title: The Influence of Dietary Calcium and Phosphorus Imbalance on Intestinal NaPi-IIb and Calbindin mRNA Expression and Tibia Parameters of Broilers.
abstract: A 2×2 factorial experiment was conducted to study the effect of dietary calcium and non-phytate phosphorus (nPP) imbalance on calbindin and NaPi-IIb mRNA levels in the small intestine and tibia parameters of broiler chicks. One hundred and forty four 1-d-old Arbor Acres male broiler chicks were divided into four treatments consisted of six replicates with six chicks each. The two dietary calcium levels were 1.10% and 0.60%, and two dietary nPP levels were 0.50% and 0.27%. Results showed that a high Ca/nPP ratio diet (4.07:1) significantly depressed feed intake and weight gain of broilers (p<0.05), but a lower Ca:nPP ratio (1.2:1) had no influence (p>0.05). Low-Ca with low-P diet resulted in low tibia minerals and tibia breaking strength of broilers, and all the tibia parameters were further decreased when the dietary ratio of Ca to P was relative higher. Low dietary Ca or P up-regulated the calbindin and NaPi-IIb mRNA expression levels. Low Ca with normal P diet up-regulated duodenal calbindin mRNA expression level to the greatest extent. Low P with a normal Ca diet significantly enhanced NaPi-IIb mRNA expression level to the highest extent. These results suggest that the calbindin and NaPi-IIb mRNA expression were enhanced by the imbalance between dietary Ca and nPP, and their expression were not only influenced by Ca or nPP level, but also the ratio of Ca:nPP.
authors: State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China ; College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Shanxi 030801, China .
authors: Jianhui
authors: J
authors: Li
authors: State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
authors: Jianmin
authors: J
authors: Yuan
authors: State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
authors: Yuming
authors: Y
authors: Guo
authors: State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
authors: Qiujuan
authors: Q
authors: Sun
authors: Henan Key Laboratory for Animal Immunology, Henan Academy of Agricultural Science, Zhengzhou 450002, China .
authors: Xiaofei
authors: X
authors: Hu
keywords: Broilers; Calbindin; Calcium; NaPi-IIb; Phosphorus; Tibia