Knowledge Bank

Many philosophies exist regarding the management of pastures for grazing. Most philosophies focus on reaching one of two goals: maximizing pasture dry matter production or optimizing dry matter production and forage quality. Either method can have merit if utilized properly, though most ruminant species, including cattle and sheep, need to consume good quality pasture to attain proper health and high production. Regardless of which goal is pursued, minimizing production costs is a priority for most graziers. One method of improving forage quality in mixed pastures is to increase pasture legume content, which can be done through rotational grazing management under a system of management intensive grazing. However, there is differing evidence on how grazing should be managed to achieve this goal. This study sought to determine whether a fast, 10-14 day, “rototinuous” management or a slow, 20-28 day “rotational” management was more effective at retaining a common legume – red clover (Trifolium pratense) – throughout the growing season in mixed grass and legume pastures grazed by sheep. The initial hypothesis was that the rotational management would retain more clover throughout the growing season than the rototinuous management due to increased rest time between grazings. Pasture species composition was measured weekly from mid-May through mid-August using visual evaluation, where randomly placed quadrats were used to select areas for data collection. Measurements of the amount of clover present in each pasture were done both pre-grazing and post-grazing, and control quadrats were harvested, separated into grass and legume fractions, dried, and weighed every week to audit the accuracy of the visual evaluations. Throughout the experiment, the average amount of clover pre-grazing in the rotational treatment was greater than the amount in the rototinuous treatment. The rotational treatment maintained clover stands at around 30% of the total pasture mass during the experiment, while the rototinuous treatment began at around 30% clover but steadily lost clover at an absolute rate of 2% of total pasture mass each week. The post-grazing data showed that the rotational treatment had more clover than the rototinuous treatment throughout the experiment, but both treatments lost clover over time at an absolute rate of 1% of pasture mass each week. These results suggested that traditional rotational grazing was superior at retaining clover compared to rototinuous grazing. It was predicted that the greater amount of clover present in the rotational pastures can result in greater animal productivity and meat quality from harvested animals over a longer term than could be measured in the study.