Physiologic and body composition changes in feeder pigs under simulated marketing conditions
1990
Becker, B.A.
Two experiments were conducted to determine changes in body composition and various physiologic variables in feeder pigs under simulated marketing conditions. In the first experiment, pigs were assigned to 1 of 4 treatment groups for 48 hours: (1) no water and feed; (2) water ad libitum, no feed; (3) no water, feed ad libitum; or (4) water and feed ad libitum. During a 48-hour recovery period, all pigs were allowed feed and water ad libitum. Plasma triiodothyronine decreased (P < 0.01) within the first 24 hours in groups-1 and -2 pigs, but increased (P < 0.01) within the first 6 hours of the recovery period. The circadian rhythm of plasma cortisol was disrupted in groups-1 and -3 pigs and during recovery in group-1 pigs. Packed cell volume increased (P < 0.05) in groups-1 and -3 pigs and returned to initial values within the first 24 hours of the recovery period. In the second experiment, body composition was estimated by the 40K technique for fat-free body mass, percentage of nitrogen, and percentage of fat. Body composition was determined before and after pigs were allotted to 1 of 2 groups for 48 hours: group-1 pigs were given feed and water ad libitum and group-2 pigs were not given feed and water. Group-1 pigs gained 2.2 kg of body weight (P < 0.01), 0.6% fat (P < 0.01), 0.7 kg of fat-free body mass, and 0.02% nitrogen (P > 0.01). Group-2 pigs lost 2.3 kg of body weight (P < 0.01), 0.6% fat (P < 0.01), 2.0 kg of fat-free body mass (P < 0.01), and 0% nitrogen.
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