DSpace Communidade: Embrapa Gado de Leite (CNPGL)

Effects of sodium monensin and a tannin–yeast blend on intake, milk yield, and methane emissions in lactating holstein cows.

2026-04-28T11:48:58Z

Título: Effects of sodium monensin and a tannin–yeast blend on intake, milk yield, and methane emissions in lactating holstein cows. Autoria: PIUZANA, L. G.; TOMICH, T. R.; ROTTA, P. P.; CARVALHO, D.; AMORIM, W. P. F.; SILVA, L. H. R.; VIEIRA, J. V. F.; RIBEIRO, E. F.; SILVA, A. L. da Conteúdo: This study evaluated the effects of sodium monensin or a blend containing condensed tannins and yeast products on intake, digestibility, performance, and methane emissions in lactating Holstein cows. Nine cows (three rumen-fistulated and six non-fistulated) were assigned to three 3 × 3 Latin squares. The treatments were: a control (CON), sodium monensin (MON; 12 mg/kg of dry matter [DM]), condensed Acacia tannins and Saccharomyces cerevisiae yeast blend (SUP; 2 g/kg of DM). The trial lasted 84 days, with three 28-day periods. Neutral detergent fiber (NDF) intake was higher in CON and SUP (p = 0.029). Milk yield, energy-corrected milk, and milk composition did not differ (p > 0.05). The total methane emissions were not affected by treatments (p > 0.05). Methane yield/Kg of DM intake (DMI), organic matter intake (OMI), and digestible OM tended to be lower in SUP (p = 0.091, p = 0.093, p = 0.086). SUP increased the DM, crude protein (CP), and NDF ingestion rates (p = 0.049, p = 0.028, p = 0.013) and decreased the CP rumen pool (p = 0.014). Rumen pH tended to be higher in SUP (p = 0.067). The potentially digestible NDF digestion rate decreased in MON (p = 0.007). Finally, SUP-treated animals showed a tendency to reduce their methane yield relative to DMI, OMI, and digestible OM. Further studies should investigate the long-term impacts of supplementation, rumen microbiome changes, and underlying mechanisms driving methane mitigation.

Caracterização de recursos genéticos animais como ponte do melhoramento tradicional para o melhoramento atual e futuro.

2026-04-28T18:54:56Z

Título: Caracterização de recursos genéticos animais como ponte do melhoramento tradicional para o melhoramento atual e futuro. Autoria: MARTINEZ, M. L. Conteúdo: A caracterização de uma determinada raça ou espécie pode ser realizada através de suas propriedades fenotípicas, morfológicas e fisiológicas, sua origem, seu habitat e distribuição geográfica, assim como por parâmetros genéticos (Del Lama et al., 1996; Hernandez et al., 1997). A caracterização genética de populações, raças e espécies permite se estudar a variabilidade genética, que é fundamental para o planejamento dos programas de melhoramento (Machugh et al. 1994). Nos estudos de genética de populações, é essencial o conhecimento de parâmetros que possam caracterizar as diferentes populações. No contexto dos melhoristas, o conhecimento das médias e das variâncias das características são os parâmetros mais importantes. Todavia, o que se tem em geral são estimativas obtidas em amostras das populações, que servem então para caracterizá-las. Este é na realidade o primeiro passo que necessita ser dado para que se possa utilizar racionalmente os recursos genéticos disponíveis. O melhoramento tradicional sempre se utilizou do conhecimento do desempenho dos indivíduos em um determinado ambiente para avaliá-los. As informações sobre as médias e variâncias das características quantitativas, morfológicas e qualitativas têm sido utilizadas com maior ou menor intensidade em qualquer programa que objetive maior desempenho econômico da população. A caracterização dos indivíduos, levando-se em conta o seu ambiente, é importante devido aos aspectos associados à interação genótipo-ambiente. Assim, é relevante considerar na caracterização todos os atributos relativos à adaptabilidade, sobrevivência e desempenho produtivo dos indivíduos em diversos ambientes. As estimativas dos parâmetros destes atributos permitirão uma utilização mais eficiente dos recursos genéticos.

Structural characteristics and forage biomass accumulation of dwarf elephant grass genotypes at two stubble heights.

2026-04-28T01:06:54Z

Título: Structural characteristics and forage biomass accumulation of dwarf elephant grass genotypes at two stubble heights. Autoria: SILVA, R. B. da; RIBEIRO, K. G.; GOMIDE, C. A. de M.; PACIULLO, D. S. C.; LEDO, F. J. da S.; PAIVA, L. E. F.; SOUZA, E. M. B. de; CECON, P. R. Conteúdo: The objective was to evaluate the structural traits and forage accumulation of elephant grass genotypes under two stubble heights. The experiment was conducted in a factorial scheme, with five genotypes (P 2022 S1, 1810, 2111, 2035 and BRS Kurumi) and two stubble heights (25 and 45 cm), in a randomized block design, with three replications, considering the rainy and dry periods. Forage accumulation of the rainy period was higher for genotype 2111 (P<0.05) compared to P 2022 S1 and BRS Kurumi. The 1810 and 2035 genotypes showed forage accumulation similar to 2111. In the dry period, forage accumulation values were approximately 35% of those observed in the rainy period, with the BRS Kurumi and P 2022 S1 genotypes presenting lower values (P<0.05) compared to the others. The stubble height of 25 cm resulted in lower canopies (82 cm) than that at 45 cm (96 cm). The genotypes P 2022 S1 and 2111 had a higher percentage of leaves and a lower percentage of stem at the stubble height of 45 cm. The genotypes 2111 and 1810 were superior to BRS Kurumi for the percentage of leaf blade and stem at the defoliation height of 45 cm. In the dry season, the genotype 2111 showed the highest leaf-stem ratio. The genotypes 1810, 2111, 2035 and BRS Kurumi showed the highest leaf and lowest stem percentage. The defoliation height of 45 cm resulted in higher forage density. The genotypes 2035, 2111 and 1810 stood out for the high forage accumulation and leaf percentage at both stubble heights during the rainy season. Management with a defoliation height of 45 cm increases the leaf blade percentage and the leaf-stem ratio and reduces the proportion of stem in the forage harvested above the residue.

Diallel analysis of elephantgrass clones for bioenergy production in a tropical environment.

2026-04-25T13:50:26Z

Título: Diallel analysis of elephantgrass clones for bioenergy production in a tropical environment. Autoria: PESSOA, T. de V. de S.; SANTOS, E. de F. dos; CARNEIRO, J. da C.; CARNEIRO, P. C. S.; DIAS, K. O. das G.; MACHADO, J. C. Conteúdo: Climate change caused by fossil fuels has driven the search for bioenergy sources. Elephantgrass [Cenchrus purpureus (Schumach.) Morrone] biomass is a promising alternative for diversifying the energy matrix. One of the main steps of a genetic breeding program is the selection of parents who will form the crossing block, and the use of diallel analysis is critical in this step. Therefore, this study aimed to use mixed linear models to analyze diallel crosses and estimate the general combining ability (GCA) and specific combining ability (SCA) of elephantgrass clones to select superior parents and hybrids for bioenergetic applications. Eleven parents were crossed in a diallel scheme, totaling 55 hybrid combinations, and evaluated in a randomized complete block design with three replications. The measured traits were dry biomass production (DBP), in vitro dry matter digestibility (IVDMD), and cellulose-lignin (C:L) ratio. There was a significant effect of SCA, SCA × cut interaction, and permanent effect on DBP, and a significant effect of GCA on IVDMD and C:L. There was a predominance of genes with additive effects controlling IVDMD and C:L traits, and dominance and epistasis for DBP. The parents selected for biochemical conversion processes were Embrapa’s Active Germplasm Bank of Elephantgrass (BAGCE) 38 and CNPGL 92-38-2. The parents selected for direct combustion of biomass were BRS Canará, BRS Capiaçu, and CNPGL 96-27-3. The hybrids BAGCE 21 × BAGCE 38, BAGCE 30 × CNPGL-92-38-2, and BAGCE 38 × BRS Kurumi show potential for the production of dry biomass.