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*
Department of Animal Sciences,
School of Natural Resources, The Ohio State University and The Ohio Agricultural Research and Development Center, Columbus, OH 43210-1094
3To whom correspondence should be addressed. E-mail: mahan.3{at}osu.edu.
In Experiment 1, we evaluated liver L-gulono-
-lactone
oxidase (GLO) activity and tissue concentration of ascorbic acid in
young pigs from birth to weaning (14 d) and through a 28-d postweaning
period; in Experiment 2, we evaluated the effect of three weaning ages
on these measurements. Sow colostrum and milk collected in both
experiments demonstrated a linear decline (P < 0.01) in ascorbic acid concentration as lactation progressed. In
Experiment 1, three pigs were killed at 0, 3, 7, 14, 21, 28, 35 and
42 d of age for determining liver GLO activity and serum and
tissue ascorbic acid. Liver GLO activity decreased by 80% from 0 to
3 d of age and remained low until d 14 (weaning). After weaning,
liver GLO activity increased linearly (P < 0.01).
Tissue ascorbic acid concentrations decreased during the nursing period
and again after weaning, but then increased to 42 d of age
(P < 0.01). In Experiment 2, pigs were weaned at
10, 17 or 24 d of age. Three pigs from each group were killed at
weaning and at each week postweaning until 38 d of age. Liver GLO
activity was low during the nursing period but increased linearly
(P < 0.01) for each group during the subsequent
postweaning period. Pig serum and tissue ascorbic acid concentrations
increased postweaning in each group. These results suggest that a
factor in sows milk, possibly ascorbic acid, suppressed liver GLO
activity of nursing pigs but upon weaning, liver GLO activity of pigs
increased in a linear manner (P < 0.01).
KEY WORDS: L-gulonolactone oxidase ascorbic acid nursing weaning pigs