Effects Of Emulsifier And L-carnitine On Growth Performance And Nutrients Availability In Broilers

Two experiments were conducted to investigate the effects of emulsifier and L-carnitine during d22to42and d1to49on the growth performance, slaughter performance and nutrients availability in broilers. After49d, serum lipids, intestinal morphology and lipid enzyme activity of broilers were measured.Experiment1:Effects of dietary emulsifier and L-carnitine on growth performance and nutrients availability in broilers from d1to49.Total nine hundred and sixty1-d-old Cobb commercial male broilers were randomly assigned to4dietary treatments (6replicates per treatment with40birds per replicate) as follows:1) control,2) basal diet supplemented with emulsifier (265mg/kg from d1to21;400mg/kg from d22to49),3) basal diet supplemented with L-carnitine (100mg/kg),4) basal diet supplemented with emulsifier (265mg/kg from d1to21;400mg/kg from d22to49) and L-carnitine (100mg/kg). This experiment included two stage:starter (1to21d) and grower (22to49d). The broilers accessed to feed and water ad libitum.1) Growth and slaughter performance Compared with the control treatment, emulsifier supplementation significantly decreased F/G during d1to21and d1to49(P<0.05), and supplemental L-carnitine, or L-carnitine plus emulsifier significantly decreased F/G in two stage (P<0.05). The interaction between emulsifier and L-carnitine significantly decreased F/G during the starter and the whole periods (P<0.05); The addition of emulsifier, L-carnitine and the combination of emulsifier and L-carnitine had no significant effect on slaughter performance, but can increase the rate of breast muscles0.91%,3.42%and3.25%respectively.2) Nutrients utilization and intestinal physiological Compared with the control treatment, dietary emulsifier, L-carnitine, and the combination of L-carnitine and emulsifier had a trend to increase the apparent utilization of metabolizable energy and crude fat (P>0.05), and the21d and49d villous height of jejunum (P>0.05), and the49d villous height of ileum (P<0.05). The supplementation of emulsifier, L-carnitine, and their combination can improve the lipase activity of duodenum content at d49, and jejunum content at d21and49(P>0.05). The interaction between emulsifier and L-carnitine significantly affected crude fat digestibility (P<0.05); Dietary L-carnitine significantly increased lipase activity of duodenum content at d21compared with the other treatments (P<0.05). 3) Serum lipids and enzyme activity of liver and pancreatic Compared with the control treatment, the supplementation with emulsifier significantly increased serum FFA at d21and49(P<0.01); Supplemental L-carnitine significantly decreased serum TG,VLDL at d21(P<0.05) and increased serum FFA at d49(P<0.05); The combination of L-carnitine and emulsifier significantly decreased serum TG,VLDL at d21(P<0.05). The supplementation of L-carnitine and emulsifier together significantly increased the activity of liver LPL compared with the other treatments (P<0.05). The activity of liver LPL+HL in treatment4was higher than that of L-carnitine treatment (P<0.01); Main effect analysis showed that dietary emulsifier significantly increased serum total bile acid, FFA (P<0.05), liver LPL,LPL+HL at d21(P<0.05), and liver LPL,HL,LPL+HL at d49(P<0.05); Dietary L-carnitine decreased serum TG,VLDL at d21and49(P<0.05) and serum total cholesterol, FFA at d21(P<0.05). The supplementation of emulsifier or L-carnitine were significantly increased lipase activity of pancreatic (P<0.05). The interaction between emulsifier and L-carnitine significantly affected serum FFA (P<0.01).Experiment2:Effects of dietary emulsifier and L-carnitine on growth performance and nutrients availability in broilers from d22to42Total eight hundred22-d-old Cobb commercial male broilers were randomly assigned by body weight to4dietary treatments (5replicates per treatment with40birds per replicate) as follows:1) control,2) basal diet supplemented with emulsifier (350mg/kg),3) basal diet supplemented with L-carnitine (100mg/kg),4) basal diet supplemented with a combination of emulsifier (350mg/kg) and L-carnitine (100mg/kg). The broilers accessed to feed and water ad libitum. The results showed as follows:Compared with the control group, the combination treatment of emulsifier and L-carnitine decreased F/G (P=0.059); Main effect analysis showed that dietary emulsifier significantly decreased F/G during d22to42(P<0.05), and increased crude fat apparent digestibility (P<0.05). In conclusion, the addition of emulsifier, L-carnitine and the combination of emulsifier and L-carnitine can decrease mortality and abdominal fat, improve the growth performance and crude fat apparent digestibility, and the combination treatment was the best among the3supplement treatments.In conclusion, the supplementation of emulsifier, L-carnitine or their combination during d22to42, and during d1to49in male broilers improved growth performance and crude fat apparent digestibility. The possible reasons for these results might be that these additives can improve the intestinal development, lipid metabolism and the activities of lipid enzyme.