| Conjugated linoleic acid(CLA)has anti-cancer,prevent obesity,regulate immunity and prevent cardiovascular diseases.How to improve CLA content in ruminant meat has become a research hotspot for researchers.Animal species,physiological conditions and dietary composition may affect the CLA content of the animal.The diet as a material for growth and metabolism directly provides linoleic acid(LA),an important raw material for the synthesis of CLA.Some LA directly synthesizes CLA in the rumen and is absorbed by the small intestine.A part of LA undergoes a series of biochemical reactions in the rumen to produce TVA,which is absorbed by the rumen wall and small intestine,and reacts with related enzymes in the body to form CLA.The purpose of this study was to explore the effects of soybean oil as feed additive on growth performance,slaughter performance,meat quality and fatty acid synthesis of Guizhou Black goat by adding soybean oil to regulate the content of LA in Guizhou Black goat diet during the growing period,in order to explore the effects of soybean oil as feed additive on the growth performance,slaughter performance and fatty acid synthesis of Guizhou Black goat.In addition,Butyrivibrio fibrisolvens,as an important fatty acid metabolism bacteria in ruminants,will indirectly affect the synthesis of CLA in ruminants.The effect of LA on the growth and metabolism of Butyrivibrio fibrisolvens isolated from Guizhou black goat was also studied by adding LA to culture in vitro.The changes of microstructure,fatty acid metabolism,nucleotide content and LA utilization rate of Butyrivibrio fibrisolvens in different levels of LA medium were observed.Experiment 1: The effects of different dietary LA supplementation levels on the growth performance and conjugated linoleic acid deposition of Guizhou black goat during the growing period.Twenty-four Guizhou black goat(ram)of 5-6 months old,which were healthy and weighing basically the same(18.3 ±2.5kg),were randomly divided into 4 groups(control group,experiment group 1,experiment group 2 and experiment 3),with 6goats in each group.Soybean oil was used as the regulator of LA content,and different levels of concentrate and whole plant silage corn were fed with different soybean oil for comparative experiment.The addition level of soybean oil in the diet of experimental goats was 2% in group 1,3% in group 2,4% in group 3 and not in the control group,and the addition level of soybean oil was 2% in group 1,3% in group 2,4% in group 3 and no addition in control group.The dosage of LA in each group was about 1% in group 1,1.5% in group 2,2% in group 3 and no addition in control group.The trial period was 60 days,including 15 days of pre-trial period and 45 days of ongoing trial period.At the end of the trial period,the growth performance,slaughter performance and conjugated linoleic acid content were determined.the results were as follows:(1)Effect on growth performance: there was no significant difference in dry matter intake of concentrate,dry matter intake of silage maize and total dry matter intake among the experimental goat(P>0.05).63.1g/d in average daily gain test group3 was significantly higher than that in other test combinations.In the control group(P<0.05),group 2 was significantly higher than that in group 1 and control group(P<0.05),but there was no significant difference between the control group(P<0.05),but the feed weight in the control group was significantly higher than that in the other experimental groups(P<0.05).(2)Effect on slaughter performance:There were no significant differences in live weight,carcass weight,slaughter rate,backfat and eye muscle area among the three groups(P>0.05).The percentage of KPHfat test group 3 was significantly higher than that of other test groups and control group(P<0.05),KPHfat percentagewas no significant difference between group 3 and group 2(P<0.05),but significantly higher than that in group 1 and control group(P<0.05),However,there was no significant difference between group 1 and group 2(P>0.05).(3)Effect on meat quality: There was no significant difference in pH,drip loss and shear force between the two groups(P>0.05).The L* value of the meat color of the test group was significantly higher than that of the control group 3(P<0.05).There was no significant difference between the experimental group and the control group(P>0.05).The a* value of the meat color of the test group was significantly higher than that of the other groups(P<0.05).The difference between the other groups was not significant(P>0.05);the color b* There was no significant difference between the groups(P>0.05).(4)Effect on the content of fatty acids in plasma,muscle and subcutaneous fat.C18?c9,t11 in plasma of the experimental groups were significantly higher than those of the control group(P<0.05),but there was no significant difference among the experimental groups(P>0.05).There was no significant difference in C18?t10,c12 content between group 2 and group 3.The total content of conjugated linoleic acid in the experimental groups was significantly higher than that in the control group(P<0.05),but there was no significant difference among the experimental groups(P>0.05).According to the types of fatty acids,there was no significant difference in the contents of saturated fatty acids,monounsaturated fatty acids and polyunsaturated fatty acids between the experimental groups and the control group(P>0.05).C18?c9,t11 in muscle of the experimental group was significantly higher than that in the control group(P<0.05),but there was no significant difference among the experimental groups(P>0.05).The content of C18 ? t10,c12 in the experimental groups was significantly higher than that in the control group(P<0.05),and that in the experimental group 3 was significantly higher than that in the other experimental groups(P<0.05).There was no significant difference between the experimental group1 and the experimental group 2(P>0.05).The total content of conjugated linoleic acid in each experimental groups was significantly higher than that in the control group(P<0.05),but there was no significant difference among the experimental groups(P>0.05).In terms of fatty acid type composition,There was no significant difference in saturated fatty acid and monounsaturated fatty acid content between the experimental groups and the control group(P>0.05).The content of polyunsaturated fatty acids in the experimental groups was significantly higher than that in the control group(P<0.05),and the content in group 2 was significantly higher than that in the other experimental groups(P<0.05).There was no significant difference between the two groups(P>0.05).C18?c9,t11 in subcutaneous of the experimental groups was significantly higher than that in the control group(P<0.05),but there was no significant difference among the experimental groups(P>0.05).The content of LA in the experimental groups was significantly higher than that in the control group(P<0.05),and that in the experimental group 3 was significantly higher than that in the other experimental groups(P<0.05).There was no significant difference between the experimental group1 and the experimental group 2(P>0.05).The total content of conjugated linoleic acid in each experimental groups was significantly higher than that in the control group(P<0.05),but there was no significant difference among the experimental groups(P>0.05).In terms of fatty acid type composition,There was no significant difference in saturated fatty acid and monounsaturated fatty acid content between the experimental groups and the control group(P>0.05).The content of polyunsaturated fatty acids in the experimental groups was significantly higher than that in the control group(P<0.05),and the content in group 2 was significantly higher than that in the other experimental groups(P<0.05).There was no significant difference between the two groups(P>0.05).Experiment 2: Adding 13 C labeled LA to Butyrivibrio fibrisolvens in vitro anaerobic culture.Butyrivibrio fibrisolvens strains isolated and purified from the rumen of Guizhou black goats were cultured in vitro.12 media were randomly divided into 4 groups,3media in each group,and 2.5 mg 13C-labeled LA was added to the test group 1culture;test 2 The group added 5mg13C-labeled LA;the test group 3 added7.5mg13 C labeled LA;the blank group did not add LA,after 24 h culture,collected bacteria for detection.The results are as follows:(1)Effect on the microstructure of bacteria: the bacilli of bacteria in each number medium of each group were slightly curved(partially erect)at about 3 microns under scanning electron microscope,all of which were single cells and filamentous bodies could be seen.In accordance with the description of Berger's Manual of bacterial Identification(eighth Edition),there was no significant morphological difference among the bacteria in each test group.The bacteria in each group could normally recognize the cell structure under transmission electron microscope,but there was no significant difference in cell wall,cell membrane,cytoplasm and nucleosome among the bacteria in each group.Compared with the control group,there was no significant difference in morphology.(2)Effect on fatty acid content: in the detection of 35 fatty acids,C8:0?C11:0?C14:0?C15:0?C17:0?C17:1?C18:1n9?C18:2n6?C18:3n6?C20:0?C20:2?C20:3n3?C20:3n6?C20:5n3?C21:0?C22:0 and C22:6n3,With the increase of the concentration of LA in the medium,There was no significant difference between the two groups(P>0.05),but the synthesis of C10:0?C12:0?C16:0?C18:0?C20:4n6?C23:0 and C24:1 decreased significantly with the increase of LA content(P<0.05).The synthesis of C15:1?C18:3n3 and C16:1 was significantly higher than that of other level groups at 2.5mg level(P>0.05),and the synthesis of C14:1 in experiment 1 was significantly higher than that in other level groups(P>0.05).The amount of LA in the experimental group was significantly higher than that in the other experimental groups(P<0.05).The synthesis of C24:0 was significantly higher than that of other levels when the content of LA was increased with the increase of 7.5mg content(P<0.05),and the synthesis of C24:0 was significantly higher than that of other groups(P<0.05).(3)The effect on nucleotide content: different LA concentration medium had no significant effect on the synthesis of CMP,CMP and GMP by Butyrivibrio fibrisolvens(P>0.05).(4)Effect on LA utilization: the 13 C abundance of Butyrivibrio fibrisolvens cultured in 13 C labeled LA medium was significantly higher than that in the control group(P<0.05).However,there was no significant difference among 13 C labeled LA media(P>0.05).To sum up,the increase of CLA in animal meat products can be realized byadding soybean oil to the diet of Guizhou black goat during the growing period to regulate the LA content.when the amount of soybean oil is 3%,the daily gain can be increased.At the same time,increasing the content of LA in diet could increase the utilization rate of LA for Butyrivibrio fibrisolvens,and had no significant effect on its growth and metabolism. |
PDF Full Text Request