Utilization of barley straw, chemically treated with ammonium sulfite, anhydrous ammonia or urea, by ruminants

Abstract

Utilization of barley straw, chemically treated with ammonium sulfite, anhydrous ammonia or urea, by ruminants. Can. J. Anim. Sci. 77: 105-109. Straw treated with anhydrous ammonia, ammonium sulfite, urea or left untreated was examined in a series of feeding experiments to determine the relative efficacy of the treatments to improve the nutritive value of barley straw. In exp. 1, diets containing ammonia-and ammonium sulfite-treated barley straw were more digestible (P < 0.05) than diets with untreated straw. In exp. 2, average daily gain (ADG) and voluntary feed intake (VFI) were greatest for heifers fed ammonia-treated straw, followed by heifers fed urea-treated straw, and then by heifers fed ammonium sulfite-treated straw. Heifers fed untreated straw had the lowest ADG and VFI (P < 0.05). Although ammonium sulfite treatment improved straw digestibility, the relatively low VFI resulted in ADG lower than for animals fed other treated straw. The low VFI was attributed to the high level of sulfur in the diet. Anhydrous ammonia and urea were found to be the most effective chemicals for improving the nutritive value of barley straw. Although ammonium sulfite was as effective an anhydrous ammonia in improving digestibility of straw, it cannot be recommended because the application rates, necessary for effective treatment, resulted in depressed feed intake. Dans une seconde expérience, le GMQ et l'ingéré alimentaire libre (IAL) étaient les plus élevés chez les génisses consommant la paille traitée à l'ammoniac. Venaient ensuite la paille traitée à l'urée puis celle traitée au sulfite d'ammonium. C'est les génisses consommant la paille non traitée qui démontraient le GMQ et le IAL le plus bas (P < 0,05). Bien que le traitement au sulfite d'ammonium ait amélioré la digestibilité de la paille, le IAL relativement bas se traduisait par un GMQ plus faible que celui obtenu avec les deux autres traitements de la paille. On explique ce faible IAL par le taux élevé de soufre contenu dans l'aliment. L'ammoniac anhydre et l'urée se révélaient les produits chimiques les plus efficaces pour améliorer la valeur nutritive de la paille d'orge. Même si le sulfite d'ammonium n'était pas aussi efficace que l'ammoniac anhydre pour améliorer la digestibilité de la paille, on ne peut pas en recommander l'usage, du fait de al chute du taux d'ingestion alimentaire observée aux doses d'utilisation requises.

Effect of Fungal Treated Wheat Straw on the Diet of Lactating Cows

“…One of the ways of increasing the efficiency of utilizing straw in the diet of dairy cow is to enhance the bioavailability of the nutrients in the straw. It may be accomplished through chemical or biological treatment of the straw (Zadrazil et al, 1995;Rode et al, 1997).…”