Cappellozza Bruno I, Copani Giuseppe, Boll Erik J, Queiroz Oscar
Chr. Hansen A/S, Hørsholm, Denmark 2970.
JDS Commun. 2023 Apr 18;4(4):284-287. doi: 10.3168/jdsc.2022-0344. eCollection 2023 Jul.
Optimization and support of health and performance of preweaning dairy calves is paramount to any dairy operation, and natural solutions, such as probiotics, may help to achieve such a goal. Two experiments were designed to evaluate the effects of direct-fed microbial (DFM) 669 on performance of preweaning dairy calves. In experiment 1, twenty 4-d-old Holstein calves [initial body weight (BW) 41 ± 2.1 kg] were randomly assigned to either (1) no probiotic supplementation (CON; n = 10) or (2) supplementation with probiotic strain 669 during the preweaning period (DFM; n = 10) at 2.0 × 10 cfu/kg of whole milk. Full individual BW was analyzed every 20 d for average daily gain (ADG) and feed efficiency (FE) determination. In experiment 2, thirty 4-d-old Holstein calves (initial BW 40 ± 1.9 kg) were assigned to the same treatments as in experiment 1 (CON and DFM). The DFM supplementation period was divided into period I (from d 0 to 21) and II (from d 22 to 63), with weaning occurring when animals were 67 d of age. During the entire experimental period, DFM was mixed into the whole milk at a rate of 1.5 × 10 and 2.5 × 10 cfu/kg of whole milk/calf per day for periods I and II, respectively (6-time reduction). Full individual BW was taken every 21 d. As a routine of the experiment, calves were monitored daily, and diarrhea cases were evaluated using a daily 3-point fecal score. For both experiments, all data were analyzed using calf as the experimental unit. In experiment 1, DFM-supplemented calves were heavier on d 40 (+ 4.5 kg) and 60 (+ 6.5 kg) and had a greater ADG (+ 118 g) versus CON. In experiment 2, supplementation with DFM significantly tended to reduce diarrhea occurrence. Treatment × day and treatment × week interactions were observed for BW, ADG, and gain-to-feed ratio. Dairy calves supplemented with DFM were 1.8 and 3.5 kg heavier on d 42 and at weaning, respectively, and had a greater ADG from d 21 to 42 (+ 52 g) and 42 to 63 (+ 77 g) and gain-to-feed ratio from d 42 to 63 (+ 8.6%). In summary, supplementation of 669 to dairy calves improved preweaning performance, even when the dose of the DFM was reduced by 6- to 8-times. Additionally, initial promising results were observed on diarrhea occurrence, but further studies are warranted.
优化和支持断奶前犊牛的健康与生长性能对任何奶牛场运营都至关重要，而天然解决方案，如益生菌，可能有助于实现这一目标。设计了两项试验来评估直接投喂微生物（DFM）669对断奶前犊牛生长性能的影响。在试验1中，20头4日龄的荷斯坦犊牛[初始体重（BW）41±2.1千克]被随机分配到以下两组：（1）不补充益生菌（对照组；n = 10）或（2）在断奶前期补充益生菌菌株669（DFM组；n = 10），添加量为每千克全脂牛奶2.0×10⁹ cfu。每隔20天分析全个体体重，以测定平均日增重（ADG）和饲料效率（FE）。在试验2中，30头4日龄的荷斯坦犊牛（初始体重40±1.9千克）被分配到与试验1相同的处理组（对照组和DFM组）。DFM补充期分为第I阶段（从第0天到第21天）和第II阶段（从第22天到第63天），犊牛在67日龄时断奶。在整个试验期内，分别在第I阶段和第II阶段，以每天每头犊牛1.5×10⁹和2.5×10⁹ cfu/千克全脂牛奶的比例将DFM混入全脂牛奶中（减少了6倍）。每隔21天记录全个体体重。作为试验常规操作，每天监测犊牛，并使用每日3分制粪便评分评估腹泻情况。对于两项试验，所有数据均以犊牛作为试验单位进行分析。在试验1中，补充DFM的犊牛在第40天（重4.5千克）和第60天（重6.5千克）时体重更重，且与对照组相比平均日增重更高（高118克）。在试验2中，补充DFM显著倾向于减少腹泻的发生。在体重、平均日增重和增重与饲料比方面观察到处理×天数和处理×周数的交互作用。补充DFM的犊牛在第42天和断奶时分别重1.8千克和3.5千克，且在第21天至第42天（高52克）和第42天至第63天（高77克）的平均日增重以及第42天至第63天的增重与饲料比（高8.6%）更高。总之，向犊牛补充669可提高断奶前生长性能，即使DFM剂量减少6至8倍。此外，在腹泻发生方面观察到了初步的良好结果，但仍需进一步研究。
