Effects of selenomethionine on the growth performance and quality, redox status, and lipid metabolism of breast meat in Pekin duck

The purpose of this study was to investigate the effects of selenomethionine (SeMet) on the growth performance and the quality, redox status, and lipid metabolism of breast meat in Pekin ducks. A total of 300 one-day-old male meat ducks were selected and randomly divided into three groups (10 replicates per cage of 10 birds): the selenium-deficient (SD) group and two groups supplemented with 0.30 mg/kg sodium selenite (SS) and SeMet. The experimental period lasted from d 1-42, during which a basal diet (3.0% fat) was provided from d 1-14, followed by a high-fat diet (9.0% fat) from d 15-42. Compared to the SD and SS groups, the SeMet group presented significant increases (P < 0.05) in serum glutathione peroxidase (GSH-PX) activity and thioredoxin reductase activity on d 42, muscle redness at 45 min, yellowness at 45 min and 24 h, serum and tissue selenium content, as well as palmitoleic acid (C16:1), docosahexaenoic acid (C22:6, DHA) and n-3 polyunsaturated fatty acid (PUFA) contents. Additionally, GSH-PX activity, total glutathione content, reduced glutathione content, and the relative expression of FASD2, GPX1, GPX4, TXNRD2, and SELENOP mRNA significantly increased (P < 0.05) in the SeMet group. Conversely, compared with those in the SD and SS groups, the n-6/n-3 PUFA ratio, malondialdehyde and lipid peroxidation contents in the SeMet group were significantly lower (P < 0.05). Furthermore, compared with those in the SD group, the feed-to-gain ratios during the periods of d 15- 42 and 1-42, as well as breast muscle cooking loss and drip loss were significantly lower (P < 0.05), whereas n-3 PUFAs, redness at 24 h, and ELOVL2, TXNRD1, and DIO1 mRNA expression levels were significantly greater (P < 0.05). In summary, SeMet enhances the growth performance and meat quality of Pekin ducks, which is closely associated with its effects on selenoprotein expression and lipid metabolism in muscle tissue.