Prediction of laying hens of different genetic origins
Abstract
The article presents the results of predicting the laying capacity of hens of different genotypes during an experiment to study the effectiveness of crossing roosters of imported meat crosses with meat-egg females of domestic selection. The average percentage of deviations of the actual bearing capacity values from the theoretically calculated values was generally low. It amounted to 0.82–4.55 % according to the model of T. Bridges and 0.8–3.28 % according to F. Richards. In the same group of chickens, the last model showed slightly more minor deviations than the model of T. Bridges. The most remarkable correspondence between the actual values of laying and those predicted by both models was determined in F1 chickens of the “K-2” group. Insignificant differences between the actual laying values and those predicted by both models were noted in F10 meat-egg chickens of the original maternal form, their F1 offspring, and chickens of the “K-5” group – 0.82–1.96 % according to the model of T. Bridges, 0.81–0.91 % according to the model of F. Richards. It is possible that the actual laying level of the birds of these groups determined in our research corresponded to the active paratypic factors in their maintenance, which is shown by the applied mathematical models by the high degree of coincidence of the calculated values with the actual ones. In a somewhat specific way, the models predicted laying in hens of other experimental groups. Thus, the model of T. Bridges underestimated the predicted bearing capacity by 3.59–8.25 %. Whereas the model of F. Richards also underestimated egg laying in the 5–7 months by 0.75–3.59 %, and in the last month, on the contrary, overestimated it – by 1.79–4.33 %. Although, in the end, the deviations of the predicted values from the actual values were slight – 2.82–4.55 % according to T. Bridges and 2.15–3.28 % according to F. Richards. The analysis of load-carrying curves calculated according to models showed a significant coincidence of actual and theoretical values – the R2 value, which determined the degree of correspondence between empirical and calculated load-carrying values, was high and amounted to 99.63–99.92 % according to the model of T. Bridges and 99.65–99.98 % according to the function of F. Richards.
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