Fresh and artificially dried forages ruminal degradability. II. Perennial soybean (Neonotonia wightii) and alfafa (Medicago sativa L.) degradabilities through "in situ" dacron bags in rumen fistulates steers

Ruminal degradability rates for dry matter (DM), crude protein (CP) and crude fiber (CF) of alfafa and perennial soybean, both fresh and artificially dried, were determined by nylon bags “in situ" technique. Eight male rumen fistulated crossbred steers were used in change-over design 4 x 4, to test the following treatments. A) perennial soybean fresh; B) perennial soybean dehidrated; C) alfafa fresh and D) alfafa dehidrated. There were no statistically significant differences for DM or CP. The DM degradability rates at 48 hours were: 56.89%; 58.73%; 59.55% and 55.43%. The CP degradability at 12,24 and 48 hours was higher for perennial soybean. No statiscal differences were found between fresh and dehidrated roughages. CP degradability rates at 48 hours of incubation time were 20.10%; 21.63%; 35.71% and 29.61% respectively for treatments A, B, C and D. As taxas de degradação ruminal da matéria seca (MS), proteína bruta (PB) e fibra bruta (FB) das leguminosas alfafa e soja perene, nas formas verde e desidratada, foram determinadas pela técnica dos sacos de náilon “ in situ”. Oito bovinos machos mestiços, com fístulas de rúmen, foram usados em um delineamento “change-over” com dois grupos de 4 animais, para testar os seguintes tratamentos: A) soja perene verde; B) soja perene desidratada; C) alfafa verde; D) alfafa desidratada. Os resultados mostraram-se estatisticamente semelhantes para MS e PB. As taxas de degradabilidade foram as seguintes, com 48 horas de incubação: MS = 56,89%; 58, 73%; 59,55% e 55,43%; PB = 73,91%; 74,43%; 76,44% e 71,16%. Para fibra bruta a degradabilidade da soja perene foi mais elevada que a da alfafa, nos períodos de 12, 24 e 48 horas de incubação, não havendo diferenças entre as formas verde e desidratada. Os resultados para 48 horas de incubação foram: 20,10%; 21,63%; 35,71% e 29,61%, nos tratamentos A, B, C e D respectivamente.