High levels of whole raw soybean in diets for Nellore bulls in feedlot: effect on growth performance, carcass traits and meat quality

Abstract

The objective of this study was to evaluate the effect of whole raw soybean (WRS) in the finishing diet of Nellore cattle on productive performance, carcass traits, meat quality, fatty acid profile of meat, and blood parameters. In a completely randomized design, 52 Nellore bulls (mean body weight ± SD: 380 ± 34 kg) were allotted for 84 days. The animals received the following diets with a forage: concentrate ratio of 40/60: (i) WRS0: control diet without soybean grains; (ii) WRS8: diet containing 8% WRS in dry matter basis; (iii) WRS16: diet containing 16% WRS, and (iv) WRS24: diet containing 24% WRS. At intervals of 28 days, the animals were weighed, muscle and adipose tissue was analysed by ultrasound, and blood samples were collected. The animals were slaughtered on day 85 and liver weight and hot carcass weight were measured during slaughter. The pH and carcass dressing were calculated at 24 h after slaughter. Longissimus dorsi muscle samples were collected for the determination of fatty acid profile of meat, ether extract, tenderness and sensory analysis of meat aged for 14 days. Blood cholesterol content increased linearly with increasing proportion of whole raw soybean grains. The diet did not affect performance or carcass attributes. The WRS8 had the highest shear force values. In fatty acid profile, C14:0 decreased (p = 0.05), whereas 16:1, 20:0 and 20:1 fatty acids increased linearly with increasing proportion of WRS (p < 0.05). However, concentration of conjugated linoleic acid cis 9, trans 11 and 17:0 increased with WRS24 and WRS16. In the sensory analysis, WRS24 was more tender with respect to the other treatments (p < 0.05). Finally, the inclusion of WRS in the finishing diet of feedlot Nellore bulls only evidenced little changes in fatty acid profile and tenderness, in animals fed diets containing 16 or 24% soybean.

Nutrient digestion, microbial protein synthesis, and blood metabolites of Jersey heifers fed chitosan and whole raw soybeans

“…Fat supplementation increases lipoprotein cholesterol export by the intestine, the major site of cholesterol synthesis in ruminants (Noble, 1981). Cônsolo et al (2015) fed increasing doses of WS to Nellore bulls and found a linear increase in total cholesterol and no difference in glucose concentrations. The mechanism by which CHI alters the cholesterol metabolism is unclear, but studies in humans have demonstrated that chitosan reduced serum LDL cholesterol (Yihua and Binglin, 1997;Wuolijoki et al, 1999), and Bokura and Kobayashi (2003) suggested a reduced lipid absorption from the gastrointestinal tract.…”

Effects of ractopamine hydrochloride and dietary protein content on performance, carcass traits and meat quality of Nellore bulls

“…Shear force (SF) and cooking loss (CL) analysis SF and CL were determined at the Laboratory of Meat Quality of the University of São Paulo, using the methodology proposed by Wheeler et al (2001) and previously described by Cônsolo et al (2015). The steaks were thawed for 24 h at 4°C, weighed and roasted in an oven equipped with a thermostat adjusted to 170°C (Flexa de Ouro Industry, São Paulo, SP, Brazil).…”

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“…6 L* = Lightness, from 0 (black) to 100 (white); a* = redness, from -120 (green) to 120 (red); b*=yellowness, from -120 (blue) to 120 (yellow). Fonte: Cônsolo, 2015 Meat colour scores were not affected by RH supplementation, and values were within the accepted normal range . Dietary CP altered the b* value (P<0.01), being greater for CP120 than CP100 (15.3 vs. 10.2 for CP120 and CP100, respectively).…”

“…After 14 and 21 days of aging, cooking losses were lower than at day 0 (P<0.05, Figure 1). Fonte: Cônsolo, 2015 There was no RH x CP interaction for meat WBSF (P=0.13). There was a significant RH x Time interaction for meat WBSF (P<0.01, Figure 2).…”

“…(NRC, 2000). Fonte: Cônsolo, 2015. To measure the performance, the animals were weighed at the beginning of the ractopamine supplementation (d 0), after 18 d of supplementation (d 18), and before slaughter (d 34). Animals were weighed after 18 hours of feed and water restriction.…”