Perennial Forage Kochia for Improved Sustainability of Grass-Dominated Ecosystems

Perennial Forage Kochia for Improved Sustainability of Grass-Dominated Ecosystems

Summary

Establishment of perennial forage kochia was undertaken the first three years of this project. The time required for establishment was extended as well as the SARE project because of drought and weed infestations. However, in 2007 on the Grantsville and Rush Valley sites, cows were placed on the kochia and control pastures. Cows on the Grantsville pastures demonstrated that through 60 days of grazing there was no difference between control and kochia cows for body condition score (BCS) or weight gain. This study was terminated after 60 days due to snow levels and lack of forage. The Rush Valley study began in early December and will continue into 2008 for a maximum of 90 days.

Objectives/Performance Targets

The objectives for this study are to evaluate livestock nutrient intake and performance responses to rangeland with or without forage kochia. this will include an economic evaluation and an Extension outreach component.

Accomplishments/Milestones

In early November, 2007, 57 gravid crossbred cows were randomly assigned to one of two treatments on the Grantsville cooperative.. Treatments consisted of 25 cows being placed in a predominantly forage kochia-based pasture and 32 cows in a pasture that consisted of primarily native plants. Cows were weighed and condition scored (BCS) initially and at trial termination (60 days). Cows were allowed to graze on their respective pastures until it was determined to terminate the study due to large snow accumulations which occurred in late December, 2007 and early January, 2008. Initial BCS scores and weights (lbs) were 5.04 and 1256 for the kochia cows and 5.1 and 1253 for the control cows respectively (P>0.05). Final cow BCS and weights (lbs) were 5.56 and 1335 and 5.58 and 1330 for the kochia and control cows respectively (P>0.05). This study demonstrated that treatments for control and kochia cows resulted in similar BCS and weights. If the study could have lasted longer this may have resulted in detectable treatment differences. It was observed, however, that once the snow began to accumulate, the cows on the kochia pasture had a less difficult time foraging as the kochia plants protruded to some extent above the snow whereas the grasses tended to lie below the snow surface in the control pasture. Because beef cows are not adept at foraging through the snow the kochia cows had a marked advantage. At some point the control cows would begin to lose BCS due to decreased forage intake because of the snow. For this reason the trial was terminated.
In another study conducted in Rush Valley, Utah, in early December, 2008, 50 gravid crossbred beef cows were assigned to one of two pastures: kochia and control. In BCS and weights (lbs) were 1329 and 4.9 and 1304 and 4.8 for control and kochia treatments respectively (P>0.05). Cows will be left on these treatments until either the snow becomes too deep for foraging or a maximum of 90 days, just prior to calving.

Impacts and Contributions/Outcomes

We have demonstrated to date that perennial forage kochia can be established, even under drought conditions. However, the plant is slow to develop and will lie dormant for months until sufficient moisture is available for further development. When mositure is present the plant grows vigorously and will thrive from that point on. Drought delays the time for establishment but even under these conditions germination is possible. The animal studies are just underway, although we have shown that beef cows can meet nutrient requirements when forage kochia is available in a pasture mix.

Collaborators: