Hatching performance of Japanese quail from eggs stored for different periods - a preliminary study

Due to the fluctuating nature of the poultry market, including the need for chicks, there is often a necessity to extend the storage time of hatching eggs. Commonly they are stored at the farm to reduce the cost of daily collection, while hatcheries collect a large number of eggs to fill the entire incubator at once. In the case of hen eggs, eggs stored for three to seven days are usually used for incubation. In the case of quail eggs, there are no specific recommendations in this respect, while the common perception is that they "age" differently from hen eggs and stay fresh longer. The study was aimed to determine the maximum eggs storage time after which it is possible to obtain full-quality chicks. seven hundred and fifty six eggs of Japanese quail hatching eggs were collected at 4-day intervals for 52 days dividing them into 14 groups of 54 eggs (6 replications in each). Consecutive batches of eggs were stored (at physiological zero conditions) for 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48 and 52 days, respectively; the control group consisted of fresh, unstored eggs. Fifty two days after the first eggs were collected, all groups, including the control one, were incubated under species-specific conditions. The water loss of eggs during the incubation as well as hatching results were determined. The weight and quality of hatchlings were evaluated.

It was shown that storage time significantly affected the egg weight loss and hatchability of chicks, which were not obtained from eggs stored longer than 32 days. There was no effect of the experimental factor on hatchability from eggs stored for up to 20 days, after longer storage the ratio gradually decreased. With time passing, a decrease in early embryo viability and hatchability while an increase in embryo mortality was observed, mainly in the late incubation phase. Interestingly, the duration of egg storage did not differentiate the weight of the chicks obtained but affected their quality.

The results of the study confirmed the negative effect of long-term Japanese quail eggs storage on the hatching performance; however, the viability of Japanese quail embryos is noteworthy. The loss of egg weight during the incubation was directly proportional to the change in this trait before incubation due to the storage time. The prolonged egg storage may have negatively affected chick hatching by limiting the embryo's access to essential nutrients and oxygen. These results have important practical implications for small-scale poultry producers, as they suggest that storage times of hatching quail eggs can be extended, but not beyond 24 days, which is still three times longer than usually recommended seven days for hen eggs.