干草品质和形态对马消化率的影响

Effects of quality and physical form of hay on horse digestibility

本试验以4匹三河马为试验材料,研究不同品质和形态干草对自由或限制条件下马消化道内容物平均滞留时间和养分表观消化率的影响。试验采用4×4拉丁方设计,进行两个试验(高品质和低品质干草,切碎和研磨形态)。在试验1中马自由采食,而在试验2中马采用限饲(每100 kg体重饲喂1.6 kg干物质)。自由采食条件下干草品质、物理形态及其相互作用对采食量无显著影响(P>0.05)。在两个试验中,研磨较切碎组固态内容物的整个消化道和间断1平均滞留时间显著提高(P<0.05)。干草品质对消化道内容物滞留时间无显著影响(P<0.05)。干草切碎组较研磨组马粪便颗粒>5.5 mm的比例显著提高(P<0.05),其中饲喂高品质切碎干草的马粪便颗粒>5.5 mm的比例超过40%。试验1和试验2中研磨较切碎干草均显著提高粪便颗粒在2.4~5.5 mm和0.6~1.2 mm的比例(P<0.05)。试验1和试验2中高品质干草较低品质干草组均显著提高干物质表观消化率(P<0.05),而干草形态对试验1和2中干物质、有机物、粗蛋白质、中性洗涤纤维和酸性洗涤纤维表观消化率的影响均无显著差异(P>0.05)。结果表明,当日粮干草中小颗粒比例较高时,马消化道内容物平均滞留时间延长。即使整体或部分消化道内容物滞留时间缩短,饲喂切碎的干草也不会降低纤维的表观消化率。

In this study,4 Sanhe Horse were used as materials to study the effects of different quality and form of hay on the average retention time of digestive tract contents and nutrient apparent digestibility in horses under free or restricted conditions.Two tests(high and low quality hay,chopped and ground form)were carried out using a 4×4 Latin square design.In experiment 1,the horses were fed freely,while in experiment 2,the horses were fed on restricted diets(1.6 kg of dry matter per 100 kg of body weight).Under the condition of free feeding,hay quality,physical morphology and its interaction had no significant effect on feed intake(P>0.05).In both experiments,the total digestive tract and mean interval 1 retention time of solid contents in the grinding group were significantly increased compared with that in the chopping group(P<0.05).Hay quality had no significant effect on the retention time of digestive tract contents(P<0.05).The proportion of>5.5mm of horse manure particles in the hay chopping group was significantly higher than that in the grinding group(P<0.05,among which the proportion of>5.5mm of horse manure particles fed with high-quality hay chopping was more than 40%.In experiment 1 and experiment 2,the proportion of fecal particles in 2.4-5.5mm and 0.6-1.2 mm was significantly increased by grinding compared with chopping hay(P<0.05).In experiment 1 and experiment 2,the dry matter apparent digestibility of high quality hay was significantly improved compared with the low quality hay group(P<0.05),while the effect of hay morphology on dry matter,organic matter,crude protein,neutral washing fiber and acid washing fiber in experiment 1 and 2 was not significantly different(P>0.05).The results showed that the average retention time of the contents in the digestive tract of horses was prolonged when the proportion of small and medium grains in hay was higher.The apparent digestibility of fiber was not reduced by the use of chopped hay,even if the duration of retention of whole or partial digestive tract contents was shortened.