Short communication The effect of an exogenous enzyme treatment on production and carcass characteristics of growing and ®nishing steers

A study was conducted to determine the effect of an exogenous enzyme treatment on various production and carcass characteristics of growing and ®nishing steers. In the 84-day growing trial, 32 primarily British crossbred individually fed steers (259 kg BW) were randomly assigned control (C) or enzyme (E) treated diets (n ˆ 16 for C and E). The diet contained 65:35 (DM basis) forage:concentrate. Steers on the enzyme treated diet received a total mixed ration (TMR) that contained a solution with endoglucanase and xylanase activity at a rate of 5580 and 15,880 IU/kg of TMR DM, respectively. Average daily gain (ADG), dry matter intake (DMI) and feed ef®ciency (FE) were not affected by treatment (P > 0:05), although FE showed a trend for improvement during the ®rst 28 days for the enzyme treatment (P ˆ 0:063). The ®nishing trial consisted of 20 individually fed steers (409 kg BW) randomly assigned treatment (n ˆ 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 ®nishing 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, ribeye area, backfat, yield, quality grade or cutability. It is concluded from these growing and ®nishing trials that the enzyme concentrate used did not affect production or carcass characteristics, but may be bene®cial for improving feed ef®ciency when cattle are ®rst placed on feed. # 2000 Elsevier Science B.V. All rights reserved.