Studies on the Laying and Eggshell Characteristics of the Domestic Hen.

Eggs were co1Lected Eram 67 Shaver Black, 95 Yaffa and
5 indigenous hens reared from day old to poiat of lay in
the UnLversity of Nigeria poultry farm during their first
75 days in lay in'order to determine their characteristic
sequence lengths, oviposition time distribution, laying
intensity, egg specific gravity, egg weight, shell weight,
percent shell and shell weight per unit surface area, Also
eggs were recovered from 21 Shaver Black, 20 Yaffa, and 4
indigenous hens within the following ?!%day period and blood serum samples obtained jmt prior to egg recovery from the
shell gland in order to determine shell deposition rates and
; serum calcium, magnesium and potassium levels at the various
in utero times.