RESUMO -Este estudo visou avaliar o efeito da amonização do feno de capim-Annoni 2 (Eragrostis plana Nees) com 4% de uréia, em base de matéria seca, sobre os teores de proteína bruta (PB), fibra detergente neutro (FDN), fibra detergente ácido (FDA), hemicelulose (HEM), celulose (CEL) e lignina (LIG) e o coeficiente da digestibilidade in vitro da matéria orgânica (DIVMO), em cinco épocas de corte (30, 60, 90, 120, 150 dias). O delineamento experimental foi o de blocos completos casualisados, em número de quatro, num arranjo fatorial (2x5) com dois fatores: tratamento dos fenos (2) e épocas de corte (5). A comparação entre os dois grupos de fenos (amonizados ou não) demonstrou que a amonização propiciou aumento altamente significativo dos teores de PB. Por outro lado, a fração de FDA decresceu significantemente, juntamente com os teores de CEL, em função do tratamento com uréia. Não foram detectadas diferenças entre os tratamentos, relativamente aos teores de FDN, HEM, LIG e ao coeficiente da DIVMO. Inferiu-se que: 1. a amonização do feno de capimAnnoni 2 não afetou os teores de FDN , HEM, LIG e os coeficientes da DIVMO; 2. tratamento do feno de capim-Annoni 2 com uréia propiciou aumento nos teores de PB e decréscimo nos teores de FDA e CEL; 3. o capim-Annoni 2 pode ser fenado até os 90 dias de crescimento, sem que ocorram modificações expressivas dos parâmetros de qualidade, desde que o feno seja amonizado.Palavras-chave: celulose, fibra detergente ácido, fibra detergente neutro, hemicelulose, lignina, proteína bruta Effect of Urea-Ammonia Treatment on the Quality Parameters of Annonigrass 2 (Eragrostis plana Nees) HayABSTRACT -This study aimed to evaluate the ammoniation effect on the crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HEM), cellulose (CEL) and lignin (LIG) levels and the in vitro organic matter digestibility (IVOMD) coefficient of urea-ammonia treated (4%; dry matter basis) Annonigrass 2 (Eragrostis plana Nees) hay, at five cutting ages (30, 60, 90, 120, 150 days). A randomized complete block design was used, with four replicates in a factorial arrangement (2x5), with two factors: hay treatments (2) and cutting ages (5). The comparison among hay groups (ammoniated or not) showed a highly significant increase on the CP contents of ammoniated hay. On the other hand, FDA and CEL fraction significantly decreased as a function of urea-ammonia treatment. No differences were found for NDF, HEM, LIG contents and the IVOMD coefficients among hay groups. It was concluded that: 1. ammoniation does not affect NDF, HEM, LIG levels and IVOMD coefficients; 2. urea-ammonia treatment of Annonigrass 2 hay promotes an increase on the CP contents and a decrease on the ADF and CEL contents of this grass; 3. Annonigrass 2 hay is feasible up to 90 days of growth without prejudice to the quality parameters, since urea-ammonia is treated.Key Words: acid detergent fiber, cellulose, crude protein, hemicellulose, lignin, neutral detergent fiber R. Bras. Zootec., v.31, n.2, p.842-8...

The region of the Rio Grande do Sul campaign is characterized by having beef cattle ranching as its historical productive matrix, presenting the figure of the family rancher who has the main livelihood of the low productivity of livestock. The soil is the productive base for the agricultural activity, being necessary to find mechanisms that lead to the improvement of its natural properties. This work was carried out on soil covered by countryside vegetation belonging to the pampa biome of the state of Rio Grande do Sul with the objective of improving soil fertility conditions, acting on its chemical characteristics, from the parcel resulting from grazing with cattle, using the Voisin rotating grazing system compared to the continuous grazing system. The analysis of the data suggests that Voisin grazing in relation to the continuous allows doubling the amount of bovine dejections per unit area, increasing the pH and CTC and decreasing the Al content of the soil. It was concluded that the Voisin grazing system is a tool capable of improving the chemical of the soil.