Grasslands of the World.pdf - Disasters and Conflicts - UNEP

The South American Campos ecosystem 209
3 400 kg DM/ha, increased forage production to 8 600 kg DM/ha (Ayala et
al., 1999).
Stock management
Managing livestock is one of the most important options for farmers in
improving the utilization efficiency of available forage and to increase its
productivity . This low-cost technique is based on adapting the nutritional
requirements of stock classes to the grassland growth curve. Stock management
involves short seasonal mating, early weaning, pregnancy diagnosis, stock
classification according to nutritional requirements, and sales organization.
An example of the impact of this technology is found in Curuzu Cuatiá
Department. While the average liveweight gain for the Department is 56 kg/
ha/year, twelve farms that adopted these practices averaged 88 kg/ha/year
over five years.
Mineral supplementation
Phosphorus deficiency in diets is one of the limiting factors for animal
production in the region. Unsupplemented steers have a liveweight gain of
66 kg/year, while supplemented steers can gain 106 kg/year.
Other management practices
Other management practices that increase productivity include mowing of
tussock grasslands, burning , autumn deferments for winter grazing , strategic
rests for paddocks, energy-protein supplementation, and “protein banks”.
RESEARCH AND DEVELOPMENT PRIORITIES
Advances in knowledge over the last 35 years concerning the structure, function
and management of natural grasslands show that there is great potential, at
least in the Rocky Outcrops region. The next task should be to evaluate these
technologies in other ecological regions where this could be applicable. In
regions such as the malezales , factors such as drainage and use of fire have to be
studied before thinking of any further improvement . The relationship between
soil series, grass production and carrying capacity is an issue that has received
little attention. Soil has a great effect on grassland production and stability, but
research has paid little attention to this topic.
A task that has to be completed, validated and then extended is paddock
ranking . Managing natural grasslands means to manage soil, vegetation
and stock within the constraints of climate to get the best results from the
combination of factors. Each stock class has specific nutritional requirements;
each paddock has different FO and potential. Today, the pastoral value of a
paddock is subjectively evaluated. Methodology development is required to
enable simple objective paddock ranking, and to match paddock FO with
animal requirements.