Late Season Grazing Demonstration Results (Fall 2012 and 2013) Drewsey Field Ranch and Burns District BLM Upton Mt. Allotment, Drewsey, Ore.
A Cooperative Project between Univ. of Nevada, Reno, Burns District BLM, Oregon Cattlemen’s Association, Harney County Court and Wilber Ranch
This report summarizes results from two years of late season grazing on pastures with heavy concentrations of cheatgrass and medusahead in southeast Oregon. The project is a cooperative between the University of Nevada, Reno College of Ag., Burns District BLM, Harney County Court, Oregon Cattlemen’s Association and the Wilber Ranch.
In year one (2012), the Wilber’s moved 333 head of livestock into the 14,000 acre pasture in early October, 2012 and removed them on Jan. 4, 2013 after 90+ days of grazing. Animal performance on some of the herd was positive, with some animals leaving the pasture with the same body condition score, but most animals went down slightly, scoring 0.1 points less after eating dead cheatgrass and medusahead for more than 90 days. It appears the 3-4 year old cows lost the most weight, with most of that likely occurring during the two weeks of below zero weather and snow in late December before leaving the pasture.
The animals were supplemented with Anipro, and consumed about 1-1.25 lb/day at a cost of $0.28/lb. This is equivalent to about $10.50 per head per month. If we were comparing the cost of feeding hay at more than $200/ton, and monthly hay consumption per head at about 1/3 ton/head, the monthly hay feed cost would be roughly $66/head. This demonstration has already shown that utilizing this late season forage and avoiding the feeding of hay has proven to be a considerable savings to the rancher.
In year two (2013) 437 head of livestock grazed the pasture for 114 days beginning in September. Based on observations of the pasture during the grazing period, livestock were better distributed across the entire pasture, and given the dry fall weather, use of protein supplement was applied later than the first year. Sweetlix supplement was used, costing roughly $6.75 per head per month, beginning with 16% blocks, increasing to 18% as the weather got cold, and ending with 20% blocks for the last two weeks. Body condition scores went up 0.09, from 5.57 to 5.66 and all cows gained weight. Rancher savings exceeded $50/head/month.
To help show the degree of vegetative utilization, three photo monitoring plots were established in the pasture during the first week of April 2013. This provides an opportunity for us to be able to compare changes in both utilization and the vegetative response from year to year. In this first trial period, the vegetation consumed is clearly not uniform across the pasture, but in year two there was better utilization across the entire pasture . There were simply not enough animals to uniformly cover the entire 14,000 acre pasture during the time allotted. In both years we observed heaviest utilization closest to the water and protein supplement sources.
The following photos illustrate the changes in fuel load and plant community composition after two periods of late season grazing (Oct. 2012-Jan.2013) and (Oct. 2013-Jan. 2014).
Photo 1 shows Upton Mt. photo plot 1 in Oct. 2012 prior to initial late season grazing. Cheatgrass dominates the plant community, which also includes perennial grasses: crested wheatgrass, Basin wild rye, bluebunch wheatgrass, and Idaho fescue. Fuel load is 500-600 lb/ac.
Photo 2 shows Upton Mt. photo plot 1 after the first late season grazing in early April 2013 as spring green-up is emerging. Fuel load is roughly 200 lb/ac. Early green-up more advanced on perennial grasses.
Photo 3 shows Upton Mt. allotment photo point 1 after peak of 2013 annual grass growth in July 2013. With a dry spring in 2013, spring growth of cheatgrass was markedly reduced from the prior year. Cured cheatgrass is roughly 4 inches tall compared with 12 inches tall in 2012. Some perennial grasses are still green and continuing to grow in July. Fuel load is 200-300 lb/ac.
Photo 4 shows Upton Mt. Allotment photo point 1 during the second late season grazing in late November 2013. Animal distribution is widespread across the 7800 acre pasture and cows are utilizing both dry cheatgrass and medusahead and perennials. Animals consumed the majority of dry cheatgrass and perennials. Some green-up from fall rains is evident. With overstory competition reduced, perennial grass response in 2014 growing season should be excellent. Fuel load is <100 lb/ac. and associated fire risk is minimal after just two treatments.
Photo 5 is a 20+ acre patch of medusahead that cattle grazed after the initial fall rains in early November 2012. Once softened up by rain, the cattle seemed to prefer this vegetation to other adjacent plants. This degree of utilization of medusahead was unexpected. Much of the mat, so commonly formed after annual growth of this plant community, was consumed by livestock.
Photo 6, taken in July 2013, shows spring regrowth from the 2013 season. Given the dry spring, vegetative growth is only about 4 inches tall.
Photo shows utilization of 2013 plant growth in the medusahead dominated pasture as of late November 2013.