Effects Of Garlic Essential Oil On Growth Performance,Cecum Flora And Immune Function Of Laying Hens Aged 0～8 Weeks

In this experiment,different concentrations of garlic essential oil were added to the drinking water of laying hens aged 0～8 weeks old to explore the effects of garlic essential oil on growth performance,intestinal tissue morphology,immune function,blood indexes and cecum flora of laying hens,which provided theoretical basis for the rational use of garlic essential oil in practical production.In this experiment,2001-day-old Agricultural University no.3-grain-saving laying hens with good health and similar weight were selected and randomly divided into 4 groups with 5 replicates in each group and 10 chickens in each replicate.Experimental group were fed basic diet.The garlic essential oil(drinking water)with the 0.04,0.06 and 0.08 mL/L was added to the experimental groupⅠ,Ⅱ and Ⅲ on the basis of the control group(without garlic essential oil),respectively.The experiment lasted for 56 d.The body weight and feed intake were recorded every week,and the chickens were slaughtered on the 28th and 56th day,respectively.Results showed that:compared with control group,(1)growth performance:garlic essential oil adding to the drinking water(Ⅰ,Ⅱ and Ⅲ group)significantly increased the average daily gain of 8 weeks old laying hens(P<0.01).Adding 0.06 and 0.08 mL/L garlic essential oil significantly improved the daily gain of 0-28 d laying hens(P<0.05),and decreased the ratio of feed to weight(P<0.01).Adding 0.06 mL/L garlic essential oil has the most obvious effect.(2)intestinal tissue morphology:adding garlic essential oil into the drinking water(Ⅰ,Ⅱ and Ⅲ group)significantly increased the villus height of ileum of 4 weeks old laying hens(P<0.01).Adding 0.06mL/L garlic essential oil into the drinking water significantly reduced the crypt depth of ileum of 4 weeks old laying hens(P<0.01),and significantly increased the villus height of duodenum and the ratio of villus height to crypt depth of ileum and duodenum of 4 weeks old laying hens(P<0.01).Adding 0.06 mL/L garlic essential oil into the drinking water significantly reduced the crypt depth of duodenum,jejunum and il of 8 weeks old laying hens(P<0.05),and significantly increased the ratio of villus height to crypt depth of duodenum and ileum of 8 weeks old laying hens(P<0.05).(3)In terms of immunity,adding 0.06 and 0.08 mL/L garlic essential oil into the drinking water significantly increased the serum immunoglobulin G content of 4 weeks old laying hens(P<0.01).In addition,adding 0.06 mL/L garlic essential oil significantly improved the spleen index(P<0.05).(4)In terms of blood biochemical indexes,adding 0.06 and 0.08 mL/L garlic essential oil into the drinking water significantly reduced the serum uric acid content of 4 weeks old laying hens(P<0.01),and significantly increased the superoxide dismutase activity of 4 weeks old laying hens(P<0.01 and P<0.05,respectively).Adding 0.04 mL/L garlic essential oil into the drinking water significantly reduced the uric acid content of 8 weeks old laying hens.Adding 0.06 mL/L garlic essential oil into the drinking water significantly reduced the malondialdehyde content(P<0.01),and significantly increased the glutathione peroxidase content(P<0.05)of 8 weeks old laying hens.Adding 0.08 mL/L garlic essential oil into the drinking water significantly reduced the malondialdehyde content of 8 weeks old laying hens(P<0.05).(5)In terms of cecum microorganisms:adding 0.06 mL/L garlic essential oil into the drinking water significantly increased the relative abundances of Alistipes and Phascolarctobacterium in cecum of 8 weeks old laying hens(P<0.05).Adding garlic essential oil into the drinking water had no significant effect on thymus index,the index of bursa of fabricius,immunoglobulin A,immunoglobulin M,total protein,albumin,glutathione peroxidase,malondialdehyde content,total cholesterol,triglycerides,high-density lipoprotein cholesterol low density lipoprotein cholesterol and jejunum villus height,crypt depth and the ratio of the villus height and crypt depth of 4 weeks old laying hens(P>0.05).Adding garlic essential oil into the drinking water had no significant effect on average daily feed intake,duodenum villus height,spleen index,the index of bursa of fabricius,thymus index,total cholesterol,triglyceride,total protein,albumin,high-density lipoprotein cholesterol,low density lipoprotein cholesterol,superoxide dismutase content of 8 weeks old laying hens(P>0.05).In conclusion,adding garlic essential oil to drinking water can improve the intestinal tissue morphology of the duodenum and ileum of laying hens aged 0～8 weeks,adjust the intestinal bacteria,and improve the immune function and antioxidant performance,and then improve the growth performance.In addition,the suitable concentration of garlic essential oil is 0.06 mL/L,which is recommended to be applied in practical production..