Grazing behavior and performance of beef cattle as afunction of sward structure and herbage quality underrotational and continuous stocking on species-richupland pasture

摘要

An experiment to reveal functional response and heifers’ performance to sward characteristics and forage chemicalcomposition was conducted for 5 years in rotational (RSS) and continuous (CSS) stocking systems on native species-richupland grassland. We measured sward characteristics, forage chemical composition, heifers’ grazing behavior andlive-weight gains from July to September. Mean sward surface height was lower on CSS than on RSS; grass and forbdensity, and white clover stolon length, were similar. Herbage on CSS had higher crude protein content and lower crudefiber content than on RSS. No difference existed in time budgets of grazing, ruminating and resting between stockingsystems and season, while grazing rates were higher on CSS. Stocking rate was 1671 and 1332 kg per ha on CSS and RSS,individual daily live-weight gain 683 and 652 g on CSS and RSS. Gain per ha was 20 kg higher on CSS. Results suggestedstocking systems on native species-rich grassland had no effect on activity time budgets or animal performance. Both RSSand CSS allow similar outputs for stocking rates in terms of individual daily live-weight gain. Key parameters determiningheifers’ behavior and performance were sward height, grass and forb density in the sward, and content of crude fiber andprotein in forage.