Forage availability is frequently a limiting factor during the fall in winter annual grazing systems. Previous research has shown that cattle with restricted access to wheat forage early in the winter exhibit substantial compensatory gain when abundant forage allowed ad-libitum (constantly available to the livestock) grazing later in winter.
Therefore, limit grazing (giving the cattle access to forages for only a few hours per day) has the potential to stretch limited, high quality forage resources further without depressing animal performance. However, little information is available evaluating the effectiveness of different limit grazing practices.
A three-year experiment at the Noble Research Institute's Pasture Demonstration Farm used 606 beef calves to evaluate the effects of method of grazing on stocker and feedlot performance. The study compared the effectiveness of three winter pasture grazing practices from early December to late January:
- continuous 24-hour grazing (24H);
- an allowed four-hour (4H) daily limit-grazing bout; and
- an allowed eight-hour (8H) limit-grazing bout every other day.
In this project, we evaluated the effects of limit grazing and method of limit grazing on animal performance, forage utilization and feedlot performance.
Initial weights did not vary between treatments and averaged 553 pounds. Grazing method affected average daily gain (ADG) for 24H, 4H and 8H (2.2 pounds, 1.1 pounds and 0.5 pounds, respectively, P<0.01) for the 60-day grazing period. Another important observation is that even the 24H grazers did not perform well during the first 30 days of grazing, averaging less than 1.5 pounds average daily gain while the other two treatments, 4H and 8H, did not gain any weight at all during the first 30 days of grazing winter pasture. In the feedlot, average daily gain was higher for the limit-grazed calves, but their carcass weights were 22 pounds less than the continuously grazed calves.
Limit grazing can be a useful management tool in many situations. Just be aware of the performance implications if you are considering this practice and know the direction you are headed with your end product.
David Lalman, Ph.D., participated in this study. Lalman is an Associate Professor at Oklahoma State University.