The Effects Of Conjugated Linoleic Acid On Egg Production Performance And Egg Quality Of Laying Hens

In a factorial experiment, ninety six ,28 weeks old ISA brown hens were allocated to four treatment with six replication of four hens each. The four treatment were assigned randomly to four diets containing 0%, 0.5%,1%, or 2%Conjugated linoleic acid(CLA). The duration of feed trial was 60 days.The objective of this study was to investigate the effects of supplementing different level of CLA in diet on egg production performance, egg quality , relatively blood parameters, as well as the deposition of cholesterol and fatty acid and in yolk fat. The result showed that there were significant difference in feed intake .but the difference in egg mass, egg weight, feed efficiency, and laying rate was not significant. The egg mass, laying rate and feed intake in 0.5%CLA supplementing group was higher than those fed the control diet,1% and 2%CLA group by 1.68%,9.64% and 8.65%;0.72%,3.98% and 11.42% respectively. Besides CLA supplementing can significantly increase the yolk color ,while decrease albumen weight and haugh unit and also can increase CLA deposition in yolk .At sixtieth day, The cholesterol and fat in yolk of each treatment were 23.39,19.34,18.56,17.20mg/g yolk and 66.66%,77.61%,58.82%,57.20% respectively. The CLA in eggs of each treatment were 61.39,350.82,357.57,758.56mg respectively. The result of fat acid analysis showed that The supplementation of CLA to the diets had a clearly decreased in total monounsaturated fatty acid, while had a dearly increase in total saturated fatty acids and total polyunsaturated fatty acids. The result of relatively blood parameters analysis showed that The supplementation of CLA to the diets had significantly increased The serum T3,T4, HDL-C/LDL-C concentrations, while had a clearly decreased the serum E2, Ca2+ concentrations . When it containing 0.5% CLA in the diet ,the serum HDL-C/LDL-C were the highest. When it containing 1% CLA in the diets, the serum T4 concentration were the highest. When it containing 2% CLA in the diet, the serum T3 concentration were the highest ,the Ca2+ and E2 and TG concentration were the lowest.