Effects Of Fatty Acids Calcium On Redox State And Immune Function In Stressed Broiler Chickens

Fatty acids calcium has a high energy level and a relatively low price,can be partially or completely replaced fat to be added to animal feed,increasing the energy concentration of the feed and reducing the production cost.In the past,reports on fatty acids calcium were mostly limited to ruminants,and there were few studies on adding fatty acids calcium to broiler feed.Fatty acids calcium can improve animals’ performance,antioxidant capacity and immune function.Heat stress and high-density feeding are common stress factors in broiler production.Excessive stress not only affects the performance of broilers,but also causes oxidative stress,intestinal damage and immunosuppression in broilers.In this experiment,we used a comprehensive stress model of high-density cage heat stress to add fatty acids calcium to the feed of yellow-feathered broiler chickens to study the production performance,redox state,immune function and intestinal function of fatty acids calcium in stressed broilers.The impact of experiment is that providing a reference for the broiler breeding industry to find efficient and low-cost oil substitutes.The experimental design is as follows:360 yellow-feather broilers with 1-day-age were randomly divided into 4 treatment groups: positive control group and stress group(soybean oil group,feeding lard group,fatty acids calcium group),and the oil added in each group was soybean oil(Con),soybean oil(S-oil),feed grade lard(Lard),fatty acids calcium(Ca-FA).The control group was in the flat-cultivation mode,and the temperature was controlled according to the conventional feeding mode.The stress model was a high-temperature and high-density cage stress model.Metabolic tests were performed at 19 days and 40 days,and daily feed intake,daily gain,body weight,feed-to-meat ratio,and apparent metabolic rate were measured.The broilers were sacrificed at 63 days of age and samples were collected.The effects of fatty acids calcium on stress broilers were evaluated from the body’s stress status,redox status,inflammation and intestinal function.Comprehensive stress reduced the weight of broilers,decreased daily weight gain,decreased daily feed intake,increased feed-to-meat ratio,decreased apparent metabolic rate,and decreased lipase activity.Feeding lard exacerbates the adverse effects of stress on broilers’ performance.Fatty acids calcium increased the body weight,daily gain and daily feed intake of stressed broilers,reduced the ratio of feed to meat,and increased the apparent metabolism of stressed broilers.Lipase activity did not increase.Compared with the soybean oil group,fatty acids calcium increased the body weight of the stressed broilers by 0-9 weeks and the daily gain of 27%,and reduced the ratio of feed to meat by 11%.The comprehensive stress increased the plasma CRH,ACTH and CORT levels in broilers,and the HSP70 levels in plasma,liver and jejunum of broilers were significantly increased,and HSP70 genes’ expression were up-regulated.Fatty acids calcium significantly reduced the levels of ACTH and CORT in broilers and the content of HSP70 in jejunum and plasma,and decreased the expression of HSP70 genes.Comprehensive stress increased plasma and liver pro-inflammatory cytokine levels and genes’ expression,decreased inflammatory cytokine levels and genes’ expression,decreased immunoglobulin levels and genes’ expression,anddown-regulated expression of defensin genes.Fatty acids calcium can reduce the levels of proinflammatory cytokines and genes’ expression in plasma and liver of stressed broilers,increase the levels of anti-inflammatory cytokines and genes’ expression,increase the level of immunoglobulins and genes,and increase the expression of defensin genes.The anti-inflammatory mechanism of fatty acids calcium may be related to the TLR4 signaling pathway.Comprehensive stress reduced the total antioxidant capacity of broiler chickens,increased the levels of ROS and MDA,decreased the activities of antioxidant enzymes and related genes such as CAT and GSH-Px,and increased the total antioxidant activity of stressed broilers.The ability to reduce ROS,MDA content,increase CAT,GSH-Px and other antioxidant enzyme activities and related genes’ expression.The antioxidant mechanism of fatty acids calcium may be related to the Nrf2 signaling pathway.Fatty acids calcium could reduce the expression of proinflammatory cytokines and related genes in the intestine,increase the expression of anti-inflammatory cytokines and their genes,increase the content of immunoglobulins and related genes,and improve the intestinal inflammation of stressed broilers.Fatty acids calcium could increase the antioxidant level of the intestinal tract of stressed broilers,enhance the expression of antioxidant-related genes,and improve the oxidative stress in the intestinal tract of stressed broilers.The intestinal barrier function was improved by up-regulating intestinal defensin genes’ expression and tight junction protein genes’ expression.The results showed that: fatty acids calcium had the effects of improving the performance of the broilers and improving broilers’ anti-stress ability,regulating the inflammatory state and redox state of the broilers,and improving the intestinal function of the stressed broilers.