Sm. Derouen et al., PERFORMANCE OF YEARLING AND WEANLING CATTLE GRAZING BERMUDAGRASS PASTURES WITH A SELF-LIMITING PROTEIN-SUPPLEMENT, Journal of production agriculture, 6(3), 1993, pp. 419-422
The stocker cattle grazing enterprise in the southeastern USA has been
hindered by unacceptable performance of animals grazing bermudagrasse
s [Cynadon dactylon (L.) Pers.] and other warm-season perennial grasse
s, particularly during the latter stages of the grazing season. The ob
jective of this study was to determine the effect of a self-limiting p
rotein supplement on performance of yearling and weanling cattle (Bos
taurus x B. indicus) grazing bermudagrass pastures. The 2-yr study was
conducted in 1990 and 1991 and included 180 yearling cattle and 80 we
anling calves that were randomly allocated to replicate groups of the
following two treatments: (i) bermudagrass pasture alone (BGPAS); and
(ii) bermudagrass pasture supplemented with a 28% crude protein conden
sed molasses block (PMB). Stocking rates of three yearlings or five we
anlings per acre were maintained throughout the study. Durations of th
e grazing seasons for 1990 and 1991 were 112 and 152 d, respectively.
Yearlings fed PMB had average daily gains, total gains, and final weig
hts that were 0.31 lb/d, 39 lb, and 41 lb heavier (P < 0.03), respecti
vely, than those grazing BGPAS alone. Daily gains and final weights of
PMB-supplemented weanlings were 0.23 lb/d and 40 lb greater (P < 0.09
), respectively, than non-supplemented weaned calves. Average daily co
nsumption (lb/d) and conversion of supplement intake to additional gai
n (lb:lb) were 0.85 and 2.74:1 for yearlings, and 0.77 and 3.35:1 for
weanlings. Individual sales value of supplemented yearlings and weanli
ngs tended to be higher (P < 0.12) than that of unsupplemented cattle.
Both age groups responded beneficially to the PMB supplement during t
he early portion of the grazing season, but supplementation failed to
offset the reduced daily gains that occurred during the latter part of
the grazing season.