酒酵母发酵产品(SCFP)对自然暴露于高温和湿度条件下的荷斯坦奶牛的产奶效率的影响。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,和12周的数据收集。奶牛[n=1,843;牛奶中≥21d(DIM)和<100d的小牛]被纳入并分配到平衡的研究围栏(n=10),牛奶产量,和DIM。笔饲喂不含(CTRL)或SCFP(19g/d,NutriTek,钻石V)。牛奶产量,能量校正牛奶(ECM),牛奶成分,线性体细胞评分,干物质摄入量(drymatteradvance,drymatter),饲料效率(FE;牛奶/MDI和ECM/MDI),身体状况评分,和临床乳腺炎的发病率,肺炎,和扑杀被监控。统计分析包括混合的线性和逻辑模型,用于重复测量(适用时;处理圈内每头母牛的多次测量),以笔为实验单位和处理。时间(学习周),奇偶校验(1与2+),以及它们在农场内固定和围栏嵌套的相互作用和随机效应的治疗。饲喂SCFP的圈内2+奶牛比CTRL圈内的奶牛产奶更多(42.1与41.2kg/d);初产妇组之间的产量没有差异。SCFP围栏内的奶牛有较低的QI(25.2vs.26.0kg/d)和更大的FE(1.59vs.1.53)和ECMFE(1.73vs.1.68)比CTRL围栏内的奶牛。牛奶成分,线性体细胞评分,健康事件,和剔除组之间没有差异。在研究结束时(245±54DIM),SCFP奶牛的身体状况评分高于CTRL(3.33vs.第一个平价中的3.23;3.11vs.3.04在2个以上的母牛中)。向暴露于高温和湿度条件的泌乳奶牛饲喂酿酒酵母发酵产物可改善FE。
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.