饲料硒利用率测定研究——雏鸡血浆谷胱甘肽过氧化物酶活性评定法

试验用1日龄成都白鸡,以血浆谷胱甘肽过氧化物酶(GSH—Px)活性作指标,对硒利用率的测定方法进行了探讨;并测了几种饲料硒的利用率。试验一,雏鸡喂基础饲粮(含硒0.013ppm)5天后血浆GSH—Px活性显著下降,7天后趋于稳定,11天胰脏发现缺硒病变。据此认为雏鸡硒适宜耗竭时间为7至9天。硒耗竭雏鸡喂补硒(Na_2SeO_3)饲粮后,血浆GSH—Px活性显著升高的时间为:补硒0.12ppm组36小时;0.08ppm组48小时;0.04ppm组72小时;0.02ppm组第8天。36小时后血浆GSH—Px活性与饲粮补硒水平呈显著线性相关(P<0.01)。试验二,雏鸡喂基础饲粮9天后改喂测定料或标准料(添加Na_2SeO_3)9天,以血浆GSH—Px活性作指标,测秘鲁鱼粉、智利鱼粉和小麦中硒的利用率分别为44.04、26.34和25.81％。

THE DETERMINATION OF SELENIUM IN FEEDSTUFFS——AN ASSAY USING BLOOD PLASMA GLUTATHIONE PEROXIDASE ACTIVITY IN CHICKS AS A CRITERION

Two experiments were conducted with one-day-old Chengdu White chicks. The first was to study the assay for determination of selenium in feedstuffs in which the blood plasma glutathione peroxidase (GSH-Px) activity is used as a criterion. Chicks signifricantly reduced GSH-Px activity (P<0.05) in plasma after 5 days of depletion on the basal diet (0.013 ppm of Se) and not further (P>0.05) after 7 days. The initial signs of nutritional pancreatic atrophy in chicks fed the basal diet were found by the 11th day of depletion. So it is suggested that the proper time of depletion should be between 7 and 9 days. The selenium-depleted chicks show significant elevation (P<0.05) of GSH-Px activity in plasma at 39, 48, 72 hrs and eighth day after being fed diets supplemented with 0.12, 0.08, 0.04 and 0.02 ppm of Se (Na_2SeO_3) respectively. After 36hrs' repletion on diets supplemented with selenium the GSH-Px activity in plasma was linearly, highly correlated with the amount of selenium adued in the diet (P<0.01). In the second experiment the availability of selenium in several feedstuffs was determined with the plasma GSH-Px activity as a criterion. The chicks were fed the basal diet for 9 days and then changed to the test or standard diets (selenium added as Na_2SeO_3) for 9 days. The availability of selenium in Peru meal (1.32 ppm of Se), Chile fish meal (4.70 ppm of Se)and the wheat(0.24 ppm of Se) was 44;04, 26.34 and 25.81% respectively.