Dietary pharmacological or excess zinc and phytase effects on tissue mineral concentrations, metallothionein, and apparent mineral retention in the newly weaned pig

• Published in: Biological trace element research 2005, Vol.105 (1-3), p.97-116
• Main Authors: Martínez, M M, Link, J E, Hill, G M
• Format: Article
• Language: English
• Subjects: 6-Phytase - metabolism; 6-Phytase - pharmacology; Animals; Copper - metabolism; Diet; Dietary Supplements; Hogs; Jejunum - metabolism; Kidney - metabolism; Liver - metabolism; Metal concentrations; Metallothionein - metabolism; Pharmacology; Retention; Swine; Time Factors; Tissues; Weaning; Zinc; Zinc - metabolism; Zinc - pharmacology; Zinc Oxide - pharmacology
• ISSN: 0163-4984; 0163-4984; 1559-0720
• DOI: 10.1385/BTER:105:1-3:097

Feeding pharmacological zinc (Zn) to weaned pigs improves growth, and dietary phytase improves P and Zn availability. Metallothionein (MT) increases in the duodenum, kidney, and liver of pigs fed 1000 mg Zn/kg with phytase or 2000 mg Zn/kg with or without phytase when fed for 14 d postweaning. The goal of this study was to determine the effects of feeding pharmacological Zn and phytase on tissue minerals, MT, mineral excretion, and apparent retention. Twenty-four newly weaned pigs (20 d; 7.2 kg) were individually fed twice daily, a basal diet supplemented with 0, 1000, or 4000 mg Zn/kg as Zn oxide, without or with phytase (500 phytase units [FTU]/kg) for 14 d, followed by a basal diet (100 mg Zn/kg) without phytase for 7 d. Pigs fed 4000 mg Zn/kg without phytase had higher (p=0.01) plasma, hepatic, renal Zn, renal Cu, and hepatic, renal, and jejunal MT than pigs fed the basal diet or 1000 mg Zn/kg. Duodenal MT was higher (p=0.0001) in pigs fed 1000 and 4000 mg Zn/kg than in pigs fed the basal diet. In pigs fed 1000 and 4000 mg Zn/kg, Zn loading occurred during the first 11 d of supplementation; by d 14, excess Zn was being excreted in the feces.