高剂量碳酸氢钠日粮对蛋壳质量的影响及机制  

The effects and mechanism of dietary supplement with excessive sodium bicarbonate on eggshell quality

作　　者：杨俊花[1] 罗爱琼[1] 刘丹[1] 缪德年[2] 赵志辉[1] 

机构地区：[1]上海市农业科学院农产品质量标准与检测技术研究所,上海201403 [2]上海市农业科学院畜牧兽医研究所,上海201106

出　　处：《南京农业大学学报》2013年第6期67-72,共6页Journal of Nanjing Agricultural University

基　　金：国家公益性行业(农业)科研专项(201203015);上海市科委公共服务平台建设专项(11DZ2292800);上海市科技兴农重点攻关项目[沪农科攻字(2009)第61号]

摘　　要：为探讨日粮添加碳酸氢钠(NaHCO3)对蛋壳质量、蛋壳钙、血钙浓度、钙调激素水平以及蛋壳腺中Ca2+转移相关蛋白基因表达的影响,选取900只21周龄海兰褐蛋鸡随机分为对照组和1、5、25和50 g·kg-1NaHCO3添加组,每组6个重复,每个重复30只,持续10周。结果表明:与对照组相比,日粮添加1和5 g·kg-1NaHCO3对蛋壳质量不产生显著影响(P>0.05),25和50 g·kg-1组蛋壳钙含量显著降低(P<0.01),蛋壳质量、厚度降低(P>0.05),50 g·kg-1组蛋壳强度和血清Ca2+浓度亦显著降低(P<0.05)。此外,随着NaHCO3添加量的增加,25和50 g·kg-1组血液维生素D水平显著或极显著增加(P<0.05或P<0.01),蛋壳腺中瞬时性受体电位通道香草精受体6(TRPV6)、钙结合蛋白(CaBP-D28k)、钠-钙交换蛋白(PMCA 1b)和质膜钙离子ATP酶通道(NCX1)mRNA表达量显著提高(P<0.05),50 g·kg-1组碳酸酐酶(CA)mRNA水平显著降低(P<0.05)。结论:高剂量的NaHCO3(≥25 g·kg-1)使蛋壳质量下降,CA mRNA表达量降低,致使蛋壳腺Ca2+转移受阻,蛋壳钙含量减少、质量下降。其次,低血钙和高维生素D水平使TRPV6、CaBP-D28k、PMCA 1b和NCX1等基因表达增加,表明钙离子跨细胞转运途径在蛋壳腺中起补充转移作用。The purpose of this study was to analyze the effect of dietary NaHCO3 on eggshell quality, the concentration of Ca2~ in eggshell and plasma, and levels of plasma calcium regulating hormones, as well .as mRNA expression of genes related to Ca2＋ transport in eggshell gland（ESG）. Nine hundred 21-weeks-old Hy-line brown laying hens were randomly assigned to be fed with 0,1,5,25 and 50 g.kg-1 NaHCO3 for 10 weeks,and each group was composed of 6 replicates and 30 birds per replicate. The results showed as follows ：compared with control,the eggshell quality was not influenced by dietary NaHCO3 level at 1 g kg-1 or 5 g kg-1（ P〉0.05 ）. However,the content of Ca2＋ in eggshell（P〈0.01 ）, eggshell thickness and weight（ P〉0.05 ）were reduced in 25 g. kg-1 and 50 g kg-1 groups ,respectively. In addition ,eggshell strength and plasma Ca2＋ content were also significantly reduced by the supplementation of 50 g kg-1 NaHCO3 （P〈0.05）. Then, the concentration of vitamin D level in plasma was dramatically increased by dietary NaHCO3 level at 25 and 50 g＇kg-t（P〈O. 05 or P〈0.01 ）. Moreover,the mRNA expression of transient receptor potential vanilloid receptor 6（TRPV6）, calbindin-D28k（CaBP-D28k）, plasma membrane Ca2＋-ATPase （PMCA lb）arid Na＋/Ca2＋ exchangers （NCX1）in ESG tissue were increased in 25 and 50 g kg-1 NaHCO3 groups（ P〈0.05 ）,but the level of carbonic anhydrase（CA） mRNA was remarkably reduced in 50 g kg-1 group（P〈0. 05）. In conclusion： the mechanism was that lower plasrrta Ca2＋ content and CA mRNA level were induced by excessive NaHCOd（ t〉25 g.kg 1 ） ,then which led to block to Ca2＋ transfer in ESG,finally resulted in the reduction of eggshell quality. Secondly,the increase in mRNA expression of TRPV6, CaBP-D28k, PMCA l b, and NCX1 suggests that transcellular Ca2＋ transport pathway appears to compensate for low Ca2＋ intake in ESG.

关 键 词：碳酸氢钠 蛋壳质量 血钙 蛋壳腺 钙离子转移 蛋鸡 

分 类 号：S852[农业科学—基础兽医学]