Productive performance, nutrients digestibility, some blood constituents and carcass traits of growing rabbits fed diets containing probiotic [electronic resource].

Includes references.

The present study was conducted for two months to evaluate the effects of the dry active baker’s yeast culture (YC), Saccharomyces cerevisiae, on growth performance, nutrients digestibility, some blood constituents, carcass traits and relative profit. Sixty growing male New Zealand White (NZW) rabbits at five weeks of age with an average initial body weight of 720 g were randomly distributed into four experimental groups (15 rabbits/ group, each in 5 replicates). The first (basal) diet (T1) served as control, while the second, third and fourth diets (T2, T3 and T4) were supplemented with 1, 2, and 3 g YC / Kg diet, respectively. The results indicated that the addition of yeast culture at different levels in rabbit diets significantly (P<0.05) improved the final body weight, daily weight gain and feed conversion ratio, while decreased (P<0.05) daily feed consumption compared to the control diet. However, digestibility of all nutrients and nutritive value of the supplemented diets were significantly (P<0.05) higher than the control. Data of the total digestible nutrients (TDN) and digestible crude protein (DCP) percent were significantly (P<0.05) increased by adding yeast compared to the control group. The results showed the superiority (P<0.05) of yeast culture supplemented animals compared to the control animals for serum content of total proteins, albumin and globulin. However, the results showed that A/G ratio, total lipids, cholesterol, AST and ALT levels of serum were decreased (P<0.05) with increasing the level of yeast culture in the diet. Carcass characteristics for the groups fed yeast culture at different levels exhibited the highest (P<0.05) dressing percentage and relative weights of hot carcass , liver, heart, spleen and internal fat compared to the control group which gave higher (P<0.05) relative kidney and kidney fat weight compared to YC groups. The YC supplemented groups were economically superior to the control group. The rabbit’s diet supplemented with two g/kg YC produced 150.4% as net profit which was higher than those receiving one g/kg YC (149.9%), and three g YC/kg (133.2%) compared to the control group. It could be concluded that using the yeast culture up to two g/ kg in growing NZW rabbit diets gave better values of live weight gain, feed conversion, nutrients digestibility and the economic efficiency without any deleterious effects on growing rabbit performance and physiological aspects.

Summary in Arabic.

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