Liver L-gulonolactone oxidase activity and tissue ascorbic acid concentrations in nursing pigs and the effect of various weaning ages.
In Experiment 1, we evaluated liver L-gulono-gamma-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 sow's 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).
Ching
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S
Department of Animal Sciences, The Ohio State University and The Ohio Agricultural Research and Development Center, Columbus, OH 43210-1094, USA.
Mahan
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DC
Dabrowski
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K
D000367:Age Factors; D000821:Animal Feed; D000818:Animals; D000831:Animals, Newborn; D000833:Animals, Suckling / Q000378:metabolism*; D001205:Ascorbic Acid / Q000032:analysis / Q000378:metabolism*; D003126:Colostrum / Q000737:chemistry; D005260:Female; D050544:L-Gulonolactone Oxidase; D007774:Lactation; D008099:Liver / Q000201:enzymology*; D008892:Milk / Q000737:chemistry; D009752:Nutritional Status; D013401:Sugar Alcohol Dehydrogenases / Q000378:metabolism*; D013552:Swine / Q000378:metabolism*; D014886:Weaning
D013401:Sugar Alcohol Dehydrogenases; D050544:L-Gulonolactone Oxidase; D001205:Ascorbic Acid