Effect Of Feeding System On Productivity Performances And Nutrient Utilization Of Different Thailand Meat Goats

Thirty-two goats which 16 goats were Thai native goats and 16 goats were crossbred goats (Boar×Thai native) were used in this experiment. The goats were divided into 4 groups based on breeds and feeding system in a 2×2 factorial randomized complete block design experiment(A: grazing and native; B: grazing and crossbred; C: cut and carry, natice; D: cut and carry, crossbred),to study the effect of feeding system on productivity performances and nutrient utilization of different Thailand meat goats.This experiment including two parts: the growing experiment, digestion and metabolism experiment.The results of experiment were as following:1. The growing experimentThe average body gain of 4 groups were 58.63, 40.18, 36.91 and 51.49 g/d. The differences of feeding intake was not significant, but the rate of feed and body gain was significant, C group was higher than others.2. The digestion and metabolism experimentThe difference of digestibility for DM,CP,NDF and ADF was significant between the feeding system (P<0.05). But the difference of digestibility for those ones was not significant (P>0.05). The daily nitrogen intake of group A and B were higher than group C and D (p<0.05), there was the tendence that the daily nitrogen deposited of group A and B were higher than group C and D. There also was the tendence of digestibility for group A was higher than group B (p=0.0195). The digestibility of ADF for group C was lower than group D.3. The index of rumen fluidThe difference of pH for those 4 groups was significant (P < 0.01). The pH of group C was lower than others, and the pH of group A and D were near the best value pH of rumen fluid. The ammonia nitrogen of B group was lower than group C and D (p<0.05), but the difference of group A and B is not significant. The total volatile fatty acids of group D was higher than others (p>0.05); but the group A and B were lower and group C was in the middle. The population of bacteria and protozoa of group D was higher than others, and the difference of group A,B and C were not significant (p>0.05). But there was the tendence of that group B was lower than other two.4. The index of bloodThe blood urea nitrogen (BUN, mg/dl) of those 4 groups were change from 14.44～18.63mg/dl. The difference of blood urea nitrogen was not significant, but the group B was lower than others, the group A was the most ones. The change of blood urea nitrogen was like the shape of"V"from 0h after feeding to 6h. This was like the change of ammonia nitrogen in rumen fluid.