USE OF SUPPLEMENTATION OF PROBIOTIC WITH DIFFERENT LEVELS OF CITRIC ACID AS PROMETER FOR PRODUCTIVE PERFORMANCE OF LAYING HENS

Abstract

This study aimed to evaluate using of feed supplementation of probiotic with different levels of citric acid as a promoter for productive performance of Lohmman Brown layers. Field experiment continued for five months. One hundred and ninety five laying hens at 20 weeks age were reared equal numbers in 15 floor pins, area of each one were 1.5 × 2 m by 13 hens per pin, and distributed randomly into 5 equal treatments (3 replicates per treatment). First treatment was fed a standard diet without supplementation as control, second treatment was fed a standard diet with probiotic 0.25%, third treatment was fed a standard diet with citric acid 0.3%, while fourth and fifth treatments were fed a standard diet with probiotic 0.25% and different levels of citric acid 0.3 and 0.45% respectively. The results showed an improvement in the productive performance of birds fed with the probiotic and citric acid, since it got significantly higher (P<0.05) in each of egg production (Hen Day%), egg mass, feed intake, and food conversion factor compared with control group. This effect has been enhanced for addition treatments on the productive performance when fed birds from the addition combination probiotic with citric acid compared with birds fed from each of the individual added probiotic or citric acid. This improvement to productive performance of treatment birds was a reflection of the improvement in both the microbial balance of the gut, internal environment of the gut, tissue properties of the gut and immune response. The counts of coliform and the counts of lactic acid bacteria were increased significantly (P <0.05), while the counts of total bacteria in the intestines not affected, whereas the pH of intestines dropped significantly. Both the length of villi and depth of the crypts of the intestines increased significantly, also the titer of antibody against Newcastle disease in birds fed the probiotic and citric acid increased significantly compared with the control birds.