Influence of Zilpaterol and Mineral-Yeast Mixture on Ruminal Fermentation and Growth Performance in Finishing Steers

Effects of feeding different levels of chromium-enriched live yeast in hairy lambs fed a corn-based diet: effects on growth performance, dietary energetics, carcass traits and visceral organ mass

“…Likewise, Cr supplementation increased glucose uptake, enhanced protein synthesis (Pollard et al 2001), and reduced body fat (Barajas et al 2008;Valdés-García et al 2011) in feedlot cattle fed conventional finishing diets. Romero et al (2009) did not observe an effect of Cr-YC supplementation (0.18 mg/kg of DM of Cr) on measures of LM area, and external and internal fat deposition in feedlot steers. Domínguez-Vara et al (2009) observed increased HCW weight, LM area and carcass protein levels, and decreased carcass fat in finishing lambs supplemented with 0.25 mg/kg of Cr plus 0.3 mg/kg of selenium from Cr and selenium-enriched yeast.…”

“…In the present study, the average consumption of supplemental Cr per kg of BW was 0.019 (range from 0.009 to 0.028). This represents at least a 2-fold increase over that of dosages used in other studies where there was no consistent effect on growth performance or carcass traits in cattle supplemented with enriched Cr yeast (Swanson et al 2000;Domínguez-Vara et al 2009;Romero et al 2009). Thus it appears that optimal levels of supplemental Cr required to enhance growth performance and carcass characteristics in ruminants may be greater than those proposed for pigs.…”

“…Visceral organ mass and carcass traits Romero et al (2009) observed that supplementation of feedlot steers with 0.18 mg/kg of DM of Cr via Cr-YC increased the carcass dressing percentage. In contrast, Titi et al (2008) observed decreased dressing percentages in lambs supplemented with YC at rate of 12.5 g/day.head.…”

“…Expected DMI was computed as follows: DMI, kg/day = (EM/NE m ) + (EG/EN g ), where EM = maintenance coefficient of 0.056 Mcal/BW 0.75 (NRC 1985) and EG is the daily energy deposited (Mcal/day) estimated by equation: EG = [(0.276 • ADG) • SBW 0.75 , NRC 1985]. The divisors NE m and NE g are the NE of diet [calculated from tables of composition of feed (NRC 1985) supplementation on either ADG or GF of either light- (Kawas et al 2007;Tripathi et al 2008) or heavy-weight finishing lambs (Romero et al 2009;Titi et al 2008), or feedlot steers (Baumann et al 2004). The basis for inconsistencies in growth performance responses to non-mineral-enriched YC supplementation is not certain.…”

Effects of high-level chromium methionine supplementation in lambs fed a corn-based diet on the carcass characteristics and chemical composition of the longissimus muscle

“…In this sense, chromium (Cr) supplementation, as Cr propionate or Cr methionine, has shown increases in the percentage of carcass muscle and decreased carcass fat in pigs and poultries (1). In ruminants, Cr requirements have not been clearly established (2) and there is limited information available on the effects of Cr on carcass characteristics in feedlot cattle (3) and in feedlot lambs (4). In a recent study (5), linear decreases (P = 0.02) in kidney-pelvicheart fat and fat thickness were observed in finishing steers supplemented with chelated Cr (as Cr-enriched yeast) at daily levels of 0, 5, 10, or 15 mg/head.…”