Productive characteristics of the grass Digitaria umfolozi subjected to defoliation frequencies

Abstract

An experiment was carried out to evaluate the dry matter production, total dry matter availability, daily dry matter accumulation rate, light interception, leaf area index, daily accumulation rate and dry matter availability of the morphological components (leaf blades, stems + sheaths and dead material), leaf/stem ratio, crude protein, neutral detergent fibre and acid detergent fibre of Faixa-Branca grass under seven defoliation frequencies (14, 21, 28, 35, 42, 49, and 56 days). Longer defoliation frequencies reduced the percentage of leaf blades and increased the percentage of stems + sheaths. The defoliation frequency positively influenced the availability of leaf blades, stems + sheaths, dead material and total dry matter. In the range of 42 days of defoliation, light interception reached 95%. At frequencies of 14 and 21 days of defoliation, the crude protein content of the leaves was above 20%. The highest utilization efficiency of Faixa-Branca grass is achieved when the forage is managed with cutting intervals of 40 to 46 days. Higher defoliation frequencies positively contribute to the increase in the number of total white band grass leaves and higher crude protein content of the leaf blades and stems + sheaths. Key words: Crude protein. Digitaria umfolozi. Forage production. Light interception. ResumoFoi realizado um experimento com o objetivo de avaliar a produção de matéria seca, disponibilidade total de massa seca, taxa de acúmulo diária de matéria seca, interceptação luminosa, índice de área foliar, taxa de acúmulo diário e disponibilidade de matéria seca dos componentes morfológicos (lâmina foliar, colmo+bainha e material morto), relação lâmina/colmo, proteína bruta, fibra em detergente neutro e fibra em detergente ácido do capim Faixa-Branca submetido a sete frequências de desfolhação (14, 21, 28, 35, 42, 49, 56 dias disponibilidade de lâmina foliar, colmo+bainha, material morto e matéria seca total. No intervalo de 42 dias de defoliation o capim faixa branca atingiu 95% de interceptação luminosa. Nas frequências de 14 e 21 dias de desfolhação os teores de proteína bruta das folhas foram acima de 20%. Verificou-se que a maior eficiência de utilização do capim Faixa-Branca é alcançada quando a forrageira é manejada com intervalos de corte de 40 a 46 dias. As maiores frequências de desfolhação contribui positivamente para o aumento do número de folhas totais do capim Faixa-Branca e apresentam maiores teores de proteína bruta das lâminas foliares e colmo+bainha. Palavras-chaves: Digitaria umfolozi. Interceptação luminosa. Produção de forragem. Proteína bruta.

Protein Supplementation Is Vital for Beef Cattle Fed with Tropical Pasture

“…In an experiment carried out with forage grass Digitaria umfolozi submitted to different defoliation frequencies, the importance of pasture management on the productive characteristics and morphogenic and nutritional value was verified. Thus, in this study, it was found that the higher defoliation frequencies positively favored increasing number of leaf blades, stems + sheaths and total DM, characterizing this tropical forage with good potential for animal production [10]. The findings showed that the defoliation frequencies promote the growth of new Digitaria umfolozi grass plants with high concentrations of CP in leaf blades and stems + sheaths, indicating the need to identify appropriate management practices to efficiently harness the forage potential.…”