Growth performance and some physiological measurements of growing rabbits fed diets supplemented with either antibiotics or probiotics [electronic resource].

Includes references.

Experimental study was conducted to investigate the effect of using of antibiotics such as virginiamycin and zinc bacitracin or probiotics such as bioaction and yeast culture (Saccharomyces cerevisiae) as growth promoters in growing rabbit diets and their influences on growth performance, nutrients digestibility, carcass traits, some physiological traits and economic efficiency. Seventy- two growing New Zealand White rabbits aged 35 days were randomly assigned into 6 experimental groups of 12 rabbits each. Each group was divided into four replicates, each of 3 rabbits. The first group was fed the basal diet and served as control, while the groups from 2 to 6 received the basal diet supplemented with 20 mg virginiamycin, 100 mg zinc bacitracin, 1g bioaction, 1.5 g yeast or 3 g yeast/kg diet, respectively. The experimental period was extended for 8 weeks. The results obtained revealed that: - 1- Growth promoters supplementation to rabbits diet improved significantly final live body weight, daily weight gain and feed conversion ratio. 2- Digestibility coefficients of DM, OM, CP, EE and CF% increased significantly in all supplemented groups except the group supplemented with high level of yeast. 3- The highest values of DCP% and TON were recorded for group with 1.5 g yeast/kg diet. 4- The protein efficiency ratio (PER) was significantly improved by feed additives administration compared to the control diet. 5-Econimical efficiency and performance index were significantly improved in all supplemented groups compared to the control one. 6- Dressing percentage (edible parts weight %) and carcass weight % were significantly increased in all supplemented groups than those of control group. 7- Most of alimentary canal traits were not affected by supplementation except, caecum weight%, caecum length. 8- Antibiotics and Probiotics addition was associated with a decrease in stomach and caecum pH. 9- Total plasma proteins were significantly higher in all supplemented groups than those of control group. 10- Feed additives administration resulted in a significantly decrease in levels of total lipids, cholesterol, GPT, GOT, urea in blood plasma and ammonia concentration in caecum. 11- The lowest (P<0.01) level of TVFA's was recorded in the control group compared to the all other experimental groups. Generally, antibiotics and probiotics used under the conditions of this study could be considered as growth promoters for growing rabbits, specially yeast at a level of 1.5g/kg diet.

Summary in Arabic.

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