Zitnan R, Voigt J, Schönhusen U, Wegner J, Kokardová M, Hagemeister H, Levkut M, Kuhla S, Sommer A
Research Institute of Animal Production Nitra, Slovakia.
Arch Tierernahr. 1998;51(4):279-91. doi: 10.1080/17450399809381926.
Effects of structural and non-structural carbohydrates on the development of rumen fermentation and ruminal mucosa in calves were examined during the weaning period. Barley/soybean meal (SBM) group was fed a concentrate starting from 2 weeks of age, whereas alfalfa group received a mixture of concentrate and alfalfa hay in which the proportion of the latter was gradually increased from 20% to 70% between weeks 2 and 9 of age. The total volatile fatty acid concentration in rumen fluid of calves increased with age, but at 9 weeks there were no significant differences between the two diets (barley/SBM group 153 mmol/l, alfalfa group 150 mmol/l). Rumen papillae at 9 weeks of age, as compared to 6 weeks of age, were longer and fewer in number per square centimetre mucosa, with larger cut surface. This resulted in a higher surface of papillae per square centimetre mucosa at 9 weeks (barley/SBM group 286 mm2/cm2, alfalfa group 245 mm2/cm2) than at 6 weeks of age (barley/SBM group 217 mm2/cm2, alfalfa group 198 mm2/cm2). At 9 weeks of age, the pH (barley/SBM 5.0, alfalfa 5.7), the acetate to propionate ratio (barley/SBM 2.2, alfalfa 3.2) as well as the length of the papillae in the ventral ruminal sac (barley/SBM 1.96 mm, alfalfa 2.37 mm) were increased in the alfalfa group when compared to the barley/SBM group (P < 0.1). In the former group, the proportion of butyrate revealed significantly increased values at 4 and 6 weeks of age. In animals of the barley/SBM group at 9 weeks of age, characteristic protrusions with proliferated thick epithelium occurred on the papillae and increased the surface for absorption. On the epithelium (Stratum corneum) desquamating cells with parakeratosis could be observed. In the alfalfa group the papillae of the ventral ruminal sac were longer, without protrusions. The morphotypes of the adhering rumen microflora differed between the groups. It can be concluded that feeding greater amounts of non-structural carbohydrates increases the surface for absorption of the rumen epithelium in calves. The absence of hyperkeratosis and rumenitis in the barley/SBM group indicated that there is no reason to limit high starch diets in the early weaning period of calves.
在断奶期研究了结构性和非结构性碳水化合物对犊牛瘤胃发酵和瘤胃黏膜发育的影响。大麦/豆粕（SBM）组从2周龄开始饲喂精料，而苜蓿组则饲喂精料和苜蓿干草的混合物，其中苜蓿干草的比例在2至9周龄期间从20%逐渐增加到70%。犊牛瘤胃液中总挥发性脂肪酸浓度随年龄增加，但在9周龄时，两种日粮之间无显著差异（大麦/SBM组153 mmol/l，苜蓿组150 mmol/l）。与6周龄相比，9周龄时瘤胃乳头更长，每平方厘米黏膜上的数量更少，切面更大。这导致9周龄时每平方厘米黏膜的乳头表面积（大麦/SBM组286 mm2/cm2，苜蓿组245 mm2/cm2）高于6周龄时（大麦/SBM组217 mm2/cm2，苜蓿组198 mm2/cm2）。9周龄时，与大麦/SBM组相比，苜蓿组的pH值（大麦/SBM 5.0，苜蓿5.7）、乙酸与丙酸比例（大麦/SBM 2.2，苜蓿3.2）以及瘤胃腹囊乳头长度（大麦/SBM 1.96 mm，苜蓿2.37 mm）均有所增加（P < 0.1）。在前一组中，丁酸比例在4周龄和6周龄时显著增加。在9周龄的大麦/SBM组动物中，乳头出现特征性突起，上皮增厚增殖，增加了吸收表面。在上皮（角质层）可观察到角化不全的脱屑细胞。在苜蓿组中，瘤胃腹囊乳头更长，无突起。两组附着的瘤胃微生物形态类型不同。可以得出结论，饲喂大量非结构性碳水化合物会增加犊牛瘤胃上皮的吸收表面。大麦/SBM组无角化过度和瘤胃炎表明，在犊牛早期断奶期没有理由限制高淀粉日粮。
