Abstract

Dietary direct-fed microbial (DFM) and antibiotics supplementation on health status, egg laying performance and internal egg characteristics under hot humid environmental conditions were studied. Three hundred (300) layer birds at point of lay (22 weeks old) were used for the study in a completely randomized design. There were four dietary treatments which are; Basal diet (BD), BD + DFM at the rate of 1.5 ml/kg, BD + antibiotics at the rate of 10 mg/kg feed and BD + DFM+ antibiotics at the same rate as above. Feed intake was significantly (p<0.05) lower for birds fed the DFM diet as compared with the control. However, body weight gain of DFM fed birds was not negatively affected and was relatively more efficient in converting feed into body weight and eggs. Hen-day and hen-housed production and egg shell thickness were not significantly (P>0.05) influenced by dietary treatments. Eggs laid by birds fed DFM diet were significantly (P<0.05) heavier and consistent throughout the experimental period. Serum and egg cholesterol concentration were significantly reduced by DFM supplemented diet (64 and 409 mg) as compared with the control (75 and 483 mg), antibiotics (74 and 481 mg) and DFM+ antibiotics combined diet (70 and 430 mg). Intensity of yolk colour was higher for eggs laid by birds fed DFM supplemented diet. It was concluded that DFM could be a suitable alternative to antibiotics supplementation for improved health status and productive performance of layer chickens under hot and humid environmental conditions.

Key words: Direct-fed microbial, layer chickens, egg cholesterol, sub-therapeutic antibiotics.