engleski

Application of Asymetric S-Function for analysis and Valuation of the Growth of Boars

Growth capacity of the pig is a subject of permanent research. The growth rate of pigs has different quantitative and qualitative course. Profitability of pig rearing is in use of progessive growth stage, i.e. phase. This study with the curves of growth of the Large White breed based on the gain intensity of the animals tested with the body weights 30 to 100 kg. According to the average daily gains the boars were devided into three groups (0.81-0.90 kg, 0.91-1.1 kg and 1.01 to 1.10 kg). For description of the growth rate asymmetric S- function was used modelled as: \[f(t)=\frac{; ; ; ; A}; ; ; ; {; ; ; ; /(1+be^{; ; ; ; -c \gamma t}; ; ; ; )^{; ; ; ; 1/\gamma}; ; ; ; }; ; ; ; .\] Regarding the neceessary time for achievement of certain mass, the stages are separated as: preparations $(t=t_B)$, growth-both progressive and degressive $(t=t_B=t_C)$ and phase saturation $(t=t_C)$. The analysis showed that boars, entering the test in younger age, showed higher growth intensity than those beginning the test in older age (77.4 ; 83.4 and 82.6 days). In these boars the stage of progressive and degressive growth occurred earlier and lasted shorter period time. The asymmetric S-function could be therefore used for valuation of the boars growth rate in older age based on the starting control measurements of animals.

asymetric S-function ; growth model

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