| The extensive metabolism of amino acids in tissues and organs,especially portal vein reflux tissue,is an important reason for the high nitrogen emissions in pigs.From the point of view of this,finding alternative fuels for oxidative metabolism of amino acids has become an important measure to reduce pig nitrogen emissions.Glucose is an important energy supply substance for organisms to complete various life activities.In this study,glucose was added to low-protein diets to study the nutritional control measures on the growth performance,slaughter performance,meat quality and intestine of growing and finishing pigs.The health impact in this study provides a theoretical reference for further improving low-protein diets and reducing nitrogen emissions.This study has three parts:In part one: Performance of growth.48(Duroc×Landrace×Yorkshire)hybrid healthy pigs with an average live weight of 27±0.4kg were randomly divided into 3 groups with each group consisting of 16 pigs.There were three phases of the trail and each trail lasted for 28 days.The diets of first phase were: 18% CP group(control group),13.5% CP group,and 13.5% CP + 1.8% GLUC group.The diets of second phase were: 16.5% CP group(control group),12.5% CP group and 12.5% CP + 1.8% GLUC group.The third phase diets were: 15% CP group(control group),11.5% CP group and 11.5% CP + 1.8% GLUC group.At the end of the test period,the scale,growth performance and viscera index of the pigs were measured.The results showed that:(1)The average daily protein intake could be reduced by added GLUC in the low-protein diet(P<0.05);(2)There was no significant difference in growth performance between the control group and the other groups after adding GLUC(P > 0.05).In part two: Meat quality.Six healthy pigs from each group were randomly selected from part 1 and venous blood of anterior lumen were collected for blood biochemical measurement.After blood collection,pigs were slaughtered for determining carcass characteristics,meat quality,amino acid composition of dorsal longest muscle and contents of various fatty acids of intermuscular fat.The results showed that:(1)The addition of GLUC in the low-protein diet could significantly reduce the content of plasma urea nitrogen(P < 0.05);(2)There was a reduction in the water content of the muscle(P < 0.05),and the shear force of the muscle(P < 0.05);(3)There was no significant effect on carcass traits(P > 0.05);(4)There was no significant effect on the amino acids composition of muscle(P > 0.05);(5)The content of unsaturated fatty acids C17:0,C20:1,C20:2 and C22:6n3 were significantly reduced(P < 0.05),the content of saturated fatty acids C17:0 was significantly reduced(P < 0.05)while the content of saturated fatty acids C18:0 was significantly increased(P < 0.05);(6)There were no significant difference between the reduced protein levels and the contents of saturated fatty acids C18:0 in the normal diet group(P > 0.05).In part three: Intestinal microflora.Blood was collected from the anterior lumen venous to determine the plasma immune indexes.Colonic chyme and ileum tissues were also collected for the determination of microbial diversity and observation of intestinal tissue morphology.The results showed that:(1)Low-protein diet with added glucose could increase the content of IgG in the plasma of growing pigs(P< 0.05);(2)There was a significant increase in the microorganism Coriobacteriales at the family level(P < 0.05)but no significant effect was observed at other levels(P> 0.05);(3)There was no significant effect observed on the ileal tissue morphology(P> 0.05).In summary,the addition of glucose in low-protein diets has a tendency to improve pig growth performance;increase the content of immunoglobulin IgG in plasma;and has no significant effect on the intestinal microbial diversity. |
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