The Evaluation Of The Application Of Different Source N-3PUFA In Laying Hens

The two experiments were conducted to evaluate the effect of n-3PUFA application inlaying hens and different dietary n-3polyunsaturated fatty acids on performance, egg quality,lipid metabolism and fatty acid compositions of yolk lipid classes in layers so as to providethe evidence in theory and practice for producing eggs enriched DHA.1. Effect of Dietary SL on Performance, Lipid Metabolism and Fatty Acid Compositionsof Yolk Lipid in Layers.This experiment was conducted to investigate the effects of different level of Schizochy-trium on laying performance, egg quality, blood fat metabolism and DHA in yolk accumula-tion of laying hens. Two hundred and eighty eight Hy-Line brown laying hens aged29weekswere randomly divided into4groups with6replicates per group and12hens per replicate.Positive control was fed with the basal diet, experimental groups were fed with basic dietadded Schizochytrium at1%,2%, and3%.The trial lasted six weeks. The results showed:1)there were no significant effect of SL on Average egg weight and Feed/egg and Egg Produc-tion rate (P>0.05), but a significant effect of SL on Average daily feed intake（P<0.05）wasobserved;2）there were no significant effect of SL on egg quality (P>0.05),but1%level of SLsignificantly affected yolk color (P<0.05);3）there were significant decreasing of SL on se-rum TC,TG and LDL-C of laying hens(P<0.05);4）supplementation of dietary SL level im-proved linearly the deposition of n‐3PUFA and DHA in egg yolk lipids and reduced total n-6/n-3. But when SL exceeded2%, the yolk did not continue to increase the DHA and theenrichment in eggs could be saturated in15d. It may be concluded that the supplementation ofdietary at2%SL level could effectively improve the deposition of DHA in yolk and had noadverse influence on laying performance and egg quality in the experiment conditions.2. Effect of Different Source n-3PUFA on Performance, Egg quality, Liver AntioxidantIndex，Fatty Acid Compositions of Yolk Lipid and the Shelf Life of Eggs in Layers.This experiment was conducted to investigate the effects of different sources of N-3PUFA diets on laying performance, egg quality, liver antioxidant index, fatty acid composi-tion of egg yolk and the shelf life of eggs in laying hens. Two hundred and eighty eight Hy-Line brown laying hens aged25weeks were randomly divided into4groups with6replicates per group and12hens per replicate. The experimental groups were fed with basal diet adding0.91%SL oil,1.78%FO and2%SL power respectively. The trial lasted six weeks. The resultsshowed:1) there were no significant effect of different sources of n-3PUFA diets on feed in-take,Feed/egg and Egg Production rate (P>0.05);2）there were no significant effect of differ-ent sources of n-3PUFA diets on egg quality (P>0.05),but SL power group significantly af-fected yolk color (P<0.05);3）there were a significant decreasing of n-3PUFA diets on liverCAT, and T-AOC of laying hens(P<0.05);4）there were a significant improvement (P<0.05)of FO diets on the ALA、EPA and DHA in egg yolk and SL oil and SL power diet group sig-nificantly(P<0.05) improved the DHA in egg yolk;5) with the extension of storage time eachtreatment group had a significant decreasing of Albumen Height and Haugh unit (P<0.05).The SL oil group had the fastest decline. With the extension of storage time each treatmentgroup had a significant improvement of MDA in egg yolk (P<0.05) and it became stable at14days. It may be concluded that the supplementation of2%level dietary SL power could im-prove the yolk color and DHA deposition. Egg quality had little change during storage timeand the supplementation of2%level dietary SL power had no adverse effects on performanceof laying hens and other egg quality.