Forage quality and methane production of the grazing portion of grass produced under elevated [CO2].

The potential changes in nutritional quality of forages for livestock production under climate changes scenario are still scarce, despite recent works have shown that the elevated [CO2] increased biomass production, in grass lesser than in legume. This work aimed to determine the effects of season and enhanced [CO2] under Free-Air Carbon Dioxide Enrichment (FACE) condition

Indutores abióticos na resposta de diferentes genótipos de soja quanto à ferrugem-asiática e componentes de produção.

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Performance of Finishing Nellore Beef Steers in Intensively Managed Pastures and Silvopastoral Systems in Southeast of Brazil

This study evaluated the average daily weight gain (ADG), stocking rates, and live weight gain per hectare (LWG) in different intensified animal production systems. The experiment was carried out from September 2020 to September 2021 at Embrapa Southeast Livestock, São Carlos, SP, Brazil. Thirty Nellore steers (285±21 kg of live weight and 12±13 months old) were randomly distributed into five treatments, with two replicates: 1) intensively managed and irrigated Megathyrsus maximus cv. Tanzânia pasture overseeded in the dry season with Avena byzantina and Lolium multiflorum (IHS); 2) intensively managed rainfed M. maximus cv. Tanzânia pasture (RHS); 3) intensively managed rainfed pasture with a mix of Urochloa decumbens cv. Basilisk and U. brizantha cv. Marandu (RMS); 4) intensively managed silvopastoral system with U. decumbens cv. Basilisk and Brazilian native trees (312 trees ha-1) (LFS); and 5) extensively managed degraded pasture of U. brizantha cv. Marandu and U. decumbens cv. Basilisk (DP). Data were submitted to analysis of variance considering treatments and seasons as fixed effects, and the interaction between treatment×season was tested. Means were compared by the Fisher test at 5% using the PROC MIXED of SAS. For all parameters, significant interaction was found (P\u3c .0001). In general, higher ADG, stocking rate and LWG values were found for IHS (0.82 kg d-1, 6.03 AU ha-1 and 459.9 kg ha-1, respectively), while the lowest values were found for DP (0.33 kg d-1); for LFS (1.16 AU ha-1); and for LFS and DP (71.0 and 68.9 kg ha-1, respectively). It is important to consider that for LFS the competition for natural resources between the system components (pasture and trees) together with low temperatures and soil moisture during the autumn and winter seasons may explain the unexpected low performances. Overall, our results showed that more intensified systems allowed better animal performances when compared to DP

Forage Intake of \u3ci\u3eNellore\u3c/i\u3e Steers Grazing a \u3ci\u3eCajanus Cajan\u3c/i\u3eLegume-Grass Intercropped Pasture

This study evaluated forage, supplement, and total (forage + supplement) dry matter intake (DMI, expressed as kg/day and as percentage of average live weight, %ALW) of Nellore steers in different production systems, including a Cajanus cajan (Pigeon pea) legume-grass intercropped pasture by using external (titanium dioxide, TiO2) and internal (indigestible neutral detergent fiber, iNDF) markers. The experiment was carried out at Embrapa Southeast Livestock, São Carlos, SP, Brazil, in the rainy (January) and dry (July) seasons of 2021. Eighteen animals Nellore steers were randomly distributed into three treatments with three replications (1.5 ha paddocks each): 1) degraded pasture of Urochloa decumbens cv. Basilisk (DEG); 2) Intercropped legume-grass pasture composed by U. decumbens cv. Basilisk, U. brizantha cv. Marandu and Cajanus cajan cv. BRS Mandarin limed and fertilized with P, K, S, micronutrients (INT) and 3) mixture pasture of U. decumbens cv. Basilisk and U. brizantha cv. Marandu limed and fertilized with P, K, S, micronutrients and 200 kg N-urea ha-1 year-1 (REC). The statistical model considered treatment and season as fixed effects, and the treatment×season interaction was tested. Data were submitted to analysis of variance (PROC MIXED) and means were compared by the Fisher test at 5%. Significant treatment×season interaction was found (P \u3c 0.05). During the rainy season lower values of forage and total DMI were found for the INT treatment when compared to REC. However, during the dry season, the treatment with Pigeon pea inclusion (INT) presented higher values of forage and total DMI. The DEG and REC system steers reduced their DMI from the rainy season to the dry season, even receiving a mineral energetic-protein supplement with urea, while the INT steers maintained DMI between seasons without receiving the energetic-protein supplement. These results highlight the potential of including Pigeon pea in pasture-based systems, especially during the dry season when tropical grasses present low nutritional quality and forage availability

Relação acetato: propionato no líquido ruminal de novilhos Nelore em diferentes sistemas de produção a pasto.

Visando sustentabilidade, pesquisas têm buscado alimentos e estratégias que modulem a fermentação ruminal, melhorando o aproveitamento dos nutrientes e diminuindo a produção de gases do efeito estufa (GEE) nos sistemas de produção animal

Estratégias de recuperação de pastagens degradadas para aumento do sequestro de carbono no solo, incluindo o consórcio com o feijão-guandu: resultados parciais.

Resumo: O aumento no sequestro de carbono (C) é importante para melhorar a eficiência e sustentabilidade dos sistemas pastoris de produção pecuária. O objetivo dessa pesquisa foi avaliar a recuperação de pastagem e o consórcio de braquiária (Urochloa decumbens cv. Basilisk) com feijão guandu (Cajanus cajan cv. Mandarim) como estratégia para aumentar osequestro de carbono. Foram avaliados três sistemas de produção:pastagem degradada, pastagem recuperada, pastagem consorciadacom feijão guandu, em delineamento inteiramente casualizado com trêsrepetições (9 piquetes com aproximadamente 1,2 ha), tendo como referênciaa floresta estacional semidecidual. A pastagem recuperada recebeu correção efertilização do solo com macro e micronutrientes e fertilização nitrogenada de200 kg N/ha.ano-1, a pastagem consorciada recebeu os mesmos tratos culturais,entretanto, a fertilização nitrogenada foi substituída pela fixação biológica denitrogênio no consórcio com feijão guandu. A pastagem de braquiária foiestabelecida em 1996 e foi degradada, em 2010 iniciou-se a recuperaçãodas pastagens. Em 2022 foram abertas seis trincheiras por tratamento, ondeforam coletadas amostras de solo indeformadas para análise da densidadeaparente e amostras deformadas ao redor das trincheiras para análise daconcentração de N e C. Houve interação entre os tratamentos dentro doperfil do solo. A concentração de nitrogênio foi alterada até 40 cm, sendomaior no sistema consorciado e na floresta, já a de carbono variou até 10 cm,com maiores valores no sistema consorciado. A relação C:N foi menor nosistema consorciado e na floresta. A concentração de carbono foi explicadapela concentração de nitrogênio no solo. O consórcio com o feijão guandu epastagens tropicais é uma tecnologia potencial para aumentar o sequestrode carbono no solo. | Abstract: Increasing carbon sequestration is important for improving the efficiency and sustainability of pastoral livestock production systems. The objective of this research was to evaluate the recovery of pasture and the mix of signal grass pasture (Urochloa decumbens cv. Basilisk) with pigeon pea (Cajanus cajan cv. Mandarim) as a strategy to increase carbon sequestration. Three treatments were evaluated: degraded pasture, recovered pasture, pasture intercropped with pigeon pea, in a completely randomized design with three replications (9 paddocks with approximately 1.2 ha) and the semideciduous seasonal forest was the reference area. The recovered pasture received correction and soil fertilization with macro and micronutrients, and nitrogen fertilization of 200kg N/ha.year-1, the intercropped pasture received the same cultural treatments, however, nitrogen fertilization was replaced by biological nitrogen fixation in the mix with pigeon pea. The signal grass pasture was established in 1996 and was degraded, in 2010 the recovery of the pastures began. In 2022 six trenches per treatment were opened, where undisturbed soil samples were collected for bulk density analysis and deformed samples around the trenches for N and C concentration analysis. There was interaction between treatments within the soil profile. Nitrogen concentration was altered up to 40 cm, being higher in the intercropping system and in the forest, whereas carbon concentration varied up to 10 cm, with higher values in the intercropping system. The C:N ratio was lower in the intercropped system and in the forest. The carbon concentration was explained by the nitrogen concentration in the soil. The tropical pasture mixed with pigeon pea is a potential technology to increase soil carbon sequestration

Análise comparativa entre uma equação de predição de NDT e a DIVMS de pastagens utilizadas para a alimentação animal.

A determinação da composição bromatológica dos alimentos é fundamental e várias técnicas laboratoriais e métodos alternativos, assim como modelos matemáticos, têm sido desenvolvidos ao longo dos anos para a melhor caracterização das dietas fornecidas aos animais

DIALYSIS MINERAL BONE DISEASE

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Partitioning of environmental and taxonomic controls on Brazilian foliar content of carbon and nitrogen and stable isotopes

The Neotropics harbor some of the most diversified woody species in the world, and to understand the nutrient dynamics in these ecosystems, it is crucial to understand the role of plant taxonomy. In addition, biological nitrogen (N) fixation (BNF) in the tropics is one of the key processes affecting the global N cycle. Our objective was to (i) investigate the role of taxonomy and sampling site as predictors of foliar carbon (C) and N concentration and its stable isotopes (i.e., δ13C and δ15N); (ii) assess differences in foliar N, C:N ratio, and δ15N among three functional groups: species of N2-fixers and non-fixers of the Fabaceae family, as well as non-Fabaceae species; and (iii) examine the effect of wood density on tree foliar properties. We hypothesized that Fabaceae specimens in symbiosis with N2-fixers would possess a higher foliar N than non-fixing plants, including those of the Fabaceae family, as well as high-density trees would have higher foliar C and C:N ratio relative to low-density trees, where the latter invest in nutrients instead of structural C. We used a data set composed of 3,668 specimens sampled in three main biomes of Brazil: Amazon, Atlantic Forest, and Cerrado. The partitioning of variance had a higher influence of taxonomy on leaf C, N, and C:N ratio. Conversely, foliar δ13C and δ15N were environmentally constrained. While family was the most important taxonomy level for C, N, and C:N ratio, species played a major role for δ13C and δ15N. Foliar N followed the pattern fixers > non-fixers > non-Fabaceae, while C:N ratio had an opposite trend. In addition, foliar C was correlated with wood density, where high-density > medium-density and low-density woods. The large variability of δ15N was observed among Fabaceae species, demonstrates the complexity of using δ15N as an indicator of BNF. The higher foliar N of Fabaceae non-fixers than non-Fabaceae specimens support the hypothesis that an N-demanding lifestyle is an inherent pattern in this family. Lastly, although observed in some studies, the prediction of foliar properties using wood density is challenging, and future research on this topic is needed