Observations on the patterns of embryonic mortality over the laying season of pheasants

Abstract

1. Embryonic mortality of domestic pheasant (Phasianus colchinus) eggs was recorded for a 10-week laying season for two groups of laying hens maintained under mating ratios of 8:1 and 12:1 (females:males). 2. Mating ratio had no significant effect on embryonic mortality between 1 and 4 or 5 and 20 d but values for these categories doubled as the laying season progressed, both rising to 8% to 9% of fertile eggs. 3. Higher embryonic mortality was observed between 21 and 25 d for the eggs from the 8:1 mating ratio (14.5% of fertile eggs compared with 12.1%) but this was unaffected by week of setting. 4. Reasons for these patterns of embryonic mortality were not clear and further research is needed to determine the factors affecting embryonic mortality in pheasants.

Effect of sight barriers in pens of breeding ring-necked pheasants (Phasianus colchicus) II. Reproductive parameters

“…Patterns of embryonic mortality reported here are very similar to that reported by Deeming and Wadland, 2001). The level of early mortality was near identical to that reported for pheasants by Deeming and Wadland (2001) although laying week had no significant effect in the present study.…”

“…The level of early mortality was near identical to that reported for pheasants by Deeming and Wadland (2001) although laying week had no significant effect in the present study. Early embryonic mortality is also comparable to other bird species (Deeming and van Middelkoop, 1999;Deeming, 2009).…”

“…Early embryonic mortality is also comparable to other bird species (Deeming and van Middelkoop, 1999;Deeming, 2009). Levels of late mortality were lower than previously reported (Deeming and Wadland, 2001), which is reflected in the higher hatchability reported here. Indeed reported hatchability in commercial pheasants are typically around 65% or less (Deeming and Wadland, 2002;Demirel and Kirikçi, 2008;Deeming, 2009) and the higher values (69-71% averaged over 10 weeks) recorded in the present study may reflect the quality of the incubator used or the operation of the hatchery.…”

“…Hatchability of other eggs laid and incubated at the game farm was generally 2% lower than the trial eggs and this may reflect better scrutiny of eggs prior to setting. These results highlight the continued need for research into the factors causing embryonic mortality after 5 days of incubation in pheasants (Deeming and Wadland, 2001) because a better understanding of these factors would have significant effect on profitability of many game farms.…”

The influence of stocking rate and male:female ratio on the production of breeding ostriches (<i>Struthio camelus</i> spp.) under commercial farming conditions

“…Based on the results in the study it can be assumed that breeding quads will be more productive on a per female basis than larger flocks. However, it has to be conceded that the number of replicates studied for the breeding quads was relatively small when compared to other studies (Craig et al, 1977;Bates et al, 1987;Deeming & Wadland, 2001 Our results are contradictory to results reported by More (1997) who found that the laying performance of breeding pairs tended to be better than that of both trios and a breeding flocks. However, although female age influenced egg production significantly, no mention was made of the composition of the respective breeding systems.…”