SEASONAL HAIR-GROWTH IN THE ADULT DOMESTIC CAT (FELIS-CATUS)

Determination of amino acid requirements by the factorial method requi res an estimate of the amount of amino acids required for the replacem ent of hair. Hair growth rates in a total of 39 adult male and female domestic short-haired cats were determined throughout the year using t he mid-side patch technique. The ratio of hair on the mid-side area to total hair on the body was also determined to allow conversion bf mid side hair growth rates to hair growth rates over the entire body. The mid-side hair growth rate showed a sinusoidal pattern throughout the year, similar to that found for day length and daily mean air temperat ure, with a maximum hair growth rate of 289 mu g/cm(2)/day in summer a nd a minimum hair growth rate of 62 mu g/cm(2)/day in winter. The peak hair growth rate for the female cats was reached earlier than that fo r the male cats. Sine-functions describing day length, minimum and max imum daily air temperatures and daily hair growth rates are presented. Adult domestic short-haired cats were found to grow 32.7 g of hair pe r kg body weight per year. Monthly amounts of hair growth per unit of body weight and body surface area are calculated. Copyright (C) 1996 E lsevier Science Inc.