Morgan N K, Walk C L, Bedford M R, Burton E J
School of Animal, Rural, and Environmental Science, Nottingham Trent University, Southwell, Nottinghamshire NG25 0QF, United Kingdom
AB Vista Feed Ingredients, Woodstock Court, Blenheim Road, Marlborough Business Park, Marlborough, Wiltshire SN8 4AN, United Kingdom.
Poult Sci. 2015 Jul;94(7):1577-83. doi: 10.3382/ps/pev108. Epub 2015 Apr 23.
There is little consensus as to the capability of poultry to utilize dietary phytate without supplemental phytase. Therefore, an experiment was conducted to examine the extent to which endogenous phytase of intestinal and cereal origin contributes to phytate degradation in birds aged 0 to 14 d posthatch. Ross 308 broilers (n = 720) were fed one of 4 experimental diets with differing dietary ingredient combinations and approximate total phytate levels of 10 g/kg, dietary phytase activity analyzed at 460 U/kg, dietary calcium (Ca) levels of 11 g/kg, and nonphytate-phosphorus (P) levels of 4 g/kg. Broiler performance, gizzard, duodenum, jejunum and ileum pH, Ca and P digestibility and solubility, amount of dietary phytate hydrolyzed in the gizzard, jejunum, and ileal digesta phytase activity were analyzed at d 4, 6, 8, 10, 12, and 14 posthatch. Intestinal endogenous phytase activity increased significantly (P < 0.001) between d 4 and 6, resulting in increased phytate hydrolysis in the gizzard (P = 0.003), jejunum (P < 0.001), and ileum (P < 0.001). Phytase activity and phytate hydrolysis continued to increase with age, with a greater phytase activity and associated increase in phytate hydrolysis and mineral utilization between d 10 and 12. Gizzard and jejunum Ca and P solubility and ileal Ca and P digestibility increased significantly (P < 0.001), and gastrointestinal pH decreased significantly (P < 0.001) between d 4 and 6. By d 14, phytase activity recovered in the ileum was approximately 45 U/kg. There were strong correlations between phytase activity measured in the ileum and phytate hydrolyzed in the gizzard (r = 0.905, P < 0.001), jejunum (r = 0.901, P = 0.023), and ileum (r = 0.938, P = 0.042). This study shows intestinal- and dietary-derived endogenous phytase activity is responsible for phytate-P hydrolysis in broilers.
关于家禽在不添加植酸酶的情况下利用日粮中植酸盐的能力，目前几乎没有一致的看法。因此，进行了一项实验，以研究肠道和谷物来源的内源性植酸酶对出壳后0至14天雏鸡植酸盐降解的贡献程度。将罗斯308肉鸡（n = 720）分为4组，分别饲喂4种不同日粮成分组合的实验日粮，日粮总植酸盐含量约为10 g/kg，日粮植酸酶活性为460 U/kg，日粮钙（Ca）含量为11 g/kg，非植酸磷（P）含量为4 g/kg。在出壳后第4、6、8、10、12和14天分析肉鸡的生产性能、肌胃、十二指肠、空肠和回肠的pH值、钙和磷的消化率及溶解度、肌胃中水解的日粮植酸盐量、空肠和回肠食糜中的植酸酶活性。肠道内源性植酸酶活性在第4天到第6天之间显著增加（P < 0.001），导致肌胃（P = 0.003）、空肠（P < 0.001）和回肠（P < 0.001）中植酸盐水解增加。植酸酶活性和植酸盐水解随着日龄的增加而持续增加，在第10天到第12天之间植酸酶活性更高，植酸盐水解和矿物质利用率也相应增加。在第4天到第6天之间，肌胃和空肠中钙和磷的溶解度以及回肠中钙和磷的消化率显著增加（P < 0.001），胃肠道pH值显著降低（P < 0.001）。到第14天，回肠中恢复的植酸酶活性约为45 U/kg。回肠中测得的植酸酶活性与肌胃（r = 0.905，P < 0.001）、空肠（r = 0.901，P = 0.023）和回肠（r = 0.938，P = 0.042）中水解的植酸盐之间存在很强的相关性。本研究表明，肠道和日粮来源的内源性植酸酶活性是肉鸡植酸磷水解的原因。
