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VITAMIN A AND TRACE MINERAL SUPPLEMENTATION OF SORGO SILAGE AND GRASS HAY FOR YEARLING STEERS AND Research Progress Report 30	HEIFERS, SOUTHERN INDIANA FORAGE FARM
May 1962, Project 795
Nov. 30, 1961-Mar. 29, 1962 (119 Days)
R. C. Peterson, W. M. Beeson, M. E. Heath and G. O. Mott, Agronomy and Animal Sciences Departments
It is an established fact that beef cattle need Vitamin A and trace minerals in their ration. During past years it has been thought that most, if not all, of their vitamin A and trace mineral requirements could be met by natural feedstuffs.
Ordinarily the beef cow can convert carotene, which occurs naturally in forage plants, to vitamin A. There is evidence, however, that when a forage plant is heavily nitrated it can concentrate nitrates within the plant cells. When the cow beast eats the herbage which contains a high level of nitrate, the nitrates are changed to nitrites. This process may interfere with the ruminant converting the carotene to vitamin A.
Generally speaking southern Indiana is not considered to be a trace mineral deficient area, however, it could be that soil depleted of major elements could well be limited so far as the minor minerals are concerned also.
Experimental Objective
This feeding trial was designed to ascertain whether the addition of synthetic vitamin A and/or trace minerals would result in growth stimulation of yearling steers and heifers fed a forage ration that had been heavily nitrated.
Experimental Plan
Twenty-eight weanling steers and 36 weanling heifers were allotted to four groups.
Each lot contained 7 steers and 9 heifer calves. The experiment was started on November 30, 1961 and terminated on March 29, 1962, a period of 119 days. All animals were weighed individually at 28-day intervals. All four groups were wintered in outside lots which were adjacent to each other. No barn shelter was provided.
There were many days during the winter when these calves had no dry place to "bed down."
Experimental Treatments
Lot 1 (Control). Silage and mixed brome, timothy and orchardgrass hay plus 1 pound of soybean oilmeal with no synthetic vitamin A or trace minerals. These calves were fed a mineral mixture consisting of 2 parts dicalcium phosphate and 1 part iodized salt, free choice; plain salt was also fed free choice.
Lot 2. Same as Lot 1, except that
1.54	grams of the trace mineral mixture presented in Table 2 was added to the pound of soybean oilmeal that each calf was fed.
Lot 3. Same as Lot 1 except that 20, 000 I.U. of synthetic vitamin A was added to their pound of soybean oilmeal.
Lot 4. Same as Lot 1 except that
1.54	grams of trace mineral mixture and 20, 000 I.U. of synthetic vitamin A was added to the pound of soybean oilmeal that each of these calves consumed daily.
PURDUE UNIVERSITY • Agricultural Experiment Station • Lafayette, Indiana