University of Nigeria, Nsukka
The study investigated the probiotic effects of Saccharomyces cerevisiae on pullets development and hen-day egg performance of the layers. A total of 120 chicks were brooded for 4 weeks, after which 100 pullets were randomly selected and placed in 4 groups (A-D) of 25 birds each. Each group was subdivided into 5 replicates of 5 birds in each replicate. Groups A, B and C had their feed supplemented with S. cerevisiae at graded levels of 0.6, 0.8 and 1.0 g/kg of feed respectively. Group D diet did not contain S. cerevisiae (control). The diets for all the groups contained 25% PKC and they were isocaloric and isonitrogenous. The pullets were weighed weekly. Probiotic supplemented groups recorded significantly (p≤0.05) higher weekly weight gain than the control up to the 10th week of age. Mean weight at 10th week were 0.866±0.033, 0.946±0.016, 0.914±0.041 and 0.856±0.013 kg/bird for groups A, B, C and D respectively. After the 10th week, there was no significant difference (p>0.05) in weekly weight gain until point-of-lay. Group C had an overall significantly (p<0.05) higher hen-day egg performance of followed by groups B and A, while group D had the least hen-day egg performance. Birds in the supplemented groups had significantly higher (p<0.05) serum total proteins and significantly lower serum cholesterol compared to the control. Eggs from the supplemented groups had significantly (p<0.05) lower cholesterol content compared to the control. Group C birds had a significantly (p<0.05) longer colon than the control. There was no significant difference (p>0.05) in egg qualities (egg size, egg weight and shell thickness) between the supplemented groups and the control. It was concluded that supplementation with probiotic S. cerevisiae significantly (p<0.05) enhanced pullet development, hen-day egg performance and significantly (p<0.05) lowered serum and egg cholesterol levels. The probiotic supplementation was most effective at the level of 1.0 g/kg of feed, and this level was recommended.