Comparative Study On The Effects Of Different Functional Additives On The Performance,Meat Quality And Nutrient Utilization In Broilers

The objective of this study is to compare the effects of four mixed functional additives on the production performance,meat quality and nutrient utilization efficiency of commercial broilers.The main effective components of the four functional additives are star anise extract,Macleaya Cordata extract,probiotics and multi-enzyme,respectively.In this study,450 healthy 1-day-old AA broilers with almost equal initial weight were randomly divided into five treatments with five replicates per treatment and 18 birds per replicate.Treatment 1 was the control group,which was given a conventional diet without any additives.Treatments 2,3,4 and 5 were supplemented with 1000 mg/kg additive A,250 mg/kg additive B,250 mg/kg additive C and 250 mg/kg additive D on the basis of the same diet as treatment 1,respectively.Chickens were raised in cages and fed with pellet feed.The basal dietary composition and nutritional level were consistent among the five treatments.During the 26 to35 d,the utilization efficiency of conventional nutritive ingredients was determined by the metabolic experiment,which was carried out by means of collection full excrements analysis method.At 21 and 42 d,ten chickens was slaughtered randomly from each treatment（two chickens per replicate）in order to determine the slaughter performance,antioxidant capacity（of serum,liver,and muscle）,vitamin deposition（of liver and muscle）,muscle color and drip loss,immune organ index and serum cytokine content,and the growth performance,including the average daily gain（ADG）,average daily feed intake（ADFI）and feed/Gain（F/G）,was calculated.（1）Growth performance and slaughter performance: the ADFI,ADG and F/G between1-21 d,22-42 d and 1-42 d,as well as the body weight on 21 and 42 d had no significant difference among five treatments（P > 0.05）.There was also no significant difference in the survival rate and European index among five treatments（P > 0.05）.The half-eviscerated yield rate,eviscerated yield rate,pectorales rate and crureus rate also had no significant difference among five treatments at either 21 or 42 d（P > 0.05）.The above results indicate that the four functional additives had no significant effects on the growth and slaughter performance of broilers.（2）Antioxidant capacity of serum,liver and muscle: the content of malondialdehyde（MDA）in serum of broilers was significantly different among five treatments（P < 0.05）,and the additive C significantly increased the content of MDA in serum compared with the control group;the activities of total superoxide dismutase（T-SOD）and glutathione peroxidase（GSHPX）in serum were not significantly different among five treatment（P > 0.05）.The content of MDA in liver were greatly different among treatments（P < 0.01）: although there was no significant differences between each treated group and the control group,additive A and B significantly reduced the liver MDA content compared with additive C and D.The activity of T-SOD in liver showed greatly difference among treatments（P < 0.01）,and the additive A and B significantly increased the activity of T-SOD compared with the control group.The activity of GSH-PX in liver had no significant difference among five treatments（P > 0.05）.In both pectorales and crureus,there was no significant difference in the content of MDA,as well as the activities of T-SOD and GSH-PX among five treatments（P > 0.05）,but the additive A could significantly reduced the content of MDA in crureus（P < 0.05）.The above results suggest that the additive A could improve the antioxidant capacity of liver and crureus,compared with other functional additives and the control group.（3）The color and drip loss of the muscles as well as the vitamin deposition of liver and muscles: the color scores（including the L value,a value,b value and the comprehensive score）and drip loss of both pectorales and crureus showed no significant difference among five treatments（P > 0.05）.The addition of functional additives had a greatly significant effect on the deposition of vitamin A（VA）and vitamin E（VE）in both pectorales and liver,as well as the deposition of VA in crureus（P < 0.01）,and the specific effects of each functional additive are as follows: Additive A significantly increased the deposition of VE in both pectorales and liver compared with other functional additives and the control group,and it also increased the deposition of VA in liver compared with the control group;additive B significantly increased the deposition of VA in crureus compared with other functional additives and the control group,and it also increased the deposition of VE and VA in liver compared with the-control group;additive C significantly increased the deposition of VA in pectorales compared with other functional additives and the control group,and it also increased the deposition of VA in crureus as well as the deposition of VE and VA in liver compared with the-control group;additive D significantly increased the deposition of VA in liver compared with other functional additives and the control group,and it also increased the deposition of VA in crureus and the deposition of VE in liver compared with the control group.Based on the above results,the effect of additive A on increasing the deposition of VE was better than that of other functional additives,and the additive B,C and D each had a better effect on increasing the deposition of VA in crureus,pectorales and liver,respectively.（4）Utilization efficiency of the conventional nutritive ingredients: the addition of functional additives had a significant effect on the apparent utilization efficiency of dry matter（DM）and ether extract（EE）（P < 0.05）,and a greatly significant effect on the apparent utilization efficiency of organ matter（OM）and crude protein（CP）（P < 0.01）.Additive B significantly improved the apparent utilization efficiency of DM,OM,CP and EE compared with the control group;it also significantly improved the apparent utilization efficiency of DM,OM and CP compared with additive A and the apparent utilization efficiency of CP compared with additive D.Additive C significantly improved the apparent utilization efficiency of DM,OM,CP and EE compared with the control group;it also significantly improved the apparent utilization efficiency of DM,OM and EE compared with additive A and the apparent utilization efficiency of EE compared with additive D.Additive D significantly improved the apparent utilization efficiency of DM,OM and CP compared with the control group.The addition of functional additives had a significant effect on the real utilization efficiency of DM and OM（P < 0.05）.Additive B significantly improved the real utilization efficiency of DM and OM compared with the control group and additive A.Additive C significantly improved the real utilization efficiency of DM and OM compared with the control group.Based on the above results,the effect of additive B and C on improving the utilization efficiency of the conventional nutritive ingredients were better than that of other functional additives.（5）Immune organ index and serum cytokine content: the spleen index,thymus index,aswell as the serum content of TNF-α,IL-1β,IL-6 and IL-10 had no significant difference among five treatments at either 21 or 42 d（P > 0.05）.This result suggests that all four functional additives have no significant effects on the immune organ index and serum cytokine content of the broilers.（6）Comparative analysis of economic benefits: Calculate the gross profit according to the output benefit minus the input cost,and sort the economic benefit according to the gross profit.The additive C can significantly improve the economic benefit of broiler breeding.In conclusion,additive A had a better effect on improving the antioxidant capacity of liver and crureus than other functional additives in AA broilers.All four functional additives could significantly increase the deposition of VA or VE in pectorales,crureus and liver of AA broilers;the effect of additive A on increasing the deposition of VE was better than that of other functional additives,and the additive B,C and D each had a better effect on increasing the deposition of VA in crureus,pectorales and liver,respectively.The effects of additive B and C on improving the utilization efficiency of the conventional nutritive ingredients were better than that of other functional additives in AA broilers.The economic benefit evaluation shows that the economic benefit of additive C is the best.