Mixed Grazing by Cattle and Goats for the Control of Broadleaf Weeds in Rhizoma Peanut-Grass Pastures.

Mixed Grazing by Cattle and Goats for the Control of Broadleaf Weeds in Rhizoma Peanut-Grass Pastures

N. Krueger, L. E. Sollenberger, N. L. Santos.L.S. Lemos, , J.M.B. Vendramini, A.R. Blount, A.T. Adesogan

Rhizoma peanut (Arachis glabrata Benth.; RP)-grass pastures are currently attracting attention as a low-input, high nutritive value option for livestock production. One of the challenges associated with established RP swards is the occurrence of broadleaf weeds, especially blackberry briar (Rubus sp.). Our objectives were to determine if single livestock species vs. mixed grazing by cattle and goats affected briar herbage mass, height, and leaf removal, and additionally whether different methods of mixed grazing (concurrent vs. sequential) achieved different results. Treatments during 2011 included grazing by cattle only, goats only, concurrent grazing by both species at medium and high stocking rates, and two sequential treatments in which one animal species followed the other on the same paddock. Goats alone and all mixed grazing treatments reduced briar botanical composition in the sward by 8 to 18 percentage units and increased the proportion of forage by zero to 15 percentage units. over the course of the grazing season. Cattle grazing alone resulted in increased briar and reduced RP-grass proportion (19 and -18 percentage units, respectively) in herbage mass. In general, goats alone and all mixed grazing treatments reduced briar herbage mass (30-50 g m^-2), decreased briar height (7-8 cm), and increased briar leaf removal (45-53%) more than cattle alone (13 g m^-2, 1 cm, and 1% respectively). Within mixed grazing treatments, percentage of bites that of were briar was always less than 1% for cattle, was least for goats when they grazed pastures first and were followed by cattle (37%), and was greatest for goats when cattle grazed first followed by goats (50%). Results show that mixed grazing by goats and cattle reduced briar proportion in herbage mass of RP-grass pastures, and further, that the method of mixed grazing (sequential vs. combined) impacts diet selection.