'HiMag' tall fescue (Festuca arundinacea Schreb,) was selected for hig
h Mg concentration to reduce grass tetany risk to ruminants, but neith
er animal preference nor consumption of HiMag were known, The objectiv
es were to evaluate methods of quantifying perference and to determine
intake and preference by cattle (Bos taurus L.) of HiMag relative to
seven other tall fescues, AU entries were free of a fungal endophyte [
Neotyphodium coenophialum (Morgan Jones & Gams) Glen, Bacon & Hanlin]
that reduces cattle performance, The experimental design was a randomi
zed complete block with three replications of eight cultivars nested w
ithin each of three test pastures, Six heifers grazed the vegetative t
o boot-stage pastures for 48 h in May, June, August, and September of
1993 and 1994, The pastures, located at 1200 m elevation, were furrow
irrigated, Pre-and postgrazed forage were clipped and weighed to deter
mine yield and utilization (48-h utilization < 50%), Preference scorin
g of 0 to 10 (0 to 100% of forage eaten) was done by four trained obse
rvers at 24, 30, and 48 h, The heifers quickly learned to distinguish
between cultivars, and their order of preference was Kenhy > KY 31 > H
iMag = Barcel = C1 = Stargrazer > MO96 = Mozark. The cultivar x trial(
year) interaction for preference indicated that cultivars responded di
fferently to weather conditions, which in turn affected animal prefere
nce. Preference scoring had high repeatability and ranked cultivars si
milarly to the clip-and-weigh method of measuring utilization, Prefere
nce scoring was accomplished with 27% of the experimental error and on
ly 6% of the time required for clip-and-weigh. Only 44% of the variati
on in preference score (PS) was explained by the model: PS = 8.8 - 1.1
(Mg DM yield ha(-1)), Estimated dry matter (DM) intake of HiMag was 6
.4 kg (animal unit day)(-1). Consumption and preference of HiMag by ca
ttle are satisfactory relative to other tall fescue cultivars.