Effects of supplementation with a commercial source of selenium in a laying hens feeding system
Selenium enriched eggs are included as functional food in the market, because the role of selenium in human health and diseases has been recognized. The objective of this study was to enrich eggs with selenium from an organic source of selenium (seleno-yeast) on production parameters, egg quality and Leukocyte differential counts. Six hundred thirty Laying hens of the Babcock line were used, between 27 to the 65th weeks of age. Hens were kept in cage and randomly distributed into 2 treatments with 5 replicated. The control treatment (T0) based on commercial feed without addition of seleno-yeast, and T1 treatment, based on commercial feed plus 450 ppm of seleno-yeast (1000 ppm selenium Kg-1). The eggs were lyophilized and selenium was measured through a plasma spectrophotometer ICAP 6300. The egg production and classification was recorded weekly, laying percentage and the feed conversion ratio were calculated. Egg tasting and conceptual evaluations were done. The egg selenium content was higher (P < 0.05) for T1 group with 1.376 mg kg-1 of lyophilized egg compared with T0 with 0.173 mg kg-1of lyophilized egg. The addition of selenium did not significantly affect the egg production. The egg production percentage was 94.6 ± 3.88 and 95.2 ± 5.15; and the feed conversion ratios were 1.49 ± 0.061 and 1.48 ± 0.082 for T0 and T1, respectively. Therefore, leukocyte differential counts were not affected. The heterophile: lymphocyte ratios were 1.22 ± 0.31 and 1.58 ± 0.45 to T0 and T1 treatments, respectively. Egg organoleptic characteristics such as taste, color and texture, did not presented differences. This study confirmed that it is possible to enrich the content of selenium in eggs under an egg commercial production system without affecting the growth performance and the organoleptic characteristics. The cost of feed with selenio-yeast inclusion did not exceed the 1%, thus producing selenium enriched eggs is technically feasible to improve consumer health and competitiveness of the poultry industry.
Keywords: Antioxidant, egg, Glutathione