Predicting animal production on sourveld: A sward‐based approach

Abstract

Abstract Simulation models were developed to assess the effects of sward structure and species composition on average daily gain (ADG) and seasonal live mass gain (LWG) in cattle and sheep on Dohne Sourveld. The models used diet quality and intake data collected from sites of different sward structures and species compositions on this veld type. In model 1, predicted ADG was highest at an optimum sward height (Hopt) of 60‐ 80 mm for sheep and approximately 120 mm for cattle but Hopt is likely to decrease as forage quality declines through the season. Species composition appeared to be the major determinant of ADG above Hopt while sward height appeared to be more important below Hopt. Potential rates of DM intake generally far exceeded predicted voluntary intake, suggesting that on sourveld, intake is seldom likely to be restricted by the effects of sward height on intake rate per se. In model 2, species composition had a major effect on animal production with sites showing large differences in predicted L...