Comparative Studys Of Laying Performance And Egg Quality Of Three Hens Breeds On Cage And Cage-free Housing System

We made a comprehensive study about the egg-laying performance, egg quality, the storage time of egg, and so on. In this study, we used theGreen-shell chickens, Jiuyuan Black Fowl and Roman laying hens as the experimental animal, they were raised in different housing systems (in-cage and free-range). We combined our results and the market condition of different eggs, give a comparison of economic benefit among those three layer. The research results offer a certain theory basis for housing system and market position of local layer.The laying performance measurement results show that the Roman laying hens was higher than other layers in both in-cage and free-range housing system. The egg weight (57.95 ± 8.29 g) and eggshell weight (8.06 ± 0.97 g) of Roman laying hens was the heaviest. When compared for the Haugh unit (HU), the Green-shell chickens is the highest (81.68 ± 10.57) (P＜0.05).In free-range condition, the weight of egg and eggshell of Roman laying hens is the highest (58.07 ± 6.05g and 7.75 ± 0.77 g), however, is lowest when compared for the yolk color. The shell color of Roman laying hens is the highest (55.99±3.54). Our results demonstrated that those indexes which we measured can reflect breeding specificity, additionally, the egg weight, yolk color and the Haugh unit are higher in free-range group than in-cage group (P＜0.05).We also measured the nutrient factors, the highest content of cholesterol was found in the Roman laying hens group, the lowest in blue-shell chickens, and the former group have the highest Vitamin A (VA) but not significant. The Jiuyuan Black Fowl is rich in Zinc whereas the Green-shell chickens is rich in Selenium, and significant higher than other groups (P<0.05) and the Roman laying hens is the lowest in Zinc and Selenium. The protein content in Green-shell chickens is higher than Jiuyuan Black Fowl and the Roman laying hens is the lowest. In addition, no matter which breeding chickens we choose, the free-range group have the higher concentration of Zinc and Selenium, our results demonstrated that the housing system was involved with the enrichment of trace elements, but a converse result in the VA concentration, it might relate with the content of fodder.After the analysis of economical values, we found that the blue-shell chickens is the best, and the free-range group is better than in-cage group.