Obesity induced by force‐feeding and accompanying changes in body temperature and fertility in the male domestic fowl

Excessive amounts of food (two-fold more than the ad libitum intake) introduced into the gastro-intestinal tract of three adult male fowls, for 5 weeks, caused a marked increase in body weight resulting mainly from fat deposition. 2. The induced obesity was accompanied by an increase of the rectal temperature (0-2 to 0-3 degrees C) and a decrease of the skin and comb temperatures, a cessation in the growth of the comb, a reduction in the blood packed cell volume, an eight-fold reduction in the number of spermatozoa in the vasa deferentia and a concomitant depression in their motility. 3. A decrease of the testosterone and an increase of luteinising hormone concentrations in the blood plasma was obtained in two of the three treated birds.