Effects of Mineral- and Vitamin- Enhanced Supplementation on Egg Production, Egg Quality and Concentration of Calcium and Phosphorus in Serum of Spent Laying Hens

Abstract

This study was conducted to evaluate the effects of mineral and vitamin-enhanced supplementation on egg production, egg quality and concentrations of calcium and phosphorus in serum of spent laying hens. A total of 240 (72-wk-old) Hy-line brown commercial hens were used in the current trial for 4 weeks. Dietary treatments included 1) CON (basal diet), 2) ESS1 (basal diet + Egg shell strengthen 0.1%), 3) ESS2 (basal diet + Egg shell strengthen 0.2%) and 4) FESS (basal diet + Fe egg shell strengthen 0.2%). During the overall period, egg production was increased in CON and ESS2 treatments compared with ESS1 treatment (P<0.05). Egg shell breaking strength and final egg shell thickness were significantly higher in ESS2 treatment than CON and FESS treatments (P<0.05). Egg yolk color index was significantly lower in ESS1 treatment than other treatments (P<0.05). Moreover, Haugh unit was significantly lower in ESS1 and FESS treatments than CON treatment (P<0.05). Mineral-and vitaminenhanced supplementation did not affect either egg shell color or calcium and phosphorus concentration in serum. In conclusion, mineral-and vitamin-enhanced supplementations of laying hens diet are helpful in improving egg shell breaking strength and thickness by supplementation of Egg shell strengthener 0.2%.(Key words : mineral, vitamin, egg shell quality, egg shell strengthen, spent laying hens) † To whom correspondence should be addressed : inhokim@dankook.ac.kr