The objective of this work was to characterize condensed tannins (CT) from six tropical forage legumes and to determine their biological activity. The monomers propelargonidin, prodelphinidin and procyanidin were analyzed, as well as extractable condensed tannin (ECT), protein-bound CT (PBCT) and fiber-bound CT (FBCT), molecular weight, degree of polymerization, polydispersity index, and biological activity by protein precipitate by phenols (PPP) of leaves of the legumes Cajanus cajan, Gliricidia sepium, Stylosanthes capitata x Stylosanthes macrocephala (stylo), Flemingia macrophylla, Cratylia argentea, and Mimosa caesalpiniifolia, and of the bark of this latter species. Differences were observed in the concentrations of ECT, PBCT, PPP, and total condensed tannin among species, but not in that of FBCT. The highest value of PBCT occurred in F. macrophylla. Total CT varied from nondetected concentration in C. argentea to the highest concentration in M. caesalpiniifolia leaves that contain the greatest levels of PPP. No differences were observed for polymerization degree in stylo, F. macrophylla, and M. caesalpiniifolia. Leaves of stylo, C. cajan, and G. sepium, all containing between 20 and 50 g kg-1 total CT, should be beneficial CT sources, if offered as sole feeds in ruminant diets. The ratio of prodelphinidin:procyanidin varies from 10:80 (stylo) to 65:35 (F. machrophylla), and propelargonidin is only determined in C. argentea.

-The objective of this work was to evaluate the use of soybean (Glycine max), pigeon pea (Cajanus cajan), and jack bean (Canavalia ensiformis) as urease sources for elephant grass (Pennisetum purpureum) hay ammoniated with urea. The experimental design was completely randomized in a double factorial arrangement with one additional treatment: 4 urease source levels x 3 urease sources + 1 control. Chemicalbromatological analyses and carbohydrate fractionation were performed in the hay, and cumulative gas production in vitro was determined. There were interactions between urease level and source for neutral detergent fiber and acid detergent fiber, in which 1 and 2% jack bean lowered acid detergent fiber values, and 2% jack bean and 3% soybean reduced lignin content. The addition of milled legume grains reduces fiber components and increases non protein nitrogen content in elephant grass hay ammoniated with urea. Adding 4% milled soybean increases gas production in the soluble fraction.Index terms: Cajanus cajan, Canavalia ensiformis, Pennisetum purpureum, non-protein nitrogen, roughage. Grãos de leguminosas moídas como fonte de urease para amonização do feno de capim-elefanteResumo -O objetivo deste trabalho foi avaliar o efeito da inclusão de soja (Glycine max), feijão-guandu (Cajanus cajan) e feijão-de-porco (Canavalia ensiformis) como fonte de urease para feno de capim-elefante (Pennisetum purpureum) amonizado com ureia. O delineamento experimental foi inteiramente casualizado, em arranjo fatorial duplo, com um tratamento adicional: 4 níveis de fonte de urease x 3 fontes de urease + 1 controle. Realizou-se a análise química-bromatológica e o fracionamento de carboidratos no feno, e a produção cumulativa de gás in vitro foi determinada. Houve efeito da interação entre o nível e a fonte de urease para fibra em detergente neutro e fibra em detergente ácido, em que a adição de 1 e 2% de feijão-deporco resultou nos menores valores de fibra em detergente ácido, e a adição de 2% de feijão-de-porco e 3% de soja, nos menores valores de lignina. A adição de grãos moídos das leguminosas reduz os componentes da fibra e aumenta o teor de nitrogênio não proteico do feno de capim-elefante amonizado com ureia. A adição de 4% de grão de soja moído aumenta a produção de gás proveniente da fração solúvel.Termos para indexação: Cajanus cajan, Canavalia ensiformis, Pennisetum purpureum, nitrogênio não proteico, volumosos.

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The aim of this study was to evaluate the effect of ammoniation by urea on the nutritional value of elephant grass hay harvested after flowering. A completely randomized design, in double factorial designs with an additional treatment: 4 urea doses (2, 4, 6 and 8%) x 2 treatment periods (30 and 45 days) + 1 (Control) with four replicates each, was employed. Dry matter, ash, ether extract, neutral detergent fiber, acid detergent fiber, cellulose, lignin, neutral detergent fiber corrected for the ash and the protein, total nitrogen, acid detergent insoluble nitrogen, neutral detergent insoluble nitrogen, non-protein nitrogen, in vitro gas production and carbohydrates fractionation were analyzed. The treatments influenced the contents of DM, EE, NDF, ADF, lignin, cellulose, NDFap, fraction A + B1, fraction B2, fraction C, TN, NPN, ADIN, NDIN, L and Vf2. There was a positive linear effect of urea dose for NDF, ADIN, NDIN and L, positive linear effect on fraction A + B1, NT and NPN, and positive quadratic effect for Vf2, with absolute maximum point of 4.5%. Elephant grass hay harvested after flowering has its nutritional value improved, with a minimum dose of 4.5% urea on a dry matter basis.

Plant extract is an excellent alternative to reduce methane emissions and ameliorate ruminal fermentation due the presence of the secondary metabolites, however, there are many studies with plants used on human’s diet that shows a good result but may occur competition and elevate the costs for the system. Plants consumed by animal have secondary metabolites in quantity and diversity, it can be a good strategy. This work aimed to determine the bromatological composition and characterize the Urochloa humidicola methanol extract such as the presence of secondary metabolites. The samples of the leaves of U. humidicola were collected, dried in the shade with temperature below 40°C, ground in a willey mill in 2 mm particles and subjected to cold maceration with methanol. The solution obtained was filtered by filter paper and concentrated in a rotary evaporator and put to finish the process, drying under airflow. The results of bromatological analyses were subjected to ANOVA by comparing averages by Fisher’s test using the 9.1 Saeg software and phytochemical prospecting testes were characterized as the intensity of the presence of each class of metabolites and represented via the cross-system where:(+++) implies a large presence, (++) implies a considerable presence, (+) implies a small presence and (0) implies a no presence. The dry crude methanolic extract was subjected to analysis of chemical composition and phytochemical prospecting. The extract showed 10.20% crude protein and 35% ether extract and traces of fibrous constituents, because the methanol extraction extracted only soluble constituents. A phytochemical prospecting was positive for the presence of saponin. tannin, alkaloids, catechins, non-protein amino acids and saccharides and was negative for the presence of flavonoids and purines. The U. humidicola methanol extract can be used as a phytogenic additive in the feeding of ruminants.