日粮精粗比、能量和酵母培养物添补对体外干物质降解的影响

EFFECTS OF DIETARY CONCENTRATE AND FORAGE RATIO,ENERGY AND YEAST CULTURE SUPPLEMENTATION ON IN VITRO DRY MATTER DEGRADABILITY FOR LACTATING DAIRY COWS

本试验采集泌乳期奶牛的瘤胃液,按2×4×2因子设计,用体外尼龙袋发酵技术研究了60:40和50:50两种精粗比日粮,棉籽油作为能源在奶牛日粮中分别添补0%、2.5%、5%、10%和在日粮中分别添加0%、0.5%的酵母培养物及其互作对体外干物质降解率的影响。体外实验结果表明,对于高产泌乳期奶牛而言,精粗比为60:40的奶牛日粮其干物质降解率高于50:50的精粗比日粮;奶牛日粮中添补植物油和酵母培养物均能显著提高体外干物质降解率(P<0.05);日粮精粗比与能量的互作对6小时的干物质降解率有显著影响(P<0.01);日粮能量添补与酵母培养物添补亦对体外干物质降解率有显著互作影响(P<0.05);而日粮精粗比与酵母培养物添补的互作影响则不明显;植物油作为奶牛日粮能源其添补量不宜超过10%。

A study was conducted to examine the effects of concentrate and forage ratio,energy and yeast culture supplementation on in vitro dry matter degradability(DMD) for lactating dairy cows,using in vitro nylon bag fermentation technique.The treatments included eighteen kinds of combinations of two types of concentrate and forage ratio(60:40 and 50:50),four concentrations of cotton seed oil as energy supplements(0%,2.5%,5% and 10%),and two kinds of yeast culture supplements(0% and 0.5%)in a 2×4×2 factorial arrangement.All statisitic analyses were shown that,for high producing dairy cows,the in vitro DM degradability of high concentrate and forage ratio diet(60:40) was higher than that of low concentrate diet(50:50),supplementation with cotton seed oil as energy source and with yeast culture significantly increased in vitro DM degradability(P<0.05),the interaction effects of dietary concentrate:forage and energy supplementation,energy supplementation and yeast culture supplementation were significant,however the interaction effect of dietary concentrate:forage and yeast supplementation was not significant.The suitable content of cotton seed oil supplementation should be lower 10% in the total mixed ration.