Effects of food restriction on blood pressure, heart rate and certain organ weights of the chicken

Experiments were carried out to investigate some of the physiological effects, on chickens, of food restriction at the 70 per cent level from 3 to 21 weeks of age.

Blood pressure and heart rate were depressed after 18 weeks of food restriction, but rose to normal levels after a few weeks of full‐feeding.

Organ weights were measured at the end of the restriction period and at the end of the laying period. The thyroid, adrenal, pituitary, liver, heart, spleen and abdominal fat from the restricted birds weighed less than from the full‐fed birds at the end of the restriction period. The gizzard was increased in size. When the organ weights were adjusted for differences in body size most of the differences between treatments were eliminated. Of the three exceptions, the abdominal fat was less in the restricted birds, whereas the gizzard and pancreas were larger than for the full‐fed birds. By the end of the laying period, only the differences in pancreas weight remained.