Seasonal Hair Growth in the Adult Domestic Cat (Felis catus)

Abstract

Determination of amino acid requirements by the factorial method requires an estimate of the amount of amino acids required for the replacement of hair. Hair growth rates in a total of 39 adult male and female domestic short-haired cats were determined throughout the year using the 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 of 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 temperature, with a maximum hair growth rate of 289 μg/cm2/day in summer and a minimum hair growth rate of 62 μg/cm2/day in winter. The peak hair growth rate for the female cats was reached earlier than that for the male cats. Sine-functions describing day length, minimum and maximum daily air temperatures and daily hair growth rates are presented. Adult domestic short-haired cats were found to grow 32.7 g of hair per kg body weight per year. Monthly amounts of hair growth per unit of body weight and body surface area are calculated.