Investigation of the effects of long-term storage of breeder broiler eggs treated with in ovo glucose and oleuropein on hatchability, growth and carcass characteristics of chicks and some biochemical parameters

This research was carried out to determine the effects of long-term storage of breeder broiler (Ross 308) eggs treated with in ovo glucose and oleuropein on egg quality traits, hatching performance, chick quality, chick growth performance, slaughter and carcass characteristics and some biochemical parameters. The study was carried out using eggs obtained from a 35-week-old breeder flock. Storage duration groups (DS) in the research were; 1: 21 days and 2: 14 days; in ovo injection time groups (IEZ) within each storage duration group; 1: 1st day of storage and 2: 7th day of storage; treatment groups within each IEZ (UYG); 1: no treatment on eggs, 2: in ovo sterile distilled water (0.5 ml), 3: in ovo 50 mM HEPES (0.25 ml) + 10% glucose (0.25 ml), 4: in ovo 50 mM HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) (0.25 ml) + 0.75% oleuropein (0.25 ml). In the research, application subgroups (UYAG) were created as 20 eggs for each replicate in each IUG and 80 eggs for a total of 4 replicates. A total of 1280 eggs with an average weight of 64.30±0.13 g were used. A total of 224 eggs were examined on different days of storage to determine the effects of different storage periods, in ovo injection times and substances on the quality characteristics of the eggs. In addition, 192 eggs were used for determining albumin pH, early, middle and late embryo deaths and embryo development during the incubation process. In the study, egg weight losses (%) during the storage process and on the 18th day of incubation, hatching performance and daily age quality of the chicks were determined. In order to evaluate the effects of in ovo injection applications on the immune system in chicks, 96 day-old chicks were used for determining immunoglobulin levels (IgG, IgA and IgM), spleen, liver and bursa fabricius weights and ratios and some stress, antioxidant and blood parameters. 256 chicks were used for determining the performance and mortality rates of the chicks during the 0-42 day growth period. 128 of these chicks were used for determining slaughter and carcass characteristics. In this study, it was determined that the in ovo application of HEPES+Glucose and HEPES+Oleuropein substances on the 1st and 7th days of storage to eggs stored for 14 and 21 days had a positive effect on egg quality characteristics such as yolk height, yolk index and yolk color during the storage process and prevented the increase in albumin pH. The highest albumin pH value was determined as 9.67±0.07 in the group stored for 21 days and to which HEPES+Oleuropein substances were applied in ovo on the 7th day, while the lowest among the groups stored for 14 days was determined as 8.55±0.15 in the group to which HEPES+Oleuropein substances were applied in ovo on the 7th day. Regarding the hatchability performance parameters, the highest early embryo mortality was observed in the group stored for 14 days and in ovo distilled water injection on the 7th day with an average of 35.29±20.85%, while no mid-term embryo mortality was observed in this group. The highest late embryo mortality was observed in the group stored for 14 days and in ovo Hepes + Oleuropein applied on the 7th day. After the control group stored for 14 days with the highest hatchability of 85.20±9.46%, the highest hatchability was observed in the group stored for 21 days and in ovo HEPES + oleuropein injection on the 1st day. HEPES + oleuropein injection increased the hatchability in eggs stored on the 21st day. In terms of chick quality, the chicks with the highest quality score (81.86) and the largest chick length (19.22 cm) were in the in ovo HEPES+Oleuropein injection group. It was determined that the mortality rates of the chicks during the 0-42 day growth period were the same as the control group (4.69%), and that the substances applied in ovo did not generally have negative effects in terms of slaughter and carcass characteristics. During the 0-42 day growth period of the chicks, the group that was stored for 21 days and was applied in ovo HEPES+Oleuropein on the 7th day reached the highest average live weight (3027.79±154.79 g). The feed conversion ratio among the in ovo application groups was found to be lower than the control group (control 0.43%, in ovo applied groups 0.42%), but no significant difference was determined. The slaughter weight determined in the study was 2617.58 g in the control group stored for 21 days and 2814.04 g in the control group stored for 14 days, while the highest slaughter weight of 3010.02 g was seen in the group stored for 21 days and injected with HEPES + Oleuropein on the 7th day of storage. As a result, in this study, it was determined that HEPES+Oleuropein application injected on the first day of the 21-day storage period (UYAG-4) increased the chick average length and chick quality score, and HEPES+Glucose application injected on the first day of the 21-day storage period (UYAG-10) increased the chick hatching weight. Keywords: In ovo - Broiler - Oleuropein - Glucose - Hatching performance - Chick quality - Carcass – Biochemical parameters