Effect of different Levels of Protein and Probiotic on performance, weight of internal organs and biochemical parameters in Broiler Chickens

This experiment was carried out to determine the effects of different levels of protein and probiotic (protexin) on performance, weight of internal organs and biochemical parameters in Ross (308) broiler chicks. In this experiment, 360, one-day old broilers were used in a completely randomized design with a 2×3 factorial arrangement with 3 replicate for a treatment. The diets were formulated according to catalog recommendation with protein levels (90, 100 and 110% of catalog recommendations) and probiotic (0, 200 and 400 ppm, containing 2×109 cfu/g of spores). The results indicated that the 5% decrease of protein level in diet did not affected on feed intake, weight gain and feed conversion ratio. The different levels of probiotic significantly increased body weight gain compared to control group in starter, grower and 0-42 days (p<0.05), and decreased feed conversion ratio in grower, finisher and 0-42 days (p<0.05). Feed intake did not affected by addition of probiotic. The different levels of probiotic and protein did not change the carcass traits (percentage of carcass, breast, thigh, abdominal fat, relative weight of gizzard, heart, spleen, liver and pancreas). The effect of feeding probiotic and protein levels was not significant on biochemical parameters (total protein, albumin, cholesterol, triglyceride, glubolin, glucose, high density lipoprotein, low density lipoprotein and very low density lipoprotein) at 42 days of age (p<0.05). But Serum total protein concentration, was significantly higher in broilers fed 400 ppm probiotic, than those received diet without probiotic (p<0.05). These data suggest that the using of probiotic is helpful in diets containing lower than catalog standard in Ross broiler.