Effect Of Dietary Ferrous Glycine Supplementation On Growth Performance、Carcass Quality And Intestinal Health Of Meat Ducks

Researches have indicated that the addition of ferrous sulfate（Fe SO₄）can improve the growth performance and intestinal development of meat ducks,and the organic iron source（ferrous glycine,Fe-Gly）has numerous merits such as stable chemical structure and high biological potency,etc.,which may make the addition effect better.However,the effect of adding Fe-Gly on the growth performance,carcass quality and intestinal health of meat ducks is still unclear.The present study was designed to investigate the effects of dietary Fe-Gly on production performance and intestinal development of meat ducks.A total of672 one-day-old Cherry Valley ducks were allotted into 6 groups according to the principle of no difference in body weight.The ducks were fed with the diets containing 0（basic group）,30,60,90,120 mg/kg Fe-Gly and 120 mg/kg Fe SO₄（All in Fe）respectively.a five-week feeding trial and one-week metabolic trial were carried out.The results were as follows:（1）With the Fe-Gly supplementation level increased,35 d BW,15-35 d ADG,15-35 d and 1-35 d ADFI of meat ducks were markedly increased（P<0.05）,and the 90 mg/kg Fe-Gly group was optimum;However the 15-35 d and 1-35 d F/G in 30 mg/kg Fe-Gly group were significantly lower than those in the basic group（P<0.05）.And the 1-35 d ADFI,15-35 d and 1-35 d F/G in 120 mg/kg Fe-Gly group were noticeably superior to those in 120 mg/kg Fe SO₄ group（P<0.05）.（2）With the Fe-Gly supplementation level increased,the HB、HCT and MCV of meat ducks on 35 d were dramatically increased（P<0.05）.（3）With the Fe-Gly supplementation level increased,the apparent utilization of energy,crude fat and dry matter in meat ducks on 35 days were remarkably improved（P<0.05）.（4）Compared with the basic group,the eviscerated percentage,half eviscerated percentage and breast muscle percentage in 30 mg/kg Fe-Gly group were significantly increased（P<0.05）;The p H 45 min of breast muscle and p H 24 h of thigh muscle were markedly improved,while the shear force of thigh muscle substantially decreased in 120mg/kg Fe-Gly group;the p H 24 h and shear force of thigh muscle in 120 mg/kg Fe-Gly group were remarkably superior to those in 120 mg/kg Fe SO₄ group（P<0.05）.（5）Intestinal development and health:（1）Compared with the basic group,the jejunum and ileum absolute weight in 90mg/kg Fe-Gly group were noticeably increased on 35 days（P<0.05）;With the Fe-Gly supplementation level increased,the duodenum,jejunum and ileum absolute length were dramatically increased（P<0.05）,the duodenum,35 d jejunum and 14 d ileum relative length were appreciably improved（P<0.05）;and the duodenum,35 d jejunum and 14 d ileum relative length in 120 mg/kg Fe-Gly group were distinctly superior to those in 120mg/kg Fe SO₄ group（P<0.05）.（2）With the Fe-Gly supplementation level increased,the activity of T-AOC and CAT in jejunum and the activity of SOD in ileum were remarkably increased（P<0.05）;the activity of lipase and trypsin of ileum in 30 mg/kg Fe-Gly group were dramatically higher than those of the basic group（P<0.05）.（3）With the Fe-Gly supplementation level increased,the villus height of jejunum and the ratio of villus height to crypt depth of jejunum and ileum were notably improved（P<0.05）;（4）Dietary Fe-Gly supplementation remarkably increased the relative abundance of Firmicutes（P<0.05）,but dramatically decrease the relative abundance of Bacteroidetes（P<0.05）,meanwhile alter the cecal microbial composition,add the dominant bacteria such as Ruminococcus torques group,and increase theαandβdiversity index（P<0.05）.（5）Dietary Fe-Gly supplementation noticeably decreased the m RNA expression level of CLAUDIN2 and OCCLUDIN（P<0.05）,however markedly upregulated the gene expression of ZO-1,ZO-2,CLAUDIN 1,MUC2,LYZ and p Ig R in jejunum of meat ducks on 35 days（P<0.05）.The results indicated that optimal level of Fe-Gly in diet improved intestinal morphology,intestinal flora and intestinal barrier function,promoted nutrients utilization,thereby improved production performance of meat ducks.The addition of Fe-Gly was better than Fe SO₄ on the growth performance,meat quality and intestinal length.The phenotypic indicators of growth performance showed that the optimum dietary iron addition level of meat ducks is 60 mg/kg,which was close to the appropriate iron addition amount determined by using the apparent utilization of dry matter as the effect indicator.