Veterinary Medicine Teaching and Research Center, School of Veterinary Medicine, University of California Davis, Tulare 93274.
Scibus, Camden 2570, NSW, Australia.
J Dairy Sci. 2021 Apr;104(4):4290-4302. doi: 10.3168/jds.2020-19425.
The objective of this clinical trial was to evaluate the effectiveness of probiotic, prebiotic, and synbiotic supplementation on average daily weight gain (ADG), duration of diarrhea, age at incidence of diarrhea, fecal shedding of Cryptosporidium oocysts, enteric pathogens, and the odds of pneumonia in preweaning dairy heifer calves on a commercial dairy. Feeding prebiotics and probiotics may improve health and production of calves. Hence, healthy Holstein heifer calves (n = 1,801) from a large California dairy were enrolled at 4 to 12 h of age and remained in this study until weaning at 60 d of age. Calves were block randomized to 1 of 4 treatments: (1) control, (2) yeast culture enriched with mannan-oligosaccharide (prebiotic), (3) Bacillus subtilis (probiotic), and (4) combination of both products (synbiotic), which were fed in milk twice daily from enrollment until weaning. Serum total protein at enrollment and body weight at 7, 42, and 56 d of age were measured. Fecal consistency was assessed daily for the entire preweaning period. A subgroup of 200 calves had fecal samples collected at 7, 14, 21, and 42 d for microbial culture and enumeration of Cryptosporidium oocysts by direct fluorescent antibody staining. Synbiotic-treated calves had 19 g increased ADG compared with control calves for overall ADG, from 7 to 56 d. From 42 to 56 d, prebiotic-treated calves had 85 g greater ADG and synbiotic-treated calves had 78 g greater ADG than control calves. There was no difference in duration of the first diarrhea episode, hazard of diarrhea, or odds of pneumonia per calf with treatment. Probiotic-treated calves had 100 times lower fecal shedding of Cryptosporidium oocysts at 14 d and prebiotic-treated calves had fewer Escherichia coli and pathogenic E. coli at 42 d compared with control calves. Although there were no effects on duration of diarrhea or pneumonia incidence, greater ADG in the late preweaning period may reflect treatment effects on enteric pathogens during the rearing process. The decreased shedding of Cryptosporidium should reduce infectious pressure, environmental contamination, and public health risks from Cryptosporidium. Our findings suggest ADG and potential health benefits for calves fed prebiotics, probiotics, and synbiotics and can help the dairy industry make informed decisions on the use of these products in dairy production.
这项临床试验的目的是评估益生菌、益生元和合生菌补充剂对平均日增重（ADG）、腹泻持续时间、腹泻发病年龄、粪便脱落隐孢子虫卵囊、肠道病原体和肺炎发病率的影响在商业奶牛场的哺乳期奶牛犊牛身上。喂养益生元和益生菌可能会改善牛犊的健康和生产。因此，从加利福尼亚州的一家大型奶牛场招募了健康的荷斯坦奶牛犊牛（n = 1801），在出生后 4 至 12 小时内入组，并在 60 日龄断奶前一直留在本研究中。犊牛被随机分为 4 种处理之一：（1）对照组，（2）富含甘露寡糖的酵母培养物（益生元），（3）枯草芽孢杆菌（益生菌），（4）两者的组合（合生菌），从入组开始每天两次在牛奶中喂养，直到断奶。在入组时测量血清总蛋白，在 7、42 和 56 日龄时测量体重。在整个哺乳期每天评估粪便稠度。200 头小牛的亚组在 7、14、21 和 42 日龄时收集粪便样本进行微生物培养，并通过直接荧光抗体染色对隐孢子虫卵囊进行计数。与对照组相比，合生菌处理组犊牛的 ADG 增加了 19 克，7 至 56 日龄的 ADG 总体增加。42 至 56 日龄时，与对照组相比，益生元处理组犊牛的 ADG 增加了 85 克，合生菌处理组犊牛的 ADG 增加了 78 克。处理组之间首次腹泻发作的持续时间、腹泻的发病风险或每头犊牛患肺炎的几率没有差异。与对照组相比，益生菌处理组犊牛在 14 日龄时粪便中隐孢子虫卵囊的脱落量减少了 100 倍，在 42 日龄时粪便中大肠杆菌和致病性大肠杆菌减少。虽然对腹泻持续时间或肺炎发病率没有影响，但哺乳期后期 ADG 的增加可能反映了饲养过程中对肠道病原体的治疗效果。隐孢子虫脱落量的减少将降低隐孢子虫的感染压力、环境污染和公共卫生风险。我们的研究结果表明，给犊牛喂食益生元、益生菌和合生菌可以提高 ADG，并可能带来潜在的健康益处，并有助于奶牛养殖业就这些产品在奶牛生产中的使用做出明智的决策。
