Fatty acid profile of eggs produced by laying hens fed diets containing different shares of fish oil.

This paper presents the results of the research on the use of fish oil (FO) in combination with soybean oil (SO) in laying hens diet on physical and chemical properties of fresh eggs and those stored in a refrigerator for 28 d at + 4°C. Fatty acids (FA) profile, as well as thiobarbituric acid reactive substances (TBARS) values in yolks are also presented. The following feeding treatments have been used: C (control, without FO), E1 (0.3% FO + 4.7% SO), E2 (0.6% FO + 4.4% SO), E3 (0.9% FO + 4.1% SO), E4 (1.2% FO + 3.8% SO) and E5 (1.5% FO + 3.5% SO). Laying hens diets were balanced at the level of 176.10 g/kg crude protein and 11.50 MJ/kg ME. The results of the study showed that feeding treatments affected the relative shares of the eggs basic parts (P < 0.05). The egg storage duration significantly reduced Haugh units (HU), egg and albumen egg weight, and increased the yolk color intensity (P < 0.001). Fish oil share increment in the diets resulted in the EPA (eicosapentaenoic FA) content increase from 10.27 to 20.10 mg/100 g egg; DHA (docosahexaenoic FA) from 105.44 to 236.87 mg/100 g egg and ∑ n-3 PUFA (polyunsatureated FA) from 204.59 to 327.35 mg/100 g egg. The ∑ n-6 PUFA/∑ n-3 PUFA ratio decreased from 8.69 (C group) to 4.54 (E5 group). TBARS values were affected by feeding treatments as well as treatment-storage interactions (P < 0.01).

Antioxidative Characteristics of Chicken Breast Meat and Blood after Diet Supplementation with Carnosine, L-histidine, and ß-alanine.

The objective of the study was to test the effect of diets supplemented with ß-alanine, L-histidine, and carnosine on the histidine dipeptide content and the antioxidative status of chicken breast muscles and blood. One-day-old Hubbard Flex male chickens were assigned to five treatments: control diet (C) and control diet supplemented with 0.18% L-histidine (ExpH), 0.3% ß-alanine (ExpA), a mix of L-histidine\ß-alanine (ExpH+A), and 0.27% carnosine (ExpCar). After 28 days, chicken breast muscles and blood samples were analyzed for the antioxidant enzyme activity (catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD)), carnosine and anserine content, amino acid profile, and anti-radical activity (ABTS, DPPH, ferric reducing antioxidant power (FRAP)). The results of the study showed that carnosine supplementation effectively increased body weight and breast muscle share in chicken carcasses. Carnosine and L-histidine supplementation with or without ß-alanine increased carnosine content in chicken breast muscles up to 20% (p = 0.003), but the boost seems to be too low to affect the potential antioxidant capacity and amino acid content. The ß-alanine-enriched diet lowered dipeptide concentration in chicken blood serum (p = 0.002) and activated catalase in chicken breast muscles in relation to the control group (p = 0.003). It can be concluded that histidine or dipeptide supplementation of chicken diets differently affected the total antioxidant potential: in breast muscles, it increased dipeptide content, while in blood cell sediment (rich in erythrocytes), increased SOD and GPx activities were observed.