Competitive adaptive reweighted sampling-partial least squares (CARS-PLS) and negative-ion mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI(-) FT-ICR MS) data were adopted to assess the total acid number (TAN) of crude oil distillation cuts. Two crude oil samples and 24 derivatives with TAN ranging from 0.20 to 0.39 mg of KOH g-1 were investigated. The multivariate calibration PLS model was built with 18 calibration samples and tested with 8 validation samples. CARS-PLS reduced the number of variables from 1610 to only 4, allowing the identification of molecular formulas that are truly related to the TAN. The root mean square error of prediction (RMSEP) obtained was 0.01 mg of KOH g-1, which is lower than the error when using all variables (0.03 mg of KOH g-1). Finally, it was observed that the N and O2 compound classes are the most important classes for providing a better correlation between ESI(-) FT-ICR mass spectra and TAN values.

A batata-doce é bastante utilizada para a alimentação humana, mas tem também reconhecido potencial para utilização na alimentação animal. Foram avaliados a produtividade e a qualidade de ramas emurchecidas de 15 genótipos de batata-doce (BD-31TO, BD-26, BD-13, BD-17, BD-22, BD-24, BD-54, BD-56, BD-69, BD-43, BD-44, BD-46, BD-52, BD-35 e a cultivar Brazlândia Rosada) e selecionados os mais indicados à produção de silagem, em delineamento de blocos ao acaso com três repetições. Na colheita foram determinadas a produtividade de massa verde e posteriormente de massa seca de ramas. Após 190 dias de ensilagem foram determinadas as concentrações de matéria seca, proteína bruta, fibra em detergente neutro e ácido, lignina, cinzas, carboidratos solúveis das ramas e de suas silagens; capacidade tampão e capacidade fermentativa das ramas e pH das silagens. Os genótipos BD-13, BD-17, BD-54, BD-56, BD-43, BD-44, BD-46, BD-52 apresentaram produtividade de massa verde e seca das ramas de média a alta. Foram observadas diferenças significativas entre genótipos nas características bromatológicas estudadas, exceto para as concentrações de carboidratos das ramas emurchecidas e de suas silagens. Considerando as ramas emurchecidas, os genótipos BD-26, BD-13, BD-56, BD-46, BD-35 e Brazlândia Rosada apresentam a composição bromatológica mais adequada à alimentação animal. Já para produção de silagens, o genótipo BD-56 foi o mais indicado.

Sweet potato is widely used for human consumption, but has also potential for its use in animal feeding. In this study we evaluated yield and quality as forage of wilted vines of various sweet potato genotypes and selected the most suitable for silage. Fifteen genotypes were evaluated (BD-31TO, BD-26, BD-13, BD-17, BD-22, BD-24, BD-54, BD-56, BD-69, BD-43, BD-44, BD-46, BD-52, BD-35, and cultivar Brazlândia Rosada), in a randomized complete blocks design, with three replications. At harvest we determined the yield of fresh matter and subsequently dry matter of vines. After 190 days of ensilage, we determined the concentrations of dry matter, crude protein, neutral and acid detergent fiber, lignin, ash, soluble carbohydrates in both vines and its silages; buffering and fermentative capacities of vines, and pH of silages. Genotypes BD-13, BD-17, BD-54, BD-56, BD-43, BD-44, BD-46, and BD-52 showed medium to high yield of fresh and dry matter. There were significant differences among genotypes in all studied bromatological characteristics, except for carbohydrate concentrations in wilted vines and their silages. Considering wilted vines, genotypes BD-26, BD-13, BD-56, BD-46, BD-35 and cultivar Brazlândia Rosada were those with the most suitable bromatological composition for animal feeding. Genotype BD-56 was the most appropriate for silage production.

Competition between weeds and crops results in a lower availability of some resources to crop species, which causes deficiencies, such as water and nutritional deficiencies and low light quality or quantity. The aims of this study were to evaluate the effects of Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster, cv. Xaraes (brachiaria) emergence times comparing with corn (Zea mays L.), in addition to the fertilization and application of different nicosulfuron and atrazine herbicides levels, on the physiological characteristics of intercropped species. The physiological characteristics Brachiaria plants that were treated with herbicides were negatively affected. The emergence time of Brachiaria plants in comparison with corn altered the physiological characteristics of both. The Brachiaria plants that emerged before corn presented higher photosynthetic and transpiration rates and reduced the intensity of these characteristics in corn. Thus, the Brachiaria plants that emerged before the corn crop presented a higher physiological efficiency, and they were more competitive than the weeds that emerged during other seasons.

A variação na disponibilidade de forragem ao longo do ano, aliada à necessidade de se utilizar alimentos de menor custo para ruminantes, têm contribuído para um aumento na procura por novas alternativas para alimentação animal. Objetivou-se avaliar a produtividade de massa seca (PMS) de ramas e o efeito do emurchecimento na composição bromatológica e capacidade fermentativa (CF) de ramas de batata-doce visando a produção de silagens. Foram avaliados os genótipos BD-08, BD-23, BD-25, BD-31TO, BD-38, BD-43 e Brazlândia Roxa, utilizando-se o arranjo fatorial 7 x 2 (genótipos x ramas emurchecidas ou não), em delineamento em blocos ao acaso, com 4 repetições. Foram determinados a produção de massa seca e os teores de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose, celulose, lignina, cinzas, carboidratos solúveis (CS), nitrogênio insolúvel em detergente ácido (NIDA), capacidade tampão (CT) e capacidade fermentativa (CF) das ramas in natura e emurchecidas. A PMS das ramas variou de 4,2 a 7,9 t ha-1, com destaque para BD-25, BD-08 e BD-23 com produtividades superiores a 7,0 t ha-1. O emurchecimento promoveu aumento nos teores de MS (15,7 para 25,7%), de PB (11,0 para 11,9%), FDA (29,2 para 41,7%), lignina (8,6 para 15,5%), celulose (19,3 para 24,3%), cinzas (8,9 para 10,0%) e NIDA (9,7 para 32,8%), e redução nos teores de CS (15,0 para 7.6%), tornando as ramas emurchecidas de pior qualidade. O emurchecimento não influenciou a CF das ramas (média de 37,2) e promoveu elevação nos teores de FDN de forma diferenciada para cada genótipo. Os teores mais elevados de MS nas ramas emurchecidas compensaram o mais baixo teor de CS, tornando a CF das ramas semelhante. As ramas de batata-doce de todos os genótipos apresentaram elevado potencial de ensilabilidade.

The variation in the availability of forage throughout the year and the need to use low-cost food for ruminants contributed to an increase in the search for new food alternatives. This study aimed to evaluate the yield of the dry mass of vines and the effect of wilting on the chemical composition and fermentative capacity of sweet potato vines for silage production. The evaluated genotypes were BD-08, BD-23, BD-25, BD-31TO, BD-38, BD-43 and Brazlândia Roxa, using a 7x2 factorial arrangement (genotype x wilted vines or not), in a randomized block design, with four replications. We determined the dry matter yield (PMS) and dry matter (MS), crude protein (PB), neutral detergent fiber (FDN), acid detergent fiber (FDA), cellulose, hemicellulose, lignin, ash, water soluble carbohydrates (CS), acid detergent insoluble nitrogen (NIDA), buffering capacity (CT) and fermentative capacity (CF) of fresh and wilted vines. The MS of vines ranged from 4.2 to 7.9 t ha-1, with emphasis on BD-25, BD-08 and BD-23 with yields higher than 7.0 t ha-1. Wilting promoted increase in MS (15.7 to 25.7%), PB (11.0 to 11.9%), FDA (29.2 to 41.7%), lignin (8.6 to 15.5%), cellulose (19.3 to 24.3%), ash (8.9 to 10.0%) and NIDA (9.7 to 32.8%), and reduced levels of CS (15.0 to 7.6%), making the wilted branches of poorer quality. Wilting did not affect the CF of the vines (average 37.2) and promoted an increase in FDN differently for each genotype. The highest levels of MS in wilted vines offset the lower level of CS, making similar the CF of vines.The sweet potato vines of all genotypes presented high potential for silage.