Hydroxy-selenomethionine enhances the productivity and egg quality of 50- to 70-week-old semi-heavy laying hens under heat stress.

Oxidative stress significantly compromises the production efficiency of laying hens. It has been reported in literature that selenium (Se) in poultry diets has a positive effect on mitigating these effects. This study has been carried out to evaluate the effects of Se supplementation in feeds, from either an inorganic or a hydroxy-selenomethionine (OH-SeMet) source, on the performance and physiological traits of 50- to 70-wk-old Dekalb Brown laying hens under heat stress, and on their egg quality after different storage durations. The treatments consisted in supplementing 0.3 ppm of Se as sodium selenite (SS; 45%-0.7g/ton) or OH-SeMet (2%-15g/ton) in twelve 16-bird replicates. Supplementation with OH-SeMet resulted in a better performance of the laying hens than with SS: -5% feed conversion ratio and +3.6% of egg mass. A reduction in egg quality was observed with prolonged egg storage, which was mitigated with the use of OH-SeMet in laying hen diets. The use of OH-SeMet increased the antioxidant capacity of the birds, which showed higher glutathione peroxidase levels in the blood, kidneys, liver, and intestinal mucosa, in addition to a higher Se content in the eggs and a greater bone resistance. Thus, supplementing feeds with 0.3 ppm of OH-SeMet to 50- to 70-wk-old semi-heavy laying hens enhances their antioxidant capacity and leads to a higher egg quality and productivity than SS supplementation.

Hydroxy-selenomethionine as an organic source of selenium in the diet improves boar reproductive performance in artificial insemination programs.

This study aimed to compare different selenium (Se) sources in the diet on boar's semen quality and fertility. For this, 28 boars aged 8 to 28 mo were fed with the following dietary treatments for 95 d: 0.3 mg Se/kg as sodium selenite (SS; n = 14) and 0.3 mg Se/kg as hydroxy-selenomethionine (OH-SeMet; n = 14). During this period, two experiments were carried out. In experiment 1, the semen of all boars was evaluated every 2 wk. Raw semen was initially evaluated for the processing of seminal doses, which were stored at 17 °C for 72 h, followed by sperm quality assessments. Furthermore, Se concentration and glutathione peroxidase (GPx) activity were measured in the seminal plasma. In experiment 2, 728 females were inseminated weekly with seminal doses from boars of the different experimental groups to further assess in vivo fertility and litter characteristics. Results demonstrated that boars fed OH-SeMet had more Se in their seminal plasma (P < 0.05), showing the greater bioavailability of the organic source in the male reproductive system. Moreover, boars fed OH-SeMet tended (P < 0.10) toward a higher total sperm count in the ejaculate (66.60 vs. 56.57 × 109 sperm) and the number of seminal doses (22.11 vs. 18.86; 3 × 109 sperm/dose) when compared with those fed SS. No effect of the dietary treatments was observed on GPx activity in seminal plasma (P > 0.05) as well as on raw and stored semen quality (P > 0.05). Under in vivo conditions, seminal doses from boars fed OH-SeMet tended (P < 0.10) toward a higher pregnancy rate at weeks 3, 5, and 8, and also resulted in a higher (P < 0.05) percentage of pregnant females in the overall period (99.30 vs. 97.00). In conclusion, the replacement of SS with OH-SeMet in boars' diet can improve sperm production and results in better reproductive performance for them, bringing greater productivity and profitability to artificial insemination centers and commercial pig farms.