玉米秸秆切碎长度对肉羊瘤胃发酵及养分消化代谢的影响

Effect of corn straw chopping length on rumen fermentation and nutrient digestion and metabolism of mutton sheep

文章旨在研究玉米秸秆不同切碎长度对肉羊瘤胃发酵及养分消化代谢的影响。试验选择体况良好,体重相近,3~4月龄的育肥羊45只,随机分为3组;试验Ⅰ、Ⅱ和Ⅲ组按照10、20、30mm的长度规格切碎玉米秸秆后青贮,且以全混合日粮方式饲喂肉羊,预饲期10d,试验期为60d。结果表明,试验Ⅰ组瘤胃液的pH和氨态氮含量显著低于试验Ⅱ组和Ⅲ组(P <0.05),微生物蛋白和总挥发酸含量显著高于试验Ⅱ组和Ⅲ组(P <0.05)。同时,试验Ⅰ组干物质、有机物、粗脂肪、无氮浸出物、中性和酸性洗涤纤维的消化率均显著高于试验Ⅱ组和Ⅲ组(P <0.05)。试验Ⅰ组总排出氮含量显著高于试验Ⅱ和Ⅲ组(P> 0.05);试验Ⅰ组和Ⅱ组的沉积氮及氮表观消化率显著高于试验Ⅲ组(P <0.05)。综上所述,降低玉米秸秆切碎长度可提升肉羊对饲料营养物质的吸收和利用。

The experiment was conducted to study the effects of different cut lengths of corn straw on rumen fermentation and nutrient digestion and metabolism of mutton sheep. 45 fattening sheep with good body condition and similar weight,3 ~ 4 months old,were randomly divided into three groups;The trial groups I,II and III cut corn stalks according to the length specifications of 10,20 and 30 mm,then silage them,and fed mutton sheep with full mixed diet. The pre experiment period was 10 days,and the formal experiment period was 60 days. The results showed that the pH and ammonium nitrogen content of rumen juice in test group I were significantly lower than those in test groups II and III(P < 0.05),and the microbial protein and total volatile acid content were significantly higher than those in test groups II and III(P < 0.05). At the same time,the digestibility of dry matter,organic matter,crude fat,nitrogen free extract,neutral and acid detergent fiber in Group I was significantly higher than that in Group II and Group III(P < 0.05). The content of total nitrogen excretion in test group I was significantly higher than that in test groups II and III(P > 0.05);Deposited nitrogen,apparent digestible nitrogen and apparent digestibility of nitrogen in Group I and Group II were significantly higher than those in Group III(P < 0.05). To sum up,reducing the cut length of corn straw can improve the absorption and utilization of feed nutrients by mutton sheep.