The Effect of Vitamin C in-ovo Injection on Incubation Results of Fertile Goose Eggs

ABSTRACT


Introduction
One of the most important problems in goose breeding is incubation.The low egg yield and the fact that they do not lay eggs during natural incubation increase the importance of artificial incubation in goose breeding.The hatching efficiency, which is reported as 75% in natural hatching in geese, drops considerably when the necessary conditions are not met in artificial hatching (Tilki and İnal, 2004;Pesmen and Yonetken, 2020).
The technique, also known as in-egg feeding, is applied by injecting nutrients such as protein, vitamins, minerals, and various substances such as hormones and antibodies into the embryonic sacs in the form of a liquid solution at any stage of incubation.The in ovo technique was first used at the end of the 1970s, and in 1995; automatic injection systems (in ovoject) started to become an alternative application that has come to the fore in recent years (Abdulqader et al., 2017).Introducing various nutrients (protein, minerals, vitamins etc.) into the egg increases the hatchability and ensures high survival and performance after hatching (İpek et al., 2003;Nowaczewski et al., 2012;Sözcü and Curabay, 2014;Zhu et al., 2019).
Vitamin C has anti-stress properties.It helps collagen synthesis, positively affects connective tissue, bone, and cartilage tissue strengthens the immune system and increases disease resistance (Santos et al., 2018).Vitamin C is absent in a newly laid egg and begins to be synthesized by the developing embryo on the 3 rd -4 th day of incubation due to endogenous biosynthesis.However, the quantities produced may not be sufficient towards the end of the incubation period, when the embryo is exposed to extreme overheating.This is mainly observed in ducks and geese but is also observed during broiler incubation.Waterfowl have exceptionally high vitamin C requirements and are more susceptible to vitamin C deficiency.Therefore, in ovo application of vitamin C to the egg during embryogenesis can reduce the negative effects of overheating (thermal stress) and, as a result, increase hatchability.
Therefore, vitamin C injection may provide more effective results in the middle and late stages of incubation, when the embryo is expected to overheat (Nowaczewski et al., 2012).
In hot environmental conditions, the level of vitamin C in the blood and tissues decreases significantly, and exogenous vitamin C increases the level of vitamin C in the blood, reducing the rise in the birds' body temperatures under heat stress conditions.It is known that positive responses to vitamin C supplementation are further enhanced under adverse conditions such as high temperature and low protein levels (Pardue and Thaxton, 1986).Khan et al. (2012) reported that heat stress caused a decrease in feed consumption, food use, growth rate, egg production and quality, feed efficiency, immunity level, performance, and productivity.Decreased antioxidant levels can characterize heat stress due to increased oxidative stress.Zhu et al. (2019), in the prenatal period, vitamin supply (in egg feeding of exogenous vitamins (IOF)) improves broiler chickens' hatchability and growth performance, antioxidation, and immune function.Brake and Pardue (1998) reported that the anti-stress feature of vitamin C is one of its most essential features.Giving additional ascorbic acid to animals in different ways, especially at high temperatures, reduces the negative effects that may occur in the yield characteristics.
To summarize the results obtained in various studies by administering Vitamin C to fertile poultry eggs in ovo at multiple stages of incubation; -High hatchability in broiler eggs with in ovo application of 3 mg Vit C to the air sac on the 18th day of hatching (İpek et al., 2003), -In ovo application of 8 mg Vit C to the air sac on the 20th day of hatching in Pekin duck eggs, an increase in hatchability and a significant decrease in embryo mortality (Nowaczewski et al., 2012), -In broiler eggs, with the application of 3 mg Vit C to the air sac in ovo on the 13th day of hatching, an increase in hatchability, a significant decrease in embryo deaths, -In ovo application of 3 mg Vit C to egg yolk on the 15th day of hatching to broiler eggs increased hatchability and chick weight and improved immune function (Zhu et al., 2019), -In broiler eggs, on the 14th day of hatching, an increase in hatchability and an increase in growth performance after hatching were observed with in ovo application of 6 µg Vit C to the air sac (Ismail et al., 2019).
This study was carried out to determine the effects of vitamin C in ovo injection during the incubation of fertile domestic goose eggs on hatchability, chick quality, chick weight, chick length, and 1-week survival rate.

Material and Method
A total of 82 fertile goose eggs were used in the study.Goose eggs were weighed and numbered with an accuracy of 0.01 g before being placed in the incubator.It was then incubated according to the method in Table 1.On the 10th day of incubation, a fertility examination was performed on the eggs with lamp control, and the infertile eggs were removed from the incubator.Eggs identified as fertile were placed back in the incubator to continue the normal incubation process.Until the 27th day of the incubation period, automatic rotation was performed at an angle of 45 degrees every hour.

Days
Heating During to incubation fertile eggs were subjected to treatments on the 24th days of incubation given in Table 2.After the area above the air cell was wiped with 70% ethanol before in-ovo injection, a small 1 mm hole was drilled with a micromotor from the egg shell along the central axis at the top of the egg.0.1 ml of a solution containing doses of Vitamin C (8 mg and 10 mg) was injected through the hole drilled in the eggshell, through the inner membrane of the eggshell, with a needle of 3-4 mm in length.The hole was then sealed with a small drop of sterilized molten paraffin, and the eggs were placed back in the incubator.The eggs were transferred to the hatching section on the 27th day.At the end of the incubation period (30th day), hatchability, chick weight, chick length, chick quality, and 1-week survival rate were determined.Hatchability; is evaluated as the ratio of chicks obtained from eggs determined to be fertile due to fertility control.The hatchability was determined by dividing the number of chicks hatched in each group by the number of fertile eggs (Aksoy, 1999).
Hatchability= number of hatched chicks/number of fertile eggs x 100 Chick weight; was determined with a digital scale with a sensitivity of 0.01 g.
Chick length; the length from the tip of the beak to the tip of the finger was measured in cm with the help of a ruler (Wolanski et al., 2005).
Chick quality; was evaluated and scored according to Tona et al.'s (2003) chick quality scale.General activity, feather condition, and appearance, remaining egg yolk, eyes, legs, navel region, and remaining, membrane parameters were evaluated in scoring.
Survival rate: Survival rate values were calculated according to the formula below by determining the ones that died at the age of 1 week among the goose chicks in each group (Şenköylü, 1991).
Survival rate (%) = (Initial number of animals of the group-number of animals that died)/initial number of animals of the group x100 Statistical analysis was made with the SPSS statistical package program (SPSS, 2018).ANOVA test was used to determine the differences between groups regarding chick weight, length, and quality.The chi-square test determined the differences between groups regarding hatchability and survival rate.

Results and Discussion
The Effects of Vitamin C injection in fertile goose eggs on the 24th day of incubation on chick weight, length, quality, hatchability, and survival rate are given in Table 3. Chick Length: Chick lengths in K, NK, AA1, and AA2 groups, respectively, were found as 23.32 cm, 23.70 cm, 24.78 cm, and 24.36 cm.A significant difference was found between the K and AA1 groups in terms of chick length (p≤0.05).The highest chick length was found in the AA1 group and the lowest in the K group.
The highest chick quality was determined in the AA1 group and the lowest in the control group.
There was no significant difference between the groups in terms of hatchability (p≥0.05).The lowest

Figure 1 .
Figure 1.Drilling holes in fertile goose eggs with a micro motor and Vit C injection.

Table 2 .
Application procedures according to trial groups.

Table 3 .
Effects of Vitamin C injection in fertile goose eggs on the 24 th day of incubation on chick weight, length, quality, hatchability, and survival rate., and 112.92 g.A significant difference was found in chick weight between NK, AA1, and AA2 groups (p≤0.05).The highest chick weight was determined in the AA2 group and the lowest in the NK group.