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The objective of this study was to determine the best level and the effect of diets containing different levels of crude protein (CP) on performance and carcass characteristics of feedlot Santa Inês lambs. In trial 1, eight intact lambs with an average live weight of 25.8 kg were distributed in two 4 x 4 Latin squares and were kept in individual metabolic cages. The total collection of feces was used to estimate digestibility and the total urine collection was used to determine the nitrogen balance. In trial 2, 32 intact lambs with an average live weight of 22.0 kg were distributed in an completely randomized design with eight repetitions and were kept in individual metabolic cages. For both trials, the diets consisted of four levels of CP (14.25; 15.50; 16.75; and 18.0%), with 40% corn silage and 60% concentrate in the dry matter. The increase in crude protein levels in the diets did not alter the digestibility, performance, or carcass characteristics of feedlot-finished Santa Inês lambs; therefore, a level of 14.25% crude protein is recommended, as it allowed for satisfactory gains in animal performance., Revista de Ciências Agrárias, vol. 38 n.º 1 (2015)

The objective of this study was to determine the best level and the effect of diets containing different levels of crude protein (CP) on performance and carcass characteristics of feedlot Santa Inês lambs. In trial 1, eight intact lambs with an average live weight of 25.8 kg were distributed in two 4 x 4 Latin squares and were kept in individual metabolic cages. The total collection of feces was used to estimate digestibility and the total urine collection was used to determine the nitrogen balance. In trial 2, 32 intact lambs with an average live weight of 22.0 kg were distributed in an completely randomized design with eight repetitions and were kept in individual metabolic cages. For both trials, the diets consisted of four levels of CP (14.25; 15.50; 16.75; and 18.0%), with 40% corn silage and 60% concentrate in the dry matter. The increase in crude protein levels in the diets did not alter the digestibility, performance, or carcass characteristics of feedlot-finished Santa Inês lambs; therefore, a level of 14.25% crude protein is recommended, as it allowed for satisfactory gains in animal performance., O objetivo deste estudo foi determinar o melhor nível e o efeito de dietas contendo diferentes níveis de proteína bruta (PB) sobre o desempenho e características de carcaça em cordeiros Santa Inês confinados. No ensaio 1, oito cordeiros, não castrados, com peso vivo médio de 25,8 kg foram distribuídos em dois quadrados latinos 4 x 4, sendo mantidos em gaiolas metabólicas individuais. A colheita total de fezes foi utilizada para estimar a digestibilidade e o método de colheita total de urina foi utilizado para determinar o balanço de nitrogénio. No ensaio 2, 32 cordeiros, não castrados, com peso vivo médio de 22,0 kg, foram distribuídos num delineamento inteiramente casualizado, com oito repetições e mantidos em gaiolas metabólicas individuais. Em ambos os ensaios, as dietas consistiram em quatro níveis de PB (14,25; 15,50; 16,75 e 18,0%); com 40% de silagem de milho e 60% de concentrado, com base na matéria seca. O aumento nos níveis de proteína bruta nas dietas não alterou a digestibilidade dos nutrientes, desempenho ou as características da carcaça nos cordeiros Santa Inês terminados em confinamento, portanto, recomenda-se o nível de 14,25% de PB, por permitir ganhos satisfatórios no desempenho de carcaça.

Despite the forage potential of elephant grass, controlling canopy structure during grazing has limited its use in pasture. This study was conducted to determine the effect of grazing frequency and post-grazing height on canopy structural characteristics of elephant grass genotypes. The treatments consisted of the factorial combinations of two dwarf elephant grass genotypes (BRS Kurumi and CNPGL 00-1-3), two levels of light interceptions (LI; 90% and 95%) at initiation of grazing, and two post-grazing heights (30 and 50 cm) arranged in a completely randomised design with three replications. The average pre-grazing canopy height ranged from 75 cm for BRS Kurumi to 127 cm for CNPGL 00-1-3. The interval between grazing events averaged 22 and 50 d for BRS Kurumi and CNPGL 00-1-3, respectively. The percentage of leaves was higher for BRS Kurumi compared to CNPGL 00-1-3, for the 30 cm vs 50 cm post-grazing height, and for 95% vs 90% LI. The genotype BRS Kurumi had greater tiller density (298 vs 107 tillers m−2), allowing faster recovery after grazing. The cultivar BRS Kurumi represents an attractive alternative for grazing use, and it should be managed, during the rainy season, using a pre-grazing canopy height of around 75 cm with a 30 cm post-grazing height.Keywords: canopy height, forage density, leaf percentage, leaf:stem ratio, Pennisetum purpureum, rest period

O presente trabalho teve como objetivo selecionar clones de batata-doce com potencial para uso na alimentação animal. O experimento foi conduzido em blocos ao acaso, com 11 clones e quatro repetições. Os clones avaliados fazem parte do banco de germoplasma da Universidade Federal dos Vales do Jequitinhonha e Mucuri, sendo: BD-06, BD-25, BD-15, BD-38, Cambraia, BD-31-TO, BD-67, BD-45, BD-42, BD-54 e a cultivar Brazlândia Rosada. Nas ramas coletadas do experimento foram avaliados o teor de matéria seca e as produtividades de massa verde e massa seca. Nas silagens de ramas foram avaliados o pH e os teores de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), nutrientes digestíveis totais (NDT), fósforo, cálcio e sódio. Não houve diferença significativa para a produtividade de massa verde e de massa seca das ramas entre os clones de batata-doce. As silagens produzidas caracterizam-se como volumosos de boa qualidade, apresentando teores satisfatórios de proteína bruta (11,59%), FDN (31,98 a 39,68%), FDA (29,65 a 35,45%) e NDT (62,90 a 66,91%), comprovando o potencial de utilização das ramas da batata-doce na forma de silagem. The objective of this study was to select potential clones of sweet potato for animal feeding purposes. The experiment was carried out in a randomized block design with four replications. Eleven clones BD-06, BD-25, BD-15, BD-38, Cambraia, BD-31-TO, BD-67, BD-45, BD-42, BD-54 and the cultivar Brazlândia Rosada belonging to germplasm bank of the Federal University of Vales do Jequitinhonha and Mucuri (UFVJM) were evaluated. We estimated the dry matter content and the productivity of green and dry mass of the vine. The traits pH, dry matter, crude protein phosphorus, calcium and sodium were estimated in the evaluation of silages quality. There was no significant difference in productivity of green mass and dry mass among the clones of sweet potato. The obtained silages had sufficient levels of crude protein (11.59%), neutral detergent fiber (31.98 to 39.68%), acid detergent fiber (29.65 to 35.45%) and total digestible nutrients (62.90 to 66.91%) proving the potential use of the sweet potato vine as silage in animal feeding.