Effects Of Attapulgite Growth Promoters On Growth Performance,Intestinal Development And Body Immunity Of Meat Ducks

A series of problems caused by long-term use of antibiotic growth promoters,such as increased bacterial resistance,drug residues,food hygiene and safety,have attracted widespread attention.Attapulgite is a kind of basic magnesium-aluminosilicate clay ore.There are a lot of pore structures distributed in the rod-like crystal of attapulgite,which has the properties of strong adsorption capacity,good colloid performance,strong ion exchange performance and salt and alkali resistance.Attapulgite as active material carrier combined with zinc oxide and carvol composite product has potential antibacterial and growth promotion effect.Therefore,attapulgite growth promoter was selected as a growth promoter in this study to study its effects on the growth,intestinal development and body immunity of meat ducks,evaluate its effectiveness and determine the optimal supplemental amount,so as to provide a theoretical basis for the application of this product in the production of meat ducks.The main research contents and results are as follows:1.Effects of attapulgite growth promoters on growth performance and slaughter performance of meat ducks.A total of 360 healthy one-day-old Cherry Valley ducks with similar body weight were randomly divided into 6 treatment groups with 6 replicates per group and 10 ducks per replicate.The control group was fed basal diet(no antibiotics added).Chlortetracycline group was fed the basal diet supplemented with 0.05 g/kg aureomycin.Attapulgite growth promoter group was fed basal diet supplemented with0.25 g/kg,0.50 g/kg,1.00 g/kg,2.00 g/kg attapulgite growth promoter with different dose gradients.The feeding period was 36 days.The results showed that compared with the control group,the average daily gain of meat ducks was increased by 8.72%,8.82%,0.73% and 7.43% in attapulgite growth promoter supplemental groups,respectively,and the best improvement effect was when the attapulgite growth promoter supplemental dose was 0.50 g/kg.Compared with the control group,the average daily feed intake was increased by 1.94% and 2.63% when the attapulgite base growth promoting dose was 0.25 g/kg and 0.50 g/kg,respectively.Compared with the control group,the feed/gain of each group was decreased by 6.33%,5.20%,3.38% and 13.92%,respectively.The feed/gain of each attapulgite growth promoter group was not significantly different from that of the chlortetracycline group(P>0.05).Compared with the control group,the death and scrubbing rate of attapulgite growth promoter groups decreased to different degrees.The results showed that attapulgite growth promoters had no significant effects on growth performance and slaughter performance of meat ducks(P>0.05).2.Effects of attapulgite growth promoters on intestinal development of meat ducksThe test design is the same as test 1.Compared with control group and chlortetracycline group,attapulgite growth promoter group significantly increased the duodenal index of meat ducks(linear,P=0.071;).However,attapulgite growth promoters did not significantly change the intestinal indexes of jejunum and ileum of meat ducks(P>0.05).Compared with the control group,attapulgite growth promoter group significantly increased the villus height of duodenum,jejunum and ileum,and significantly increased the velocious-secreted ratio of duodenum and jejunum(P<0.05).The effect was better when the added dose was 0.50 g/kg.Dietary attapulgite growth promoters significantly reduced the content of D-lactic acid in meat ducks compared with the control group(linear,P<0.001 quadratic P<0.001),there was no significant difference compared with the chlortetracycline group,and the effect was the most significant when the dosage was 0.50 g/kg.The activity of DAO in meat ducks was decreased by attapulgite growth promoter compared with control group(linear,P<0.001 quadratic,P=0.018).The results showed that dietary attapulgite growth promotors could promote the development of small intestine and protect the intestinal barrier function and integrity of meat ducks.3.Effects of attapulgite growth promoters on antioxidant capacity and body immunity of meat ducksThe test design is the same as test 1.There were no significant differences in spleen index,thymus index and bursa of Fabricius index between attapulgit-based growth promoter groups and control group and chlortetracycline group.Compared with the control group,attapulgite growth promoter group significantly increased the serum Ig G content of meat ducks(linear,P<0.001;quadratic,P=0.030),Ig M(quadratic,P=0.004),Ig A(linear,P<0.001)levels were not significantly different from those of the chlortetracycline group.Compared with the control group,attapulgite growth promoter significantly increased duodenum(P=0.001),jejunum(linear,P=0.013;quadratic,P=0.011)and ileal(linear,P<0.001;quadratic,P=0.029)and there was no significant difference in the number of goblet cells compared with the chlortetracycline group,with 0.50 g/kg as the best additive dose.Compared with the control group,attapulgite growth promoter significantly increased serum T-AOC of meat ducks(linear,P=0.002;quadratic,P=0.002),GSH-Px(linear,P=0.004)and T-SOD activity(quadratic,P<0.001)were not significantly different compared with the chlortetracycline group(P>0.05).Had no significant effect on MDA content(P>0.05).Compared with the control group and the chlortetracycline group,the supplementation of attapulgite growth promoter significantly increased the activity of T-AOC in jejunum of meat ducks(linear,P<0.001;quadratic,P=0.034);Compared with the control group,attapulgite growth promoter significantly increased the activity of T-SOD in jejunum of meat ducks(P<0.05),and significantly decreased the content of MDA(linear,P=0.010;Quadratic(P=0.020)and there was no significant difference(P>0.05)between the two groups.Compared with control group and chlortetracycline group,attapulgite growth promoter group significantly increased NO content in serum of jejunum of meat ducks(linear,P=0.020;quadratic,P=0.015)TNOS activity(linear,P<0.001;quadratic,P<0.001);There was no significant effect on i NOS activity(P>0.05).The results showed that the supplementation of attapulgite growth promoters could improve the antioxidant capacity,serum immunoglobulin and NO contents,increase the number of small intestinal goblet cells,and improve the immune performance of meat ducks.The optimal supplemental amount was 0.50g/kg.