Effects Of Dietary Lipid On The Growth,Metabolism,and Immunity Of Broiler Chickens

The relationship between fat metabolism and immune function of poultry is closely.By feeding normal high-fat diets(1-21 d,ME = 12.34MJ/kg;22-42 d,ME = 12.76 MJ/kg)and mixed oisl diets to research the fat intake and fatty acids(monounsaturated fatty acids,polyunsaturated fatty acids and short chain fatty acids)effect on growth performance,metabolism and immunity by feeding normal high-fat diet and mixed oils to further clarify the regulatory mechanism of oil type and level of healthy poultry production,in order to provide new ideas and methods for the efficient use of dietary fat.In Experiment 1,we studied the effects of nomal high-fat diet on growth,metabolism and immunity of broilers.100 broilers aged 1 days were randomly divided into 2 groups.5replicates in each group,and 10 chickens each.The experiment was divided into three periods:prophase(1-14day),middle(15-21day)and late(21--38day).The control group was fed normal diet.experimental group was fed with normal high-fat diet,and the samples were sampled at 14,21 and 38 d respectively,sample blood,thymus,spleen,bursa of fabricius,duodenum,jejunum,ileum,cecum samples.On spleen weight and spleen index and inflammatory signaling pathways related gene expression,feeding high-fat diet group is significantly higher than feeding on a normal diet group(P < 0.05),blood triglyceride level is significantly lower than feeding on a normal diet group and has no effect on the content of blood glucose(P > 0.05)feeding high-fat diet significantly reduces the villus/crpyt of duodenum(P < 0.05).The results showed that high fat diet was not the reason of hyperglycemia or hyperlipidemia.Prolonged feeding of high-fat diet could activate inflammatory signaling pathway and inhibit the development of small intestinal mucosa.Experiment two studied the effects of mixed oils on growth,metabolism and immunity of broilers.540 male AA broilers aged 1 days were randomly divided into 9 groups,6replicates in each group,and 10 chickens each.The experiment was conducted at two feeding stages(1-21day)and 22-42(day)Adding 2% and 3% respectively in the feed.The first group and the second group was the control group witch fed soybean oil and duck oil.The 3-9 group was the experimental group which were fed with the mixed coconut oil,soybean oil and duck oil mixed fat respectively.At the end of each feeding phase(21 and 42 days of age),eachrepeated selection of 2 chickens was slaughtered.Sample blood,the thymus,liver,spleen,bursa of fabricius,duodenum,jejunum,ileum,cecum chyme,leg muscle and chest muscle samples take organs weight.Detecting blood biochemistry,intestinal morphology,caecum microorganism,liver fat metabolism related indicators.The results showed that at the early stage,compared with the other groups,soybean oil group has significant differences in body weight(P < 0.05),feed intake and feed conversion ratio have no difference(P > 0.05),body weight and duodenum weigh index has obvious difference(P < 0.05),other organs index has no obvious difference(P > 0.05),at the early stage mixed oil does not affect the early liver fat metabolism and intestinal inflammation(P > 0.05).At the late stage,body weight gain,feed intake and feed conversion ratio have no difference(P > 0.05),coconut oil accounted for a larger proportion of group,abdominal fat index significantly increased(P < 0.05),thymus index has a downward trend,blood TG,VLDL,LPL,NEFA,liver triglycerides and liver fat metabolism related genes significantly increased(P < 0.05),Intestinal villus/crypt is significantly higher than the proportion of coconut oil that are lower than coconut oil accounted for a larger proportion of group and the single oil,cecum probiotics rise and reduce the number of pathogens.The second experiment showed that at early age single fat(soybean oil or duck oil)enhanced performance of production and promoted tissue development.At late age Mixed oils which coconut oil had big-density can promote the development of intestinal mucosa and improve the microbial composition of caecum,but also increase the accumulation of abdominal fat and reduce the index of immune organs.Above all,too much fat is bad for growth and development of poultry,mixed oil is more advantageous to the growth and development of broilers.