Nutritional value of feed used in diets for Saanen goats/ Valor nutricional de alimentos utilizados nas racoes de cabras Saanen

This study was performed to characterize feed used in diets for Saanen goats. The feedstuffs were: Tifton 85 hay (Cynodon spp.), soybean meal, ground corn, soybean hulls, ground ear corn and dried cassava residue. Contents were determined for dry matter, ash, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, physically effective fiber and lignin, and organic matter, total carbohydrates and non-fiber carbohydrates were estimated. Carbohydrates were divided into fractions A + B1 (rapidly degradable), B2 (potentially degradable) and C (non-degradable); and the protein in fractions A (soluble), B1 (rapid ruminal degradation), B2 (intermediate degradation), B3 (slow degradation) and C (indigestible). To determine the gas production an automatic technique in vitro was used, modified by Ankom[R]. Significant differences were observed among feed for the parameters A, B, C, E and A + D of ruminal degradation kinetics, and feed with high non-fibrous carbohydrates content presented higher fraction A (rapid degradation), and the hay showed longer lag time (fraction C). The total gas production was higher for ground corn, ground ear corn and dried cassava residue. Keywords: byproduct, fractioning, gas production, goats, ruminal degradation. Objetivou-se no presente trabalho caracterizar alimentos utilizados nas ragoes de cabras Saanen. Os alimentos avaliados foram: feno de Tifton 85 (Cynodon spp.), farelo de soja, milho moido, casca do grao de soja, milho desintegrado com palha e sabugo e residuo seco de fecularia de mandioca. Foram determinados os teores de materia seca, cinzas, proteina bruta, extrato etereo, fibra em detergente neutro, fibra em detergente acido, fibra fisicamente efetiva e lignina, e estimados a materia organica, os carboidratos totais e os carboidratos nao fibrosos. Os carboidratos foram divididos nas fragoes A + B1 (rapidamente degradaveis), B2 (potencialmente degradaveis) e C (nao degradaveis); e a proteina, nas fragoes: A (soluvel), B1 (rapida degradagao ruminal), B2 (degradagao intermediaria), B3 (lenta degradagao) e C (indigestivel). Para determinar a produgao de gas foi utilizada a tecnica automatica in vitro, modificada pela Ankom[R]. Foram observadas diferengas entre os alimentos para os parametros A, B, C, E e A + D da cinetica de degradagao ruminal, sendo que os alimentos com alto teor de carboidratos nao fibrosos apresentaram maior fragao A (rapida degradagao), e o feno apresentou maior tempo de colonizagao (fr