复合酶制剂对低蛋白日粮饲养的肉鸡养分表观消化率和肝脏代谢相关酶活性的影响

Effects of compound enzyme preparation on nutrients apparent digestibility and hepatic metabolizing enzymes of broilers fed a low protein diet

为了探讨复合酶制剂对低蛋白日粮饲养的肉鸡养分表观消化率及肝脏代谢相关酶活性的影响,试验将240只1日龄商品代肉鸡随机分为6组,对照组饲喂基础日粮;试验Ⅰ~Ⅴ组饲喂蛋白质水平依次降低(0、0.5%、1.0%、1.5%、2.0%)的基础日粮+0.1%复合酶制剂。饲养至42日龄,采集粪便和血清,分别用于测定钙(Ca)、磷(P)和粗蛋白(CP)的表观消化率,以及丙氨酸氨基转移酶(GPT)、天门冬氨酸氨基转移酶(GOT)、碱性磷酸酶(ALP)活性。结果表明:试验Ⅰ组Ca、P、CP的表观消化率均显著高于对照组(P<0.05),血清中ALP活性显著升高(P<0.05),GPT和GOT活性显著下降(P<0.05)。与试验Ⅰ组相比,试验Ⅱ~Ⅴ组Ca、P的表观消化率呈下降趋势,但试验Ⅱ组、Ⅲ组Ca、P的表观消化率仍显著高于对照组(P<0.05),CP的表观消化率呈上升趋势。另外,试验Ⅲ组GOT活性与对照组相比仍显著降低(P<0.05),ALP活性显著升高(P<0.05)。说明在基础日粮中添加0.1%复合酶制剂的同时降低1.0%蛋白质含量仍能改善肉鸡肝脏代谢功能,提高饲料消化利用率,从而减少生产成本。

To investigate the effects of compound enzyme preparation on nutrients apparent digestibility and hepatic metabolizing of chickens fed a low protein diet, a total of 240 one-day-old commercial broilers were randomly divided into six groups in this study. Chickens in the control group was fed a basic diets, and chickens in the experimental groups Ⅰ-Ⅴ were fed base diets with different protein levels(0, 0.5%, 1.0%, 1.5%, 2.0%) and 0.1% compound enzyme preparation, respectively. After feeding for 42 days, feces and serum were collected and used to detect the apparent nutrient digestibility of calcium(Ca), phosphorus(P) and crude protein(CP), as well as the activities of Glutamic-pyruvic transaminas(GPT), Glutamic oxaloacetic transaminase(GOT) and Alkaline phosphatase(ALP). The results showed that the apparent digestibility of Ca, P, CPs as well as ALP in group Ⅰ was significantly higher than that in the control group(P<0.05), and ALP activity in serum was significantly increased(P<0.05), but the activities of GPT and GOT were significantly lower(P<0.05). Compared with group Ⅰ, the apparent digestibility of Ca and P in group Ⅱ-Ⅴ showed a downward trend, but Ca and P in group Ⅱ-Ⅲ still significantly higher than that in control group(P<0.05). The apparent nutrient digestibility of CP showed an upward trend. In addition, the GOT activity in group Ⅲ was significantly decreased compared with control group(P<0.05), and ALP activity was significantly increased(P<0.05). The results indicated that the basal diet supplemented with 0.1% complex enzyme preparation while reducing 1.0% protein content could still improve the liver metabolism of broilers and increase the utilization rate of feed digestion, thus appropriately reducing the production cost.