Effects of organic selenium supplementation on growth performance, carcass measurements, tissue selenium concentrations, characteristics of reproductive organs, and testis gene expression profiles in boars

• Published in: Journal of animal science Vol. 90; no. 2; pp. 533 - 542
• Main Authors: Speight, S. M, Estienne, M. J, Harper, A. F, Barb, C. R, Pringle, T. D
• Format: Journal Article
• Language: English
• Published: United States American Society of Animal Science 01-02-2012
• Subjects: accessory sex glands; Animals; average daily gain; barns; Blood; boars; Body Weight - drug effects; Body Weight - physiology; Carcasses; Color; Dietary supplements; Diets; Epididymis; Fat-free; feed conversion; Feed efficiency; firmness; Gene expression; Glands; Glutathione Peroxidase - genetics; Glutathione Peroxidase - metabolism; growth performance; Kidney; kidneys; liver; Male; marbling; Meat - standards; microarray technology; Oligonucleotide Array Sequence Analysis - veterinary; phospholipid-hydroperoxide glutathione peroxidase; physiological response; Polymerase chain reaction; Random Allocation; Real-Time Polymerase Chain Reaction - veterinary; Reproductive organs; RNA - chemistry; RNA - genetics; selenite; Selenium; Selenomethionine - blood; Selenomethionine - pharmacology; Sex; Sodium selenite; Sodium Selenite - blood; Sodium Selenite - pharmacology; Swine - metabolism; Testes; Testis - drug effects; Testis - metabolism; Weaning
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jas.2010-3747

The objective was to compare growth and physiological responses in boars fed diets supplemented with organic or inorganic sources of Se. At weaning, crossbred boars (n = 117; 8.3 kg of BW) were placed in nursery pens (3 boars/pen) and assigned within BW blocks to receive on an ad libitum basis 1 of 3 dietary treatments: I) basal diets with no supplemental Se (controls), II) basal diets supplemented with 0.3 mg/kg of organic Se, and, III) basal diets supplemented with 0.3 mg/kg of sodium selenite (13 pens/dietary treatment). Average daily gain (470 g/d), ADFI (896 g/d), and G:F (0.54) were similar among groups. Blood Se concentrations were greater (P < 0.01) for boars consuming organic Se (107.5 ± 4.8 µg/L) or sodium selenite (114.7 ± 4.8 µg/L) compared with controls (28.4 ± 4.8 µg/L). Intact pens of boars (11 pens/dietary treatment) were moved to a grow-finish barn and continued to receive appropriate diets on an ad libitum basis. Average daily gain (1,045 g/d) and ADFI (2,716 g/d) were similar among groups. Gain:feed was affected by treatment (P = 0.02) and was greater (P < 0.06) for boars fed organic Se (0.378 ± 0.004) compared with boars fed sodium selenite (0.368 ± 0.004) or controls (0.363 ± 0.004). Blood Se concentrations were greater (P < 0.01) in grow-finish boars consuming organic Se (198.9 ± 5.5 µg/L) than boars consuming sodium selenite (171.4 ± 5.4 µg/L) or controls (26.7 ± 5.4 µg/L). Treatment did not affect (P > 0.15) HCW, dressing percent, carcass length, LM area, standardized fat-free lean, lean percentage, backfat thickness, visual color, firmness, marbling, or Minolta loin color scores. Selenium supplementation did not affect (P > 0.17) testis or accessory sex gland sizes. Concentrations of Se in loin, liver, kidney, testis, cauda epididymis, and accessory sex glands were greatest (P < 0.01) in boars receiving organic Se, intermediate in boars receiving sodum selenite, and least in control boars. Microarray analysis of testis gene expression did not detect differences (P > 0.05) due to dietary treatment. Testis gene expression of glutathione peroxidase 4, as determined using quantitative PCR, was increased (P < 0.01) in boars fed organic Se compared with those fed sodium selenite. In summary, dietary supplementation of boars with organic Se failed to alter ADG or ADFI but enhanced G:F during grow-finish. More research is needed to discern the mechanism by which organic Se improves feed efficiency in boars.