Metabolic activity of zinc during late pregnancy and lactation of first-litter gilts and their offspring under low dietary zinc intake.
The metabolism of Zn-65 was studied in littermate gilts fed either low-Zn (10 mg/kg) or Zn-supplemented (50 mg/kg) diets throughout pregnancy and lactation, and dosed with 100 microCi of Zn-65 at 100 days of pregnancy. Zinc-65 appeared earlier in urine of deficient gilts and about the same time after dose in feces of both groups. Total activity and proportion of the dose excreted via feces were higher in supplemented gilts, where as specific activity (SA) of feces was higher in deficient gilts. Excretion of endogenous Zn by supplemented gilts was triple that of deficient gilts whereas true absorption of Zn by deficient gilts was more than 4-fold that of their supplemented littermates. Biological half-life of Zn-65 was 46 d for the control and twice as long in deficient gilts. Total activity and SA of colostrum was higher in deficient gilts. Muscle, followed by liver, retained the highest proportion of the dose in both groups. Proportion of the dose retained in the liver and lungs was higher in control gilts where as Zn-65 retention in brain, heart, lungs and spleen was higher in deficient gilts. Most tissues from deficient gilts showed higher SA. Liver showed the highest Zn-65 concentration in control and lung in low-Zn newborn piglets. At two weeks of age, liver from both groups of piglets showed the highest Zn-65 retention. Proportion of the dose in brain and lungs was higher in deficient piglets. Specific activity of most organs from deficient piglets was higher than that of controls at both ages. Pregnant gilts under low dietary Zn intake made maximum utilization of this mineral by increasing true absorption and reducing endogenous excretion.
Kalinowski
J
J
Crampton Nutrition Laboratory, Department of Animal Science, Macdonald College of McGill University 21, Ste. Anne de Bellevue, Quebec, Canada.
Chavez
E R
ER
D000042:Absorption; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism; D003126:Colostrum / Q000378:metabolism; D005260:Female; D006207:Half-Life; D007774:Lactation / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008892:Milk / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D013552:Swine; D015032:Zinc / Q000008:administration & dosage / Q000378:metabolism*
D015032:Zinc