Effects of dietary supplementation of hawthorn powder on growth performance，intestinal health，appetite peptide expression and serum antioxidant capacity of yellow feathered broilers

<bold>Objective</bold> Hawthorn，as a natural Chinese herbal feed additive，has functions such as improving palatability，enhancing feed utilization efficiency，and boosting the immunity of livestock and poultry.Research has shown that adding 1% hawthorn powder to feed can economically and efficiently significantly improve the production performance of livestock and poultry.This study aims to investigate the effects of adding 1% hawthorn powder to feed on the intestinal health status and appetite-related peptide expression in yellow-feathered broiler chickens，thus providing a theoretical basis for the scientific application of hawthorn powder in the healthy farming of yellow-feathered broiler chickens. <bold>Method</bold> Thirty-six 1-day-old healthy yellow-feathered broilers（cocks）were selected as experimental materials.According to the principle of similar body weight，they were randomly divided into 2 groups（control group and experimental group），with 6 replicates in each group，3 broilers per replicate，and raised in individual cages.The pre-feeding period lasts for 2 days，during which all broilers are fed the basal diet.From the age of 3 days，the control group was fed with basal diet，and the experimental group was fed with basal diet supplemented with 1% hawthorn powder（1% HP）.The feed intake was recorded every day for 28 days.The growth performance，intestinal morphology，intestinal integrity and appetite peptide-related gene expression，hypothalamic appetite peptide-related gene expression，and serum antioxidant indexes of broilers were detected and statistically analyzed. <bold>Result</bold> （1）Compared with the control group，the dietary supplementation of 1% HP significantly increased the final body weight（<italic>P</italic>&lt;0.05），average daily gain（ADG）（<italic>P</italic>&lt;0.05）and average daily feed intake（ADFI）（<italic>P</italic>&lt;0.05）of the yellow feathered broilers，and significantly decreased Feed/Gain Ratio（F/G）（<italic>P</italic>&lt;0.05）.（2）At 31 days of age，the duodenal and jejunal pH of yellow feather broilers in the 1% HP group were significantly lower than those of the control group（<italic>P</italic>&lt;0.05）.The duodenal morphology analysis showed that the villus height of the 1% HP group was significantly higher than that of the control group（<italic>P</italic>&lt;0.05），the depth of crypts was significantly lower than that of the control group（<italic>P</italic>&lt;0.05），and the ratio of villus height to crypt depth（V/C）was significantly higher（<italic>P</italic>&lt;0.05）.（3）The mRNA expression levels of tight junction proteins-1（<italic>claudin-1</italic>），<italic>occluding</italic>，and <italic>ZO-1</italic>，which are related to the maintenance of intestinal barrier integrity，did not differ significantly between the two groups.（4）The mRNA expression of glucagon-like peptide-1（<italic>GLP-1</italic>），an appetite suppressor，was significantly lower in the intestines of the 1% HP group compared with that of the control group（<italic>P</italic>&lt;0.05）.The mRNA expression of Peptide YY（<italic>PYY</italic>）also showed a trend of decrease（<italic>P</italic>=0.0609）.The mRNA expression of Cholecystokinin（<italic>CCK</italic>），which is an appetite suppressor，was significantly lower in the hypothalamus of the 1% HP group compared with that of the control group（<italic>P</italic>&lt;0.05）.The mRNA expression of Pro-opiomelanocortin（<italic>POMC</italic>）and Melanocortin 4 receptor（<italic>MC4R</italic>）also showed a tendency to decrease（<italic>P</italic>=0.0699，<italic>P</italic>=0.0758）.（5）The addition of 1% HP to the diet significantly increased the total antioxidant（T-AOC）capacity（<italic>P</italic>&lt;0.0001），superoxide dismutase（SOD）activity（<italic>P</italic>&lt;0.01）and catalase（CAT）activity（<italic>P</italic>&lt;0.05）in the serum. <bold>Conclusion</bold> Adding 1% hawthorn powder to feed rations can significantly improve the growth performance of yellow-feathered broilers，promote intestinal development and health，facilitate feed intake by down-regulating the expression of appetite-suppressing related genes in the intestinal tract and the hypothalamus，and significantly enhance the serum antioxidant capacity of the organism.