Effect of long-term grazing on dry matter biomass production and heifer performance

摘要

Stocking intensity is one of the main factors affecting grazing productivity. The effects of different grazing intensities on herbage production and live-weight gains of heifers were studied in an upland area in the northern part of the Czech Republicover 20 years (1998-2017). The sward was maintained at a target height of 5 and 10 cm under intensive (IG) and extensive (EG) grazing, respectively. Total biomass production in the grazing season was found to be higher under IG than under EG treatment.Heifers grazing the EG treatment had higher average daily weight gain in comparison to heifers grazing in IG. The particular year and month of vegetation season had the highest effect on seasonal daily weight gain ofheifers, but there was no significantdifference between breeds. Seasonal live-weight output per hectare under IG was approximately 1.5 times higher than EG treatment. However, if state subsidies are included, EG can be more profitable under the current Czech conditions than IG and satisfiesboth farmer and nature conservation objectives.