Akademik Veri Yönetim Sistemi
ATLAS INTERNATIONAL CONFERENCE ON RESEARCH IN APPLIED SCIENCES, Barcelona, İspanya, 9 - 10 Temmuz 2022, ss.7-15
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.