Effect of high-selenium wheat on visceral organ mass, and intestinal cellularity and vascularity in finishing beef steers1

Abstract

Twelve crossbred steers (351 +/- 24 kg initial BW) were used to determine effects of high-Se wheat on visceral tissue mass, intestinal cell growth, and intestinal cellularity and vascularity. Steers were allotted randomly by BW to one of two treatments consisting of 75% concentrate diets that supplied 1) adequate Se concentration (7 to 12 microg x kg x BW(-1) x d(-1)) or 2) high-Se concentration (60 to 70 microg x kg x BW(-1) x d(-1)). Diets were similar in composition, including 25% grass hay, 25% wheat, 39% corn, 5% desugared molasses, and 6% wheat middlings supplement on a DM basis. In the Se treatment, high-Se wheat (10 ppm Se, DM basis) was replaced with low-Se wheat (0.35 ppm Se, DM basis). Diets were formulated to be similar in CP and energy (14.0% CP, 2.12 Mcal of NEm/kg, and 1.26 Mcal NEg/kg of DM) and were offered daily (1500) to individual steers in an electronic feeding system. Diets were fed at 2.38% BW. After 126 d, steers were slaughtered, and individual visceral tissue weights determined. Concentrations of DNA, RNA, and protein of duodenum, ileum, and total small intestine were not affected (P > or = 0.33) by treatment. Similarly, RNA:DNA and protein:DNA ratios in duodenum, jejunum, ileum, and whole small intestine were not (P > or = 0.33) affected by feeding high-Se wheat. Conversely, jejunal weight was greater (P < 0.002) in steers fed high-Se wheat than in controls (916 vs. 1,427 +/- 84 g). Jejunal DNA was increased (P < 0.04) in steers fed high-Se wheat (2.95 vs. 3.56 +/- 0.19 mg/g), suggesting increased cell number. Concentrations of jejunal RNA and protein were not altered by treatment; however, because the jejunal weight increased in high-Se steers, DNA, RNA, and protein contents (grams) were greater than in control steers (P < 0.05). Vascularity of jejunal tissue decreased (P < 0.10) with high-Se wheat; however, because jejunal mass was greater for the high-Se wheat treatment, total microvascular volume was not affected by treatment. Percentage of jejunal crypt cell proliferation was not affected (P = 0.48) by treatment; however, total number of cells proliferating within the jejunum was increased in steers fed high-Se wheat. Data indicate that the lower jejunal vascularity in the diet high in Se (provided from wheat) may have resulted in increased jejunal mass to meet physiological nutrient demand. Therefore, negative effects of Se level used in this study on productive performance of feedlot steers are not expected.

Selenium and vitamin E diet inclusion for optimal reproduction performances of red-legged partridge (Alectoris rufa)

“…These results are in accordance with the major effect of highSe wheat on visceral organ mass occurred in jejunal tissue, which is one of the most metabolically active tissue (Soto-Navarro et al 2004;Read-Snyder et al 2009). In general, visceral organs are metabolically very active and represent a substantial amount of maintenance energy consumption (Caton et al 2000).…”

“…In general, visceral organs are metabolically very active and represent a substantial amount of maintenance energy consumption (Caton et al 2000). The metabolic activity of an organ is the product of the organ size and metabolic activity per unit of tissue, and jejunum had higher fractional rates of protein synthesis (Soto-Navarro et al 2004). In our research, the level of selenium and vitamin E in partridge breeder diets seemed positively affecting jejunum and ileum tissues metabolic activity.…”

“…diet composition, feed particle size, organic acids diet inclusion (Gauthier et al 2007;Yang et al 2009;Fronte et al 2013). Soto-Navarro et al (2004) demonstrated that diet selenium content also may affects the morphological and histological traits in the small intestine. Regarding growth performances, Swain et al (2010) reported the maximum daily weight gain and feed conversion rate when chickens were fed a diet containing 0.50 mg/kg of selenium.…”

Nutritional plane and selenium supply during gestation affect yield and nutrient composition of colostrum and milk in primiparous ewes1

“…Within each Se and nutritional plane treatment, one-half of the ewes were assigned to be slaughtered and necropsied after colostrum sampling (between 3 and 24 h postpartum), and the remaining ewes were mechanically milked twice daily for 20 d. This resulted in a completely randomized design with a 2 × 3 factorial arrangement of Se supply × nutritional plane (ASe-RES, ASe-CON, ASe-HIH, HSe-RES, HSe-CON, HSe-HIH; n = 14 ewes/treatment for colostrum measures, n = 7 ewes/treatment for early lactation measures). Selenium treatments were based on NRC requirements (ASe), and nontoxic supranutritional amounts of Se (HSe) that have previously elicited biological response in ruminants (Soto-Navarro et al, 2004;Reed et al, 2007;Neville et al, 2008;Carlson et al, 2009).…”

Nutrient restriction and realimentation in beef cows during early and mid-gestation and maternal and fetal hepatic and small intestinal in vitro oxygen consumption

“…A second 150 cm segment was taken following the first section for measurement of stripped weight. Demarcations of the three sections of the small intestine were made using similar methods as previously reported (Soto-Navarro et al, 2004). The intestine was dissected, gently stripped of fat and digesta and weighed.…”