Effects Of Zearalenone On Production Performance, Blood Index And Reproductive Organ Of Reserve Female Rabbits

This experiment was conducted to study the effects of zearalenone(ZEA)supplemental level on growth performance,serum biochemical parameters,immune performance,antioxidant properties,genital tissue histology and residues of zearalenone in feces and urine of reserve female rabbit.Sixty female rabbits at 3 months of age were randomly selected and divided into five groups with 12 rabbits in each group.The control group was fed a basal diet,while the rabbits in groups I to IV(experimental groups),were fed experimental diet supplemented with 250?g/kg,500?g/kg,750?g/kg,1000?g/kg ZEA on the basis of the basal diet,respectively.There was a pretrial period of 7 days followed by an experimental period of 40 days.The trial period was divided into two phases:1~20 days ahead,21~40days later.The serum and visceral tissues were collected at different stages.Feed intake was recorded in the early and late test periods and the average daily feed intake was calculated.Rabbits were weighed on a fasting basis in replicates,which on tests 20d and 40d and used for determining growth performance.Five female rabbits were randomly selected from each group on the mid-term(20d)and late(40d)period.First collected blood from the heart and then separated serum from the blood.Slaughtered test animals in a conventional manner and remove visceral tissue(liver,kidney,spleen),immune organs(thymus)and reproductive organs(uterus and ovaries).Then determined serum biochemical parameters,organ index,histopathological changes and toxin residues.The results showed that:(1)There was no effect on the performance on the mid-term(20d)and late-during(40d)trials of the reserved female rabbits when supplemented with 250~1000?g/kg ZEA on the basis of the basal diet.The main manifestations were that there were no significant differences on slaughter rate,feed intake and daily gain(P>0.05).(2)Intaking 250~1000?g/kg ZEA could lead to metabolic abnormalities in liver metabolism of the reserved female rabbits.Compared with the control group,the levels of alanine aminotransferase,aspartate aminotransferase and alkaline phosphatase in the groups ?,?,? and ? were significantly increased(P<0.01).(3)Intaking ZEA could lead to a decrease in antioxidant capacity of the rearing female rabbits.At the end of the experiment(40d),the superoxide dismutase showed a downward trend,with no significant difference(P>0.05)and 500~1000?g/kg ZEA significantly increased the serum level of malondialdehyde Aldehyde(MDA)content(P<0.05),700?g/kg ZEA significantly reduced serum glutathione peroxidase(GSH-P_X)content(P<0.01).(4)Intaking ZEA could affect the humoral immunity of the female rabbits,and decreased the serum IgG content(P<0.05).Although IgA and IgM showed a decreasing trend,the difference was not significant(P>0.05).(5)Intakeing ZEA(750~1000?g/kg)significantly reduced the spleen index of the mother rabbits(P<0.05),and had no significant effect on the liver,kidney,thymus,spleen,uterus,and ovary organ indexes;There was no effect on the organs index at the mid-term(20d).(6)ZEA could cause morphological changes of the uterus and ovaries in different degrees.In the high-dose group(750~1000?g/kg),the myometrium were significantly thickened,the uterine glands were significantly increased,the occurrence of follicular vesicles.(7)The content of ZEA in urine accounted for 11%~21%of the intake,?-/?-ZOL accounted for15%~27%of the intake;The content of ZEA in feces accounted for 8%~11%of the intake,and?-/?-ZOL accounts for 16%~26%of intake.Residues of ZEA and its metabolites in urine are higher than those in faeces.250~1000?g/kg ZEA can cause metabolic abnormalities in the liver of rabbits,destroy its antioxidant capacity,affect its immune ability,750~1000?g/kg ZEA can affect the spleen index of the breeding mother rabbit,destroy its reproduction Organ(uterine,ovarian)tissue morphology.