摘要
为了研究不同盐碱化草地混播牧草对绵羊瘤胃发酵、养分消化率和氮平衡的影响,试验选用12只5月龄、(34.6±0.57)kg体重的德国肉用美利奴杂交一代公绵羊,随机分为4组,每组3个重复,对照组饲喂精料补充料+玉米青贮;处理Ⅰ、Ⅱ和Ⅲ组分别饲喂精料补充料+轻度、中度和重度盐碱化草地混播牧草(披碱草、碱茅和沙打旺),每只羊精料补充料平均日喂600g,粗饲料自由采食。结果表明,处理Ⅰ和Ⅱ组瘤胃pH显著低于对照组和处理Ⅲ组(P<0.05),而瘤胃总挥发性脂肪酸浓度显著高于对照组(P<0.05);处理Ⅰ、Ⅱ和Ⅲ组瘤胃液丙酸、丁酸、戊酸、异丁酸和异戊酸摩尔比显著高于对照组(P<0.05),而瘤胃乙酸摩尔比和乙酸/丙酸比例显著低于对照组(P<0.05)。各组间干物质和有机物质采食量差异不显著,处理Ⅲ组中性洗涤纤维采食量显著高于其他各组,处理Ⅲ组和Ⅱ组酸性洗涤纤维含量显著高于对照组(P<0.05)。干物质、有机物质、无氮浸出物和能量消化率变化规律一致,处理Ⅲ组显著低于处理Ⅰ和Ⅱ组,处理Ⅰ和Ⅱ组显著低于对照组(P<0.05)。粗蛋白质、粗脂肪、中性洗涤纤维和酸性洗涤纤维消化率由低到高依次为处理Ⅲ组、处理Ⅱ组、处理Ⅰ和对照组,组间差异均显著(P<0.05)。处理Ⅲ和Ⅱ组采食氮显著低于处理Ⅰ组,处理Ⅰ组采食氮显著低于对照组(P<0.05)。沉积氮和沉积氮/可消化氮均以处理Ⅱ组最低,依次为处理Ⅲ、处理Ⅰ和对照组,组间差异均显著(P<0.05)。结果说明饲喂轻度和中度盐碱化草地混播牧草促进了绵羊瘤胃发酵,但降低了饲料消化率和氮的利用率,而重度盐碱化草地混播牧草则降低了绵羊瘤胃发酵、饲料消化率和氮的利用率。
The objective was to evaluate effects of grass mixture cultivated in light,moderate and serious alkalisaline grassland on rumen fermentation,feed digestibility and nitrogen balance in sheep.Twelve first filial generation（F1）sire growing-fattening sheep of a cross between Chinese Inner Mongolian Fine-wool and German Mutton Merino,averaging 5.0months of age and 34.6±0.57kg of body weight（BW）,were arranged into four groups at random.Sheep in control group fed concentrate and corn silage,while sheep in treatment I,Ⅱ and Ⅲ fed concentrate and grass mixture（Elymus dahuricus,Puccinellia distans and Astragalus adsurgens） cultivated in light,moderate and serious alkali-saline grassland,respectively.Sheep were fed 600g concentrate daily and rough forage provided ad libitum.The results showed that ruminal pH in treatment I and Ⅱ was lower than the control and treatment Ⅲ,whereas total VFA concentration was higher than control（P〈0.05）. Molar proportion of propionate,butyrate,valerate,isobutyrate and isovalerate in treatments was higher than control,but molar proportion of acetate and the ratio of acetate to propionate in treatments were lower than control（P〈0.05）.Intake of DM and OM were not affected,but NDF intake in treatment III was higher than other groups,ADF intake in treatment Ⅱ and Ⅲ was higher than control（P〈0.05）.Digestibilities of DM,OM,NFE and energy in treatment Ⅲ was lower than treatment Ⅱ and I,treatment Ⅱ and I lower than control. Digestibilities of CP,EE,NDF and ADF were significantly affected by treatments,treatment III,II,I and control is in turn from low to high.Intake of nitrogen in treatment Ⅲ and Ⅱ was lower than control and treatment I.Nitrogen retained and ratio of nitrogen retained to digestible nitrogen was significantly affected by treatments,treatment Ⅲ,Ⅱ,I and control is in turn from low to high.The results indicated that feeding grass mixture cultivated in light and moderate alkali-saline grassland potentially improves rumen fermentation,but decreased feed digestibility and nitrogen utilization in sheep.Rumen fermentation,feed digestibility and nitrogen balance were affected negatively in sheep fed grass mixture cultivated in serious alkali-saline grassland alone.
出处
《草业学报》
CSCD
北大核心
2010年第5期38-44,共7页
Acta Prataculturae Sinica
基金
"十一五"国家科技支撑计划课题(2007BAD56B01)资助
关键词
盐碱化草地
混播牧草
瘤胃发酵
消化率
氮平衡
绵羊
alkali-saline grassland
grass mixture
rumen fermentation
digestibility
nitrogen balance
sheep
