Sodium monensin or propolis extract in the diets of feedlot-finished bulls: effects on animal performance and carcass characteristics

Abstract

This study evaluates the effects of three diets: a control (CON), containing sodium monensin (MON) and containing propolis extract (PRO). The performance of 33 feedlot-finished bulls, 11 for each diet, and carcass characteristics were examined. The 27 months old bulls, with initial liveweight 400±2.33 kg, were kept in a feedlot for 84 days, till 484±6.76 kg at slaughter. The roughage and concentrate ratio of the diets was 52:48 on DM basis. Maize silage was used as roughage and maize, soyabean meal, urea, mineral salt and limestone were used as concentrate. The average final weight (501 kg), hot carcass weight (275 kg) and average daily gain (1.17 kg) were higher (P<0.05) for bulls fed with PRO than for those on the CON (472, 259 and 0.87 kg, respectively), or MON (480, 259 and 0.94 kg, respectively) diets. Dry matter conversion was better (P<0.05) for bulls fed with PRO (8.04) than those on the CON (10.9) or MON (9.72) diets. Carcass characteristics such as conformation, carcass length, leg length, cushion thickness, Longissimus muscle area, Longissimus muscle area/100 kg of liveweight, fat thickness, colour, texture and marbling were not influenced (P>0.05) by the treatments.

Propolis or cashew and castor oils effects on composition of Longissimus muscle of crossbred bulls finished in feedlot

“…The values observed for the fat thickness (5.0 mm) and LM area (58 cm 2 ) were consistent with results observed in Brazilian cattle finished in a feedlot ). Thus, the inclusion of propolis and essential oils in the diets of crossbred bulls finished in a feedlot and pH24h slightly above the normal of meat, had no effect on the fat thickness an meat subjective characteristics, as was observed in previous studies with cattle Nellore (Zawadzki et al, 2011b).…”

“…6.8); however, when finishing rations containing large amounts of cereal grain are fed, rumen pH can drop drastically. Therefore, ionophores additives were used in cattle diets to modulate rumen fermentation (Valero et al, 2011;Zawadzki et al, 2011b). The use of ionophores is well-documented in ruminant nutrition; they improve growth, feed intake and efficiency (Russell and Houlihan, 2003).…”

“…New natural additive products have been studied as a partial alternative for feed strategies to improve animal production including propolis or essential oils (Benchaar et al, 2008;Valero et al, 2011;Zawadzki et al, 2011b). Such products have several advantages over commonly used ionophores, since they are residue free and are generally regarded as safe in the food industry.…”

“…Some active substances composing propolis may disorganize the cytoplasmic membrane and cell wall, with the effects of a partial bacteriolysis. Propolis has positive results in studies involving animal nutrition, such as increased in vitro digestibility and better feed efficiency (Zawadzki et al, 2011b).…”

<b>Carcass characteristics and sensorial evaluation of meat from Nellore steers and crossbred Angus vs. Nellore bulls

“…However, the cattle finished in the pasture system need higher weights to meet the requirements of the Brazilian market Carcass dressing percentage was similar (p < 0.10) between Nellore and crossbred Nellore vs. Angus bulls. In general, in Brazil, carcass dressing percentage of Nellore or crossbred bulls can vary from 50 to 55% (Cruz et al, 2014;Rotta et al, 2009;Zawadzki et al, 2011).…”