The isotopic composition (d15N, d13C) of agricultural wastes and derived composts.

The aim of this study was to measure variations in the isotopic composition (d13C and d15N) during the composting of different agricultural wastes using bench-scale bioreactors. Four different feedstocks of agricultural wastes (Horse bedding manure + legumes residues; Dairy manure + Jatropha mill cake; Dairy manure + sugarcane residues; Dairy manure) were used for aerobic-thermophilic composting. During composting no significant differences were found between the d13C values of the source material and the compost, except for Dairy manure + sugarcane residues. d15N values increased significantly in composts of Horse bedding manure + legumes residues and Dairy manure + Jatropha mill cake. d15N values of composts may be related to NH3 volatilization during the composting process. Isotopic signatures (d13C, d15N) can be used to differentiate composts from different feedstock sources and d15N values may be a quantitative indicator of NH3 volatilization during composting. Use of bench-scale bioreactors is a promising apparatus to study the dynamics of C and N and stable isotopes signatures during composting, but future adjustments regarding sampling methodology are necessary

Bayesian Adaptive Selection of Variables for Function-on-Scalar Regression Models

Considering the field of functional data analysis, we developed a new Bayesian method for variable selection in function-on-scalar regression (FOSR). Our approach uses latent variables, allowing an adaptive selection since it can determine the number of variables and which ones should be selected for a function-on-scalar regression model. Simulation studies show the proposed method's main properties, such as its accuracy in estimating the coefficients and high capacity to select variables correctly. Furthermore, we conducted comparative studies with the main competing methods, such as the BGLSS method as well as the group LASSO, the group MCP and the group SCAD. We also used a COVID-19 dataset and some socioeconomic data from Brazil for real data application. In short, the proposed Bayesian variable selection model is extremely competitive, showing significant predictive and selective quality

Desempenho produtivo de ovelhas deslanadas submetidas ao flushing de ácidos graxos.

Resumo: Os mecanismos da atuação dos lipídeos sobre o desempenho produtivo e reprodutivo de pequenos ruminantes são bastante amplos. Em razão disso, no presente estudo, investigou-se o desempenho produtivo de ovelhas deslanadas submetidas ao flushing de ácidos graxos. Aos 21 dias antes da estação de monta as matrizes foram divididas em três grupos experimentais para o fornecimento do flushing, por um período de 42 dias. No terço final de gestação e durante o período de lactação as ovelhas foram suplementadas com concentrado na quantidade de 400g/cabeça/dia. A produtividade das ovelhas não diferiu significativamente em relação ao flushing (P>0,05) para o índice de peso total de cordeiro nascido por ovelha (PNT). A produtividade dos grupos genéticos não diferiu (P>0,05) para os índices: peso total de cordeiro por ovelha nas idades de 28 (PT28) e 56 (PT56). Para os índices: peso total de cordeiro nas idades de 84 (PT56) e 105 (PT105) dias, as ovelhas da raça Somalis Brasileira apresentaram maiores produtividades (P0,05) for the index of total weight of lamb born per ewe (PNT). The productivity of the genetic groups did not differ (P>0,05) for the indices: total weight of lamb per ewe at ages 28 (PT28) and 56 (PT56). For indices: total weight of lamb at ages 84 (PT56) and 105 (PT105) days, the ewes Brazilian Somalis had higher yields (P<0,05) when compared to the Morada Nova sheep. The flushing of fatty acids did not affect the weight of lambs at birth, however influenced the total weight of lamb per ewe parity at ages 28, 56, 84 and 105 days (weaning). Ewes Brazilian Somalis had higher yields of total weight of lamb per ewe parity at ages 84 and 105 days (weaning)

Suplementação estratégica para ovelhas em pastagem de capim-tanzânia.

Resumo: Os pastos sofrem grandes variações ao longo do ano, tanto em quantidade quanto em qualidade. Entretanto, com a irrigação em regiões tropicais estas flutuações são mínimas, ficando os períodos de déficit nutricionais mais relacionadas às exigências nutricionais em cada fase do ciclo. Nas fases em que a forragem disponível não atende às exigências dos animais, é necessário utilizar estratégias de suplementação para garantir um adequado desempenho, saúde e reprodução dos mesmos. Objetivou-se, com este estudo, propor estratégias de suplementação para ovelhas em diferentes estados fisiológicos, em pastagem de capim-tanzânia, utilizando os balanços nutricionais de energia e proteína determinados pelo o software Small Ruminant Nutrition System (SRNS). Foram utilizadas 90 ovelhas mestiças entre as raças Santa Inês e Somalis Brasileira, com distintos graus de sangue, manejadas em uma área de três hectares de pastagem de capim-tanzânia irrigada e adubada no período seco. As ovelhas foram acompanhadas durante toda sua fase fisiológica para contemplar as variações de exigências nutricionais ao longo do ano. Para estimativa da qualidade da dieta de ovinos foram coletadas amostras por meio da simulação de pastejo. Para a simulação dos balanços de energia e proteína foi utilizado o SRNS. Os dados demonstraram que há um déficit nutricional de energia e proteína nos meses de junho a outubro, período que corresponde às fases de final de gestação e lactação e que a composição dos suplementos para atender a este déficit varia conforme a fase, podendo ser tão baixa quanto 100g/cab./dia (0,33% do PV) nos momentos de menor balanço negativo, e de 400g/dia (1,33% do PV), com alta concentração de proteína bruta e energia metabolizável nas fases de maior exigência nutricional. [Strategic supplementation for ewes grazing Tanzania grass]. Abstract: Cultivated tropical pastures under irrigation vary slightly in production and quality throughout the year. Thus, the situation where intake of nutrients does not meet requirements more related to fluctuation in animal requirements along of the production cycle, than quality of forage. In those conditions it is necessary to use supplemental strategies to ensure adequate performance, health and reproduction. This study was carried out to propose supplemental strategies for ewes in different physiological states, grazing Tanzania grass under irrigation, using the nutritional balance of energy and protein predicted by the software Small Ruminant Nutrition System (SRNS). Ninety crossbred ewes between Santa Inês and Brazilian Somalis, were assigned to an area of three hectares of Tanzania grass irrigated and fertilized during the dry season. The ewes were evaluated throughout their physiological stages to encompass all changes in nutritional requirements throughout the production cycle. To estimate the quality of the diet selected by the animals, samples were collected using hand plucked forage technique. The data showed a nutritional deficit of energy and protein throughout June to October, coinciding to late gestation and lactation phases. In addition, the composition of supplements to cover those deficits must varies according to the magnitude of this deficiency, which can be as low as 100g/head/day (0.33 of body weight) when lower deficits occurs, up to 400g/head/day (1.33% of body weight), with high content of protein and energy, when the ewes are under the highest negative balance phase

Mating system parameters in a high density population of andirobas in the Amazon forest.

The objective of this work was to estimate the mating system parameters of a andiroba (Carapa guianensis) population using microsatellite markers and the mixed and correlated mating models. Twelve open-pollinated progeny arrays of 15 individuals were sampled in an area with C. guianensis estimated density of 25.7 trees per hectare. Overall, the species has a mixed reproductive system, with a predominance of outcrossing. The multilocus outcrossing rate (tm = 0.862) was significantly lower than the unity, indicating that self-pollination occurred. The rate of biparental inbreeding was substantial (tm - ts = 0.134) and significantly different from zero. The correlation of selfing within progenies was high (rs = 0.635), indicating variation in the individual outcrossing rate. Consistent with this result, the estimate of the individual outcrossing rate ranged from 0.598 to 0.978. The multilocus correlation of paternity was low (rp(m) = 0.081), but significantly different from zero, suggesting that the progenies contain full?sibs. The coancestry within progenies (O = 0.185) was higher and the variance effective size (Ne(v) = 2.7) was lower than expected for true half-sib progenies (O = 0.125; Ne(v) = 4). These results suggest that, in order to maintain a minimum effective size of 150 individuals for breeding, genetic conservation, and environmental reforestation programs, seeds from at least 56 trees must be collected