Effect of dietary supplementation with selenium-enriched yeast or sodium selenite on selenium tissue distribution and meat quality in commercial-line turkeys

Abstract

The objective of this study was to determine the concentration of total selenium (Se) and proportions of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in the tissues of female turkeys offered diets containing graded additions of selenized-enriched yeast (SY), or sodium selenite (SS). Oxidative stability and tissue glutathione peroxidase (GSH-Px) activity of breast and thigh muscle were assessed at 0 and 10 days post mortem. A total of 216 female turkey poults were enrolled in the study. A total of 24 birds were euthanized at the start of the study and samples of blood, breast, thigh, heart, liver, kidney and gizzard were collected for determination of total Se. Remaining birds were blocked by live weight and randomly allocated to one of four dietary treatments (n 5 48 birds/treatment) that differed either in Se source (SY v. SS) or dose (Con [0.2 mg/kg total Se], SY-L and SS-L [0.3 mg/kg total Se as SY and SS, respectively] and SY-H [0.45 mg total Se/kg]). Following 42 and 84 days of treatment 24 birds per treatment were euthanized and samples of blood, breast, thigh, heart, liver, kidney and gizzard were retained for determination of total Se and the proportion of total Se comprised as SeMet or SeCys. Whole blood GSH-Px activity was determined at each time point. Tissue GSH-Px activity and thiobarbituric acid reactive substances were determined in breast and thigh tissue at the end of the study. There were responses (P , 0.001) in all tissues to the graded addition of dietary Se, although rates of accumulation were highest in birds offered SY. There were notable differences between tissue types and treatments in the distribution of SeMet and SeCys, and the activity of tissue and erythrocyte GSH-Px (P , 0.05). SeCys was the predominant form of Se in visceral tissue and SeMet the predominant form in breast tissue. SeCys contents were greater in thigh when compared with breast tissue. Muscle tissue GSH-Px activities mirrored SeCys contents. Despite treatment differences in tissue GSH-Px activity, there were no effects of treatment on any meat quality parameter.

Effects of dietary selenium supplementation on tissue selenium distribution and glutathione peroxidase activity in Chinese Ring Necked Pheasants

“…Glandular visceral tissues tend to have greater total Se concentrations than muscle tissue and cardiac muscle has a greater Se content than skeletal tissue or gizzard tissue. These data agree with those reported in laying hens (Petrovič et al, 2006;Pan et al, 2007), broilers (Wang and Xu, 2008), turkeys (Juniper et al, 2011) and are also similar to those reported in lambs (Juniper et al, 2008a) and beef cattle (Juniper et al, 2008b). …”

“…The lack of effect of any significant response over time in whole blood and plasma Se concentrations of Con birds would be expected and is consistent with the findings of other authors (Echevarria et al, 1988;Pan et al, 2007;Yoon et al, 2007;Juniper et al, 2011). However, the Se values recorded in the T 0 group and Con birds were higher than those recorded in commercial lines of poultry in other studies that had received diets, which had not been augmented with supplementary Se (Petrovič et al, 2006;Yoon et al, 2007 andJuniper et al, 2011).…”

“…However, the Se values recorded in the T 0 group and Con birds were higher than those recorded in commercial lines of poultry in other studies that had received diets, which had not been augmented with supplementary Se (Petrovič et al, 2006;Yoon et al, 2007 andJuniper et al, 2011). The differences seen between comparable doses of SY and SS are indicative of improved uptake and incorporation of Se derived from SY and are consistent with the findings in sheep (Van Ryssen et al, 1989;Juniper et al, 2008a), cattle (Gunter et al, 2003;Phipps et al, 2008;Juniper et al, 2008b), pigs (Mahan and Parrett, 1996;Mahan et al, 1999;Kim and Mahan, 2001) and poultry (Petrovič et al, 2006;Juniper et al, 2011).…”

“…This may be indicative of a more efficient Se retention system in wild type classes of bird when consuming diets low in Se. However, as dietary Se levels increase this efficient scavenging system may become quickly saturated, hence why responses in pheasants are not as pronounced as those seen in commercial lines of poultry (Petrovič et al, 2006;Juniper et al, 2011). Similar observations have been reported in different breeds of pig, whereby Se uptake and metabolism of a commercial hybrid was different to that of a pure breed when fed identical diets (Banoch et al, 2009).…”

“…GSH-Px catalyses the reduction of lipid and hydrogen peroxides to less harmful hydroxides via the oxidation and subsequent reduction of the SeCys active centre of the enzyme (Surai, 2006). The antioxidant functions of Se, via the actions of tissue GSH-Px, have been shown to persist postmortem in poultry muscle tissue (Juniper et al, 2011) and delay the onset of oxidation reactions (DeVore et al, 1983).…”