Efficacy of dietary selenium sources on growth and carcass characteristics of growing-finishing pigs fed diets containing high indigenous selenium

¹ Texas Tech University, Lubbock, TX
² Seaboard Foods, Shawnee Mission, KS
³ Diamond V Mills, Inc., Cedar Rapids, IA

^* To whom correspondence should be addressed. E-mail: sungwoo.kim{at}ttu.edu.

	Abstract

A study was conducted to determine the efficacy of organic (Se-yeast; SelenoSource AF, Diamond V Mills, Inc.) and inorganic sources of Se on growth performance, tissue Se accretion and carcass characteristics of growing-finishing pigs fed diets with high indigenous Se content. A total of 180 pigs at 34.4 ± 0.06 kg of BW were allotted to 1 of 5 dietary treatments: a negative control without added Se (NC), 3 treatment diets with 0.1, 0.2, and 0.3 mg/kg added Se from an organic source and a diet with 0.3 mg/kg added Se as sodium selenite. Each treatment had 6 pens with 6 pigs per pen-replicate. Experimental diets were changed twice at 66.1 ± 0.53 kg and 99.0 ± 0.93 kg of BW, and were fed until the pigs reached market weight. Growth performance was measured at the end of each phase. Upon reaching 129.9 ± 1.35 kg of BW, the pigs were transported to a local abattoir (Seaboard Foods, Guymon, OK) where carcass, longissimus muscle (LM) and liver samples were obtained. Hair and blood samples were obtained at the beginning and end of the study for Se analysis. Growth performance did not differ (P > 0.05) among treatments. Percent drip loss of the NC pigs was greater (2.41 vs. 1.75, P = 0.011) compared to pigs supplemented with Se. Pigs fed diets with added Se had greater Se concentrations in the liver (0.397 vs. 0.323 ppm, P = 0.015), LM (0.236 vs. 0.132 ppm, P < 0.001), serum (0.087 vs. 0.062 ppm, P = 0.047) and hair (0.377 vs. 0.247 ppm, P = 0.003) compared to the NC. Percent drip loss was linearly reduced (percent drip loss = 2.305 - 2.398 x Se, r² = 0.29, P = 0.007) as dietary organic Se concentration increased. The Se concentration (ppm) in the liver (liver Se = 0.323 + 0.291 x Se, r² = 0.33, P = 0.003), LM (LM Se = 0.122 + 0.511 x Se, r² = 0.57, P < 0.001), serum (serum Se = 0.060 + 0.113 x Se, r² = 0.33, P = 0.004) and hair (hair Se = 0.237 + 0.638 x Se, r² = 0.56, P < 0.001) increased linearly as dietary organic Se concentration increased. Slope ratio analysis indicated that the relative bioavailability of organic Se for percent drip loss and LM and hair Se response was 306, 192, and 197 % of that for inorganic Se, respectively. The results of the study show a potential advantage of organic Se supplementation in reducing drip loss even when the basal diet contains indigenously high Se concentration of 0.181 ppm.

Key Words: carcass, drip loss, growth performance, pigs, selenium