Finishing steers on high-grain rations. Effects of type of silage, level of urea, vitamin A and cobalt supplementation on body-weight gain, feed efficiency and carcass composition

Abstract

Simple rations of sorghum grain and sorghum silage have been shown by Morris & O'Bryan (1965) and Morris (1966) to be suitable for the intensive finishing of steers in yards. With these rations, efficiency of feed conversion increased as the percentage grain in the final ration increased, attaining a maximum at 90 and 100 % grain. At all levels of grain feeding, groups of steers fed 60 g. urea per head daily had rates of gain and efficiencies of feed conversion superior to those not receiving urea. In the experiment reported by Morris (1966), steers fed final rations of 80, 90 or 100 % sorghum grain rapidly depleted their hepatic reserves of vitamin A.The present experiment was designed to investigate the performance of steers fed in yards on rations which ultimately contained 90% sorghum grain. Steers were accustomed to this high level of grain feeding by gradually increasing the allocation of grain according to a set schedule. Variables studied were two types of sorghum silage (sweet and grain) as the roughage component of the rations; with two levels of urea supplementation, 60 and 120 g. per head daily; with and without oral daily supplementation with vitamin A and with and without an intraruminal cobalt oxide pellet. MATERIALSFodder. Sorghum silage was prepared in two concreted hillside pit silos of similar design (Radel, 1961) from crops of sweet sorghum (Sorghum vulgare Pers. variety Sugardrip) and grain sorghum (Sorghum vulgare Pers. variety Brolga). Each variety of sorghum was planted at the rate of 7 lb. seed per acre in strips each of 16 rows. These strips were allocated in a random block design, and harvested by a single row forage harvester. Harvesting of the grain sorghum and sweet sorghum plants for silage commenced 93 and 121 days respectively after planting, when the seed was in the medium to firm dough stage.Random sampling of the standing sweet and grain sorghum crops immediately before harvesting, indicated that the silage made from sweet sorghum plants contained over 10% less grain than from the grain sorghum plants. The percentage contribution, on a dry-matter basis, of the seed head to total plant weight for sweet sorghum was 28-0 + 4-5andforgrainsorghum43-6± 7-1. Similarly, the percentage grain in the seed head and in the whole plant for sweet sorghum was 89-9 ± 4-0 and 25-1, and for grain sorghum 82-2 + 5-1 and 35-9. Sorghum grain (Sorghum vulgare Pers. variety Alpha) was purchased from a single source of production, rolled, and 1 % of superfine limestone added before feeding.

The survival feeding of pregnant and lactating beef cows on all-sorghum grain rations: the effects of two levels of grain and early weaning of the calves

“…The hepatic concentration of vitamin A in the cows was measured on biopsy samples taken and analysed by the method described by Morris & Gartner (1967). Biopsy samples were taken at the commencement of all-grain feeding, at parturition and 70 days after parturition.…”

Intensive beef production from sorghum grain and sorghum stubble: Effects of methods of processing the grain and the stubble, vitamins A, E and K and selenium supplementation and anthelmintic treatment on rate and efficiency of body weight gain and carcass composition

“…Burroughs et al (1963) reported The intensive production of beef from simple that the addition of vitamins E and K to no-hay rations of sorghum grain and sorghum silage was rations fed to cattle increased their rate of body reported by Morris & O'Bryan (1965), Morris (1966) weight gain. These workers also reported that and Morris & Gartner (1967). In these experiments selenium added at either 0-05 or 0-10 ppm to the grain was fed in a coarsely rolled condition and ration gave a similar growth response, and insilage in a chopped form.…”

“…A.C. (1960) with the modi-Beef production from sorghum grain and stubble fications described by Morris & Gartner (1967). Tocopherols and beta carotene were estimated by the methods of Nobile (1963) and Hausheer et al (1964) respectively.…”