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Mob grazing effects on cattle performance in Southeast Arkansas
Ultra-high-density stocking or mob grazing management has become increasingly popular with producers. Mob grazing systems are typically characterized by extremely high stocking densities for approximately one day or less with the goal of improving soil organic matter and diversification of forage species composition in the long-term. The objective of this study was to evaluate animal performance and health measurements of calves from a mob grazing management option compared with a moderate rotational stocking program. Beefmaster calves (n = 58; 221 ± 8.7 kg initial BW) were stratified by sex and body weight and then allocated randomly to 1 of 4 pastures that were assigned randomly to treatments consisting of: 1) a moderate rotational stocking program (MS) or 2) an ultra-high-density rotational stocking program (UH). Pastures consisted primarily of bermudagrass (Cynodon dactylon), but also contained significant amounts of broadleaf signalgrass (Brachiaria platyphylla), crabgrass (Digitaria sanguinalis) and dallisgrass (Paspalum dilatatum). Calves began grazing on July 16, 2015 and continued for 75 d until September 29, 2015. The MS calves were managed on 6 paddocks with rotations at 5 to 7-d intervals; the UH calves were managed using 60 paddocks with rotations daily, Monday-Friday. This created a stocking density of approximately 5,000 kg of BW/ha and 50,000 kg of BW/ha for MS and UH, respectively. This stocking density is at the low end of UH programs, but was chosen to reduce the negative impacts of extremely high grazing pressures on animal gains. Blood samples were collected on September 29 and analyzed for complete blood counts. Data were analyzed using PROC MIXED of SAS. Calf BW and BW change did not differ (P ≥ 0.18) between MS and UH calves, but were greater (P < 0.05) for steers than heifers. Total and differential white blood cell counts and red blood cell concentrations were not affected (P > 0.21) by treatment, sex of calf, or the treatment by sex of calf interaction. Therefore, after the first year of a long-term study, mob grazed calves performed similarly to calves managed using a moderate rotational stocking program, indicating that such systems can be implemented without having negative impacts on animal growth and health.
Keywords: Mob grazing, cattle, performance