Effect And Mechanism Of Aging Corn And Rice Bran Oil On Performance,Antioxidative Status,Intestinal Physiology And Meat Quality Of Meat Duck

Corn is one of the most widely distributed food crops in the world.It is an important food accounts for 30% of the proportion of feed and economic crop in China and plays an important role in agricultural production in China.Since from 2017,China have been facing the problems of destocking of corn.A large amount of corn has to be added into feed production.However,the possible impact and mechanism of aging corn diets on animal production and health is still not clear thus,for this reason four experiments were carried out to evaluate the effect and mechanism of aging corn and rice bran oil(fresh vs oxidative)on performance,intestinal morphology and microbiota,antioxidative status,and meat quality of cherry valley male ducks.This study includes the following sections:Exp.1 Effect of soybean oil supplementation on growth performance,meat quality and antioxidative ability in meat ducks fed diets containing different levels of aging corn.This study investigated the effects of dietary aging corn with or without supplementation of soybean oil on performance,meat quality and antioxidative ability in meat ducks.A total of 768,one day old ducks were allotted randomly into 6 treatments with 8 replicates per treatment for 35 days(d)as follow: T1(0% aging corn and 0% oil),T2(0% aging corn and 3% oil),T3(50% aging corn and 0% oil),T4(50% aging corn and 3% oil),T5(100% aging corn and 0% oil)and T6(100% aging corn and 3% oil).Results showed that 50% aging corn replacing normal corn or addition of 3% soybean oil did not affect on duck growth performance.Although 100% aging corn replacing normal corn significantly(P < 0.05)decreased the feed intake(FI)from 15 to 35 d.However,the oil addition in 100% aging corn diet increased FI during 15 to 35 d,feed conversion ratio(FCR)at 15 to 35 d and 1 to 35 d.In contrast,the oil addition in non-aging corn diet increased FCR significantly(P < 0.05)during 1 to 14 d,while significantly(P < 0.05)decreased FCR from 15 to 35 d and 1 to 35 d.Aging corn levels with 50% and 100% resulted in breast meat color change with decreased of b* value at 35 d.Addition of oil in 100% aging corn significantly reduced the breast meat pH,a*,and b* value and skin L* value at 35 d.The aging corn and oil addition resulted in change of antioxidative enzymes e.g.CAT,SOD,TAOC and the concentration of MDA,may relate to the aging corn percent,duck age,and the interaction of aging corn and oil.In conclusion,the aging corn reduced FI with 100% aging corn from 15-35 d,while decreased the breast meat and skin color b* value with 50% and 100% aging corn,it could be associated to the oxidative stress by aging corn.The oil addition may increase the effects of aging corn on meat and skin color.Exp.2 Effects of fresh rice bran oil levels on performance,antioxidative status,intestinal morphology and microbiota,and meat quality in ducks fed a basal diet with aging cornThis present study investiagted the effects of fresh rice bran oil(FRBO)levels on performance,antioxidative status,intestinal morphology and microbiota,and meat quality in ducks fed a basal diet with aging corn.A total of 512,one-day old male ducks were randomly divided into four groups,including aging corn without oil(T1),aging corn+3% FRBO(T2),aging corn + 6% FRBO(T3),and aging corn +9% FRBO(T4)for 35 d.The results showed that supplementation of various levels of FRBO in aging corn diet significantly(P < 0.05)decreased FI during 1-35 d,and ducks fed 9% oil had lowest(P < 0.05)BW and 1-35 d nonsignificant(P > 0.05)effects on BW and BWG was observed due to addition of various levels of FRBO in aging corn diet.The carcass traits such as breast muscle weight and abdominal fat percentage showed significant(P < 0.05)increased due the supplementation of FRBO.The level of GSH-PX in serum,the activity of SOD in liver at 14 d was decreased(P < 0.05)by the supplementation of FRBO while CAT did not show any difference among the treatment in breast,serum and ileum at 35 d.The ileum villus height(VH)and VH/CD ratio was significantly(P < 0.05)increased with 3 and 9% FRBO at 35 d.However the various levels of FRBO significantly(P < 0.05)affect microbial communities at diversity alpha index,phylum and genus levels at 35 d of age.The alpha diversity metrics,observed,ChaoI,ACE shanon,simpson and PD were increased with 9% while decrease with 6%.In addition,relative abundance percentage of phylum and genus levels was changed by various levels of FRBO.Overall,the results revealed that 3% and 6% FRBO supplementation in aging corn diet lessen the effects in meat ducks while 9% FRBO decrease the growth performance from 1-14 d of age.Exp.3 Effect of aging corn and oxidative rice bran oil on performance,intestinal physiology and antioxidative ability in meat duckThe objectives of this experiment were to evaluate the effect of aging corn and oxidative rice bran oil on performance,intestinal physiology and antioxidative ability in meat duck.Ducks were distributed in to 32 pens with 16 birds per pen in a completely randomized design.The 2×2 factorial arrangement of treatments consisted of oxidized oil and corn type including normal corn(T1),aging corn(T2),normal corn with 6% oxidized rice bran oil(ORBO)(T3),and aging corn with 6% ORBO(T4)for 35 d.The results showed that the main effect of supplementation of ORBO in normal corn significantly(P < 0.05)increased the BW,BWG,FI and FCR from 1-14 d,but BW,BWG decreased from 15-35 and 1-35 d.However,by the supplementation of ORBO in aging corn diet significantly(P < 0.05)decreased FI while increased BW and BWG from 15-35 d and 1-35 d.In contrast,an interaction showed non-significant(P > 0.05)effects on overall growth performance.In the meantime the interaction in carcass traits,relative organs weight,intestinal pH,meat quality,breast muscle and leg muscle pH after 24 h,color parameters were non-significant.Whereas,the main effect in color of breast meat and skin in term of yellowness(b*)were significantly(P < 0.05)increased in aging corn diet supplemented with ORBO.The main effect of serum ALT at 14 d and TG were significantly(P < 0.05)decreased when ORBO were added in the diet.An interaction occurred in serum breast and ileum where ducks fed the diet with ORBO decreased the level of GSH-PX at 35 d.An interaction was noted for ileum morphology of VH and CD where the bird fed with ORBO in aging corn significantly(P < 0.05)decreased VH and CD during 14 and 35 d,while increased with ORBO in normal corn.An interaction was observed in short chain fatty acid of cecum,where the ducks showed that ORBO increased the ratio of acetic acid and butyric acid.The alpha diversity of caecal microbiota did not change at 14 and 35 d.An interaction was found in phylum and genus where levels of relative abundance of bacterial percentage were decreased by aging corn and oxidative oil.In conclusion,the results revealed that 6% ORBO supplementation in aging corn diet showed more adverse effects on meat quality by reducing oxidative ability and changing morphology of ileum in meat ducks.Exp.4 Effect of fresh and oxidative rice bran oil on growth performance,antioxidative ability,ileum physiology,and meat quality in meat ducksA study was designed from Exp.2 and 3 to compare the effect of supplementation of FRBO and ORBO on meat duck.Three treatments were choosing from exp.2 and 3 such as aging corn + 0% oil(T1),aging corn + 6% FRBO(T2),and aging corn + 6% ORBO(T3)to compared the results.The assumption establish that supplementation of ORBO to diet containing aging corn had no effect(P> 0.05 on performance,carcass traits,pH value,drip loss and color of meat,however,markedly decreased(P<0.05)the antioxidative ability,cecum acetic acid content,alpha-diversity of caecal microbiota,and the abundance of Bacteoidetes,Anaerotruncus,and Ruminiclostridium 5,while significantly increased(P<0.05)ileal morphology,and the abundance of Firmicutes compared to supplementation of FRBO to diet containing aging corn.These results suggested that ORBO could aggravate the negative effect of aging corn on meat ducks.In whole conclusion,100% aging corn replacing with normal corn in meat duck's diet could reduce the FI and meat quality;9% FRBO or 6% ORBO supplementation in diets with 100% aging corn aggravate the negative effect which may be associated with decreasing the antioxidative capacity,impairing the intestinal morphology,and changing the caecal microbiota on the basis of the four experiments.