R. Hironaka et al., INFLUENCE OF BARLEY SILAGE-CONCENTRATE RATIO ON RATE AND EFFICIENCY OF LIVEWEIGHT GAIN, DIET DIGESTIBILITY AND CARCASS CHARACTERISTICS OF BEEF STEERS, Canadian journal of animal science, 74(3), 1994, pp. 495-501
Eighty steers were fed diets with eight ratios of 100:0, 75.1:24.9, 58
.3:41.7, 34.4:65.6, 18.9:81.1, 8.0-92.0, 3.7:96.3 or 0:100 barley sila
ge:concentrate on a dry matter (DM) basis. Diets were fed to provide a
bout equal digestible energy (DE) per unit liveweight for 24 wk, then
fed to appetite until the steers reached a market weight of about 515
kg. Steers receiving the 100% silage diet were fed for ad libitum inta
ke from week 24 to week 52 (28 wk) and were then fed 100% concentrate
diet until they reached market weight. The average daily gain (ADG) of
steers fed 100% silage was lower than that of those fed forage and co
ncentrate. Efficiency of DE utilization for liveweight gain increased
at a decreasing rate as level of concentrate in the diet increased. Ca
rcass backfat thickness increased with rate of gain. Digestibility of
energy, DM, crude protein (CP), and starch exhibited a curvilinear res
ponse to increasing levels of concentrate in the diet. The proportion
of concentrate in the diet for maximum economic benefit depends on the
cost per unit of DE from silage versus that of barley, the efficiency
of DE utilization for liveweight gain and time to reach market weight
.