Egg Weight Declines to Baseline Levels over the Laying Season in Domestic Geese29 December 2013
New research from Ireland reveals that average egg weight increases in geese between one and four years of age, and that egg weights decline during the laying season.
Egg weight increased with age - from one to four years of age - in domestic geese and was followed by a senescent decline, according to Attila Salamon of University College Dublin and John P. Kent of Arklow in County Wicklow, both in Ireland.
However, in a paper in the International Journal of Poultry Science, they highlight that a more striking finding in adult geese was a within-season decline in egg weight over the first eight weeks of lay, until baseline weight levels were achieved and were then maintained until the end of the laying season.
The egg weight decline (over weeks 1 to 8) was significantly different from the baseline egg weight (weeks 9 to 19) in adult flocks.
They attributed the within-season decline in egg weight is attributed to constraints on the ability of birds to acquire the necessary nutrients exogenously during the laying season, requiring the geese to utilise their limited endogenous reserves.
The seasonal decline in egg weight is consistent with that in other waterfowl. However, a baseline egg weight level was found here that may be difficult to identify in wild geese, as in nature clutch completion is followed by incubation. The baseline level reflect the minimum egg weight necessary for viable gosling production.
Salamon and Kent added that egg weight of one-year-old geese was lower from the genesis of egg laying through the first eight weeks and weight and then steadily increased between weeks 9 and 19 tending towards the adult baseline levels. This is consistent with the maturation of one-year-old birds and shows that young geese are working towards the production of eggs with a viable egg weight.
Salamon A. and J.P. Kent. 2013. Egg weight declines to baseline levels over the laying season in domestic geese (Anser anser domesticus). Int. J. Poult. Sci. 12(9):509-516.
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