The effect of pinealectomy on metabolism and somatic growth of immature cockerels.

Fifty-four 1-day-old Single Comb White Leghorn cockerels were randomly assigned to 18 brooder cages across three surgical treatments, pinealectomy (PX), sham-operated (PN), and non-operated controls (C). Pinealectomy and sham-operations were performed at 9 days of age. The birds were maintained for 28 days, during which time body weight, feed consumption, and oxygen consumption were measured. All parameters were similar for all treatments during the week before surgery. During the first week after surgery, the PX birds had a lower (P less than .05) oxygen consumption and lowered (P less than .05) body weight gains compared to PN and C birds. Shortly after recovering from surgery, the PX birds became very docile and engorged their crops. This unusual behavior was not seen in the PN or C birds. By the second week after surgery, the oxygen consumption was similar for all treatments. At 21 days of age the PX birds had a significantly (P less than .05) lower body weight compared to the PN and C birds.