EFFECTS OF FISH-MEAL AND SODIUM BENTONITE ON DAILY GAIN, WOOL GROWTH,CARCASS CHARACTERISTICS, AND RUMINAL AND BLOOD CHARACTERISTICS OF LAMBS FED CONCENTRATE DIETS

We evaluated the effects of replacing some soybean meal (SBM) protein with fish meal (FM) protein in diets adequate and slightly deficient i n CP, with or without .75% sodium bentonite (NaB) on performance and r uminal and blood metabolites of individually fed Suffolk lambs. Diets were based on corn, SBM, and cottonseed hulls. In Exp. 1, five lambs w ere assigned to each of the three dietary treatments (11% CP with 3% F M, 13% CP with 0 or 3% FM). Lambs fed diets that contained 11% CP with 3% FM or 13% CP with 0% FM had similar DMI and ADG. Gain and feed eff iciency were slightly improved (P = .18) by the 13% CP diet with 3% FM . In Exp. 2, 32 lambs were assigned to four dietary treatments (13.5% CP of DM) in a 2 x 2 factorial arrangement (0 or 3% FM, and 0 or .75% NaB on an as-fed basis). The DMI and ADG were increased (P < .05) by F M and NaB supplementation. Interactions(P < .05) revealed that NaB inc reased DMI, ADG, gain per feed (g/kg of DMI), and plasma urea N concen tration in the absence of FIM but not in the presence of FM in the die t. Neither FM nor NaB influenced (P = .25) wool growth. Total ruminal VFA were increased (P < .06) by FM and NaB. Differences in mineral con tent of phalanx bone, liver, and kidney were small and may be related to the mineral content of diets and the effect of NaB on mineral solub ilities. Similar DMI and ADG of lambs fed FM and NaB separately and in combination suggest that their beneficial effect is not additive.