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Effect of Nutrifen Supplementation with Different Levels of Metabolic Energy on Growth Performance, Nutrient Digestibility, Meat Quality, Blood Profile, Excreta Microflora, and Excreta Gas Emission of Broiler Chickens
A total of 816 ROSS 308 both male, female 1-day old, body weight 45.2 ± 0.7 g broiler chicken were used in this 4 weeks trial to evaluate the effect of nutrifen supplemented to broiler chicken diets containing different levels of metabolizable energy. Experimental diets consisted of 2 different levels; high energy diet (HE) and low energy diet (LE, 100kcal lower than HE diet，ME in HE diet: phase 1, 2950 kcal/kg; phase 2, 3100 kcal/kg) and the experimental treatments were as follows: 1) LCON (low energy diet);2) LNF (LCON + nutrifen 0.09%);3) HCON (high energy diet) and 4) HNF (HCON + nutrifen 0.09%). There were 12 replications and 17 chickens per replication in each treatment. Results showed that HNF treatment enhanced body weight gain (431 vs. 398 g; 1523 vs. 1470 g; P < 0.05) compared with LCON treatment at d 14 and 28. There was no effect (P > 0.05) on carcass and meat quality among treatments. However, yellowness in high energy level diets was increased (HCON and HNF vs. LCON and LNF: 8.53, 8.55 vs. 7.95, 7.69; P=0.036) compared with that in low energy level diets. Digestibility of dry matter in nutrifen treatments was higher (LNF and HNF vs. LCON and HCON: 77.43, 77.70 vs. 74.95, 75.47 %; P=0.025) than that in CON treatments. As to nitrogen digestibility, HNF treatment was higher (67.87 vs. 64.90 %; P<0.05) compared with that in LCON treatment. Total cholesterol in LNF treatment was decreased (106.8 vs. 117.8, 118.9mg/dL; P<0.05) than that in LCON and HCON treatments. Also, total cholesterol of chickens fed with nutrifen diets was decreased (LNF and HNF vs. LCON and HCON: 106.8, 114.1 vs. 117.8, 118.9 mg/dL; P<0.05) compared with those fed with CON diets. Ammonia gas emission in LNF treatment was decreased (34.8 vs. 42.9, 40.3 ppm; P<0.05) than that in HCON and HNF treatments. Moreover, low energy level treatments were decreased (LCON and LNF vs. HCON and HNF: 38.8, 34.8 vs.42.9, 40.3 ppm；P=0.003) excreta ammonia gas emission compared with high energy level treatments. No interaction effect was observed in this trial. These results showed that adding nutrifen at a level of 0.09% in diet can improve the growth performance, nutrient digestibility, blood cholesterol contents of broiler chickens.
Keywords: broiler chickens, energy level, growth performance, nutrifen