DairyExperts Inc., Tulare, CA 93274, USA.
Native Microbials Inc., San Diego, CA 92121, USA.
J Anim Sci. 2022 Oct 1;100(10). doi: 10.1093/jas/skac275.
The objective of this study was to evaluate the effects of two rumen-native microbial feed supplements (MFS) on milk production, milk composition, and feed efficiency. A total of 90 multiparous cows between 40 and 60 d in milk were enrolled in a randomized block design study. Within each block (baseline milk yield), cows were randomly assigned to: control (no microbial feed supplementation), MFS1 (0.33 g/kg total mixed ration [TMR] of an MFS containing a minimum of Clostridium beijerinckii at 2 × 106 CFU/g and Pichia kudriavzevii at 2 × 107 CFU/g), or MFS2 (0.33 g/kg TMR of a MFS containing a minimum of C. beijerinckii at 2 × 106 CFU/g, P. kudriavzevii at 2 × 107 CFU/g, Ruminococcus bovis at 2 × 107 CFU/g, and Butyrivibrio fibrisolvens at 2 × 107 CFU/g). Cows were housed in a single group and fed the study diets ad libitum for 270 d. Individual milk yield was recorded using electronic milk meters, and milk fat and protein were measured using optical in-line analyzers at each of two daily milkings. Treatment and treatment by time effects were assessed through multiple linear regression analyses. Treatment effects were observed for milk and energy-corrected milk (ECM) yields, milk fat and protein yields and concentrations, dry matter intake (DMI), and feed efficiency; those effects were conditional to time for milk yield, DMI, and feed efficiency. Overall, milk, ECM, fat, and protein yields were higher for MFS2 compared with control cows (+3.0, 3.7, 0.12, and 0.12 kg/d, respectively). Compared with MFS1, milk yield was higher and protein yield tended to be higher for MFS2 cows (+2.9 and 0.09 kg/d, respectively). In contrast, MFS1 cows produced 0.17 and 0.08 units of percentage per day more fat and protein than MFS2 cows, and 0.07 units of percentage per day more protein than control cows. Dry matter intake and feed efficiency were higher for MFS2 cows compared with MFS1 cows (+1.3 kg/d and 0.06, respectively), and feed efficiency was higher for MFS2 cows compared with control cows (+0.04). Where observed, treatment by time effects suggest that the effects of MFS2 were more evident as time progressed after supplementation was initiated. No effects of microbial supplementation were observed on body weight, body condition score, somatic cell count, or clinical mastitis case incidence. In conclusion, the supplementation of MFS2 effectively improved economically important outcomes such as milk yield, solids, and feed efficiency.
本研究的目的是评估两种瘤胃原生微生物饲料补充剂（MFS）对产奶量、乳成分和饲料效率的影响。共有 90 头处于泌乳期 40-60 天的经产奶牛参加了一项随机分组设计研究。在每个分组（基础产奶量）内，奶牛随机分为：对照组（不添加微生物饲料补充剂）、MFS1 组（每公斤全混合日粮 [TMR] 添加 0.33 克，包含至少 2×106CFU/g 的拜氏梭菌和 2×107CFU/g 的毕赤酵母）或 MFS2 组（每公斤 TMR 添加 0.33 克，包含至少 2×106CFU/g 的拜氏梭菌、2×107CFU/g 的毕赤酵母、2×107CFU/g 的瘤胃球菌和 2×107CFU/g 的丁酸梭菌）。奶牛在单个群组中饲养，自由采食研究日粮 270 天。使用电子奶计量器记录个体产奶量，使用在线光学分析仪在每天两次的挤奶时测量乳脂和乳蛋白含量。通过多元线性回归分析评估处理和处理时间的影响。观察到处理对奶和能量校正奶（ECM）产量、乳脂和乳蛋白产量和浓度、干物质采食量（DMI）和饲料效率的影响；这些影响取决于奶产量、DMI 和饲料效率的时间。总体而言，与对照组相比，MFS2 组的奶、ECM、脂肪和蛋白质产量更高（分别为+3.0、3.7、0.12 和 0.12kg/d）。与 MFS1 相比，MFS2 组的产奶量更高，乳蛋白产量也有上升趋势（分别为+2.9 和 0.09kg/d）。相比之下，MFS1 组奶牛的脂肪和蛋白质日产量分别比 MFS2 组高 0.17 和 0.08 个百分点，比对照组高 0.07 个百分点。MFS1 组奶牛的 DMI 和饲料效率比 MFS2 组高（分别为+1.3kg/d 和 0.06），MFS2 组奶牛的饲料效率比对照组高（+0.04）。观察到的处理时间效应表明，MFS2 的效果在补充开始后随着时间的推移更为明显。微生物补充剂对体重、体况评分、体细胞计数或临床乳腺炎病例发生率没有影响。总之，MFS2 的补充有效提高了产奶量、固形物和饲料效率等经济重要指标。
