日粮中添加不同浓度吡啶甲酸铬对生长肥育猪氧化作用的影响

Effects of Varying Levels of Dietary Chromium Picolinate on Oxidation in Growing-Finishing Pigs

本研究旨在观察日粮中持续添加不同浓度吡啶甲酸铬对生长肥育猪氧化作用的影响。选取30头(30±1)kg三元杂交型(杜×长×大)生长肥育猪,按体重、遗传基础和性别随机平均分成5个处理。5个处理分别饲喂铬的添加水平为0、200、800、1600、3200μg/kg(以吡啶甲酸铬的形式添加)的日粮,试验期为80d。试验第35天和第80天时,测定吡啶甲酸铬对动物血清中超氧化物歧化酶(SOD),过氧化氢酶(CAT),谷胱甘肽过氧化物酶(GSH-Px)的活力和丙二醛(MDA)的含量,以及动物尿液中8-羟基脱氧鸟苷(8-OHdG)的水平。试验结束时,屠宰动物并取肝脏和肾脏样品,分别测定这些组织中的SOD、GSH-Px、CAT的活力和MDA的水平。结果表明,日粮中长期添加高剂量(≥800μgCr/kg)的吡啶甲酸铬显著降低第80天时肥育猪血清中的SOD和肾脏中CAT的活性(P<0.05),但对其他指标都没有显著影响(P>0.05)。结果提示,在生产肥育期全程(80d)添加适宜量(200μgCr/kg)的吡啶甲酸铬不会造成猪的氧化损伤;添加16倍适宜量的吡啶甲酸铬导致猪血清SOD和肾CAT活性降低,但不引起脂质过氧化和DNA损伤。

This experiment was designed to assess the effects of varying levels of dietary chromium picolinate （CrPic） on oxidation in growing-finishing pigs. Thirty crossbred （Duroc x Landrace × Yorkshire）, （30 ＋ 1） kg growing-finishing pigs were randomly and equally separated into five treatments based on their weight, heredity basis and gender. Pigs in each treatment were respectively fed diets supplemented with 0, 200, 800, 1 600, 3 200 μg Cr/kg （adding in the forms of CrPic） for 80 days. To evaluate the effects of CrPic on oxidation, the activities of superoxide dismutase（SOD）, glutathione peroxidase （GSH-Px）, eatalase（CAT） and the amount of malondialdehyd （MDA） were examined in the serum on the 35^th day and 80^th day. And the level of 8-hydroxyguanine （8-OHdG） were also assessed in urine on the same days. At the end of experiment, all animals were slaughtered, the livers and kidneys were harvested. Similarly, the activities of superoxide dismutase （SOD）, glutathione peroxidase （GSH-Px）, eatalase （CAT） and the amount of malondialdehyd （MDA） were examined in the livers and kidneys. The results showed that the high dose of CrPic （≥800 μg Cr/kg） significantly decreased the activities of SOD in the serumand the activities of CAT in kidney on the 80th day （P〈0.05）, However, other parameters had no notable differences （P〉0.05）. In conclusion, adequate intakes of CrPic （200 μg Cr/kg） during the entire growing-finishing period did not resulted in oxidative damage in pigs. The high dose of 3 200μg Cr/kg （in forms of CrPic） significantly decreased the activity of SOD in serum and CAT in kidney, but did not cause lipid peroxidation and oxidative DNA damage.