Silagem de capim-elefante, em três estádios de maturidade, submetido ao emurchecimento. III - Valor nutritivo das silagens
Resumo

Foi avaliado, em experimento no Instituto de Zootecnia, SP, o valor nutritivo das silagens de capim-elefante (Pennisetum purpureum Schum.), cultivar Guaçu, nas idades de 56, 70 e 84 dias.. As silagens foram confeccionadas com a forragem de 3 parcelas de 490 m², uma para cada idade. O delineamento foi de blocos casualizados, com 3 repetições, e os tratamentos arranjados em fatorial (3 idades X 3 tipos de forragem: forragem fresca, emurchecida inteira e emurchecida triturada). O capim foi rebaixado nas datas de 16/01/97, 30/01/97 e 13/02/97, respectivamente para as idades de 84, 70 e 56 dias e colhido em 10/04/97. Cada parcela recebeu 100 kg de N, 80 kg de P₂O₅ e 100 de K₂,O/ha, utilizando-se sulfato de amônio, superfosfato simples e cloreto de potássio, respectivamente. As silagens confeccionadas com as forragens emurchecidas apresentaram maior consumo de matéria seca, não havendo, porém, alteração na porcentagem e no consumo de nutrientes digestíveis totais e nos coeficientes de digestibilidade da matéria seca, proteína bruta , fibra bruta e extrativos não nitrogenados.

Wilted elephant grass (Pennisetum purpureum Schum.) Silage made from plants cut at three maturity stages. III. Nutritive value of the silages
Abstract

The present study was carried out at Instituto de Zootecnia, SP, in order to evaluate the nutritive value of the silages made from green and wilted herbage of elephantgrass (Pennisetum purpureum Schum.) cv. “Guaçu”. Each plot rcceived 100 kg N, 80 kg P₂O₅, and 100 kg k,O as (NH₄)₂SO₄, simple superphosphate, and KC1, respectively. Nitrogen and potassium were split-applied, one half mowing and the other half 28 days later. The plots used for silage making were staged on the same dates and received the same fertilization. Silages were made from both fresh and wilted herbage, whole and choppcd plants, with whole plants being dehydrated for 24 hours under field conditions. Chopped herbage was wilted in the sun for 4 hours on a brick-fioored area. Experimental silos were 150-L plastic drums. The feeding trial was set up in a randomized complete block design with three replications. Treatments consited of ali possible combations of three forage ages (maturities) and three types of forage (thus a 3 x 3 factorial). Voluntary intake increased with wilting of whole plants belore ensiling although digestibility, TDN concentration, and TDN intake were not affected by wilting.