Title: Predicted mineral intake utilizing both water and forage analysis varies by source and location of livestock water in Eastern Montana Authors
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 2010
Publication Date: February 17, 2010
Citation: Mulliniks, T., Muscha, J.M., Petersen, M.K. 2010. Predicted mineral intake utilizing both water and forage analysis varies by source and location of livestock water in Eastern Montana. Society for Range Management Meeting Abstracts PC-8. (online only) Technical Abstract: Livestock water can play an important role in contributing to mineral intake of cows grazing rangelands. Mineral analysis of both forage and water is needed to accurately assess mineral intake compared to animal requirements. Therefore, 93 pasture and water source combinations were sampled in May 2009 with the objective to predict total mineral intake (forage intake and water consumption) on a DM basis at the 22,257 ha USDA-ARS Fort Keogh Livestock and Range Research Laboratory in Miles City, MT. Mineral intake was predicted of a lactating beef cow with an estimated water and forage intake of 43.15 L/d (25.4 kg/d) and 2.4% of BW, respectively. Mineral content from hand plucked forage samples were analyzed from 43 pastures representing 3 geographical locations: north (N), southeast (SE), and southwest (SW). All drinking water locations from each pasture were sampled for mineral analysis (Midwest Labs Inc.) from four sources: springs, pumped ground water, reservoirs, and flowing surface water. Location, source and the location by source interactions were evaluated and analyzed as a 3 × 4 factorial arrangement of treatments. Predicted intake of chloride, copper, dietary anion-cation difference (DACD), phosphorus, and potassium was affected (P < 0.05) by geographical location. Differences (P < 0.05) in mineral consumption due to water source were found in 5 analyzed minerals (Ca, Cl, DACD, Fe, and Mg). Location by source interactions (P < 0.05) were found for fluoride, sodium, and sulfur. Predicted fluoride and sulfur intake concentrations were at or above the maximum tolerable concentrations in the ground water sources in most pasture locations. Copper and zinc were below requirements for a lactating beef cow; whereas, most minerals were found at safe intake concentrations and meet a lactating cow requirements. These results suggest that developing a mineral supplement to meet grazing cattle’s requirement should take into account both forage and water mineral content.