Rearing system effects on live weight gain of large white turkeys

The aim of this study was to determine the effect of three production systems on live weight gain (LWG) of white turkeys by repeated measures analysis of variance (ANOVA) and profile analysis. A total of 81 turkey poults were assigned to intensive (7 male and 19 female), semi-intensive (9 male and 19 female) and extensive groups (11 male and 16 female) at one day old. The poults were wing-banded at day 1 after hatching and weighed individually each week through 16 weeks old. The birds were managed similarly through eight weeks old. After that time, the intensive group was fed concentrated feed indoors. The birds of the semi-intensive group had access to pasture for eight hours a day, and received 50% of the concentrated feed that was consumed by the intensive group. The birds in the extensive group were kept outdoors with shade and grazed on pasture, but did not receive concentrated feed. The bi-weekly LWG of the extensive, intensive and semi-intensive groups were 1191.4 g, 990.6 g and 872.1 g, respectively. Through the 16 weeks of the trial, the effects on LWG of production system, age, and interaction of age and production system were highly significant (P <0.01) in the repeated measures ANOVA. The profile analysis also showed highly significant (P <0.01) production system effects and interaction of production system and age on LWG. Scheffe’s test indicated that the intensive, semi-intensive, and extensive treatments differed (P <0.05)

Usability of CART algorithm for determining egg quality characteristics influencing fertility in the eggs of Japanese quail

The objective of this study was to determine the effects of egg quality characteristics (egg weight, egg width, egg height, and shape index) on fertility of eggs of Japanese quail with different colored feathers (yellow, white, grizzled, and normal), which are of economic importance for poultry production. For this purpose, 383 eggs of Japanese quail with various feather colors were used. In the study, usability of classification and regression tree (CART) data-mining algorithm as a classification tree method is necessary for poultry breeders to define proper cut-off values of egg quality characteristics that ensure Japanese quail eggs at good quality in fertility. Fertility as the dependent variable in the study was examined as a binary trait (fertile and infertile) and all the egg quality traits accepted as explanatory variables were continuous variables. Feather color was also included as a nominal categorical explanatory variable. The classification tree results showed that the highest fertility ratio of 90.9% was obtained from the eggs of Japanese quail of white, grizzled, and normal feather colors with 10.425 g ? egg weight, 24.565 mm ? egg width, or the fertility ratio of 88.2% of the eggs was observed with 10.425 g ? egg weight and 25.605 mm ? egg width. Consequently, usability of the tree-based CART algorithm is important in practice for properly establishing fertilized eggs, depending on feather color types of Japanese quail. © 2016 Sociedade Brasileira de Zootecnia