Influence of temperature of the incubation of eggs on the embryogenesis of descendants of different age hens

Eggs from 25 and 64-week hens of the breed Moscow black have been incubated 18 days in IUP-F-45 cases at 37.6±0.1°C and humidity of air of 53.0-55.0% and then they were shifted in three different cases of IUV-F-15, having created experimental I-25, II-25 and III-64, IY-64 and control (K-25 and K-64) parties. In hatch cases the following temperature conditions were supported: K-25 and K-64 (37.2±0.1°C), I-25 and III-64 (38.2-38.4°C), II-25 and IY-64 (37.2±0.1°C - during the hatch period except for two hours daily when temperature was increased to 38.2-38.4°C). The mass of eggs from hens of the elder age group was increased by 13.3%, in comparison with an indicator from younger hens. On the contrary thickness of a shell of eggs has decreased from 0.34 to 0.32 mm or by 5.9%. In K-25 pipping of shells began on 3.8 h later, than in K-64. Hatchability of eggs in K-64 was reduced in comparison with K-25, respectively 90.1 and 91.5%. The delay of a pipping of a shell in I-25 and II-25 in comparison with K-25, was more significant, than in III-64 and IY-64 K-64. Distinctions between K-25 and II-25 have made 3.2 h, and between K-64 and IY-64 - 2.7 h. In I-25, III-64 and K-25, K-64 the level of hatchability was almost identical. However in II-25 and IY-64 this indicator has increased in comparison with K-25 and K-64 respectively by 2.9% (Р≤0.05) and 3.5% (Р≤0.01). The mode of influence with the temperature of 38.2-38.4°C daily on 2 h a day during the hatching period was the most effective. On the basis of the conducted researches we can say that productivity of the approved thermocontrast modes of incubation depends on quality of eggs of the mothers hens determined by the age.