Olagunju Lydia K, Casper David P, Officer Michael, Klanderman Keith, Anele Uchenna Y
Department of Animal Science, North Carolina Agricultural and Technical State University, Greensboro, NC 27411.
Department of Animal Science, North Carolina Agricultural and Technical State University, Greensboro, NC 27411; Casper's Calf Ranch LLC, Freeport, IL 61032.
J Dairy Sci. 2024 Dec;107(12):10838-10850. doi: 10.3168/jds.2024-25137. Epub 2024 Sep 17.
Botanical extracts (BE; Apex, Adisseo North America, Atlanta, GA) are known to enhance DMI and gut health, whereas direct-fed microbials (DFM), such as a Lactobacillus acidophilus fermentation product (EX: Excel; Pacer Technology Inc., Murtaugh, ID), have demonstrated improved gut health and growth performance when fed to growing neonatal Holstein calves. The hypothesis was this combination may be synergistic to neonatal calf growth performance and intestinal health. Eighty Holstein bull calves aged 2 to 5 d were blocked by BW and randomly assigned to 1 of 4 treatments arranged using a randomized complete block design. Treatments were as follows: (1) control, no additives; (2) BE added at 496 mg/kg to the calf starter (CS); (3) EX added to the CS at 2.50 g/kg with EX added to the milk replacer (MR) at 5 g/d; and (4) BE+EX: BE and EX added to CS at same rates and added EX to MR. Calves received 0.283 kg of MR in 1.9 L fed 2×/d for the first 14 d, then increased to 0.42 kg in 2.84 L fed 2×/d through d 35, followed by 0.42 kg of MR in 2.84 L fed 1×/d through d 42, followed by weaning. The CS was a 25% CP DM basis mini-pellet and the MR was a 22:20 (CP:fat) fed 2×/d at 0630 and 1800 h along with free choice water. Weaning occurred after d 49 of the 70-d experiment. Calves fed CS EX alone demonstrated greater BW gain compared with calves fed BE+EX, with calves fed control and BE being intermediate and similar (63.9, 63.5, 65.0, and 59.7 kg for control, BE, EX, and BE+EX, respectively). Total DMI (MR+CS) was lower for calves fed BE+EX compared with calves fed the remaining treatments (116.5, 114.2, 116.4, and 104.9 kg). The feeding of a BE in combination with EX (DFM) to neonatal calves reduced BW during wk 8, 9, and 10 and reduced 0 to 70 d ADG (874.7, 870.0, 889.7, and 817.6 g/d) compared with calves fed the remaining treatments. Calves fed BE+EX demonstrated the lowest calf starter intake during wk 4 through 10 compared with calves fed the other treatments. The study average CS intake for calves fed control and EX was greater compared with calves fed BE+EX with calves fed BE being similar and intermediate. Calves fed EX and BE+EX demonstrated greater total days of fecal scour score = 1 (5.4, 5.7, 8.0, and 8.3 d) compared with calves fed control and BE. Gains in frame measurements of hip height, hip width, withers height, and body length were similar whereas calves fed BE+EX demonstrated lower heart girth gains (19.2, 18.3, 19.7, and 17.6 cm) during the milk feeding phase (0-7 wk) compared with calves fed control and EX, with calves fed BE being similar and intermediate. It is not known why this study demonstrated an antagonism between BE and EX in growth performance and feed intake but further research is needed to identify the mechanism of action.
植物提取物(BE;Apex,安迪苏北美公司,佐治亚州亚特兰大)已知可提高干物质采食量(DMI)并改善肠道健康,而直接投喂微生物(DFM),如嗜酸乳杆菌发酵产物(EX:Excel;Pacer Technology Inc.,爱达荷州默托),在饲喂生长中的新生荷斯坦犊牛时已证明可改善肠道健康和生长性能。假设是这种组合可能对新生犊牛的生长性能和肠道健康具有协同作用。80头2至5日龄的荷斯坦公牛犊按体重进行分组,并随机分配到采用随机完全区组设计安排的4种处理中的1种。处理如下:(1)对照组,不添加任何添加剂;(2)在犊牛开食料(CS)中添加496 mg/kg的BE;(3)在CS中添加2.50 g/kg的EX,并在代乳料(MR)中添加5 g/d的EX;(4)BE + EX:以相同比例在CS中添加BE和EX,并在MR中添加EX。犊牛在最初14天每天分两次饲喂1.9升含0.283千克MR的代乳料,然后在第35天前每天分两次饲喂2.84升含0.42千克MR的代乳料,随后在第42天前每天一次饲喂2.84升含0.42千克MR的代乳料,之后断奶。CS是以25%粗蛋白干物质为基础的微型颗粒饲料,MR是22:20(粗蛋白:脂肪)的饲料,每天在0630和1800时饲喂两次,并提供自由饮水。在为期70天的试验中,第49天后断奶。与饲喂BE + EX的犊牛相比,单独饲喂CS EX的犊牛体重增加更大,饲喂对照组和BE的犊牛体重增加处于中间水平且相似(对照组、BE组、EX组和BE + EX组分别为63.9、63.5、65.0和59.7千克)。与饲喂其他处理的犊牛相比,饲喂BE + EX的犊牛总干物质采食量(MR + CS)更低(分别为116.5、114.2、116.4和104.9千克)。与饲喂其他处理的犊牛相比,给新生犊牛同时饲喂BE和EX(DFM)会在第8、9和10周降低体重,并降低0至70天的平均日增重(分别为874.7、870.0、889.7和817.6克/天)。与饲喂其他处理的犊牛相比,饲喂BE + EX的犊牛在第4至10周犊牛开食料摄入量最低。与饲喂BE + EX的犊牛相比,饲喂对照组和EX的犊牛的研究平均CS摄入量更高,饲喂BE的犊牛摄入量处于中间水平且与前两者相似。与饲喂对照组和BE的犊牛相比,饲喂EX和BE + EX的犊牛粪便腹泻评分为1的总天数更多(分别为5.4、5.7、8.0和8.3天)。髋高、髋宽、鬐甲高和体长的体尺增长相似,而与饲喂对照组和EX的犊牛相比,饲喂BE + EX的犊牛在喂奶阶段(0 - 7周)胸围增长更低(分别为19.2、18.3、19.7和17.6厘米);饲喂BE的犊牛胸围增长处于中间水平且与前两者相似。尚不清楚为何本研究表明BE和EX在生长性能和采食量方面存在拮抗作用,但需要进一步研究以确定其作用机制。