ABSRACT

1. An experiment was designed to compare the effects of supplementing laying hen diets with phytase and myo-inositol (inositol).

2. Five diets were formulated: high balanced protein (HBP – 840 mg of Dlys/hen/day), HBP with inositol (HBP+I – 0.16%), reduced balance protein (RBP – 672 mg of Dlys/hen/day), RBP with inositol (RBP+I – 0.16%) and RBP with phytase (RBP+P – 3000 FTU/kg).

3. Laying hen production, inositol concentrations, digestive tract morphology, amino acid digestibility and intestinal inositol transporters transcript abundance were evaluated. Data were analysed with a one-way ANOVA in SAS 9.4. Contrasts were used to assess the effect of protein, inositol, phytase and phytase vs. inositol. Differences were accepted when P ≤ 0.05.

4. No effect on hen-day egg production or feed efficiency was found. However, feed intake and the incidence of abnormally shaped eggs were 0.77 g/h/d and 0.17% higher, respectively, in inositol treatments. Inositol decreased egg specific gravity from 1.088 to 1.0865.

5. Inositol concentration in egg yolk was similar among HBP+I, RBP+I and RBP+P, and higher than for the HBP and RBP diet groups. Both gizzard and ileal digesta were enriched in inositol in all supplemented treatments, and phytase supplementation decreased the level of IP5 and IP6 in the gizzard and ileum. Generally, neither phytase or inositol affected amino acid digestibility.

6. Inositol increased transcript abundance of alkaline phosphatase in the ileum, while phytase upregulated duodenal alkaline phosphatase and SMIT1, jejunal SMIT2 and reduced ileal HMIT and SMIT1 abundance.

7. In conclusion, no effect of phytase or inositol was found for laying hen production performance or amino acid digestibility, but egg quality was reduced by inositol supplementation. Inositol concentration in egg yolk was similar among supplemented treatments.

摘要

1. 一项实验旨在比较在蛋鸡日粮中添加植酸酶和肌醇（肌醇）的效果。

2. 制定了五种饮食：高平衡蛋白质（HBP – 840 毫克 Dlys/母鸡/天）、HBP 与肌醇（HBP+I – 0.16%）、减少的平衡蛋白质（RBP – 672 毫克 Dlys/母鸡/天） , 含肌醇的 RBP (RBP+I – 0.16%) 和含植酸酶的 RBP (RBP+P – 3000 FTU/kg)。

3.评价了蛋鸡产量、肌醇浓度、消化道形态、氨基酸消化率和肠肌醇转运蛋白转录物丰度。在 SAS 9.4 中使用单向方差分析对数据进行分析。对比用于评估蛋白质、肌醇、植酸酶和植酸酶与肌醇的作用。当 P ≤ 0.05 时，差异被接受。

4. 未发现对母鸡日产蛋量或饲料效率有影响。然而，在肌醇处理中，饲料摄入量和异常形状蛋的发生率分别高出 0.77 g/h/d 和 0.17%。肌醇将鸡蛋比重从 1.088 降低到 1.0865。

5. 蛋黄中肌醇浓度在 HBP+I、RBP+I 和 RBP+P 之间相似，并且高于 HBP 和 RBP 饮食组。在所有补充处理中，胼胝和回肠食糜都富含肌醇，补充植酸酶降低了胼胝和回肠中 IP5 和 IP6 的水平。通常，植酸酶或肌醇都不影响氨基酸消化率。

6. 肌醇增加回肠中碱性磷酸酶的转录丰度，而植酸酶上调十二指肠碱性磷酸酶和 SMIT1、空肠 SMIT2 并降低回肠 HMIT 和 SMIT1 丰度。

7. 综上所述，未发现植酸酶或肌醇对蛋鸡生产性能或氨基酸消化率有影响，但添加肌醇会降低蛋品质。蛋黄中肌醇浓度在补充处理中相似。