| The aim of this thesis was to study the effect of sheep eating AFB1-contaminated diets on their growth performance and organism health status,and to further investigate the inhibitory effect of dietary supplementation with microecological preparations and glucose oxidase on AFB1 toxicity.Experiment 1: Ten Mongolian sheep were selected and randomly divided into 2groups of 5 animals each according to the principle of non-significant difference in body weight.the control group was fed the basal diet;the toxin group was supplemented with0.2 mg/kg AFB1 in the basal diet;the experiment was divided into a pre-feeding period and a formal period,with a pre-feeding period of 7 d and a formal period of 28 d.The formal period was further divided into two phases: the toxin feeding period(0-14 d)and toxin clearance period(15-28 d).The results of the experiment showed that.1.AFB1 significantly reduced mean daily feed intake and average daily gain during the toxin feeding period(P<0.01),significantly decreased average daily feed intake during the toxin removal period and the whole period(P<0.05),and significantly increased feed conversion ratio during the whole period(P<0.05).2.AFB1 significantly increased IL-6 and TNF-α levels at the end of the toxin feeding period(P<0.05);AFB1 significantly decreased Ig M levels(P<0.05),highly significantly increased SAA levels(P<0.01),and significantly increased CRP levels(P<0.05)by the seventh day of the toxin clearance period.3.AFB1 caused a highly significant decrease(P<0.01)in serum T-AOC activity and GSH/GSSG values;a significant decrease(P<0.05)in CAT,SOD,GSH-Px and GSH activities;and a highly significant increase(P<0.01)in GSSG activity at the end of the toxin feeding period.At the seventh day of the toxin clearance period,T-AOC,GSH-Px activity and GSH/GSSG values in the serum of sheep in the toxin group were highly significantly decreased(P<0.01);CAT and GSH activities were significantly decreased(P<0.05);and GSSG activity was highly significantly increased(P<0.01).4.AFB1 caused a highly significant increase(P<0.01)in DBIL;a significant increase(P<0.05)in TBIL;a highly significant decrease(P<0.01)in ALB;and a significant decrease(P<0.05)in TP and GLU in the serum of sheep.On the seventh day of toxin clearance period,the AST level in the serum of sheep in the toxin group increased highly significantly(P<0.01)and the ALP level increased significantly(P<0.05).5.AFB1 highly significantly increased toxin residues in sheep serum during the toxin feeding period and seven days of toxin clearance(P<0.01).Experiment 2: twenty Mongolian sheep were selected and randomly divided into 4groups of 5 animals each according to the principle of non-significant difference in body weight.The control group was supplemented with 0.2 mg/kg AFB1 in the basal diet;group I was supplemented with 0.5% microecological preparation on top of the control group;group II was supplemented with 0.5% glucose oxidase on top of the control group;group III was supplemented with 0.5% microecological preparation and 0.5% glucose oxidase on top of the control group.The trial was divided into a pre-feeding period and a formal period,with a pre-feeding period of 7 d and a formal period of 28 d.The formal period was divided into two phases: the toxin feeding period(0-14 d)and the toxin removal period(15-28 d).The results of the experiment showed that:1.At the end of the toxin feeding period,compared with the control group,average daily gain was highly significantly elevated in groups I and II(P<0.01);at the end of the toxin removal period,average daily gain was highly significantly elevated in group III(P<0.01);from the whole period,average daily gain was highly significantly elevated in groups I,II and III(P<0.01),and the feed conversion ratio was highly significantly reduced(P<0.01).2.At the end of the toxin feeding period,compared with the control group,the Ig G,IL-1β and IL-6 contents were highly significantly increased in group II(P<0.01),Ig M contents were significantly increased in groups I,II and III(P<0.05),IL-2 contents were highly significantly increased in groups I and II(P<0.01),and SAA contents were significantly increased in group II(P<0.05).On the seventh day of the toxin clearance period,Ig A,SAA,IL-1β and TNF-α contents were highly significantly elevated in group II(P<0.01),Ig G,IL-2,IL-6 and IL-10 contents were significantly elevated in group II(P<0.05),and Ig M contents were highly significantly elevated in groups I,II and III(P<0.01).3.At the end of the toxin feeding period,compared to the control group,T-AOC activity and GSH/GSSG ratio were significantly increased in group III(P<0.05),CAT and SOD activities were highly significantly increased in groups I,II and III(P<0.01),and GSH-Px activity was significantly increased in group II(P<0.05).On the seventh day of the toxin removal period,T-AOC activity increased significantly(P<0.05)in group III,SOD activity increased highly significantly(P<0.01)in groups I,II and III,GSH-Px,GSH activity and GSH/GSSG ratio increased significantly(P<0.05)in group II,and MDA content decreased significantly(P<0.05)in groups I and III.4.At the end of the toxin feeding period,compared to the control group,the ALT content was highly significantly decreased in groups I,II and III(P<0.01),the AST and ALP content was significantly decreased in group II(P<0.05),the TBIL content was significantly decreased in groups I and II(P<0.05),and the DBIL and LDH content was highly significantly decreased in groups II and III(P<0.01).On the seventh day of the toxin clearance period,the AST content in group II decreased significantly(P<0.05),and the ALP and TBIL content in groups I,II and III decreased extremely significantly(P<0.01).5.At the end of the toxin feeding period,the toxin residues in the serum of sheep in groups II and III were highly significantly reduced compared to the control group(P<0.01);on the seventh day of the toxin removal period,the toxin residues in the serum of sheep in groups I,II and III were significantly reduced(P<0.05).In conclusion,AFB1 has a great impact on the production performance,immune index,antioxidant index,blood biochemical index,and toxin residues of sheep,and the addition of microecological preparations,glucose oxidase,and the combination of both to the diet will improve the growth performance and body health of sheep to some extent,and thus can be added to the sheep diet as an effective detoxification agent. |
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