The effects of the breeder index value on the microscopic structure of egg shells, hatching results, and hybrid performance.

The quality of egg shell and bone properties of hen are important for hen welfare, consumers, and producers. Parameters of the genetic selection have both desirable and undesirable effects among themselves. Until recently, it has been stated that the concept of shell quality is not only about breaking strength, thickness, and weight of shell, but also microscopic properties of the shell. In this study, the effect of index selection including age and weight at sexual maturity, number of eggs and egg weight on eggshell structures, hatching results, and hybrid performance was determined. Ninety Barred Rock 1 (BAR-1) and ninety Rhode Island Red 1 (RIR-1) hens and twenty RIR-1 cocks (46 weeks old) were used. BAR-1 and RIR-1 were classified according to the breeder index value as low and high. Egg quality characteristics, embryo development and hatching results were examined in eggs obtained from these lines. In the hybrid eggs with high breeder index, the thickness of the palisade layer, breaking strength, ash, and Ca level of the shell were lower and cone similarity and egg weight were higher than that with low breeder index. The breaking strength of the egg shell had a significantly positive correlation with the palisade layer thickness of the shell. In addition, the tibia weight of the high breeder index group was lower than that of the low breeder index group. Differences in femur and tibia weights in hybrids with low and high breeder index increased with age. A negative correlation was observed between hatchability and the thickness of the palisade layer. Further studies are needed to determine which selection programs positively affect the thickness of the palisade layer, the Ca level and the breaking strength of the shell, the number of broken eggs, and the tibia weight in layer hybrids.

Effects of oregano juice on eggshell microbial load, layer embryo development, hatching results, and growth at the first 2 weeks after hatch.

One of the factors affecting the hatching results and chick quality is the implementation of an appropriate disinfection program with effective disinfectants. This study was carried out to evaluate the effectiveness of oregano juice as a disinfection of hatching layer eggs as an alternative to formaldehyde. In the study, 1800 eggs collected from 48-week old Akbay white layer breeders were used. Eggs were divided into 3 equal disinfection groups (fumigation with formaldehyde, 50% oregano juice, and 100% oregano juice). In the study, the characteristics of the eggshell, microbial load, embryo development, egg weight loss, hatching results, chick weight and quality, and performance in the first 2 weeks were determined. No differences were observed among the disinfection groups in egg shell characteristics, microbial load in the shell, hatchability of fertile and set eggs, embryonic deaths, and body weight, body weight gain, and feed conversion ratio in female chicks. Egg weight loss was higher (P < 0.001) in the 50% oregano juice group (13.75%) compared to the formaldehyde fumigation group (12.11%). Chick quality score was found to be lower in the formaldehyde fumigation group (96.44) compared to the other two oregano juice groups (P < 0.001). The chicks hatched from the eggs in the formaldehyde fumigation group consumed more feed (119 g/week) in the first 2 weeks (P < 0.001). The use of 50% oregano juice in the disinfection of hatching eggs did not have any negative effects compared to the fumigation process with formaldehyde. Therefore, it is concluded that disinfection with 50% oregano juice was effective in reducing the microbial load in the egg shell as much as formaldehyde fumigation, and even it was superior in chick quality score.