饲粮非纤维性碳水化合物/中性洗涤纤维对黔北麻羊瘤胃发酵参数、血浆生化指标和养分消化率的影响

本试验旨在研究不同饲粮非纤维性碳水化合物(NFC)/中性洗涤纤维(NDF)对黔北麻羊瘤胃发酵参数、血浆生化指标和养分消化率的影响。采用3×3拉丁方试验设计,选取6只健康成年黔北麻羊为试验动物,将其分为3组,每组2个重复,每个重复1只羊。试验Ⅰ组、试验Ⅱ组、试验Ⅲ组饲粮NFC/NDF分别为2.14∶1.00、1.05∶1.00、0.40∶1.00(实测值)。试验分3期,每期15 d,包括10 d预试期和5 d正试期。检测指标包括:饲粮养分消化率、瘤胃发酵参数(pH、缓冲力、氨态氮和挥发性脂肪酸浓度、纤维素酶活性)、血浆生化指标(脂多糖、白蛋白、尿素氮、葡萄糖含量及过氧化氢酶、谷草转氨酶、超氧化物歧化酶、谷胱甘肽过氧化物酶活性)。结果显示:1)3个试验组干物质采食量差异不显著(P0.05),试验Ⅲ组各养分消化率均显著低于试验Ⅰ组、试验Ⅱ组(P0.05)。2)试验Ⅰ组瘤胃液pH显著低于试验Ⅱ组、试验Ⅲ组(P0.05);试验Ⅲ组瘤胃液缓冲力显著高于试验Ⅰ组(P0.05),纤维二糖酶活性、乙酸浓度显著低于试验Ⅰ组(P0.05),总挥发性脂肪酸、丁酸浓度显著低于另外2组(P0.05);试验Ⅰ组、试验Ⅱ组、试验Ⅲ组瘤胃液乙酸/丙酸依次升高、丙酸浓度依次下降,各组间差异显著(P0.05);3组间瘤胃液羧甲基纤维素酶、木聚糖酶、微晶纤维素酶活性差异不显著(P0.05)。3)试验Ⅰ组、试验Ⅱ组、试验Ⅲ组血浆脂多糖含量依次显著下降(P0.05),其余血浆生化指标差异不显著(P0.05)。综合来看,过高NFC/NDF对黔北麻羊瘤胃发酵参数和血浆生化指标有不良影响,本试验条件下,饲粮NFC/NDF以1.05∶1.00为宜。

Effects of Non-Fiber Carbohydrate to Neutral Detergent Fiber Ratio on Rumen Fermentation Parameters,Plasma Biochemical Indexes and Nutrient Digestibility of Qianbeima Goats

The present study was conducted to investigate the effects of non-fiber carbohydrate to neutral detergent fiber ratio (NFC/NDF) on rumen fermentation parameters, plasma biochemical indexes and nutrient digestibility of Qianbeima goats.Six healthy adult Qianbeima goats were selected and allocated to 3 groups with 2 replicates per group and 1 goat per replicate using 3×3 Latin square design.Trial group Ⅰ, trial group Ⅱ, and trial group Ⅲ were fed diet with varying NFC/NDF at 2.14∶1.00, 1.05∶1.00 and 0.40∶1.00 (measured values), respectively.The trial lasted for 45 d consisted of 3 periods with 10 d of pre-trial period and 5 d trial period each.The detecting indexes were as follows: dietary nutrient digestibility, rumen fermentation parameters (pH, buffer capacity, ammonia nitrogen and volatile fatty acid concentrations, and cellulose activity) and plasma biochemical indexes [the contents of lipopolysaccharide, albumin and urea nitrogen glucose, and the activities of hydrogen peroxidase, glutamic-oxal(o)acetic transaminase and superoxide dismutase and glutathione peroxidase].The results showed as follows: 1) there was no significant difference for dry matter intake among 3 groups (P>0.05);trial group Ⅲ showed significantly lower nutrient digestibility compared with trial group Ⅰ and trial group Ⅱ (P<0.05).2) Trial group Ⅰ resulted in significantly decreased rumen fluid pH over trial group Ⅱ and trial group Ⅲ (P<0.05);trial group Ⅲ significantly increased rumen buffer capacity compared with trial group Ⅰ (P<0.05), but significantly decreased cellobiase activity and acetic acid concentration compared with trial group Ⅰ(P<0.05), and also significantly decreased total volatile fatty acids and butyrate concentrations compared with the other two groups (P<0.05);trial group Ⅰ, trial group Ⅱ and and trial group Ⅲ resulted in gradually increased acetate to propionate ratio and gradually decreased propionate concentration, and the differences among groups were significant (P<0.05);the activities of carboxymethyl cellulose, xylanase and microcrystalline cellulose in rumen fluid were not significantly affected (P>0.05).3) Plasma lipopolysaccharide content was gradually significantly decreased in trial group Ⅰ, trial group Ⅱ and trial group Ⅲ (P<0.05), while there were no significant differences for other plasma biochemical indexes (P>0.05).It is indicated from the results that over-high NFC/NDF is not beneficial to rumen fermentation parameters and plasma biochemical index of Qianbeima goats, and 1.05∶1.00 is the appropriate level under the conditions of the present study.