A Comparative Study On The Effects Of Heterologous Carotenoids On The Early Growth And Intestinal Development Of Chickens

Carotenoids,as a natural biologically active substance,have a variety of biological functions.Our previous research has proved that it has antioxidant capacity and enhances the immunity of livestock and poultry.However,Because carotenoids are primarily produced by Haematococcuspluvialis,they are food-grade products after purification.It is cost-consuming oncethey are used as animal feed additives.Therefore,in this experiment,we added carotenoids from different sources(carotenoids from red yeast and carotenoids from Haematococcuspluvialis)to feed chicks of Hailan brown to study the effects of carotenoids on the growth performance,immunity,antioxidant capacity and intestinal morphology of Hailan brown chicks from different sources.The study aims to widen the application of carotenoids as a functional feed additive and to enhance the possibility of applying in the field,thus providing practical and theoretical basis for its production performance on laying hens,improving antioxidant capacity and immunity of laying hens,and promoting intestinal development.A total of 297 1-day-old Hailanbrown egg chicks were randomly divided into 3 groups,3 replicates in each group,and 33 chicks in each group.They were control group and Red yeast source carotene group(red yeast producing carotenoid group),algae source carotene group(the production of carotenoids from Haematococcuspluvialis).The blank control group was fed the egg basal diet,and the red yeast source carotenoid group was fed the egg basal diet containing the red yeast culture,The algae-carotene group was fed a basic diet of egg chicks containing a group of carotenoids derived from Haematococcuspluvialis.Theexperiment lasted 4 weeks.At the end of experiment,the slaughter samples were taken.The growth performance,blood immunity and antioxidant index and small intestine morphology of the chicks in each group were tested.The results showed that:1.There was no significant difference in feed-to-meat ratio,body weight and tibia length between the groups at 1-4 weeks of age(P>0.05),indicating that carotenoids from different sources had no significant effect on the growth and development of chicks.2.In the study of immune organ development and immune function,itwas found that there was no significant difference in immune organ index after heterologous carotenoid treatment compared with the blank control group.:Compared with the blank control group,the IgA content in the serum of the red yeast source carotene group and the algal source carotenoid group was significantly increased(P<0.05).The IgG content in the blood of the red yeast group and the carotene group was significantly lower(P<0.01),and the IgM content was significantly increased(P<0.05).It indicates that carotenoids from different sources have no significant effect on the development of immune organs in chicks,but have an effect on the increase of immunoglobulin content in blood.3.In the observation of antioxidant index,it was found that the content of catalase(CAT)and superoxide dismutase(SOD)in carotenoid group was significantly increased(P<0.05),and glutathione in carotenoid group produced by red yeast Glycopeptide peroxidase(GSH-PX)and malondialdehyde(MDA)were significantly decreased(P<0.05),indicating that the carotenoids that are not passed may reduce the damage of the body of Hailan brown eggs.degree.4.In the observation of intestinal development indicators,it was found that the duodenal gonads of the algae-carotene group were significantly higher than the blank control group(P<0.05),but not significantly different from the red yeast source carotene group(P>0.05);the red yeast source carotenoid group and the algae source.The ratio of jejunum and ileum in the carotene group was significantly higher than that in the blank control group(P<0.05).It indicated that the addition of carotenoids in the diet to the diet enhances the ability of the intestinal tract to digest and absorb nutrients by increasing the ratio of duodenum,jejunum and ileum of Hyline brown chicks.5.The results of small intestine IgA+cells showed that the number of IgA+cells in the duodenum,jejunum and ileum of the red yeast source carotenoid group and the algae source carotene group was significantly higher than that of the blank control group,among which the red yeast source carotenoid group and the algae source carrot.The number of IgA+cells in the duodenum and jejunum of the group was significantly higher than that of the blank control group,indicating that the addition of heterologous carotenoids in the diet could improve the intestinal immunity of the chicks.In summary,the addition of heterologous carotenoids has a positive effect on the production performance,immune index,antioxidant index and intestinal development of Hailan brown egg chicks,among which the chicks in the red yeast source carotenoid group have immune function and the effect on intestinal development is similar to that of the algae-carotene group.Therefore,it is feasible to replace the carotenoid produced by Haematococcuspluvialis with a carotenoid produced by a lower cost red yeast...