| Abstrakt: |
Four experiments were conducted with mature beef cows to determine the relative acceptability of different supplemental magnesium oxide mixtures. In the first experiment the mixtures were offered in a cafeteria arrangement to lactating beef cows on pasture, and in three additional experiments, the supplemental mixtures were offered singly, ad libitum, to gestating cows in dry lot and lactating cows on pasture. In the first three experiments the four supplemental magnesium oxide mixtures were magnesium oxide with trace mineralized salt (1:1 ratio), and magnesium oxide, trace mineralized salt and either cottonseed meal, dry sugarcane molasses or steamed bone meal (1:1:1 ratio). In the first experiment, magnesium consumption was 8.4 g/head/day for the dry molasses mixture, higher (P<.05) than for the other mixtures. In the second experiment magnesium intake was highest (30.7 g/head/ day) for the cottonseed meal mixture (P<.05). For the third experiment, consumption of magnesium was 23.2 g and 20.1 g per head per day for the cottonseed meal and dry molasses mixtures, respectively. These two levels were not significantly different from each other, but were higher (P<.05) than for the other two mixtures. Blood serum calcium, magnesium and inorganic phosphorus measured in experiments 1, 2 and 3 were normal, with no significant differences due to magnesium consumption.Supplemental magnesium oxide mixtures tested in experiment 4 contained trace mineralized salt, magnesium oxide and either dehydrated alfalfa meal, corn distillers dried grains, ground shelled yellow corn or cottonseed meal. Magnesium consumption was 19.5 g, 23.9 g, 21.3 g and 23.6 g per head per day for the four mixtures, respectively. |
