Effects Of Diets Supplemented By Different Levels Of Urea On The Growth Performance And Serum Biochemistry Indexs Of Goats

Twenty four goats were randomly allocated into four groups. Four diets were composed with roughage and different concentrate. Four concentrate were supplemented with soybean and different proportional urea respectively to attain the same nitrogen level, control group with the basal diet. Body weight was recorded in pre and post-trial. The effects of diet supplementation of different urea levels on goat growth performance and partial blood biochemical parameters were analyzed. The results indicated that: (1) Supplementation of 1% and 2% urea increase body weight, but no significant difference, compared with control. Body weight of 1% urea supplementation group is higher than 2% urea group. Body wight of 4% urea supplementation group reduces, compared with control. Supplementation of 1% and 2% urea increase Palatability, while that of 4% urea group is lowest among control and three treatment groups. (2) Hematological parameters keep constant during the whole experiment period. Only 4% urea supplementation increases erythrocyte number, haemoglobin, erythrocyte specific volume. (3) Blood parameters analyzing indicated that different urea level supplementations affected serum TBIL, DBIL, Cr, UA, ALT, AST, GGT and LDH concentration. Serum BUN concentration in 4% urea supplementation group was increased significantly (p＜0.05), compared with 1% urea group, 2% urea group and control group. Serum BUN concentration of 2% urea supplementation group is higher than 1% urea group and control group. Serum Cr, TBIL concentration in 4% urea supplementation group was increased significantly (p＜0.05), compared with 1% urea group, 2% urea group and control group. Serum ALP concentration reduced significantly (p＜0.05), compared with 1% urea group, 2% urea group and control group. These results indicates that, on the condition of the equal nitrogen levels, 1% and 2% urea supplementation have no significant effects on goat growth perform, hematological parameters and blood biochemical parameters. 4% urea supplementation has significant toxicity effects. Diet supplementation of 1% and 2% urea levels improve the Palatability. Feed costs of 2% urea supplementation group (no soybean) is significant low, compared with 1% urea supplementation group (8% soybean) and control group (16% soybean). Combined with production practicality, it suggested that diet supplementation of 2% urea was feasible in practical production.