SIMULATION STUDY OF FLOCK DYNAMICS: APPLICATION TO INTENSIVE PRODUCTION SYSTEM OF EGYPTIAN BARKI SHEEP | ||||
| Journal of Animal and Poultry Production | ||||
| Article 5, Volume 32, Issue 10, October 2007, Page 8151-8160 PDF (712.6 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jappmu.2007.220674 | ||||
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| Author | ||||
| S. M. Alsheikh, | ||||
| Department of Animal Breeding, Desert Research Center, Matareya, P. O. Box 11753, Cairo, Egypt. | ||||
| Abstract | ||||
| A dynamic flock simulator model (DFM) is presented. This model studies the complexity reproduction management systems of three lambings in two years system. Two types of data were used to build the simulator model. Ewe data (concerned 13725 records for 3120 Barki ewes from 1970 to 2000) from Barki flock management database of the Maryuot Research Station, Desert Research Center, Ministry of Agriculture, Egypt. References, on three lambing in two years management practices, were implemented by researcher to ensure the generality of the model structure. The simulator model was based on some set of specifications. The flock was divided into two batches. Data were analyzed to estimate the biological responses that are necessary for setting the model parameters. Also, input/output data were economicly analyzed at each phase corresponded to the characterization of the each batch flock, which is the set of all the ewes used for reproduction, replaced system. The result shows that, The batch production cycle (BPC) was the basic management entity for the dynamic flock model (DFM) structure. The relation between biological responses and ewe productive trajectory was the basic unit of the studied DFM performance and evolution. The average gross output of lambs, wool, manure and culling animals per production cycle was 150450 LE, 1581 LE, 12635 LE and 53813 LE, respectively. This result shows that lambs, wool, manure and culling animals contributed 69%, 1%, 6% and 24% of total gross output, respectively. It could be concluded that, this is a very simple DFM and clearly could be much improved if more detailed information on the inputs relating to reproductive and productive performances were available. Consequently, the model could be expected to produce very different outputs for different mating seasons over a range of environments. In this model, a mating program was used with a ewe batch being joined at regular 4-monthly intervals. However, modification of the system to permit shorter or longer intervals between matings may be warranted and the model is capable of indicating the effect on output of such changes. Also, the DFM is promising economic rewording. | ||||
| Keywords | ||||
| Sheep; flock dynamics; simulation and intensive production system | ||||
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