Effects Of Adding Different Proportions Of Cassava Leaf Diets On The Feeding Value Of Hainan Black Goat

This paper mainly research the effect of total mixed rations, which are made of the sun-dried cassava stems and leaves as forage mixed with concentrate feed in different proportions, on rumen metabolism, growth performance, blood biochemical indexes and nutrient apparent digestibility of Hainan black goat. This experiment carried out the method of the combination of the rumen degradation trial and animal feeding trial, to explore the ideal diet composition of fattening Hainan Black Goat, so as to provide the experimental basis of the development of using cassava stems and leafs as Hainan Black Goats feed source.1. Rumen degradation test:this experiment used the nylon bag method with permanent rumen fistula of Hainan black goats as experimental animal. Mix the concentrate feed with cassava stem leaf powder evenly according to the proportion of 2:8, 3:7,4:6,5:5,6:4 and 7:3 as the experimental samples. Then the experiment was divided into six groups:the ratio of concentrates to forage is 2:8 group,3:7group,4:6group, 5:5group,6:4group and 7:3 group.Ruminal degradation characteristics: ? DM effective degradation rate:the ratio of concentrates to forage is 6:4 was the highest,6:4,7:3,4:6,5:5 in each group was significantly higher than 3:7 group and 2:8 group (P<0.05); ? CP effective degradability rate:the trend of which is decrease with concentrated feed ratio increasing, and 2:8,3:7, 4:6 in each group was significantly higher than that of concentrate to forage ratio 5:5,6:4, 7:3 groups (P<0.05); ? NDF effective degradation rate:the ratio of concentrates to forage is 5:5 was the highest, and this group is significantly higher than the other groups (P<0.05); ?ADF effective degradation rate:the 3:7 group is the highest, and significantly higher than the 4:6,7:3,5:5 and 6:4 groups (P<0.05). Therefore, theTMR has higher nutrient rumen degradation rate when the ratio of concentrates to forage is 3:7,4:6 and 5:5.2. Animal feeding experiment:selected 20 weanling Hainan black goats, which have the simiar day-old and weight. The pre test period were 5 days, the test period were 60 days. Mix the concentrate feed with cassava stem leaf powder evenly according to the proportion of 3:7,4:6,5:5 and 6:4. Then the experiment was divided into four groups: 3:7group,4:6group,5:5group and 6:4group.Growth performance:? feed intake:during the trial period the 5:5 group had the highest food intake, four levels of feed intake showed no significant difference;? daily weight gain:during the trial period the daily from high to low in order to 5:5 group>6:4 group>4:6 group>3:7 group, and 5:5 group was significantly higher than that of 3:7 group (P<0.05); ? the feed gain ratio:during the trial period, the feed gain ratio of four groups showed no significant difference. From low to high order 5:5 group>4:6group>6:4 group>3:7 group. Thus, the 5:5 group has the highest feed gain ratio.Blood indexs:ALT of 3:7 group was significantly higher than 6:4 group (P<0.05), the other indicators were not significant differences between the groups (P>0.05). Therefore, the change of the content of cassava stems and leaves in the diet had no significant effect on the blood index of Hainan black goat.Apparent digestibility:Overall, each indicator of 5:5 group is the highest and they show increased gradually from 3:7 to 5:5 group, while the 6:4 group was reduce. Thus, the 5:5 group diet is most suitable for digestion and metabolism of Hainan black goat.Conclusion:It has higher effective degradation rate, when the the ratio of concentrates to forage of diet is 3:7,4:6, and 5:5. Hainan black goats had higher feed intake and daily weight gain, and the apparent digestibility of dietary nutrients was higher when the ratio of concentrates to forage of diet is 5:5. Therefore, in the actual production, cassava stem leaf powder and concentrate ratio of 5:5 mixed feed is recommend to feed Hainan black goat fattening goat. On this basis, it can also be appropriate to reduce the content of concentrated feed, increase the content of cassava stems and leaves, to achieve the purpose of reducing the cost of feeding, but the proportion of cassava stems and leaves should not be more than 60%.