APPLICATION OF CLASSIFICATION TREE METHOD TO DETERMINE FACTORS AFFECTING EMBRYONIC MORTALITY IN POULTRY


Kaya Başar E., Narinç D.

ATLAS INTERNATIONAL CONFERENCE ON RESEARCH IN APPLIED SCIENCES, Barcelona, Spain, 9 - 10 July 2022, pp.7-15

  • Publication Type: Conference Paper / Full Text
  • City: Barcelona
  • Country: Spain
  • Page Numbers: pp.7-15
  • Akdeniz University Affiliated: Yes

Abstract

Embryo deaths in the poultry industry cause significant economic losses and are largely affected by environmental factors. These factors may be environmental conditions not related to animals such as thermal conditions of the incubator, embryo movements, egg quality, egg storage. In addition, environmental factors such as genotype, age, disease, feed content, breeding system, stocking density, and season, which are directly related to breeders, are also associated with embryonic mortality. The aim of this study is to determine the effects of genotype, season, and stocking density on embryonic mortality in eggs obtained from Japanese quail breeder flocks. In the study, a total of 1602 hatching fertile eggs collected at the same age and in different seasons from a high body weight flock selected to increase body weight for short term, and a randomly mated control flock were used. These quails were housed in homogeneous breeder cages at the stocking density of 160 cm2/quail, and 240 cm2/quail. Collected eggs were transferred to the incubator without storage, and embryo deaths were determined by macroscopic examination after incubation. The obtained nominal scale variables were analyzed with the classification tree method, which is widely used in data mining. The classification tree method is a fairly new method in the field of animal science. Unlike other similar discriminant analysis and logistic regression methods, the classification tree method does not have hypothetical disadvantages such as normality, multi-collinearity, constant variance, and linearity. As a result of the analyzes carried out, a total of 7 nodes in factorial structure were obtained in the classification tree, while 20 nodes (2 genotypes, 3 seasons, 2 settlement frequencies) were expected. All three main effects of genotype, season, and stocking density were found to have significant effects on embryonic mortality (P<0.05 for all). While embryo mortality (10.4%) in eggs of quails with high body weight genotype group was higher, embryo mortality (10.5%) in quails raised in summer was higher than in other seasons (P<0.05). The highest embryo mortality (22.4%) was found in quail eggs in the selection group, reared at a stocking density of 160 cm2/quail in summer. As a result, it can be recommended to use individuals with the appropriate genotype, to optimize the climatic environment, and to produce under a suitable stocking density in order to reduce the embryonic mortality in eggs obtained from breeder flocks.