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Vliv podmínek inkubace na parametry užitkovosti brojlerových kuřat
Opavská, Tereza
This thesis deals with the effect of increased temperature during first 36 hours of incubation on embryonic development, hatchability, day-old chicks quality and subsequently on their growth. The chickens of the control group were hatched at a standard temperature of 100,8 °F and the experimental group had increased temperature of 102,5 °F for the first 36 hours of incubation. The growth experiment was performer on 423 roosters of the Ross 308 hybrid combination from hatch to day 31 of age. The day-old chicks from the control group weighed statistically significantly (P<0,05) more than the experimental group. However, at 10 and 17 day of age, no statistically significant (P>0,05) difference was found between the groups. At the 24 and 31 day of age, the average weight of control group was again statistically significantly (P<0,05) higher than the weight of the experimental group. There was no significant difference in the hatchability of fertilized eggs, which was 92,2 % in the control group and 90,4 % in the experimental group. However, the mean embryonic mortality was 1,76 % and the late mortality 2,47 % in the control group, while the mean mortality was 0,71 % and the late 4,17 % in the experimental group, these differences were statistically significant (P<0,05). The difference in the average weight of the yolk sacs, in the proportion of yolk sacs from live weight and in the activity of T3 (thyroid hormone triiodothyronine), which reached 1,38 nmol/l in day-old chicks of the control group and 1,35 nmol/l in the experimental group was not statistically significant (P>0,05). No statistically significant (P>0,05) difference was found in feed conversion. Based on the results, the increased incubation temperature (102,5 ° F) has had a negative impact on the growth of broiler chickens.
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