259. Effect of Strip-grazing Frequency Using Virtual Fencing on Steer Performance and Carrying Capacity of Stockpiled Oats Pasture.

Abstract

Twelve 2.43-ha paddocks of stockpiled, late-summer-planted oats (Avena sativa) were used in a completely randomized design to evaluate the effects of strip-grazing management strategy on carrying capacity and steer performance. Paddocks were randomly assigned to one of three treatments: 1) continuous grazing (CON); 2) strip grazing with weekly movements utilizing virtual fencing (WEK); or 3) strip grazing with daily movements utilizing virtual fencing (DLY), resulting in 4 replications per treatment. A total of 72 crossbred beef steers (initial BW = 266 ± 0.9 kg) were stratified by BW and randomly assigned to paddocks (6 steers/paddock). Mean oats forage mass at grazing initiation on November 19th, 2025 was 1929 kg DM/ha (SD ± 428). Steers were removed from pasture on February 2nd, 2026 after 75 d due to forage depletion in the CON. At this time WEK had used 1.71 ha and DLY 1.76 ha per paddock. Data were analyzed using the PROC MIXED procedure of SAS (SAS Institute Inc., Cary, NC) with treatment included as a fixed effect and paddock as the experimental unit. Initial body weight did not differ (P = 0.91) among treatments. Average daily gain did not differ (P = 0.11) among treatments at 0.98, 0.93 and 0.86 kg/d (SEM ±0.036) for CON, WEK and DLY, respectively. Carrying capacity, measured as animal unit months per hectare (AUM/ha), differed among treatments (P < 0.01) and was increased (P < 0.01) from 4.06 AUM/ha for CON to 5.75 and 5.25 AUM/ha for WEK and DLY, respectively. Carrying capacity of WEK and DLY did not differ (P = 0.20). Consequently, this resulted in gain per ha differing among treatments (P < 0.01). Gain per ha in CON (182 kg/ha) was lesser (P ≤ 0.04) than WEK (247 kg/ha) and DLY (221 kg/ha), which did not differ (P = 0.13). Overall, weekly strip grazing increased carrying capacity by 42% and gain per hectare by 35% relative to continuous grazing, whereas daily movements did not provide further improvement. These results indicate that strip grazing dormant oat pasture using virtual fencing increased pasture utilization without negatively affecting individual animal performance, and that weekly strip grazing may be sufficient to maximize productivity.