Effects Of Dietary Hawthorn-Leave Flavonoids On Production Performance Of Breeder Hens And Development Of Intestinal Of Offspring Chicks

With the ban on antibiotics,poultry intestinal problems have become increasingly prominent.Gut health is the key to the efficient development of the poultry industry.The intestine is the main digestion,absorption and immune organ.Therefore,finding safe and effective plant extract feed additives is of great significance for livestock and poultry production.In this experiment,hawthorn-leave flavonoids（HF）was added to the diet of aged breeder hens to clarify the effect on reproductive performance of breeder hens and intestinal development of offspring.Experiment one:Effects of HF on reproductive performance of aged breeder hensThe experiment was conducted to investigate the impact of different doses of HF on ovarian function of breeder hens in the late egg-laying period.A total of 27060-week-old Qiling breeder hens were randomly divided into three treatments:（1）basic corn-soybean diet（CON）;（2）basic corn-soybean diet supplemented with 30 mg/kg HF（LHF）;（3）basic corn-soybean diet supplemented with 60 mg/kg HF（HHF）.The results showed that supplemental HF significantly improved the egg-laying rate and hatching rate of aged breeder hens（P<0.05）.HF treatment reduced the serum TG,T-CHO and L-LDL levels（P<0.05）,and up-regulated the mRNA expressions of ESR1,ESR2,VTGⅡ,ApoB and ApoⅥ in the liver（P<0.05）.The level of estrogen in the serum of HF treated groups were elevated compared with the CON group（P<0.05）.In the HHF group,the number of the primordial follicles were increased in comparison with the CON group（P<0.05）.Furthermore,dietary supplementation with HF improved the activity of antioxidant enzymes（T-AOC,GSH-P_χ）（P<0.05）,following with the reversed ovary apoptosis and morphological damage.In addition,60 mg/kg dietary hawthorn leaves flavonoids up-regulated the protein expression of PCNA and Nrf2 in ovary（P<0.05）.In summary,dietary supplementation with HF could improve the reproduction performance through regulating liver lipid metabolism and improving ovary function in aged breeder hens.Experiment two:Effects of HF on the shell gland of aged breeder hensThe aim of our study was to investigate the effects of dietary HF on the eggshell quality of aged breeder hens.In this study,each group randomly collected 18 fertilized eggs produced by breeders at the end of Experiment one.The results showed that supplemental HF significantly improved the thickness and strength of the eggshell（P<0.05）.In comparison with the CON group,serum levels of calcium were elevated and the mRNA expressions of CaBP-D28k,OPN and OC-116 in the shell gland of HF treated groups was up-regulated（P<0.05）.In the HHF group,the activity of Ca²⁺ATP enzyme was increased in comparison with the CON group（P<0.05）.HF treatment reversed the apoptosis rate of cells in the shell gland（P<0.05）and increased the length of villi in the shell gland and the density of glands（P<0.05）.Furthermore,dietary supplementation with HF improved the activity of antioxidant enzymes（MDA,GSH-P_χ）（P<0.05）.Moreover,HHF treatment down-regulated the protein expression of KEAP1,p-NFκB/NFκB and Bax/Bcl2（P<0.05）,and up-regulated the protein expression of Nrf2,HO-1 and PCNA（P<0.05）.In summary,60 mg/kg HF treatment group could enhance the antioxidant capacity of the shell gland by activating Nrf2/HO-1 signaling pathway,thus reducing the rate of apoptosis and improving the ability of calcium transport,so as to improve the eggshell quality of aged breeder hens.Experiment three:Effect of maternal HF on intestinal development of male offspringThe study was conducted to clarify the maternal effects of HF on the intestinal development of chicks.Fifteen breeding eggs（a total of 90 eggs）were randomly collected from per replicate for incubation.Maternal HF supplementation could increase the body weight of offspring chicks,which lasted for 28 days（P<0.05）.Similarly,HF treatments increased the VCR and PCNA expression in the jejunum of chicks（P<0.05）.Meanwhile,the protein expressions of IGF-1R,PI3K and p-mTOR in the jejunum（P<0.05）of 1-day-old and 14-day-old HF treated chicks were up-regulated in comparison with the CON group.Interestingly,maternal HF treatment up-regulated the mRNA expression of tight junction-related genes（ZO-1,ZO-2 and occludin）in the jejunum of 1-day-old chick（P<0.05）.Furthermore,the maternal effects of HF on ZO-1 expression could last for 14 days（P<0.05）.In summary,maternal HF supplementation promoted the intestinal development of chick through activating IGF-1R/AKT/mTOR signaling pathway,which might improve the growth performance of offspring.