https://www.alice.cnptia.embrapa.br/alice/handle/item/277 Artigo em periódico indexado (CPPSE) Fri, 10 Apr 2026 00:34:58 GMT 2026-04-10T00:34:58Z https://www.alice.cnptia.embrapa.br/alice/handle/doc/1186170 Título: Intake, digestibility and rumen fermentation in Nellore bulls grazing degraded or recovered pastures of Urochloa ssp. or the grass intercropped with pigeon pea. Autoria: FURTADO, A. J.; ABDALLA FILHO, A. L.; PERNA JUNIOR, F.; PASQUINI NETO, R.; SILVA, G. V. da; LOBO, A. A. G.; COELHO, L. de M.; BRUNO, J. F.; BERNDT, A.; PEDROSO, A. de F.; MEDEIROS, S. R. de; OLIVEIRA, P. P. A.; RODRIGUES, P. H. M. Conteúdo: With global population growth, livestock production must be intensified with reduced environmental impact. The benefits of legume-grass intercropping are well-documented; however, no studies have evaluated ruminal fermentation and digestive kinetics. Pigeon pea, a legume intercropped with tropical grasses, can improve the nutritional value of forage, increasing digestive efficiency and mitigating methane emissions, while also reducing the need for nitrogen fertilization. Over two years, nine rumen-cannulated Nellore bulls were allocated to nine experimental paddocks (1.25 ha each; total area of 11.25 ha) in a randomized complete block design, with year as the blocking factor. Treatments followed a 3 × 2 factorial arrangement, consisting of three forage systems and two seasons (dry and rainy), with three paddock replicates per treatment: DEG, a degraded pasture; REC, recovered pasture fertilized with 200 kg of N; and MIX, mixture of legume-grass pasture. External and internal markers were used to determine dry matter intake (DMI). Grass and legume intake proportions were estimated using C3 and C4 carbon isotopes. The concentration and production of short-chain fatty acids, methane, and ammonia compounds were calculated using the ex-situ fermentation technique. Animals in DEG pasture presented a higher DMI of the supplement and higher relative energy loss as methane production, while a higher level of DM digestibility was observed in the MIX pasture. Higher ruminal concentrations of NH3-N were obtained for animals in the REC pasture. The lowest ruminal DM and NDF degradation rates were observed in the MIX pasture. Thu, 01 Jan 2026 00:00:00 GMT https://www.alice.cnptia.embrapa.br/alice/handle/doc/1186170 2026-01-01T00:00:00Z https://www.alice.cnptia.embrapa.br/alice/handle/doc/1186180 Título: Pasture management in Ferralsols drives mineral-associated organic matter storage, exceeding native soil carbon stocks and enhancing cation exchange capacity. Autoria: BENTO, L. R.; MARTIN NETO, L.; SANTOS, J. V. dos; FREITAS, V. da S.; PEZZOPANE, J. R. M.; BERNARDI, A. C. de C.; OLIVEIRA, P. P. A.; SCHWEIZER, S. A. Conteúdo: Pasture management is pivotal for enhancing soil organic carbon (SOC) storage in tropical grasslands, yet SOC recovery is often considered merely as the replenishment of historical losses following land-use change. It remains unclear whether managed Ferralsols can surpass the SOC stocks of native vegetation (NV) and which mechanisms drive such gains. We evaluated SOC pools, chemical composition, and nutrient-holding capacity after 24 years under unmanaged degraded pasture (DP) and fertilized managed pasture (MP), relative to NV. SOC storage in these systems was primarily mediated by the mineral-associated organic matter (MAOM) pool. Compared to NV, DP soils exhibited reduced MAOM stocks (119 vs. 92 Mg C ha−1), whereas MP soils stored 148 Mg C ha−1. In DP, soil acidity, low nutrient availability, and poor forage inputs induced microbial stress (as revealed by phospholipid fatty acid profiles), likely constraining MAOM formation and yielding MAOM enriched in carbohydrates with fewer carbonyl groups. In contrast, liming and fertilization in MP alleviated the Ferralsol’s low pH and nutrient deficiencies, enhancing forage yields and reducing microbial stress, likely promoting MAOM with more microbially processed signatures. NanoSIMS analyses revealed microscale organic matter patches sparsely covering clay-sized particles, indicating that SOC storage is decoupled from mineral surface area and highlighting the role of organic inputs and microbial activity in MAOM formation. Higher MAOM under MP not only increased SOC stocks but also enhanced cation exchange capacity, demonstrating that targeted pasture management can exceed native SOC stocks while improving nutrient retention. Thu, 01 Jan 2026 00:00:00 GMT https://www.alice.cnptia.embrapa.br/alice/handle/doc/1186180 2026-01-01T00:00:00Z https://www.alice.cnptia.embrapa.br/alice/handle/doc/1186091 Título: Intensified tropical pasture-based beef cattle production systems and their effects on carcass traits, meat quality and methane emissions from Nellore steers. Autoria: SILVA, G. V. da; PASQUINI NETO, R.; MELO, M. N. V. de; ANDRADE, L. B. de; FURTADO, A. J.; FABRICIO, E. C.; BERTOLONI, A. V.; LOBO, A. A. G.; PERNA JUNIOR, F.; MEDEIROS, S. R. de; BERNDT, A.; NASSU, R. T.; PEDROSO, A. de F.; OLIVEIRA, P. P. A.; PEREIRA, A. S. C.; RODRIGUES, P. H. M. Conteúdo: This study evaluated the effects of five pasture-based production systems on the carcass and meat quality traits, as well as the methane (CH4) emissions intensity of male Nellore steers per kg of carcass under tropical conditions. Over two years (2019–2021), uncastrated male steers (three/year/experimental spatial unit) were randomly assigned to five treatments (with two replicates): 1) degraded pasture without nitrogen (N) fertilization (DP0); 2) silvopastoral with 200 kg N ha-1 (SP200); 3) rainfed pasture with 200 kg N ha-1 (RP200); 4) rainfed pasture with 400 kg N ha-1 (RP400); and 5) irrigated pasture with 600 kg N ha-1 (IP600). Animals grazed exclusively, receiving water and mineral-protein supplement ad libitum until being stunned by the Brazilian-approved method cranial concussion, followed by exsanguination, without electrical stimulation. The carcass and meat quality traits observed are positively influenced by intensification. Specifically, IP600, RP400 and RP200 demonstrate a clear benefit in improving RA, BFT, LCCW, CEP and FT (including HEP, FEP and spareribs), and Bones (expressed as kg carcass-1 and %); while SP200 and DP0 restricted the growth rates and muscle development of the animals due to the competition between the trees and the pasture and lack of fertilization, respectively. For CH4 emission intensities (per kg of carcass), SP200 and DP0 exhibited the highest emissions without proportional production gains, while IP600, RP400, and RP200 showed the lowest values. Well-managed intensified pasture-based systems consistently achieved lower CH4 emission per unit of product than those observed in DP0, confirming their potential as a viable sustainability system. Thu, 01 Jan 2026 00:00:00 GMT https://www.alice.cnptia.embrapa.br/alice/handle/doc/1186091 2026-01-01T00:00:00Z https://www.alice.cnptia.embrapa.br/alice/handle/doc/1185318 Título: Contribution of Fat Adjustment to Residual Feed Intake Estimation in Beef Cattle. Autoria: TEMP, L. B.; PEREIRA, L.; YOKOO, M. J. I.; MARCONDES, C. R.; BUSSIMAN, F.; HIDALGO, J.; LOURENCO, D.; REY, F. S. B. Conteúdo: Including fat thickness as a covariate in the regression model used to calculate residual feed intake (RFI) could help preserve carcass quality traits, such as marbling, flavour and juiciness, by accounting for variation in fat deposition. This study aimed to: (1) investigate the benefits of adjusting RFI for rump fat thickness (RFT); (2) estimate variance components and genetic correlations between RFI-calculated with (RFIF) and without (RFIW) adjustment for RFT-and growth, reproduction and carcass traits using genomic information in beef cattle; and (3) compute accuracy, bias and dispersion of RFIF and RFIW genomic breeding values predicted using single-step GBLUP (ssGBLUP). We hypothesised that adjusting for RFT would account for a small proportion of RFI variability, and that genetic parameter estimates would support more balanced selection decisions. Phenotypic records were collected from 9094 Nellore animals (3253 females and 5952 males) over 14 feed efficiency tests conducted from 2011 to 2024. The pedigree included 17,407 animals, of which 5812 were genotyped. Linear and threshold animal models were applied for continuous and categorical traits, respectively. Heritability estimates were low for RFIW (0.17) and RFIF (0.16), with a strong genetic correlation between them (0.98), and a weak genetic correlation between RFIW and RFT (0.15). Spearman correlations between RFIF and RFIW breeding values were high: 0.98 in females and 0.95 in males. Genetic correlations of RFIW and RFIF with growth, reproduction and carcass traits ranged from -0.33 to 0.35. Prediction accuracy was similar for RFIF (0.43) and RFIW (0.44), whereas bias (0.00 for RFIw and 0.00 for RFIF) and dispersion (0.05 for RFIw and 0.03 for RFIF) showed minor differences. Although RFIF captured slightly more genetic variability, the impact was minimal and no differences were observed between RFIF and RFIW. The genetic correlations between RFI and traits related to growth, reproduction and carcass were close to zero to moderate, indicating that selection for RFI is unlikely to negatively impact these other traits. However, it is essential to consider the full set of traits in the selection process to avoid potential drawbacks to the overall genetic progress of the herd. Thu, 01 Jan 2026 00:00:00 GMT https://www.alice.cnptia.embrapa.br/alice/handle/doc/1185318 2026-01-01T00:00:00Z