Hatchability reduces with prolonged egg storage. Although the method of storage, breed and flock age has an influence on the level of reduction and alternative methods like SPIDES can be used to keep hatchability up for a longer time, some guidelines can be used as an indicator for the level of reduction that can be expected. In the following table a base line of 90% hatchability is used for each breeder age to demonstrate the expected reduction after storage. In reality hatchability will reduce with flock age due to a reduction in fertility. The table can be used by correcting the standard hatchability of 90% at optimum storage for the real hatchability for the particular flock that is examined.

 

Hatchability %

Egg age (days)

Average age

27-35 wks

35-50 wks

50+ wks

0-1

88

88

88

89

2-5

90

90

90

90

7

89

89

90

88

10

87

86

88

86

15

83

80

85

82

20

76

70

82

73

 

In the field there are substantial differences in hatchability due to differences in fertility, as a result of differences in flock age and flock condition, breed, management system etc. It is therefore not useful to give an average hatchability at different ages for different storage periods, as explained for the previous table. To give an indication for expected reductions, the following table gives an estimation of the differences in Hatch of Fertile eggs (HOF) due to storage time, as fertility is not influenced by egg storage. .

In the following table the estimated HOF is given for different ages of broiler breeders and different length of storage periods.

 

%HOF

Egg age (days)

25 wks

35 wks

45 wks

55 wks

65 wks

0-1

83

91

90

87

85

2-5

85

93

92

89

87

7

84

93

91

86

83

10

86

91

89

83

79

15

80

88

86

80

74

20

67

85

83

75

68

 

Eggs of prime flocks are the least sensitive for egg storage. Eggs of older flocks but also eggs of very young flocks are less easy to store and a higher reduction in hatchability than standard should be expected.

Not only hatchability reduces with egg storage, but chick quality as well. This is not taken into consideration in the tables.