Optymalizacja wykorzystania powierzchni paszowej w chowie bydła mlecznego w strefie subtropikalnej
AbstractThe aim of the studies was to investigate the possibility of obtaining maximum milk yields from dairy cattle kept on irrigated, intensively utilized land situated in the subtropical zone, Such a land, cultivated the whole year round, can produce at least two crops of forage plants yearly: in winter and summer seasons. The applied linear programming method ensured that best possible solutions under given conditions and imposed restrictions were achieved. Initial data for constructing mathematical models and calculation programs were obtained from a number of dairy cattle farms situated in Israel and in southeastern Turkey, Additional information and data were taken from literature sources and nutritional tables. Three separate initial programs designed for low, medium and high yields of forage plants were created. In the programs, the cattle stock was expressed in structural cows (dairy cows with progeny and annual replacement) which reflected the internal structure of a cattle herd, including various combinations of calving percentages (70, 80 and 90 percent) and utilization periods of cows (3, 4, 5 and 6 years). Several levels of average daily milk yield, starting from 10 kg per cow daily, were considered. As a result of the conducted calculations, 1030 optimal solutions, for the daily milk yield per cow ranging from 10 to 40 kg, were achieved. In the worst solution, annual milk production was as low as 7683 kg per ha yearly, and in the best solution it reached the level of 16 137 kg per ha, while the number of structural cows in the best solution (1.79 per ha) was by 30% lower than in the worst one (2.56 per ha). In 30 best solutions, milk production per 1 ha exceeded 16 000 kg yearly with the number of structural cows per 1 ha of land varying between 1.6 and 2,2. Milk production reached its maximum at a daily milk yield of 30-34 kg per cow, depending on the combination of the investigated factors. The further increase in the daily milk yield above the optimal level resulted in a slow decline in the number of structural cows and a parallel decrease in the annual milk production per ha until last optimal solutions at a daily milk yield of 36-40 kg were obtained. The conducted investigations proved the usefulness of linear programming and adequate computer techniques in optimizing the utilization of forage area for milk production in the subtropical zone. With small alterations, the proposed mathematical model can also be used for similar calculations designed for the temperate zone.
|Other language title versions||Optimization of forage area utilization in dairy cattle kept in subtropical zone|
|Publisher||Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie, MNiSW |
|Publishing place (Publisher address)||Kraków|
|Book series /Journal (in case of Journal special issue)||Zeszyty Naukowe Akademii Rolniczej im. H. Kołłątaja w Krakowie. Rozprawy, ISSN 1233-4189, (0 pkt)|
|Publication size in sheets||5.8|
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