Effect Of Different Dietary Starch Levels And Sex On Productive Performance And Digestive Enzymes Activity Of Growing Rabbits

Abstract

Seventy two sexed New Zealand White rabbits (NZW) 25 days of age (36 males +36 females) were used in this experiment to study the effect of different dietary starch levels and sex on productive performance, nutrients digestibility coefficients, carcass characteristics, digestive tract measurements, blood constituents and enzymes activity. The rabbits were divided into three experimental diets containing three levels of starch {L (16%), M (19%) or H (22%)} with two sexes. Each group for each sex was subdivided into four replicates with 3 rabbits each and the initial live body weights of all experimental groups were almost similar. The results indicated that, male rabbits can utilize from the different levels of starch (16-22%) but female rabbits cannot do that and the highest productive performance for female was dictated when fed 19% starch only. Mortality rate of growing rabbits was high in female (25%) compared with male (10.92%). However, low mortality rate was noted for rabbit fed 19% dietary starch level. The highest digestibility coefficients were recorded for male fed 19% starch compare with those fed 16% or 22% starch. On the other hand, the highest digestibility coefficients were showed for female fed 19% starch. Low digestibility coefficients were recorded with female fed 16% or 22% starch. There were no significant effects of sex and starch levels on percentages of dressing, hot carcass and liver and liver activity enzymes (GOT and GPT). There were significant effects of treatment blood glucose, triglycerides, cholesterol and total lipid content and amylase and protease enzymes activity in the stomach, ileum and cecum. In addition, no significant effect was observed on the cellulase and carboxymethyl cellulase by the different levels of starch and sex in all segments of the digestive tract. It may be concluded that both sexes of rabbits were able to efficiently utilize the 19% dietary starch. Moreover, the male ones could accustom the 16% or 22% dietary starch level without any deleterious effects on their performance. Keywords: growing rabbit, sex, diet, starch, mortality, enzyme activity.