Author
Waldron, Blair | |
ZOBELL, DALE - UTAH STATE UNIV | |
OLSON, KENNETH - UTAH STATE UNIV | |
Jensen, Kevin | |
SNYDER, DONALD - UTAH STATE UNIV |
Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/4/2006 Publication Date: 5/4/2006 Citation: Waldron, B.L., Zobell, D.R., Olson, K.C., Jensen, K.B., Snyder, D.L. 2006. Stockpiled forage kochia to maintain beef cows during winter. Rangeland Ecology and Management 59:275-284 Interpretive Summary: Extending grazing into the fall and winter, as opposed to feeding of harvested forages, can increase the sustainability of cattle ranching in the western U.S. This study was conducted to determine the economic value of grazing stockpiled forage kochia (Kochia prostrata [L.] Scrad.) and crested wheatgrass (Agropyron desertorum [Fisch. Ex Link] Schultes) during the fall and winter. Changes in cow body weight, body condition score, and ultrasound backfat were compared for late-gestation cows grazing forage kochia-crested wheatgrass pastures versus those fed mechanically harvested alfalfa (Medicago sativa L.) hay in drylot. The study was conducted from early November to late January for two consecutive years near Promontory, Utah. Forage kochia comprised approximately 70% of available forage with November crude protein content of 116 and 76 g kg-1, in year 1 and 2, respectively. Nutritional quality declined throughout the season, presumably mostly due to preferential grazing as opposed to weathering. Averaged over years, cows grazing forage kochia-grass gained body weight (19 kg), increased in body condition (0.3 points) and maintained backfat thickness, finishing well within the range considered optimum for onset of calving and return to estrus. Pasture versus drylot fed cows did not differ for changes in body weight or body condition score. Overall, grazing was more economical, costing at least $0.24 cow-1 day-1 less than feeding alfalfa hay in drylot. For a typical 100-day winter feeding system, this could mean reducing annual cow-calf production costs by approximately 10%. Forage kochia can be used on western rangelands to extend grazing into the fall and winter thereby improving the profitability of beef production. Technical Abstract: Extending grazing into the fall and winter, as opposed to feeding of harvested forages, can increase the sustainability of cattle ranching in the western U.S. This study was conducted to determine the economic value of grazing stockpiled forage kochia (Kochia prostrata [L.] Scrad.) and crested wheatgrass (Agropyron desertorum [Fisch. Ex Link] Schultes) during the fall and winter. Changes in cow body weight, body condition score, and ultrasound backfat were compared for late-gestation cows grazing forage kochia-crested wheatgrass pastures versus those fed mechanically harvested alfalfa (Medicago sativa L.) hay in drylot. The study was conducted from early November to late January for two consecutive years near Promontory, Utah. Forage availability and nutritional quality were monitored throughout the experiment. Cows grazing stockpiled forages did not receive any protein or energy supplements. Economic analyses were conducted comparing the two feeding practices. Forage kochia comprised approximately 70% of available forage with November crude protein content of 116 and 76 g kg-1, in year 1 and 2, respectively. Nutritional quality declined throughout the season, presumably mostly due to preferential grazing as opposed to weathering. Averaged over years, cows grazing forage kochia-grass gained body weight (19 kg), increased in body condition (0.3 points) and maintained backfat thickness, finishing well within the range considered optimum for onset of calving and return to estrus. Pasture versus drylot fed cows did not differ for changes in body weight or body condition score. Both treatments increased backfat in year 1, when initial backfat was less than 0.5 cm, but both treatments resulted in loss of backfat in year 2 when initial backfat was greater than 1.0 cm. Grazing was more economical, costing $0.24 cow-1 day-1 less than feeding alfalfa hay in drylot. Forage kochia can be used on western rangelands to extend grazing into the fall and winter thereby improving the profitablility of beef production. |