A strategy for optimal beef production off sourveld.
The economic necessity of a better production strategy on sourveld promoted this study. Production of marketable two-tooth steers in the summer season and overwintering of all cattle without excessive feed costs were motivating factors. The problems of economic beef production were identified as resulting from the seasonal flow of forage quality from sourveld grass production. Season long rests, early burning and non-selective grazing of nutritious grass were identified as essential elements of a new utilization strategy. A 'forage reserve', built into the system to cater for fluctuations in grass production due to varied climatic conditions, is used as an indicator of the seasonal stocking rate. This provides a barometer in relation to the economic and ecological carrying capacity of the property. Research was conducted on the winter utilization of rested veld and its effects on grass species composition and vigour in the following season. It was found that the winter grazing of the rested veld did not affect (P>0.05) the subsequent production in the three seasons of this study on 'Stratherne' in the Dundee district, KwaZulu-Natal South Africa (30°17'E 28°17'S). The grass species composition of four transects was recorded in 1994, prior to the implementation of the grazing system under test. The same transects were recorded again in 2002 to determine the effect of the change in utilization on grass species composition. It was found that a more productive state was developing in response to the strategy implemented in this study. The general trend has been for sites to move from a Hyparrhenia hirta dominated state to a more productive one associated with species such as Themeda triandra. Summer mass gains of steers (147 kg and 143 kg over the two summers) have improved over the previous systems applied (average 119 kg), as a result of the more nutritious grazing. A greater proportion reached market readiness as two-year old to two and half year olds (97%) on veld, which is far superior to the 38% quoted from research using similar Bonsmara type steers from 'conventional' systems. Monitoring and flexibility are important in the application of the strategy to conditions in Africa. The principles of adaptive management (monitoring, recording, constant learning and adaptation) will build a data base to ensure long-term success of the strategy. A change of focus in grazing strategy from needs of animals to the needs of plants is strongly advocated.