External and internal quality traits of eggs from different ornamental chicken breeds.

This study analyzed the internal and external quality traits of eggs derived from hens of different breeds, including Silkie, Sultan, Cochin Bantam, Brahma and White Leghorn. The highest mean weight was noted for eggs originating from the White Leghorns breed, and the lowest was for eggs from the Cochin Bantams. Simultaneously, both a positive correlation between the egg weight and the percentage of albumen (r = 0.876) and a negative correlation between egg weight and the percentage of yolk (r = - 0.842) were found. The eggshell composition varied significantly in mean phosphorus amount, whereas the calcium content did not differ significantly. Despite this, eggshell strength varied significantly between breeds. Regarding cholesterol and fatty acid levels, the highest amount of cholesterol was noted in the Cochin Bantam breed, and the lowest was in the White Leghorn, although Leghorn was the breed characterized by the highest saturated fatty acid levels, and Cochin Bantam was the lowest. Regarding the polyunsaturated fatty acids (which have been proven to positively influence the cardiovascular system), the highest levels were obtained by Leghorn eggs, and the lowest were obtained by Silkie eggs. In conclusion, the study indicates that ornamental chicken breeds are a source of high-quality products, which could be attractive to consumers, additionally supporting traditional farming and animal genetic resources.

The effect of raw and fermented rapeseed cake on growth performance, carcass traits, and breast meat quality in turkey.

The objective of this study was to determine the effect of including 15% of raw or fermented rapeseed cake (RRC or FRC) in turkey diets on growth performance, carcass traits, and breast meat characteristics. A total of 1,350 day-old female Hybrid Converter turkeys were allocated to 3 dietary treatments (9 replicates per treatment and 50 birds each) and fed complete isocaloric and isonitrogenous diets. In the control group, soybean meal was the main source of dietary protein, whereas the experimental groups were fed diets containing 15% of RRC or FRC. The fermentation of rapeseed cake reduced the content of glucosinolates and phytate-phosphorus. In comparison with RRC, turkeys receiving FRC achieved significantly higher final BW, comparable with that noted in the control group. The experimental factor had no effect on carcass dressing percentage or carcass fat content, whereas turkeys fed diets containing rapeseed cake were characterized by lower relative weight of breast muscles and higher relative gizzard weight. The muscles of birds from groups RRC and FRC had also significantly lower cholesterol concentration. In comparison with control diet, diets RRC and FRC contributed to a significant decrease in the levels of saturated fatty acids and an increase in the share of n-6 polyunsaturated fatty acids in the total fatty acid pool in breast meat. The highest concentrations of n-3 polyunsaturated fatty acids and the most desirable n-6/n-3 polyunsaturated fatty acid ratio were noted in the breast muscles of RRC group turkeys. Both RRC and FRC reduced catalase and superoxide dismutase activity, and decreased the malondialdehyde content of muscle tissue. In conclusion, the replacement of RRC with FRC in diets led to an increase in the final BW of turkeys, but it had no influence on carcass quality and the majority of meat quality traits. The inclusion of rapeseed products in turkey diets positively affected meat quality, improving the fatty acid profile and antioxidant status, but it also decreased the yield of breast muscles.

The effect of different dietary levels of vitamin E and selenium on antioxidant status and immunological markers in serum of laying hens.

The effect of different dietary levels of selenium (Se) and vitamin E on egg production, the antioxidant status and the immune system response of hens was investigated in the current study. A total of 32 Lohman Brown hens were divided into four groups and were fed diets with 5% of soybean oil and two levels of Se (0.15 and 0.30 mg/kg) and vitamin E (30 and 60 mg/kg). During 10 weeks of experimental feeding, the body weights of hens and egg production were similar in all dietary treatments, but a higher Se content of diets contributed to a significant increase in egg weight. A higher vitamin E level significantly increased alpha-tocopherol concentrations (2.71 vs. 2.05 microg/mL, p = 0.001), superoxide dismutase (SOD) activity (43.3 vs. 39.9 U/mL, p = 0.049) and the ferric reducing ability of serum (FRAP) (123.0 vs. 105.7 micromol/L, p = 0.029). A higher Se content increased the concentrations of ascorbic acid (0.309 vs. 0.073 microg/L, p = 0.001), retinol (1.48 vs. 1.15 microg/mL, p = 0.001) and alpha-tocopherol (2.86 vs. 1.90 microg/mL, p = 0.001), the activity levels of catalase (3.40 vs. 2.98 U/L,p = 0.010) and SOD (43.4 vs. 30.8 U/mL, p = 0.040) as well as the total antioxidant status (TAS) of serum (0.38 vs. 0.28 mmol/L, p = 0.026). There were no significant differences in the concentrations of tumor necrosis factor-alpha (TNF-a) and interleukin-6 (IL-6) between treatments, while a higher vitamin E content of diets increased serum immunoglobulin A (IgA) concentrations (370.6 vs. 321.3 microg/mL, p = 0.026). Higher dietary levels of vitamin E and Se increased the serum concentrations of retinol (1.66 vs. 2.20 microg/mL, p = 0.013) and a-tocopherol (3.33 vs. 1.71, p = 0.014), but they had no effect on the other physiological parameters. It is recommended that the levels of both supplements, Se and vitamin E, be increased in laying hen diets as they have a beneficial effect on the serum concentrations of retinol and alpha-tocopherol.