本研究的目的是评估饲喂牛初乳(BC)的消化道恢复和代谢,过渡奶(TM),或牛奶替代品(MR)在奶牛的饲料限制和禁食(FRF)事件后。35只荷斯坦公牛(22±4.8d大)参与了一项50天的研究。每天两次饲喂2L补液3d,禁食19h(研究的第1天)后,小牛被随机分配到5种喂养处理之一(n=7):小牛在4(C4)或10(C10)天期间被提供合并的BC,在4(TM4)或10(TM10)天期间汇集TM,或MR为10d(CTRL),DM含量为720g/d。然后,所有小牛都被喂食相同的喂食程序,在12.5%DM下,MR从每天两次3L逐渐降低到每天一次2L,直至断奶(d42),和浓缩饲料,水,和稻草随意提供,直到d50。瓜氨酸,Cr-EDTA,β-羟基丁酸酯(BHB),在d-3、1、2、5和11相对于FRF测定血清和全血计数(CBC)中的非酯化脂肪酸(NEFA),除了BHB和NEFA在d-3。挥发性脂肪酸(VFA),乳铁蛋白(LTF),在早晨喂食前的第5天和第11天,对粪便中的IgA和微生物群(厚壁菌与拟杆菌的比例和Fecalisprausnitzii)进行了分析。从d-3到d14以及d23和30每天记录健康评分。饲料浓缩物,MR,每天记录秸秆摄入量,和体重在d-3、1、2、5和11,然后每周一次。小牛性能,摄入量,血清Cr-EDTA,CBC,在整个研究过程中,粪便LTF浓度和微生物群参数相似。从第2天到第11天,与CTRL相比,TM4,TM10和C10小牛的血清NEFA浓度更高,并且在FRF之后,CTRL小牛的血清BHB浓度低于其他处理,在第11天,长期治疗(C10和TM10)中的血清BHB浓度仍高于较短治疗(C4和TM4)和CTRL。在所有处理中,d-3和1的血清瓜氨酸浓度相似,但是在d2和5的C4,C10,TM4和TM10中,它们更大,在d11中,它们仅在C10和TM10中大于在CTRL小牛中。C10的粪便IgA浓度倾向于高于CTRL,TM4和TM10小牛,C4和TM10比CTRL动物。C10中的粪便丙酸盐比例低于CTRL中的比例,TM4和TM10小牛,C4和C10的丁酸高于TM4和CTRL小牛。C10饲喂小牛的非正常粪便评分比例大于TM4和TM10小牛。结果表明,TM和BC可能有助于恢复肠道功能,提供肠道免疫保护,并增加FRF发作后小牛的肝脏脂肪酸氧化。
The objective of this study was to evaluate the digestive tract recovery and metabolism of feeding either bovine colostrum (BC), transition milk (TM), or milk replacer (MR) after an episode of feed restriction and fasting (FRF) in dairy calves. Thirty-five Holstein male calves (22 ± 4.8 d old) were involved in a 50-d study. After 3 d of feeding 2 L of rehydration solution twice daily and 19 h of fasting (d 1 of study), calves were randomly assigned to one of the 5 feeding treatments (n = 7): calves were offered either pooled BC during 4 (C4) or 10 (C10) days, pooled TM during 4 (TM4) or 10 (TM10) days, or MR for 10 d (CTRL) at the rate of 720 g/d DM content. Then, all calves were fed the same feeding program, gradually decreasing MR from 3 L twice daily to 2 L once daily at 12.5% DM until weaning (d 42), and concentrate feed, water, and straw were offered ad libitum until d 50. Citrulline, Cr-EDTA, β-hydroxybutyrate (BHB), and nonesterified fatty acids (NEFA) in serum and complete blood count (CBC) were determined on d -3, 1, 2, 5, and 11 relative to FRF, except BHB and NEFA at d -3. Volatile fatty acids (VFA), lactoferrin (LTF), IgA, and microbiota (Firmicutes to Bacteroidetes ratio and Fecalis prausnitzii) were analyzed in feces on d 5 and 11 before the morning feeding. Health scores were recorded daily from d -3 to d 14 as well as d 23 and 30. Feed concentrate, MR, and straw intake were recorded daily, and body weight on d -3, 1, 2, 5, and 11 and weekly afterward. Calf performance, intake, serum Cr-EDTA, CBC, fecal LTF concentrations and microbiota parameters were similar among treatments throughout the study. Serum NEFA concentrations were greater in TM4, TM10 and C10 calves compared with the CTRL ones from d 2 to 11, and after the FRF, serum concentrations of BHB were lower in CTRL calves than in the other treatments, and on d 11, serum BHB concentrations in the long treatments (C10 and TM10) remained greater than those in the shorter ones (C4 and TM4) and CTRL. Serum citrulline concentrations were similar on d -3 and 1 in all treatments, but they were greater in C4, C10, TM4, and TM10 on d 2 and 5, and on d 11 they were only greater in C10 and TM10 than in CTRL calves. Fecal IgA concentrations tended to be greater in C10 than in CTRL, TM4, and TM10 calves, and in C4 and TM10 than in CTRL animals. Fecal propionate proportion was lesser in C10 than in CTRL, TM4, and TM10 calves, while butyrate was greater in C4 and C10 than in TM4 and CTRL calves. The proportion of non-normal fecal scores of C10 fed calves was greater than TM4 and TM10 calves. Results showed that TM and BC may help to recover intestinal functionality, provide gut immune protection, and increase liver fatty acid oxidation in calves after a FRF episode.