饲粮中钼水平的不足,适量和过量对雏鸡的影响

INFLUENCE OF SUPPLEMENENTING DIFFERENT LEVELS OF MOLYBDENUM IN THE DIETS ON CHICTS

用360只父母代经铝耗竭的一日龄红布罗雏鸡观察了采食自然低铝饲粮情况下,钼的不足、适量和过量对雏鸡生长、死亡、红细胞溶血、组织中钼含量,肝脏、粪尿中钙、磷含量,临床症状和组织病变的影响。结果表明:采食低钼饲量(1.38ppm)的雏鸡,羽毛呈结节状,生长缓慢、死亡率高、红细胞溶血较严重。补钼3 ppm时,结节状羽毛恢复正常,红细胞溶血现象消失。补钼7ppm时,生长最快,死亡率最低,但与补5ppm组差异不显著(P>0.05),当补钼50ppm时,生长受阻(P>0.01),死亡率增加(P>0.05)。补铝100pdm时,大小肠出现出血点,红细胞发生溶血。随着钼水平的提高,肝脏、肾脏、心脏中的钼含量也随之升高。当补钼3—7ppm时,组织中钼含量趋于稳定,低钼及过量钼时,钙在肝脏中沉积减少,粪尿中排泄增加,而对磷无显著影响。雏鸡饲粮中添加5ppm左右钼较为适宜。补钼50ppm即可引起雏鸡中毒。

The test was conducted with 360 one—day—old Redbro chicks with parent-depletion treatment.The effects of adding various levels of molybdenum (Mo) to natural low Modiets on chick performanco was primariy observed.The results showed that the chieks with low Modiet (1.38ppm) had crisp feather, lower growth rate, higher mortality and more serious red cell haemolysis.With 3 ppm supplementation, the crisp feather turned into normal state and the red cell haemolysis disappeared And the 7 ppm supplementing resulted in highest growth rate and the lowest mortality but not significantly different from 5 ppm supplementing (P>0.05).After the Mo level increased to 50ppm, the growth rate was significantly decreased (P<0.01) and the mortality was significantly increased (P<0.05) There were blood spots in the s,mall and large intestes ofin the chicks and the red cell haemolysis with lOOppm supplementing. The increased Mo levels in diets also brought about the increased Mo concentrations in livers, kidneys,, and hearts, but the concentrations tended to keep stable when the Mo levels were between 3—7 ppm.Morever, the low or high Mo levels resulted in less calcium deposition in livers and higher calcium in excreta, but had no significant effect 5 ppm supplementation to the chick diets was maximum and the 50ppm Mo in diets might be toxic.