Circadian rhythms and dynamic dietary calcium feeding affect laying performance,calcium and phosphorus levels in laying hens |
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| Authors: | Xue Lin Yilin Liu Chunyan Xie Yulong Yin |
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| Institution: | 1. Hunan Co-Innovation Center of Safety Animal Production, College of Animal Science and Technology, Hunan Agricultural University, Changsha, China;2. Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China;3. Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Changsha, China;4. Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China;5. College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, China |
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| Abstract: | This study was conducted to determine the effects of dynamic feeding low and high Ca in layer diets on laying performance, calcium, and phosphate concentration in both serum and tibia. 180 Brown Hy-line, 41 weeks old of laying hens were randomly distributed into 3 groups with 6 replicates and each replicate was 10 birds. During the 10-week experiment period, control group (CON group) received control diet (contained 3.4% Ca) at both 0730 and 1530 h, low–high group (LH group) received low Ca diet (contained 3.2% Ca) at 0730 h and high Ca diet (contained 3.6% Ca) at 1530 h, while high–low group (HL group) received the contrary to the LH group. Blood and tibia samples were collected at 4 h intervals. The dynamic Ca feeding schedule exerted significant effects on Ca intake in the morning and afternoon, also on feed conversion ratio (FCR) of the HL group comparing to the LH group (p<0.05). Serum Ca in the LH group were lower at 0000, 0400 and 1600 h comparing with the CON group (p < 0.05), and serum Ca: P ratio values in the LH group were lower at 0000, 0800, and 2000 h comparing with the CON group (p<0.05). These results indicated that dynamic feeding Ca improved FCR and affected the circadian variation of serum Ca concentration in laying hens. |
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| Keywords: | Dynamic feeding calcium feed conversion ratio circadian rhythms |
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