Effect of dietary supplementation with selenium-enriched yeast or sodium selenite on selenium tissue distribution and meat quality in beef cattle1

Abstract

The objective was to determine the concentration of total Se and the proportion of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in postmortem tissues of beef cattle offered diets containing graded additions of selenized enriched yeast (SY; Saccharomyces cerevisiae CNCM I-3060) or sodium selenite (SS). Oxidative stability and tissue glutathione peroxidase (GSH-Px) activity of edible muscle tissue were assessed 10 d postmortem. Thirty-two beef cattle were offered, for a period of 112 d, a total mixed ration that had been supplemented with SY (0, 0.15, or 0.35 mg of Se/kg of DM) or SS (0.15 mg of Se/kg of DM). At enrollment (0 d) and at 28, 56, 84, and 112 d following enrollment, blood samples were taken for Se and Se species determination, as well as whole blood GSH-Px activity. At the end of the study beef cattle were killed and samples of heart, liver, kidney, and skeletal muscle (LM and psoas major) were retained for Se and Se species determination. Tissue GSH-Px activity and thiobarbituric acid reactive substances were determined in skeletal muscle tissue (LM only). The incorporation into the diet of ascending concentrations of Se as SY increased whole blood total Se and the proportion of total Se comprised as SeMet, as well as GSH-Px activity. There was also a dose-dependent response to the graded addition of SY on total Se and proportion of total Se as SeMet in all tissues and GSH-Px activity in skeletal muscle tissue. Furthermore, total Se concentration of whole blood and tissues was greater in those animals offered SY when compared with those receiving a comparable dose of SS, indicating an improvement in Se availability and tissue Se retention. Likewise, GSH-Px activity in whole blood and LM was greater in those animals offered SY when compared with those receiving a comparable dose of SS. However, these increases in tissue total Se and GSH-Px activity appeared to have little or no effect in meat oxidative stability.

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

“…In addition, there were no appreciable differences between the two Se sources in terms of both GSH-Px activity and whole blood SeCys, whereas SeMet contents were greater in SY-supplemented birds. This observation in turkey poults is unlike those reported for lambs (Juniper et al, 2008a), beef cattle (Juniper et al, 2008b) and dairy cattle (Phipps et al, 2008) that had received similar sources and doses of supplementary Se, in which SeCys was the predominant selenized AA, irrespective of treatment.…”

“…Glandular visceral tissues tend to have greater total Se concentrations than muscle, and cardiac muscle has a greater total Se content than skeletal muscle. These data agree with those reported in laying hens (Petrovič et al, 2006;Pan et al, 2007) and broilers (Wang and Xu, 2008) and are also similar to those reported in lambs (Juniper et al, 2008a) and beef cattle (Juniper et al, 2008b). The differences seen in cardiac, skeletal and gizzard muscle tissue total Se concentrations, when comparing comparable doses of the two sources of Se, are indicative of improved Se uptake and incorporation within those birds supplemented with SY.…”

“…The differences seen between comparable doses of the different Se supplements from the current study are indicative of better uptake and incorporation of Se derived from SY and are consistent with findings in sheep (Van Ryssen et al, 1989;Juniper et al, 2008a), cattle (Gunter et al, 2003;Juniper et al, 2008b;Phipps et al, 2008) and pigs (Kim and Mahan, 2001). Yoon et al (2007) reported that there were differences between Se sources in 6-week-old broilers that had received diets containing comparable doses of SS and SY; but differences also existed between comparable doses of different organic sources.…”

“…The predominance of SeMet in breast tissue is similar to observations that have been observed in the skeletal muscle of beef cattle (Juniper et al, 2008b) in which SeMet concentrations were seen to increase with ascending SY inclusion, most probably reflecting increases in SeMet intake and subsequent uptake and non-specific incorporation into muscle protein. However, this same trend was not apparent within thigh tissue where SeMet and SeCys comprised almost equal proportions of total Se.…”

“…Selenized AA content of tissues The predominance of SeCys in both liver and kidney tissue has been reported in both lambs (Juniper et al, 2008a) and beef cattle (Juniper et al, 2008b) and may reflect the greater metabolic activity of these tissues and the relative associated changes in selenoenzyme activity. However, unlike the current study where SeCys comprised the greater proportion of total Se regardless of treatment, within lamb and beef cattle higher SY doses tended to result in SeMet comprising the greater proportion of total Se in liver tissue.…”