Effects Of Organic Micro Mineral Addition On Growth Performance,serum Indexes And Intestinal Development Of Meat Ducks

As essential trace elements for animals,copper,iron,manganese and zinc play very important roles in maintaining body health and promoting growth.There are two forms of trace elements used in animal feeds,which are organic and inorganic.The utilization efficiencies of different forms of trace elements in animal organs are quite different,that the utilization rate of inorganic trace elements is significantly lower than that of organic trace elements.How to replace inorganic trace elements with organic trace elements in livestock and poultry production with high efficiency and low cost has become a hot issue in production and scientific research.The purpose of this experiment was to study the effects of different levels of organic compound trace elements on the growth performance,slaughter performance,serum indexes related to antioxidative and immunological capacities,intestinal development and cecal microbial diversity of cherry valley meat ducks,so as to provide data support for the scientific application of organic trace elements in meat duck breeding and feed production.525 0-day-old healthy cherry valley meat ducks were randomly divided into 5 treatments,with7 repetitions for each treatment and 15 for each repetition.The experimental period was 42 days.Based on the recommended trace elements(copper,iron,manganese and zinc are 8.0,60,100 and 60 mg / kg respectively)in《NY / T 2122-2012 meat duck feeding standard》,the control group was provided with copper,iron,manganese and zinc in the form of sulfate at100% of the recommended amount,and the four experimental groups were provided with copper,iron,manganese and zinc in the form of hydroxymethionine chelation at 25%,50%,75% and 100% of the recommended amount respectively.The test results showed that:1.There were no significant differences on average daily gain,average daily feed intake and survival rate of meat ducks among groups(P > 0.05).Compared with the control group,the feed weight ratios during 21 ～ 42 days and 1 ～ 42 days in the four organic groups decreased significantly(P < 0.05),and the feed weight ratios during 21 ～ 42 days and 1 ～ 42 days in the100% organic group were the lowest,which were 8.62% and 5.29% lower than that in the control group,respectively(P < 0.05).2.Compared with the control group,the slaughtering rate,half-eviscerated rate and eviscerated rate of the organic groups were increased,that 25% and 75% organic groups were significantly higher than those of the control group(P < 0.05).Different levels of organic micro minerals in the diet had no significant effects on the pectoral muscle rate,leg muscle rate,abdominal fat rate and tibial rate of the experimental ducks(P > 0.05).Compared with the control group,the pectoral muscle rate of the four organic groups increased 14.42%,7.35%,15.75% and 14.82% respectively(P > 0.05).3.There were no significant differences in the deposition of copper,iron,manganese or zinc in liver,chest muscle and tibia of 21 day old meat ducks(P > 0.05).The contents of copper and zinc in the liver of 42 day old meat ducks were the highest in the 75% organic group,which was significantly different from those of the control group(P < 0.05).The iron contents of breast muscle in all organic groups were higher than that in control group,and the iron content in 75% organic group was significantly higher than that in control group(P <0.05).The amount of iron depositions in tibia in 25% and 75% organic groups were significantly higher than that in control group(P < 0.05).4.Compared with the control group,there were no significant differences in the activities of T-SOD,Cu Zn-SOD,Mn-SOD,CAT and total antioxidant capacity in the serum of meat ducks at the age of 21 days in organic groups(P > 0.05).The activities of T-SOD and Cu ZnSOD in the four organic groups at 42 days old were higher than those in the control group.The activities of T-SOD in the 75% and 100% organic groups were significantly higher than those in the control group(P < 0.05),and the activities of Cu Zn-SOD in the 25%,75% and100% organic groups were significantly higher than those in the control group(P < 0.05).There were no significant differences in the serum activities of Mn-SOD,CAT and total antioxidant capacity of 42 day old meat ducks among groups(P > 0.05).5.The contents of C4,Ig A and Ig G in serum of 21 day old meat ducks were not significant different among groups(P > 0.05).The contents of Ig M in serum of 21 day old meat ducks in25%,50% organic groups and control group were significantly higher than that of 75% and100% organic group(P < 0.05).The contents of C3 in serum of 21 day old meat ducks in 100%organic group and control group were significantly higher than that of organic 75% group.The contents of C3 and Ig A in serum of 42 day old meat ducks were significantly higher than those in the control group(P < 0.05).The content of Ig G in serum of 42 day old meat ducks in 75%and 100% organic groups was significantly higher than that in the control group(P < 0.05).There were no significant differences in the contents of C4 and Ig M in serum of 42 day old meat ducks among the groups(P > 0.05).6.Compared with the control group,the intestinal density of 25%,50% and 100% organic groups were significantly higher(P < 0.05).There was no significant difference in villi height and recess depth of duodenum,jejunum and ileum among groups(P >0.05)7.The total number of OTUs owned by all groups was 436.There were 337 unique OTUs in the control group.The numbers of unique OTUs in the four organic groups were 28,57,20 and 25 respectively.At the phylum level,the top five dominant bacterial phyla of cecal microorganisms were: Bacteroidota > Firmicutes > Fusobacteriota > unidentified bacteria >Proteobacteria.The main dominant bacterial phyla were Bacteroidetes and Firmicutes,accounting for 80% ～ 90% of the total bacteria.At the genera level,the top 5 dominant bacterial genus of cecal microorganisms were: Bacteroides > Listipes > Streptococcus >Megamonas > Fusobacterium.There were no significant differences in Simpson index and Chao1 index of cecal microorganisms among groups(P > 0.05).The biological Shannon index of cecal chyme in 25% and 100% organic groups was significantly higher than that in control group and 50% organic group(P < 0.05).According to the PCo A diagram,the distributions of microorganisms among groups were relatively concentrated,and the species compositions were similar.However,the bata diversity index of the 50% organic group was significantly higher than that of the organic 25% and 100% groups.To sum up: completely replacing the nutritional needs of inorganic copper,iron,manganese and zinc with low levels of organic copper,iron,manganese and zinc in the diet would not have negative impacts on the growth performance of cherry valley meat ducks,but reduced the feed weight ratio during 21 ～ 42 days of age and the whole period,which improved the production performance and improved the antioxidant and immune performance of cherry valley meat ducks.It is beneficial to the development of small intestine of cherry valley meat duck by changing the composition and structure of cecal microbiota,and improving the digestion and absorption capacity of intestine.