| Summary: | 碩士 === 國立屏東科技大學 === 動物科學與畜產系所 === 101 === This study was examined to evaluate the effect of dietary supplementation with rumen bacteriocin yeast on the growth performance and lipid metabolism of broiler chickens. One hundred and thirty five day-old Arbor Acres broilers were randomly allocated to 3 treatments, including basal diet, 0.125%, and 0.25% rumen bacteriocin yeast groups. Growth performances, relative organ weight, blood biochemistry, intestinal flora, lipid contents of liver and abdominal fat and lipid metabolism related genes in liver were measured at 21 and 35 days of age. The results of growth performance showed that dietary supplementation with rumen bacteriocin yeast were no significant differences among treatments at the age of 21 days. However, the body weight of broilers at 35 days old in 0.125% group was significantly decreased than in the control group, and there was no significant difference between the control and the 0.25% supplemental group. Feed conversion ratio among treatments was no significant difference. Relative spleen weight in 0.125% group was significant higher than that in the 0.25% rumen bacteriocin group at the age of 21 days. Relative liver and bursa weight in rumen bacteriocin group were no significant differences with control. The results of blood biochemistry showed that dietary supplementation with 0.125% rumen bacteriocin yeast elevated glucose concentration than the other groups in sera, and 0.25% rumen bacteriocin yeast tended to decrease the level of triacylglycerol and cholesterol in sera, 25% and 10% respectively. AST and ALT values were no significant differences among treatments at the age of 35 days. Results of intestinal microflora population, dietary supplementation with 0.25% rumen bacteriocin yeast have lower Enterococcus count in the jejunum at the age of 35 days, revealed higher concentration Lactobacilli in stool at the age of 21 days. The lipid content of the liver, dietary supplementation with rumen bacteriocin yeast was no significant difference in 21 day old broiler, but with increase of concentration of rumen bacteriocin yeast, the total lipids, triglycerides, total cholesterol and non-esterified fatty acid content in the liver, were ended to decrease after comparison with the control group. The concentration of non-esterified fatty acid in liver was significantly decreased in rumen bacteriocin yeast administration group at 35 days of age. To evaluate the results more precisely, the mRNA expression levels of lipid metabolism related genes were determined by semi-quantitative real-time PCR. In the RT-PCR results, fatty acid transport protein, peroxide proliferator activated receptors, sterol regulatory region binding protein, liver X receptor, hepatocyte nuclear factor and fatty acid synthesis of mRNA expression were no significant differences with the control, but the fatty acid binding protein and retinoic acid X receptor mRNA expression were significantly lower than the control group, the mRNA expression level of sterol regulatory region binding proteins expression was 70% of the control group. The results illustrated that dietary supplementation with rumen bacteriocin yeast can down regulation some of the genes involved in fatty acid metabolism and fatty acid binding protein. To sum up, dietary supplementations with rumen bacteriocin yeast was no significant difference on growth performance, but significantly lower non-esterified fatty acids of liver content. The gene analysis showed that rumen bacteria yeast may affect the liver fatty acid oxidation and fatty acid synthesis, thereby reducing the total lipid and non-esterified fatty acid content of the liver.
Key Words：Blood biochemistry, Broilers, Lipid metabolism, Rumen bacteriocin yeast
|
|---|
