Effect of Omega-3 Enriched Layer Rations on Egg Quality

Effect of pomegranate seed oil on egg production, egg quality and yolk fatty acid deposition in laying hen

BACKGROUND

Pomegranate seed oil (PSO) contains punicic acid as well as conjugated linolenic acid isomers, including α-eleostearic and catalpic acids, along with phytosterols, especially β-sitosterol, campesterol and stigmasterol, with lipotropic impact and egg fortifying effect in laying hens.

OBJECTIVES

The present experiment was designed to examine the effects of PSO on egg production, egg quality, blood lipids and yolk fatty acid deposition in laying hens.

METHODS

A total of 360 Hy-line laying hens (w-80), at 25 weeks of age, were randomly allotted to five dietary treatments in a completely randomized design during a 10-week period. Experimental treatments consisted of a basal diet or supplementation of 1, 2, 3 and 4 g PSO/kg to basal diet. Performance indicators and fatty acid composition of egg yolk were evaluated during different experimental periods. Blood lipid attributes were evaluated at the end of the experiment.

RESULTS

Dietary supplementation of 4 g PSO/kg feed increased daily feed intake and egg production rate of laying hens (p < 0.05). There was not any significant influence of experimental treatments on egg quality, whereas an increasing trend observed in egg yolk colour of hens received dietary graded levels of PSO. Dietary supplemental 4 g/kg PSO increased the proportion of yolk poly-unsaturated fatty acid (PUFA) concentration (p < 0.05). Furthermore, the PUFA to saturated fatty acid ratio increased after dietary supplementation of 1 or 4 g/kg PSO (p < 0.05). Serum concentration of cholesterol, triacylglycerol and low-density lipoprotein decreased in response to the supplementation of more than 3 g PSO/kg in the feed (p < 0.05).

CONCLUSIONS

In conclusion, dietary supplementation with 4 g/kg PSO improved production rate and decreased blood lipids in laying hens. Moreover, dietary supplemental PSO modified yolk fatty acid deposition without detrimental effects on the egg quality.

Improved biological value of eggs due to the addition of pomegranate seed oil to laying-hen diets

In this study, the effects of the addition of pomegranate seed oil (PSO) at different levels (0, 0.5, 1, and 1.5  mL kg - 1 ) to laying-hen rations on performance values, egg quality criteria, egg shelf life, some enzyme activity, and the fatty acid composition of yolks were investigated. In the study, 96 Lohman LSL laying hens at 64 weeks of age were used. The trial consisted of four groups, each containing 24 hens. Chickens were given feed and water ad libitum during the 8-week experiment. The first group was the control group and was fed with a basal diet, while the other groups were fed with feeds with 0.5, 1.0, and 1.5  mL kg - 1 PSO added to the basal feed, respectively. The lowest feed consumption and the highest egg weight were determined in the 1  mL kg - 1 PSO group. The highest feed conversion ratio, the lowest eggshell weight, and the shell-breaking strength were determined in the 0.5  mL kg - 1 PSO group. It was determined that the egg yolk malondialdehyde (MDA) value in the groups to which pomegranate seed oil was added was significantly lower than the control group on the 28th day of storage. The lowest glutation (GSH) and catalase values were found in the control group, and the highest total antioxidant capacity (TAC) was found in the 1  mL kg - 1 PSO group. It was determined that the addition of PSO to the diet significantly increased the rate of saturated fatty acids (SEFA), conjugated linoleic acid (CLA), and conjugated linolenic acids (CLnA) in yolk. The results showed that the addition of 1  mL kg - 1 pomegranate seed oil to the feeds decreased feed consumption, increased egg weight, and positively affected the shelf life of the egg. In short, the addition of PSO had a positive effect on shelf life, and it increased punicic acid and CLA levels without reducing egg quality.

Feeding to Produce n-3 Fatty Acid-enriched Table Eggs

This study aimed to modify the feed mixtures of laying hens to enrich the consumer eggs with n-3 polyunsaturated fatty acids (PUFA): α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). One hundred and twenty Tetra-SL laying hens used in the study were divided into three groups of 40 laying hens arranged in five repetitions: C, control with 5% soybean oil; E1, 0.5% fish oil + 0.5% microalgae Schizochytrium limacinum; and E2, 0.75% fish oil + 0.75% microalgae. The composition of the mixtures was balanced at the level of 17.5% raw protein and 11.81 MJ/kg metabolic energy (ME). Feed and water were provided ad libitum, and the experiment lasted for 21 days. In this study, the different physical and chemical properties of eggs, the fatty acid profile and lipid oxidation of fat in egg yolks were analyzed. The results of the study showed that the weight of the egg yolk and that of the shell depended on the feeding treatments (P=0.014 and P<0.001), and the weight of eggs and basic parts, as well as the thickness of the shell depended on the storage duration (P<0.001). The storage time affected the pH of egg yolks and albumen and the reduction in Haugh units and albumen height (P<0.001). Significant differences were observed in the content of ALA, DHA, ∑n-3 PUFA (mg/100 g) and the n-6/n-3 PUFA ratio between the C and E1/E2 egg groups (P<0.001). The results of the study indicate that it is sufficient to use a lower level of fish oil and the microalgae Schizochytrium limacinum in hens' feed to achieve a satisfactory increase in n-3 PUFA in eggs, while maintaining optimal values of egg quality and freshness indicators.

Effect of dietary pomegranate seed oil on laying hen performance and physicochemical properties of eggs

The objective of the study was to determine the effects of pomegranate seed oil, used as a source of punicic acid (CLnA) in the diets of laying hens, on the physicochemical properties of eggs. Forty Isa Brown laying hens (26weeks old) were equally subjected to 4 dietary treatments (n=10) and fed a commercial layer diet supplying 2.5% sunflower oil (control) or three levels (0.5, 1.0 and 1.5%) of punicic acid in the diets. After 12weeks of feeding the hens, eggs collection began. Sixty eggs - randomly selected from each group - were analysed for physicochemical properties. Eggs naturally enriched with CLnA preserve their composition and conventional properties in most of the analysed parameters (including chemical composition, physical as well as organoleptic properties). Dietary CLnA had positive impact on the colour of the eggs' yolk, whereas the hardness of hard-boiled egg yolks was not affected. Additionally, increasing dietary CLnA led to an increase not only the CLnA concentrations, but also CLA in egg-yolk lipids.

Effect of trans, trans CLA egg enrichment from CLA-rich soy oil on yolk fatty acid composition, viscosity and physical properties

CLA egg accumulation studies using cis, trans (c,t) isomers have been effective, but they reported adverse egg quality. trans, trans (t,t) CLA isomers have shown superior nutritional effects in rodent studies, but reports of t,t CLA-rich yolks are limited. The objectives were to determine the effect of t,t CLA-rich soy oil in feed on egg yolk viscosity, and yolk quality during refrigerated storage. Yolk fatty acids, viscosity, weight, index, moisture, pH, and vitelline membrane strength (VMS) were determined at 0, 20, and 30 storage days. CLA had minimal effect on fatty acid profiles, relative to c,t reports. CLA-rich yolk viscosity was greater than controls, and CLA yolks maintained higher viscosities during storage. Yolk weight and index were not affected by t,t CLA-rich soy oil. Yolks with the greatest CLA concentrations had the greatest VMS after 20 days of storage, and yolks containing lower CLA levels maintained greater VMS throughout 30 days of storage, relative to controls.