The Effect Of Pine Bark Extracts On Growth Performance And Meat Quality Of Broilers And Screening Of Active Polyphenols

Pine bark contains volatile oil,polyphenols,polysaccharides,trace elements and other chemical components.It has been reported to possess a variety of biological functions such as bacteriostasis,antioxidant,anti-inflammatory and immunity enhancement,and it has a wide range of sources,and low price,so it has a good application prospect in animal feed.However,at present,the research on pine bark extract in livestock and poultry production is relatively small,which limits its reasonable use in livestock and poultry production to a great extent.In this experiment,the effects of pine bark extract on growth performance,meat quality and serum biochemical indexes of broilers were studied by adding different doses of pine bark extract in feed.The main active components were screened by macroporous resin and liquid chromatography tandem mass spectrometry,which provided a scientific basis for the rational use of pine bark extract in animal feed.In Experiment 1,252 1-day-old broilers were randomly divided into 3 treatments with 6replicates in each treatment and 14 broilers in each replicate.The control group was fed the basic diet,and the low-dose pine bark extract group and the high-dose pine bark extract group were fed the basic diet with 250 mg / kg and 1000 mg / kg respectively The experiment lasted for 51 days.The results showed that: 1)250 mg / kg pine bark extract significantly increased the average daily gain(ADG)of broilers in the early stage(1-21days)and the whole period(P < 0.05);1000 mg / kg pine bark extract significantly decreased the ADG and ADFI of broilers in the whole period(P < 0.05).2)Adding 250mg/kg pine bark extract to the diet significantly reduced the abdominal fat rate of broilers(P<0.05),and increased the content of high-density lipoprotein cholesterol(HDL-C)and albumin(ALB)in the serum(P<0.05).0.05);the addition of 1000mg/kg pine bark extract significantly increased the content of free fatty acids(FFA)and ALB in the serum(P<0.05).The addition of 250 mg/kg pine bark extract to the diet significantly reduced the LDL-C content of liver low-density lipoprotein cholesterol(P<0.05).3)Adding 250mg/kg or1000mg/kg pine bark extract has the tendency to reduce malondialdehyde(MDA)and increase the total antioxidant capacity(P<0.10).4)adding 250 mg / kg pine bark extract to the diet could increase the total antioxidant capacity Mg / kg pine bark extract increased the p H value of leg muscle(P < 0.05),decreased the water loss rate of leg muscle(P < 0.05)and MDA content of leg muscle(P < 0.05);adding 250 mg / kg or 1000 mg / kg pine bark extract could reduce the drip loss of chest muscle(P < 0.05).In Experiment 2,the pine bark extract was divided into three parts: 20% ethanol elution,40% ethanol elution and 60% ethanol elution.It was found that 40% ethanol elution had the best scavenging effect on DPPH,but 20% ethanol elution contained more active substances such as protocatechuic acid,ethyl gallate,rosmarinic acid and proanthocyanidins,which may be related to the growth of porcine intestinal epithelial cells.In conclusion,dietary supplementation of 250 mg / kg pine bark extract can improve growth performance,enhance antioxidant capacity,improve lipid metabolism and meat quality of broilers.The main potential active substances include protocatechuic acid,ethyl gallate,rosmarinic acid and proanthocyanidins.