Document Type : Research Paper
Authors
1 Department of Animal Sciences, Faculty of Agriculture, University of Tehran, Karaj, Iran.
2 Department of animal science, Faculty of agriculture and natural sources, university of Tehran
3 Department of Animal Sciences, Faculty of Agriculture, University of Tehran, Karaj, Iran
Abstract
Objective: This study was conducted to evaluate the effects of different levels of flaxseed oil and fish oil on productive performance, egg quality, yolk fatty acid pattern, and egg enrichment in laying hens.
Method: A total of 324 white Shaver laying hens, 65 weeks old, were used in an 8-week trial arranged in a completely randomized block design with repeated measures. Six dietary treatments were applied, each with six replicates of nine birds per replicate. The experimental treatments included: Treatment one: control containing crude soybean oil and no source of flaxseed and fish oil, Treatment two: 1.5% flaxseed oil, Treatment three: 1.5% fish oil, Treatment four: 3% flaxseed oil, Treatment five: 3% fish oil and Treatment six: 1.5% flaxseed oil + 1.5% fish oil. Diets were based on corn and soybean meal and formulated according to the nutritional requirements of Shaver layers in the late production phase.
Results: The results of this study showed that the use of flaxseed oil and fish oil had a significant effect on egg weight, egg laying percentage and feed conversion ratio (P<0.05), but egg mass and feed intake were not affected. Egg weight in the 1.5% fish oil treatment was higher than the 1.5% flaxseed oil + 1.5% fish oil treatment (P<0.05), but there was no significant difference with other treatments. Egg production in the 3% flaxseed oil treatment was higher than the control and 3% fish oil treatments (P<0.05), but there was no significant difference with other treatments. The feed conversion ratio in the 3% fish oil treatment was significantly higher than 1.5% flaxseed oil and 1.5% fish oil (P<0.05), but did not show any difference compared to the control and other experimental treatments. In the study of egg quality traits, it was found that only the Haugh unit was affected by the experimental treatments. So that in the treatments containing 1.5 and 3% flaxseed oil, the amount of Haugh unit was higher than the treatment containing 3% fish oil (P<0.05), however, no significant difference was observed between the other treatments. Examination of the yolk fatty acid profile showed that there was a significant difference between the experimental treatments. The treatment containing 3% fish oil had the highest concentration of the sum of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with a value of 182.14 mg/100 g of egg contents. In contrast, the 3% flaxseed oil treatment showed the highest level of alpha-linolenic acid (269.7 mg/100g egg). Also, the lowest ratio of omega-6 to omega-3 fatty acids was observed in the 3% flaxseed oil treatment (P<0.05). The most economical treatment in terms of egg enrichment was the 1.5% fish oil treatment, which increased the level of EPA plus DHA by about 35% compared to the Veterinary Organization standard of Iran.
Conclusions: In overall, the results showed that vegetable and animal sources of omega-3 have different effects on laying hen egg performance and egg quality. Fish oil, especially at the 3% level, produced the highest increase in yolk eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentration, while flaxseed oil increased alpha-linolenic acid and improved internal egg quality. The lowest omega-6 to omega-3 ratio was observed in flaxseed oil treatments. From an economic perspective, 1.5% fish oil treatment showed appropriate effect in egg enrichment by EPA+DHA. Overall, choosing the appropriate level and source of omega-3 can be an effective strategy in producing enriched eggs.
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