Dual-purpose wheat grain and animal production under different grazing periods

The objective of this work was to evaluate the influence of different grazing periods on beef animal production and on wheat forage and grain yield. The experiment was carried out in Pato Branco, PR, Brazil. Six grazing periods were evaluated (0, 21, 42, 63, 84, and 105 days) on dual-purpose wheat cultivar BRS Taruma. Puruna steers, with average live weight of 162 kg and ten months of age, were kept under continuous grazing using a variable stocking rate, in order to maintain the established sward height of 25 cm. Greater increases in total animal gain (TAG) occurred with longer grazing periods. However, there was little increase after 63 days (490 kg ha(-1)), and TAG decreased from 552 to 448 kg ha(-1) between 84 and 105 days. Grain yield decreased from 2,830 to 610 kg ha(-1) when the grazing period increased from 0 to 105 days, but there was little change after 63 days (750 kg ha(-1)). Cultivar BRS Taruma shows excellent animal production potential, and the decision on how long wheat pastures should be grazed must be based on relative prices of grain and livestock.