Effect of supplementing the laying hen diets with choline, folic acid, and vitamin B-12 on production performance, egg quality, and yolk phospholipid

摘要

This study was designed to investigate the effect of choline, folic acid, and vitamin B-12 supplementation on yolk phosphatidylcholine (yolk-PC) and phosphatidylethanolamine (yolk-PE) concentration in laying hens, and to examine the subsequent production performance, and egg quality. Two experiments were conducted. In Exp. 1, a total of 840 forty-four-week-old laying hens were randomly allocated to 5 treatments of 6 replicates each. The replicate contained 4 adjacent cages (7 hens/cage or 28 hens/replicate). Treatments were feeding of basal diet supplemented with 0, 1000, 1500, 2000, or 2500 mg choline/kg by adding choline chloride for 6 wk. The results of Exp.1 indicated that supplementation with 0-2500 mg choline/kg had no effect on production performance or egg quality, but choline supplementation improved eggshell strength quadratically (P = 0.04) with the greatest eggshell strength was observed at 1000 mg choline/kg. Yolk-PC concentration increased linearly (P 0.001) and quadratically (P 0.001) whereas Yolk-PE concentration decreased linearly (P = 0.004) and quadratically (P = 0.01). The greatest content of yolk-PC concentration and the lowest content of yolk-PE concentration were detected when diet supplemented with 1500 mg choline/kg. However, there was no difference in yolk-PE concentration between supplementation with 1500 and 2000 mg choline/kg. Thereafter, Exp. 2 was conducted, and a total of 288 seventy-two-week-old laying hens were randomly allocated to 9 treatments of 4 replicates each. The replicate contained 2 adjacent cages (4 hens/cage or 8 hens/replicate). The basal diet containing additional 1500 mg choline/kg was supplemented with 0, 4, or 8 mg folic acid and 0, 0.02, or 0.04 mg vitamin B-12/kg in a 3 x 3 factorial arrangement of treatments and fed to laying hens for 8 wk. The results indicated that supplementation with folic acid, vitamin B-12, or both had no effect on yolk-PC or yolk-PE concentration, as well as production performance and egg quality. In conclusion, the greatest yolk-PC concentration in laying hens could be achieved by supplementing with 1500 mg choline/kg which is more than the recommendation guideline without causing any adverse impacts on production performance and egg quality.