A proposed methodology to standardize the determination of enzymic activities present in enzyme additives used in ruminant diets

Abstract

. 2003. A proposed methodology to standardize the determination of enzymic activities present in enzyme additives used in ruminant diets. Can. J. Anim. Sci. 83: 559-568. There is increasing interest in using enzymes that degrade plant cell walls in ruminant diets to enhance production efficiency. Despite strong evidence from several studies suggesting a beneficial effect of enzyme supplementation on nutrient utilization and animal performance, overall the results have been somewhat inconsistent. One of the main problems faced by researchers is the lack of adequate biochemical characterization of the products used, which leads to a poor understanding of their mode of action. Of these biochemical characteristics, enzyme activities are the most important, but they are not always evaluated prior to use. Furthermore, as many arbitrary units of expression for these activities coexist, direct comparisons among studies are essentially impossible. In this paper, we propose a methodology that we feel accounts for the requirements of accuracy, simplicity and safety of use. In addition, a rationale for the standardization of the assays as a function of the conditions under which the enzymes are expected to act is presented. The standardization of these assays will benefit researchers, the feed industry, regulatory organizations, and ultimately the consumer, as it will result in the development of better, safer and more consistent enzyme additives for use in ruminant diets. On s'intéresse de plus en plus à l'addition d'enzymes qui s'attaquent à la paroi cellulosique aux aliments des ruminants, cela en vue d'accroître la production de ces derniers. Bien que plusieurs études suggèrent nettement l'effet bénéfique d'un tel supplément sur l'assimilation des éléments nutritifs et le rendement des animaux, dans l'ensemble, les résultats manquent de cohérence. Une des principales difficultés auxquelles se butent les chercheurs concerne la caractérisation inadéquate des produits utilisés sur le plan de la biochimie, si bien qu'on en comprend mal le mode d'action. L'activité des enzymes demeure le principal paramètre biochimique, mais on ne l'évalue pas toujours avant emploi. D'autres part, l'existence de maintes unités arbitraires pour mesurer l'expression d'une telle activité interdit pratiquement la comparaison des études. Cet article propose une méthode qui devrait satisfaire aux exigences usuelles de précision, de simplicité et de sécurité. On y explique aussi pourquoi il faudrait normaliser le dosage d'après les conditions dans lesquelles les enzymes devront agir. Pareille normalisation facilitera la tâche des chercheurs, des fabricants d'aliments pour animaux et éventuellement des consommateurs, car elle débouchera sur la création de meilleurs additifs enzymatiques, plus sûrs et plus uniformes, pour les aliments destinés aux ruminants.

Effects of Exogenous Enzymes on Ruminal Fermentation and Degradability of Alfalfa Hay and Rice Straw

“…Others have reported short-term effects of enzymes on digestion with limited effects later during the incubation (Tricarico, 2001;Colombatto et al, 2003a). Colombatto and Beauchemin (2003) suggested that enzymes enhance alfalfa digestion by removing structural barriers retarding microbial colonization, thus increasing the rate of degradation.…”

“…Mainly, this is because the enzymes must work synergistically with the ruminal microbial community to alter feed digestion (Morgavi et al, 2000). Therefore, the selection of enzymes for use as ruminant feed additives should be first tested in a ruminal environment (Colombatto and Beauchemin, 2003). It is also important to test enzymes on individual feeds, as their activity may be specific to the type of feed.…”

Inclusion of exogenous enzymes in feedlot cattle diets: Impacts on physiology, rumen fermentation, digestibility and fatty acid profile in rumen and meat

“…These authors explain that this greater weight gain occurs due to the improvement in nutrient digestibility, since the product did not affect DM intake [ 32 ]. It is believed that when using proteolytic enzymes they act by removing protein structures from the cell wall of the forage, allowing faster access for ruminal microorganisms [ 33 ], which leads us to justify the gains in performance when using the enzymes in combination.…”