Effects of dietary fat sources on growth performance, microbial population and pH values in the small intestine and cecum of broiler chicks

The effects of four dietary fat sources were studied on growth performance, bacterial community and pH values in digesta of small intestine and cecum of broiler chickens. A total of 240 one d-old male broiler chicks were randomly assigned to four experimental diets with 6 replicates per each. The four experimental diets were diet without fat (control diet), diet containing 6% beef tallow (BT), diet containing 6% sunflower oil (SO) and diet containing 6% fish oil (FO) and fed to chicks from 0-42 days of age. Our results showed that FO diets significantly increased weight gain of chicks compared to control or BT diets from 1 to 21 d of age (P=0.022). At the same age, the best feed conversion ratio was observed in chicks fed SO and FO diets as compared with chicks fed BT treatment (P=0.038). Body weight gain, feed intake and feed conversion ratio of birds were not significantly affected by dietary fat sources at the entire experimental period (1-42 d). The birds fed SO and FO diets, had higher counts of Lactobacillus spp. in small intestine and cecum digesta and lower counts of coliforms in cecal digesta as compared to birds fed BT diet (P<0.05). A significant decrease was also observed in pH of cecal digesta of birds fed FO diet (P=0.039) compared to those fed BT diet at 42 d of age. In conclusion, the dietary fats rich in polyunsaturated fatty acids can improve growth performance, intestinal microflora and pH value in broiler chicks as compared with the dietary fats rich in saturated fatty acids.