Simulation Model for a Nomadic Animal Production System in Southern Iran

Document Type : Research and Full Length Article


1 Research Center for Agriculture and Natural Resources Fars province

2 Department of Animal Science, Faculty of Agriculture, University Putra Malaysia, 43400 UPM Serdang, Selangor,

3 Rainforest Academy, University Putra Malaysia, 43400 UPM Serdang, Selangor

4 Faculty of Natural Resources, University of Teheran, Karaj


The first motive for the determination and evaluation of an energy production
system is the need to change. Such system is dynamic in nature and is influenced by
many factors such as age and physiological status of individual sheep or goat, quantity
and quality of available feed and environment including the management systems.
Traditional pastoral resource assessments do not always account for the complex,
interrelated nature of land, forage and livestock. Modeling may overcome the limitations
of traditional methods by improving the understanding of complex pastoral systems, and
makes fast repetitive analyses, spanning time, incorporating variability and representing
more realistically complex interactions possible within the system. The estimated values
of metabolisable energy for maintenance and production in this study are based on the
results of two feeding systems linked together by grazing the energy intake in the
Nomadic Production System (NPS) and the dynamic system modeling used to study the
assessment of these complex systems. In this study, validation of model relied on the
observations of Torki Ghashghaii (TG) sheep (like those in Bakkan) under pen-fed and
integrated rangeland-cropland feeding systems, and was carried out mainly by studying
the body weight gain of growing animals and also body weight changes of ewes due to
pregnancy and lactation. After validation, the study indicated that the mean value of
actual data of male and female lambs (weaners) and ewes were in close agreement with
the simulated data. These results validate the generalized structure of energy utilization
models of grazing sheep under production sub- systems of NPS. These results will enable
the prediction of carrying capacities in any given situation under conditions similar to
those in Bakkan.


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