Chen Xue, Han Zhiyi, Dong Jianan, Xiao Jun, Zhao Wei, Rong Jiye, Aschalew Natnael D, Zhang Xuefeng, Qin Guixin, Zhen Yuguo, Sun Zhe, Wang Tao
Key Laboratory of Animal Nutrition and Feed Science of Jilin Province, Key Laboratory of Animal Production Product Quality and Security Ministry of Education, College of Animal Science and Technology, JLAU-Borui Dairy Science and Technology R&D Center, Jilin Agricultural University, Changchun, China.
Postdoctoral Scientific Research Workstation, Feed Engineering Technology Research Center of Jilin Province, Changchun Borui Science and Technology Co., Ltd., Changchun, China.
Front Microbiol. 2023 Mar 1;14:1065721. doi: 10.3389/fmicb.2023.1065721. eCollection 2023.
The diet structure is very important for the growth and development of calves. This study aimed to investigate the effects of dietary protein-to-starch metabolizable energy ratios (DPSRs) on growth performance, blood index, and gastrointestinal microbiota of calves. Forty-eight Holstein bull calves were fed six dietary DPSRs including A20-35 (20% CP and 35% starch), B20-30, C20-25, D22-35, E22-30, and F22-25 at d 4 to d 60, and then changed to another six dietary DPSRs at d 61 to d 180 (A18-30, B18-27, C18-24, D20-30, E20-27, and F20-24). Twelve calves (d 60) from groups A20-35, C20-25, D22-35, and F22-25 ( = 3) and another twelve calves (d 180) from groups A18-30, C18-24, D20-30, and F20-24 ( = 3) were euthanized. The growth performance parameters were measured. Blood, ruminal fluid, and cecum digesta were collected for further analysis. Results showed heart girth gain of B18-27 was significantly higher than A18-30, C18-24, and heart girth gain (d 180) was significantly affected by protein × starch (DPSRs; < 0.05). Blood urea nitrogen (BUN; d 60) in C20-25 was significantly higher than A20-35 and B20-30 ( < 0.05). The BUN (d 180) in D20-30 was significantly higher than A18-30 ( < 0.05). The BUN was significantly affected by protein × starch ( < 0.05) on d 60. The albumin (ALB) levels in C20-25 and C18-24 were significantly higher than that in A20-35 on d 60 and A18-30 on d 180, respectively ( < 0.05). The ALB level in D22-35 on d 60 and E20-27 on d 180 was significantly higher than that in other groups ( < 0.05). The ALB level was significantly affected by protein and starch, respectively, on d 60 ( < 0.05). In the rumen, the genera (C20-25) and (D22-35), (C18-24), and (F20-24) were found in significant higher relative abundances than those in other groups ( < 0.05). In the cecum, the genera and (F22-25), and (A18-30), and 4 (D20-30), and and (F20-24) were found in significant higher abundances than those in other groups ( < 0.05). Collectively, these results indicated that the heart girth, BUN, ALB, and gastrointestinal microbiota responded distinctly to differing DPSRs.
日粮结构对犊牛的生长发育非常重要。本研究旨在探讨日粮蛋白质与淀粉代谢能比（DPSR）对犊牛生长性能、血液指标和胃肠道微生物群的影响。48头荷斯坦公牛犊在第4至60天饲喂六种日粮DPSR，包括A20 - 35（20%粗蛋白和35%淀粉）、B20 - 30、C20 - 25、D22 - 35、E22 - 30和F22 - 25，然后在第61至180天更换为另外六种日粮DPSR（A18 - 30、B18 - 27、C18 - 24、D20 - 30、E20 - 27和F20 - 24）。对来自A20 - 35、C20 - 25、D22 - 35和F22 - 25组（每组3头）的12头犊牛（60日龄）以及来自A18 - 30、C18 - 24、D20 - 30和F20 - 24组（每组3头）的另外12头犊牛（180日龄）实施安乐死。测量生长性能参数。采集血液、瘤胃液和盲肠内容物用于进一步分析。结果显示，B18 - 27组的胸围增长显著高于A18 - 30、C18 - 24组，且胸围增长（180日龄时）受蛋白质×淀粉（DPSR；P < 0.05）显著影响。C20 - 25组的血液尿素氮（BUN；60日龄时）显著高于A20 - 35和B20 - 30组（P < 0.05）。D20 - 30组的BUN（180日龄时）显著高于A18 - 30组（P < 0.05）。60日龄时BUN受蛋白质×淀粉显著影响（P < 0.05）。C20 - 25组和C18 - 24组的白蛋白（ALB）水平在60日龄时分别显著高于A20 - 35组，在180日龄时显著高于A18 - 30组（P < 0.05）。D22 - 35组60日龄时和E20 - 27组180日龄时的ALB水平显著高于其他组（P < 0.05）。60日龄时ALB水平分别受蛋白质和淀粉显著影响（P < 0.05）。在瘤胃中，发现C20 - 25组的[具体菌属1]和D22 - 35组的[具体菌属2]、C18 - 24组的[具体菌属3]、[具体菌属4]和F20 - 24组的[具体菌属5]相对丰度显著高于其他组（P < 0.05）。在盲肠中，发现F22 - 25组的[具体菌属6]和[具体菌属7]、A18 - 30组的[具体菌属8]和[具体菌属9]、D20 - 30组的[具体菌属10]和[具体菌属11]以及F20 - 24组的[具体菌属12]和[具体菌属13]丰度显著高于其他组（P < 0.05）。总体而言，这些结果表明胸围、BUN、ALB和胃肠道微生物群对不同的DPSR反应各异。
