Some Productive, Reproductive and Physiological Effects of Using Different Dietary Protein Levels in Rabbit Does

Three groups of 11 New Zealand White (NZW) rabbit does, each were reared from 12 weeks of age on iso-energetic diets containing 16, 14 or 12% crude protein (CP) were used to study influences on productive performance, digestibility, some carcass traits, haematological, biochemical and hormonal parameters of rabbit does. The results showed rabbits fed on 16% protein diet had heavier body weights (BW) and body weight gains (WG) than the other groups. Daily feed intake (DFI) decreased and daily protein intake (DPI) increased by increasing dietary CP level whilst the feed conversion ratio (FCR) slightly improved as dietary CP increased. Dressing percentage increased slightly with increasing dietary protein level, while, rabbits fed 12% protein diet had a lower carcass weights compared to others. Moreover, the assessment results of mated does clarified significant increase in average daily or total FI and FCR, but significant decrease in kindling (%) in group fed 14% CP and in fertility and prolificacy% in 12 and 14% CP groups assessment of reproductive parameters, low protein levels had an adverse effect on litter size and kidney and liver weights of kids, while bunny weight decreased in the group fed 14% CP. However, plasma biochemical analysis showed a decrease in blood urea nitrogen (BUN) levels and activity of alanine-aminotransferase (ALT) and increase in creatinine in both two CP levels while no significant change in the concentration of total protein (TP), albumin (A), globulin (G), A/G ratio, calcium (Ca), phosphorous (Ph), iron (Ir) and aspartate-aminotransferase (AST) activity among three experimental groups was recorded. Furthermore, hormonal assay revealed a decrease in insulin.