| This study was conducted to study aflatoxin B1(AFB1)singly,combined with ochratoxin A(OTA)or/and zearalenone(ZON)on performance,blood parameters,serum biochemical parameters,antioxidant status and immune functions of late lactation Laoshan dairy goats as well as the effects of AFB1 on serum metabolomics.The object of this study was to approach the effects of multi-mycotoxins on blood metabolism in dairy goats,which provide the theoretical basis and reference for multi-mycotoxins control in management.The research is mainly including the following aspects:1.Effects of AFB1 single,combined with OTA or/and ZON on lactation performance and blood metabolism.Fifty late lactating Laoshan dairy goats were randomly divided into one of five groups(n=10)according to milk yield(1.36±0.4 kg/d),days in milk(193 ±13 d),parity(3.4 ± 0.5).One of five treatments diets,assigned randomly to one of five groups,consisted of 0,50 ug/kg AFB1,50 ug/kg AFB1 + 100 ug/kg OTA,50 ug/kg AFB1 + 500 ug/kg ZON,50 ug/kg AFB1 + 100 ug/kg OTA + 500 ug/kg ZON based on dry matter(DM).The experiment lasted for 21d,including 7d of adaptation and 14d of formal experiment period.The results revealed that diets supplemented with AFB1 combined with 100 ug/kg OTA and 500 ug/kg ZON significantly decreased the dry matter intake(DMI)(P<0.05),which in AFB1+OTA group and AFB1+ZON group were lower than AFB1 and control groups;goats fed diets added AFB1 combined with OTA and ZON and AFB1 combined with OTA significantly decreased milk yield compared with control(P<0.05),but no difference was observed in rest groups.Supplemented with various combinations of mycotoxins has no effect on body weight in dairy goats(P>0.05).These results indicated that AFB1 combined with OTA and ZON had greatest effect on DMI and milk yield,AFB1 combined with OTA had greater effect on milk yield than AFB1 combined with ZON.Supplemented with various combinations of mycotoxins extremely significantly decreased RBC,MCV,MCH and MPV concentration(P<0.01),significantly increased the quantity of WBC(P<0.05).Supplemented with various combinations of mycotoxins had tendence to decrease MCHC concentration(P=0.08),but no significant variation was observed in serum concentrations of HGB,HCT and PLT(P>0.05).Significantly difference was observed in MCV、MCHC and MPV concentration between AFB1+ZON group and AFB1+OTA+ZON group(P<0.05),but was no variation was observed between AFB1+OTA group and AFB 1+ZON group(P>0.05).AFB1 combined with OTA and ZON had the highest concentration of MCHC and the maximum quantity of WBC as well as the minimum quantity of RBC,AFB1 combined with OTA had greater effects than AFB1 combined with ZON on the quantity of WBC and RBC as well as the concentrations of MCHC.These results revealed that AFB1 combined with OTA and ZON made greatestadverse effect on blood parameters in dairy goats.Goats fed diets supplemented with mycotoxins significantly increased GPT and TBIL content in serum(P<0.05),but had no effect on serum concentrations of CR,GLU,TC,TP and UERA(P>0.05).Mycotoxins supplementation has the tendece to improve the ALP content(P<0.1).Significantly increasing of GOT,GPT,ALP activities and TBIL concentrations were observed in AFB1+OTA+ZON group(P<0.05),and no difference was observed in other treated groups(P>0.05),but GOT,GPT,ALP activities and TBIL levels of AFB1+OTA group were higher than AFB1+ZON group.These results suggest that AFB1 combined with OTA and ZON made maximum effect on blood biochemical parameters in dairy goats and caused the most serious liver damage,AFB1 combined with OTA has a more severe liver damage than AFB1 combined with ZON.Supplemented with mycotoxins significantly decreased IgA level in serum(P<0.05)and has the tendence to improve the IL-6 concentration(P<0.1);but had no effected on serum levels of IgG,IgM,IL-2 and IL-4(P>0.05).The diets supplemented with two and three mycotoxins significantly decreased IgA concentration(P<0.05).IgA concentrations were descending as the following sequence:AFB1+OTA+ZON group,AFB1+OTA and AFB1+ZON group.IL-6 concentration in AFB1+OTA+ZON group significantly increased compared with control and AFB1 group(P<0.05);although no significantly difference was onserved between AFB1+OTA group and AFB1+ZON group,but IL-6 concentration AFB1+ OTA group was higher than AFB1 + ZON group.AFB1 combined with OTA and ZON had the greatest impact on immune function lessening,AFB1 combined with ZON hadn’t as much of an impact on immune function as AFB1 combined with OTA.Diet supplemented with various mycotoxins extremely significantly decreased SOD activity and increased MDA concentration(P<0.01),significantly decreased GSH-Px activity(P<0.05)and had tendence to decrease T-AOC activity(P<0.1).SODD、GSH-Px、T-AOC activity and MDA concentration in AFB1+OTA+ZON group significantly decreased compared with control(P<0.05);supplemented with ZON on the basis of AFB1 combined with OTA had no effect on SOD、GSH-Px、T-AOC activity and MDA concentration in serum(P>0.05);no different was observed between AFB1+ZON group and AFB1 group as well as control(P>0.05).SOD、GSH-Px、T-AOC activity and MDA concentrations were descending as the following sequence:AFB1+OTA+ZON group,AFB1 + OTA and AFB1 + ZON group,these results showed that AFB1 combined with OTA and ZON had largest impact on antioxidant capacity,followed by AFB1 combined with OTA and AFB1 combined with ZON.2.Effects of AFB1 on the serum metabolism in dairy goats.Experimental animals and experimental design was the same as the above.The control group and AFB1 group serum samples of each 10 at 7d which collected and stored in refrigerator were dissolved at room temperature.The principal metabolites in serum of AFB1 and control groups were analysised by nuclear magnetic resonance(NMR)method and the diversion of endogenous metabolites were tested with principal component analysis(PCA)and orthogonal signal correction partial least square discriminate analysis(OSC-PLS)respectively.Research indicates that content of lipoprotein,3-hydroxybutyrate,acetate,L-isoleucine,isoleucine,valine,lactate and choline was significantly decreased and citrate,glucose,betaine and glycine was significantly increased in AFB1 group when compared with controls(P<0.05).AFB1 produce toxicity to animals by the way of changing in lipid,amino acid metabolism and glycometabolism pathways.Overall,AFB1 combined with OTA and ZON decreased feed intake,milk production,metabolism,antioxidant ability,and immune function in dairy goats.Therefore,AFB1 combined with OTA and ZON induced most side effects of dairy goats,AFB1 combined with OTA had larger side effects on goats than AFB1 combined with ZON.AFB1 cause toxicity to animals by the way of changing in lipid,amino acid metabolism and glycometabolism pathways. |
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