The influence of comb type on growth rate in the domestic fowl¹

From a thesis submitted by the senior author to the Graduate Faculty of McGill University in partial fulfilment of the requirements of the M.Sc. degree, May, 1964.

Synopsis

Studies were made to determine the influence of comb type genes on growth rate. Three trials compared body weights of young birds while a fourth was concerned with embryonic weight at 13 days of incubation.

One of the trials on young birds included a comparison of thyroid and adrenal weights, shank length and breast angle. The majority of birds studied were heterozygous at any particular comb type locus. The following conclusions were based on results from these studies:

No consistent effects of comb type on mean body weight, thyroid weight, adrenal weight, shank length or breast angle were found. However, there were indications that comb type may affect the variances of these characters.

No significant weight differences were found among embryos of different comb types.

Notes

From a thesis submitted by the senior author to the Graduate Faculty of McGill University in partial fulfilment of the requirements of the M.Sc. degree, May, 1964.

Present address: Department of Poultry Science, University of British Columbia, Vancouver 8, British Columbia.