The effect of an exogenous enzyme treatment on production and carcass characteristics of growing and finishing steers

A study was conducted to determine the effect of an exogenous enzyme treatm ent on various production and carcass characteristics of growing and finish ing steers. In the 84-day growing trial, 32 primarily British crossbred ind ividually fed steers (259 kg BW) were randomly assigned control (C) or enzy me (E) treated diets (n = 16 for C and E). The diet contained 65:35 (DM bas is) forage:concentrate. Steers on the enzyme treated diet received a total mixed, ration (TMR) that contained a solution with endoglucanase and xylana se activity at a rate of 5580 and 15,880 IU/kg of TMR DM, respectively. Ave rage daily gain (ADG), dry matter intake (DMI) and feed efficiency (FE) wer e not affected by treatment (P > 0.05), although FE showed a trend for impr ovement during the first 28 days for the enzyme treatment (P = 0.063). The finishing trial consisted of 20 individually fed steers (409 kg BW) randoml y assigned treatment (n = 10 for C and E) in an 84-day trial. Steers on the enzyme treated diet received the same enzyme solution and level as in the growing trial. The finishing ration consisted of a 20:80 forage:concentrate ratio (DM basis). Results indicated no difference (P > 0.05) for ADG, DMI or FE as well as various carcass traits including hot carcass weight, ribey e area, backfat, yield, quality grade or cutability. It is concluded from t hese growing and finishing trials that the enzyme concentrate used did not affect production or carcass characteristics, but may be beneficial for imp roving feed efficiency when cattle are first placed on feed. (C) 2000 Elsev ier Science B.V. All rights reserved.