Avian Science Research Centre, Scotland's Rural College, Auchincruive, Ayr, KA6 5HW, UK.
Poult Sci. 2013 Aug;92(8):2101-8. doi: 10.3382/ps.2012-03005.
Two 21-d broiler experiments were conducted to assess the efficacy of a bacterial 6-phytase expressed in Aspergillus oryzae on growth performance, nutrient utilization, and intestinal molecular markers. Two hundred forty birds in 5 treatments (experiment 1) or 256 birds in 4 treatments (experiment 2) were used. The treatments included a negative control diet that was marginally deficient in P (NC) or NC plus tricalcium phosphate, 500, 1,000, or 2,000 phytase units/kg (experiment 1), and NC or NC plus monocalcium phosphate, 500 or 1,000 phytase units/kg (experiment 2). In both experiments, excreta were collected on d 19 to 21, whereas birds and feed were weighed and ileal digesta collected on d 21. For experiment 1, mucosa scraping was collected from the duodenum, jejunum, and ileum from all birds for quantification of expression level of gut level inflammatory cytokines, Toll-like receptors, and phosphate transporter (NaPi-IIb). In both experiments, tricalcium phosphate, monocalcium phosphate, and phytase supplementation improved (P < 0.05) weight gain and percentage tibia ash. Phosphorus and Ca retention and phytic acid disappearance improved (P < 0.05) with phytase supplementation (experiment 1) and there was an increase (P < 0.01) in Ca and P retention in response to phytase supplementation (experiment 2). Diets did not affect the expression of gut level cytokines, Toll-like receptors, or the mucin gene. Phytase supplementation tended to decrease (P < 0.10) the expression of NaPi-IIb. It was concluded from these studies that the bacterial 6-phytase was effective in enhancing growth of broilers receiving low-P diets as well as in increasing efficiency of P utilization and phytic acid degradation.
进行了两项 21 日龄肉鸡试验，以评估在米曲霉中表达的细菌 6-植酸酶对生长性能、养分利用和肠道分子标记的功效。在 5 个处理组（试验 1）或 4 个处理组（试验 2）中使用了 240 只鸡或 256 只鸡。处理组包括低磷（NC）或 NC 加磷酸三钙、500、1000 或 2000 植酸酶单位/千克的负对照组（试验 1），以及 NC 或 NC 加磷酸一钙、500 或 1000 植酸酶单位/千克的负对照组（试验 2）。在这两个试验中，在第 19 天至第 21 天收集粪便，在第 21 天称重鸡和饲料，并收集回肠消化物。对于试验 1，从所有鸡的十二指肠、空肠和回肠刮取粘膜，用于定量测定肠道炎症细胞因子、Toll 样受体和磷酸盐转运体（NaPi-IIb）的表达水平。在这两个试验中，添加磷酸三钙、磷酸一钙和植酸酶提高（P < 0.05）了体重增加和胫骨灰分百分比。添加植酸酶提高（P < 0.05）了磷和钙保留率和植酸消失率（试验 1），并随着植酸酶添加而增加（P < 0.01）了钙和磷保留率（试验 2）。日粮不影响肠道细胞因子、Toll 样受体或粘蛋白基因的表达。添加植酸酶有降低（P < 0.10）NaPi-IIb 表达的趋势。综上所述，本研究表明，细菌 6-植酸酶可有效提高接受低磷日粮的肉鸡的生长性能，提高磷利用效率和植酸降解效率。
