Considerando-se a importância da palma forrageira como alternativa alimentícia para os rebanhos do semiárido brasileiro e o efeito do espaçamento de cultivo entre plantas, este estudo objetivou avaliar a morfometria, produtividade e composição químico-bromatológica de genótipos de palma forrageira, em diferentes densidades de cultivo. O delineamento experimental utilizado foi em blocos completos casualizados, em esquema fatorial 3x4. Os tratamentos constituíram-se da combinação de três genótipos de palma forrageira (Gigante, Redonda e Miúda) e quatro densidades de cultivo (10.000 plantas ha-1, 20.000 plantas ha-1, 40.000 plantas ha-1 e 80.000 plantas ha-1), com três repetições. Os genótipos de palma forrageira apresentaram comportamentos diferentes, quanto à morfometria, produtividade e composição químico-bromatológica, e, independentemente da espécie, o plantio adensado elevou a produtividade (toneladas ha-1). A palma Miúda apresentou maior produtividade de matéria seca e, consequentemente, maior acúmulo de nutrientes digestíveis totais, proteína bruta e água por hectare, bem como maior digestibilidade in vitro da matéria seca.

Considering the importance of cactus pear as an alimentary alternative for the herd of cattle of the Brazilian semiarid region and the effect of crop spacing among plants, this study aimed to evaluate the morphometry, yield and chemical-bromatological composition of cactus pear genotypes, under different cropping densities. The experimental design was completely randomized blocks, in a 3x4 factorial scheme. Treatments consisted of a combination of three cactus pear genotypes (Gigante, Redonda and Miúda) and four cropping densities (10,000 plants ha-1; 20,000 plants ha-1; 40,000 plants ha-1; and 80,000 plants ha-1), with three replications. The cactus pear genotypes reacted differently, regarding morphometry, yield and chemical-bromatological composition, and, regardless of the species, the denser planting increased yield (tons ha-1). The Miúda palm presented the highest dry matter yield and consequently the greater accumulation of total digestible nutrients, raw protein and water per hectare, as well as the highest in vitro dry matter digestibility.

The objective of this study was to characterize the nutritional value of forage legumes Mimosa caesalpiniifolia (Benth.), Bauhinia cheilantha (Bong.) and Leucaena leucocephala (Lan.) and evaluate the anatomy of plants incubated and not incubated in the rumen. The experiment was conducted from September 2007 to November 2008. The experimental plot consisted of three useful plants, totaling three plots per block, and four repetitions. Plants were cut at 1 m height at intervals of 70 days; samples of leaf plus stem with a diameter smaller than 4 mm were collected for determination of dry matter, crude protein, neutral detergent fiber, acid detergent fiber, insoluble protein bound to acid detergent fiber and in vitro dry matter digestibility. The anatomical characterization occurred through the analysis of the proportion of plant tissue nonincubated and incubated in the rumen for a period of 48 hours. The legumes had high crude protein, with an average of 26.1% to Leucena, 22.4% to Sabiá and 18.5% to Mororó, and low levels of in vitro digestibility of dry matter, with an average of 47.3% to Leucena, 42.8% to Mororó and 37.2% to Sabiá. In the leaf blade of Sabiá plants, much lignified tissues that differed from plants of Leucena and Mororó were observed. The degradation process was more visible in the leaves of the Leucena, Sabiá and Mororó plants. The degradation was more pronounced in the spongy parenchyma, leaving the incubated material intact. The average proportion of the epidermis in the incubated and not incubated leaves was 15.8 and 16.4% in Leucena, 16.8 and 19.2% in Mororó and 27.2 and 25.5% in Sabiá, respectively. There are differences in the digestion and nutritional value of leaf tissues of the evaluated legumes.

Objetivou-se obter estimativas de coeficientes de correlação genética e avaliar os desdobramentos das correlações em efeitos diretos e indiretos (análise de trilha) das variáveis independentes explicativas sobre a produção de matéria seca (variável dependente principal) em cinco clones de capim-elefante. Foram realizados cinco cortes a cada 60 dias nas condições edafoclimáticas da Zona da Mata de Pernambuco. Cada parcela experimental apresentou 24 m², com 2 m² de área útil. Houve alta correlação entre quase todas as variáveis explicativas e a variável principal. Entretanto, a característica número de lâminas foliares por perfilho explicou melhor o potencial de produção de matéria seca e atuou de forma direta e indireta sobre as variáveis explicativas.

This work aimed to estimate the correlation coefficients, determining the direct and indirect effects (path analysis) of explanatory independent variables on total dry matter production (main dependent variables) of five elephant grass clones in five cuts accomplished at the forest zone of Pernambuco. Each experimental plot measured 24 m² with 2 m² of utile area. There was high correlation between almost all the independent variables and the main variable. The characteristic leaf blade number per tiller, however, explained better the potential of dry matter production and leaf blade dry matter production, acting, respectively, in a direct and indirect way on the explanatory variables.