The tannin extract of Quebracho Colorado wood (Schinopsis balansae and Schinopsis lorentzii) is rich in proanthocyanidins with demonstrated powerful scavenging activity against free radicals. Currently, this extract is used in the wine industry to improve sensory attributes, stabilize color, and act as a redox buffer. In this study, we hypothesized that condensed tannins from Quebracho Colorado wood could be incorporated into beef patties as a natural antioxidant source to improve shelf life. Patties formulated with tannin extract (0, 0.5%, 1%, and 1.5%) were evaluated for instrumental color, lipid oxidation, and sensory attributes. Patties were displayed under refrigerated aerobic conditions (PVC film) for 6 days for color and lipid oxidation analysis. For sensory analysis, patties were frozen immediately after formulation. Control (0%) samples were redder than samples formulated with 1.5% tannin during the first 4 days of display. For b*, samples formulated with 1.5% tannin were predominantly yellower during display. After day 4, chroma values were higher in samples formulated with 1.5% tannin. The inclusion of tannin extract improved lipid stability, however, levels above 0.5% decreased tenderness, softness, juiciness, and overall desirability of patties.

Quick and reliable methods to estimate body and carcass composition of beef cattle are needed to predict the most profitable slaughter weight. This study evaluates body compositional equations using biometric measurements (BM), dissected fat (kg) at the 9–11th rib section and rib fat depth (cm). The present independent dataset used to evaluate the equations comprised of 48 F1 Nellore × Angus bulls (B) and steers (S); aged 12.5 ± 0.51 months with a mean shrunk BW (SBW) of 233 ± 23.5 and 238 ± 24.6 kg for B and S, respectively. Animals were fed a diet of 60% corn silage and 40% concentrate ad libitum. Eight animals were slaughtered at the beginning of the trial and the remaining animals were randomly assigned into a 2 (sex) × 3 (slaughter weights) factorial arrangement, and slaughtered when the average BW of the group reached 380 (6B and 5S), 440 (6B and 5S), 500 kg (5B and 5S). In addition, eight animals (4B and 4S) were fed at the maintenance level intake and slaughtered with the 500-kg group. Before slaughter, animals were led through a squeeze chute to collect BM, which included hook bone width, pin bone width, abdomen width, body length, rump height, height at withers, pelvic girdle length, rib depth, girth circumference, rump depth, body diagonal length, and thorax width. The following post-mortem measurements were included: total body surface, body volume (BV, m3), subcutaneous fat, internal fat, intermuscular fat, carcass physical fat (CF, kg), empty body fat (EBF, kg), carcass chemical fat (kg), empty body chemical fat (kg), fat thickness (cm) in the 12th rib, and 9–11th rib section fat. The predicted values were compared with the observed. Among all evaluated equations, only five were found to be adequate for F1 Nellore × Angus: Eqns (7): BV = 0.036 (±0.016) + 1.028 (±0.049) × BVcylinder (n = 28, RMSE = 0.016 m3, r2 = 0.942) and (8): BV = –0.011 (±0.004) + 9.8 × 10–4 (±1.84 × 10–5) × SBW (n = 27, RMSE = 0.003 m3, r2 = 0.997), to estimate BV; and Eqns (27): EBF = –16.8 (±2.68) + 0.142 (±0.008) × SBW (n = 36, RMSE = 4.17 kg, r2 = 0.897), (28): EBF = 0.011 (±0.002) × SBW + 1.22 (±0.024) × CF (n = 35, RMSE = 0.69 kg, r2 = 0.999), and (32): EBF = 1.445 (±0.010) × CF (n = 43, RMSE = 1.51 kg, r2 = 0.998), to estimate EBF. More research is needed to create a robust prediction of carcass and empty body fat using BM for animals of different breeds under diverse production conditions.

Objective: Twenty-four pregnant Nellore primiparous grazing cows were used to evaluate the effects of energy-protein supplementation and supplementation frequency during pre (105 d before calving) and postpartum (105 d after calving) on performance and metabolic characteristics.Methods: Experimental treatments consisted of a control (no supplementation), daily supplementation (1.5 kg/d of concentrate/animal) and infrequent supplementation (4.5 kg of concentrate/animal every three days). During the pre and postpartum periods, concentrations of blood metabolites and animal performance were evaluated. Ureagenesis and energy metabolism markers were evaluated at prepartum period.Results: Supplementation frequency did not alter (p>0.10) body weight (BW), average daily gain (ADG), and carcass traits during pre and postpartum. The BW (p = 0.079), adjusted BW at day of parturition (p = 0.078), and ADG (p = 0.074) were greater for supplemented cows during the prepartum. The body condition score (BCS; p = 0.251), and carcass traits (p>0.10) were not affected by supplementation during prepartum. On postpartum, supplementation did not affect animal performance and carcass traits (p>0.10). The dry mater intake was not affected (p>0.10) by supplementation and supplementation frequency throughout the experimental period. Daily supplemented animals had greater (p0.10) the levels of blood metabolites, neither the abundance of ureagenesis nor energy metabolism markers.Conclusion: In summary, our data show that the reduction of supplementation frequency does not cause negative impacts on performance and metabolic characteristics of primiparous grazing cows during the prepartum.

This study evaluated the effects of supplementing dry live yeast (LY; Saccharomyces cerevisiae) on in vitro gas production (IVGP) fermentation dynamics, pH, and CH₄ concentration at 48 h, and in situ rumen parameters and digestibility of DM (DMD) and NDF (NDFD) of growing cattle during 3 feeding phases: grower (GRW) for 17 d (38% steamed-flaked corn; SFC), transition (TRANS) for 15 d (55.5% SFC: 1.2 Mcal/kg NE_g), and finisher (FIN) for 13 d (73% SFC: 1.23 Mcal/kg NE_g). Twenty British-crossbred, ruminally cannulated steers (183 kg ± 44 kg) 6 mo of age were blocked by weight into 5 pens containing Calan gate feeders and received a control (CON) diet (17.2% CP, 35.8% NDF, 86.7% DM) without LY on days −12 to 0. After that, animals were randomly assigned to treatments (TRT), 5 animals per TRT: CON or LY at inclusion rates of 5 g/d (LY1), 10 g/d (LY2), or 15 g/d (LY3) top dressed every morning at 0800 for 45 d. The DMD and NDFD were assessed during 7 separate collection days using in situ nylon bags containing 5 g of GRW, TRANS, or FIN diets, incubated at 1200 for 48 h. Protozoa counts (PC) were determined during 5 collection periods. Data were analyzed as a repeated measure within a randomized complete block design, assuming a random effect of the pen. For GRW, TRT altered the total gas production of the nonfiber carbohydrate (NFC; P = 0.045) and the fractional rate of degradation (kd) of the fiber carbohydrate (FC) pool (P = 0.001) in a cubic pattern (P ≤ 0.05): LY2 had the most gas production and fastest kd. TRT also influenced DMD (P = 0.035) and NDFD (P = 0.012) with LY2 providing the greatest digestibility. For TRANS, TRT tended to affect the NFC kd (P = 0.078) and influenced pH (P = 0.04) and DMD (P < 0.001) in which LY2 yielded the fastest kd, highest pH, and greatest DMD. For FIN, there was an effect of TRT on total gas production (P < 0.001) and kd (P = 0.004) of the NFC pool, FC kd (P = 0.012), in vitro CH₄ concentration (P < 0.001), PC (P < 0.001), DMD (P = 0.039), and NDFD (P = 0.008). LY1 had the highest PC and provided the greatest DMD and NDFD. LY2 had the fastest kd of both the NFC and FC pools and had the least CH₄ concentration. LY3 had the greatest NFC gas production. No specific dose–response pattern was observed, but 10 g/d provided the most beneficial result for all diets. We concluded that supplementation with LY affected IVGP as well as ruminal parameters and digestibilities.

Urea is one of the most widely used sources of non-protein nitrogen (NPN) in ruminant diets due to its low cost and high availability. However, its rapid solubilization in the rumen can result in abrupt ammonia release, leading to toxicity risks and low nitrogen utilization efficiency. In this context, slow-release technologies, particularly microencapsulation, have been developed to synchronize NPN release with fermentable carbohydrate availability, thereby enhancing microbial protein synthesis, improving animal performance, and reducing environmental impacts. This review compiles recent advances in urea microencapsulation, emphasizing different wall materials such as waxes, lipids, polysaccharides, and fatty acids, as well as drying techniques and formulation strategies. Slow-release urea (SRU) addition in small ruminants’ diet may increase nutrient intake and digestibility, improve N balance, and reduce urinary excretion losses. Regarding performance, positive responses are observed when nitrogen release is properly synchronized with energy availability, although the results may vary depending on the encapsulant type, forage-to-concentrate ratio, and ruminal passage rate. Additionally, effects on meat quality and environmental parameters indicate that this technology holds not only zootechnical but also socio-environmental potential. It is concluded that urea microencapsulation can represent a promising alternative to optimize NPN use efficiency in ruminant production systems, though greater methodological standardization, long-term evaluations, and comparative economic analyses are required to encourage its broader adoption.