Losses in weight and body water in sows after weaning

The loss of body water of eight sows in the 7 d following weaning was determined using the deuterium oxide dilution technique. Four of the sows had received a concentrate diet in restricted amounts while the other four had been given the same diet mixed with two-thirds its weight of oat husks ad lib. during the whole of the preceding lactation. Certain blood and urine constituents were also measured. Loss of body water was significantly less (P less than 0.05) than weight loss of fasted animals, but body water losses were considerable in six of the eight animals. Excretion of urinary nitrogen, urea and creatinine and levels of plasma urea were higher, while levels of plasma non-esterified fatty acids and the hydroxyproline index were lower 1 week after weaning compared with values obtained on the day following weaning. These results indicate that in addition to water loss, depletion of body tissue, including protein, occurs in the newly-weaned sow.