Mathematical model analyses of laying curves for layer breeders in natural mating cages

Objective  To screen the best mathematical model of laying curves for layer breeders in layer breeder houses installed natural mating cages with four overlap tiers.

Method  All the experimental Hy-Line Brown parent stock layers were fed in the closed layer breeder houses installed natural mating cages with four overlap tiers, and laying records from the 19th to 61th week were collected. The laying rates were fitted using Wood model, McMillan model and Yangning model respectively, and their fitting effects were compared.

Result  All three mathematical models were available for laying rate fitting. The R values of Yangning model, McMillan model and Wood model were 0.997 87, 0.964 63 and 0.764 57 respectively, which showed that Yangning model was the best, followed by McMillan model and Wood model successively. Yangning model was more suitable for actually observed data, and the suitability degree was 1.160 37×10²⁶ times of McMillan model, 1.599 31×10⁴² times of Wood model. The laying rate curves showed different characteristics in different periods. Compared with the standard laying rates of Hy-Line Brown stock layers in the same age, the experimental laying rates of layer breeders during early rising stage were lower.

Conclusion  Yangning model is most suitable for laying rate fitting of layer breeders in layer breeder houses installed natural mating cages with four overlap tiers. The feeding management should be carried out scientifically and reasonably according to fitting model and egg production curve to maximize the benefits in production process.