Resumen de New Zealand White rabbit does and their growing offsprings as affected by diets containing different protein level with or without lacto-sacc supplementation.

M.S. Ayyat, I.F.M. Marai, T.A. El Aasar

• Forty New Zealand White rabbit does and their 456 (133 males and 233 females) 28 day old weaned offsprings were used in this investigation to study the effects of diets containing different protein levels with (0.1 %) or without Lacto-Sacc supplementation on their reproductiva and productiva performance. Rabbit does fed normal protein (18.4%) diet 4 recordad significantly higher litter size and weight at weaning (P<0.05) and total milk yield (P<0.01) than those fed low protein level (16.3%) and supplementation doe diets with 0.1% Lacto-Sacc in·creased significantly litter size and weight at 21 and 28 day (P<0.05) and total milk yield (P<0.01 ). The interaction effects between dietary protein and Lacto-Sacc on litter size and weight and total milk yield were not significant. In offsprings, diets containing the normal protein level (16.3%) showed significantly (P<0.01) higher values of post-weaning litter weight at 8 and 12 weeks and daily gain at 4-4, 8-12 and 4-12 weeks of age and also Lacto-Sacc addition gave significantly (P<0.05) higher values in body weight at 12 weeks and daily gain at 8-12 and 4-12 weeks of age, than in those fed diets containing low protein level (14.8%) and without Lacto-Sacc supplementation, respectively. The male rabbits were significantly (P<0.01) higher than females in litter body weight and gain. lnteraction between dietary protein and Lacto-Sacc addition showed highly significant effects (P<0.01) on final body weight at 12 weeks and daily gain at 8-12 and 4-12 weeks of age in offsprings. Lacto­Sacc effect was apparent with the normal protein level than with the low level. The interaction effects between sex and Lacto-Sacc supplementation were highly significant on final body weight and daily gain at 4-8, 8-12 and4-12 weeks of age. Male rabbits seemed to be more affected than females by Lacto-Sacc supplementation. Feed conversion and the margin were improved with increasing dietary protein and addition of Lacto-Sacc. Analysis of covariance of carcass and non-carcass components relatively to live body weight at slaughter did not show any significant effects for the factors studied.