State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193 PR China.
J Anim Sci. 2013 Sep;91(9):4315-21. doi: 10.2527/jas.2012-5731. Epub 2013 Jul 23.
This study investigated the effects of a mixture of steam-flaked corn and extruded soybeans on performance, ruminal development, ruminal fermentation variables, and intestinal absorptive capability in Holstein male calves (n = 39). Calves were assigned to 1 of 3 treatments (13 calves per treatment): 1) milk replacer (MR), 2) one-half of the amount of MR in treatment 1, plus a mixture of 62.1% steam-flaked corn and 30.5% extruded soybeans provided ad libitum (HMCS), or 3) a mixture of 62.1% steam-flaked corn and 30.5% extruded soybeans provided ad libitum (CS). All the calves were started at 2 ± 1 d of age and studied for 150 d. Each 30 d was defined as 1 period. Dry matter intake and growth were measured daily and monthly, respectively. All calves were harvested at 150 d of age, after which rumen fluid was collected. Rumen and intestine samples were gathered. Calves fed MR exhibited greater BW (P = 0.001) and ADG (P < 0.001), compared with calves fed HMCS and CS from period 2 to 3; however, from period 4 to 5, CS calves had greater (P < 0.04) ADG than MR calves. The treatments did not differ in final BW (P = 0.72) and ADG (P = 0.20) from period 2 to 5. Compared with HMCS and MR calves, CS calves had the greatest DMI (P < 0.001) and the least feed efficiency (P < 0.001) from period 2 to 5. For ruminal fermentation parameters, CS calves had decreased (P = 0.04) rumen pH than MR calves. The NH3 concentrations were greater (P = 0.03) in calves fed HMCS than calves fed MR and CS. Total VFA concentrations were greatest in CS calves (P = 0.02). Calves fed CS had the greatest molar concentrations of propionate, butyrate, and valerate (P < 0.002), and calves fed HMCS had the greatest molar concentrations of isobutyrate (P = 0.001) and isovalerate (P = 0.001). The CS calves exhibited greater empty rumen weight (P = 0.001), papillae length (P < 0.001), papillae width (P < 0.001), rumen wall thickness (P = 0.012), and papillae density (P = 0.003). The greatest villus heights in the jejunum (P = 0.04) and ileum (P = 0.005) were observed in CS calves. Compared with HMCS calves, calves fed CS had greater villus:crypt ratios in the duodenum (P = 0.001) and jejunum (P = 0.001). Results indicate that CS improves ADG in period 4 to 5 and positively contributes to ruminal development, ruminal fermentation, and intestinal absorptive capability in veal calves.
本研究旨在探讨蒸汽压片玉米和膨化大豆混合物对荷斯坦公犊（n = 39）生长性能、瘤胃发育、瘤胃发酵变量和肠道吸收能力的影响。将犊牛分为 3 种处理之一（每组 13 头）：1）牛奶代用品（MR）；2）处理 1 中 MR 量的一半，再添加 62.1%蒸汽压片玉米和 30.5%膨化大豆混合物自由采食（HMCS）；3）62.1%蒸汽压片玉米和 30.5%膨化大豆混合物自由采食（CS）。所有犊牛于 2 ± 1 日龄开始试验，试验期为 150 天。每 30 天定义为 1 个时期。分别对干物质采食量和生长速度进行每日和每月测量。所有犊牛于 150 日龄时屠宰，采集瘤胃液。采集瘤胃和肠道样本。从第 2 期到第 3 期，与 HMCS 和 CS 组相比，MR 组犊牛表现出更大的体重（BW）（P = 0.001）和平均日增重（ADG）（P < 0.001）；然而，从第 4 期到第 5 期，CS 组犊牛的 ADG 显著高于 MR 组（P < 0.04）。从第 2 期到第 5 期，处理组之间最终 BW（P = 0.72）和 ADG（P = 0.20）无显著差异。与 HMCS 和 MR 组相比，CS 组犊牛的 DMI（P < 0.001）最大，饲料效率最低（P < 0.001）。从第 2 期到第 5 期，CS 组犊牛的瘤胃 pH 值降低（P = 0.04）。与 MR 组相比，HMCS 组的 NH3 浓度升高（P = 0.03）。CS 组的总挥发性脂肪酸（VFA）浓度最高（P = 0.02）。CS 组的丙酸、丁酸和戊酸摩尔浓度最高（P < 0.002），HMCS 组的异丁酸和异戊酸摩尔浓度最高（P = 0.001）。CS 组的空瘤胃重量（P = 0.001）、乳头长度（P < 0.001）、乳头宽度（P < 0.001）、瘤胃壁厚度（P = 0.012）和乳头密度（P = 0.003）最大。CS 组犊牛的空肠（P = 0.04）和回肠（P = 0.005）绒毛高度最大。与 HMCS 组相比，CS 组的十二指肠（P = 0.001）和空肠（P = 0.001）的绒毛：隐窝比更大。结果表明，CS 提高了第 4 期到第 5 期的 ADG，对犊牛瘤胃发育、瘤胃发酵和肠道吸收能力有积极作用。
