Effects of two fibrolytic enzyme mixtures on growth performance, digestion and ruminal fermentation in lambs fed corn stover based diets

The objective of this study was to compare the effects of two fibrolytic enzyme mixtures (Fibrozyme and Promote) on growth performance, digestion and ruminal fermentation in lambs fed corn stover based diets. Forty-two crossbred (Black Belly x Dorper) lambs (20 +/- 1.6 kg) were randomly assigned to three treatments defined as Control (no enzymes), Fibrozyme (Alltech, Nicholasville, KY, USA), and Promote (Cargill Corp., Minneapolis, MN, USA). Growth performance evaluation lasted 55 days. On day 55, rumen fluid samples were obtained. Both Fibrozyme and Promote improved growth performance, feed conversion and digestion as compared to Control. Enzymes increased total volatile fatty acids, but only Fibrozyme increased molar proportion of propionate, decreased molar proportion of butyrate, and reduced the acetate: propionate ratio. It is concluded that both Fibrozyme and Promote improved growth performance and digestion in lambs fed high-forage diets.