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The aim of the study was to assess an effect of incubation temperature (36.4, 36.7, and 37.1°C) on hatching performance of emu. The fewest dead embryos (13.7%) were found in group I with the lowest incubation temperature. Raising the temperature by 0.3°C and 0.7°C in, respectively, group II and III reduced the hatchability indices, primarily due to an increased rate (by approx. 12%) of dead embryos in both groups. Temperature significantly influenced the duration of incubation period, as well as duration of hatching. Incubation at the highest temperature took the shortest time (49.9 days), whereas that at the lowest temperature lasted longest (51.5 days). A reversed pattern was found in the case of hatching duration, which at the higher temperature expanded by 282 minutes in group II and by 406 minutes in group III, as compared with group I.
Little information on emu incubation techniques has been published so far both in the Polish and foreign literature; hence this study, which is aimed to investigate effects of various levels of incubation relative humidity on the hatchability of emu eggs. Three levels of relative humidity (RH), 20, 25, and 30%, were applied to groups I, II, and III, respectively. The temperature 36.4°C was maintained constant in all the groups during the incubation. The poorest results were recorded in the group III with 30% relative humidity. Keeping lower humidity in the groups I and II resulted in improved hatchability, especially due to reduced percentage of crippled and weak chicks. It was found that humidity significantly influenced egg weight loss during incubation; lower relative humidity resulted in increased egg weight loss.
The study involved 113 emu eggs, laid by 4–yr–old hens kept by a Canadian breeder in Ontario. Those eggs which the shells had been damaged during transport were used for chemical assays to determine dry matter, protein, and fat contents in the yolk. The egg weight and shape index were determined as well.
In emus, the duration of the fertile period was measured following a single artificial insemination (AI) and investigated the effect of time of AI in the egg cycle on the duration of the fertile period. Semen was collected by artificial cloaca, pooled and used undiluted for AI within 30 minutes. For insemination, a female was followed until she assumed the voluntary crouch. A speculum was then inserted into the cloaca and an insemination straw introduced into the vagina to a depth of 1-2 cm, and semen deposited. Following a single insemination with 100, 200 or 400 million spermatozoa, female emus laid fertilized eggs for 10.0±0.4, 12.0±0.9, and 15.0±0.6 days. When 400 million spermatozoa were used for insemination on Day 1, 2 or 3 of the oviposition cycle, the duration of the fertile period appeared to change in a day-dependent manner. After AI on Day 1, female emus laid fertilized eggs for 15.8±1.1 days, after AI on Day 2 for 12.5±2.2 days, and after AI on Day 3 for 10.0±1.5 days. The results suggest that female emus need to be inseminated the day after oviposition to maximize the duration of their fertile period.
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