2009-06-172009-06-171978https://hdl.handle.net/10365/4927Through the cooperation of USDA-APHIS inspectors in six slaughter plants, 723 serum-liver samples were collected from August through November of 1977. The average copper level in these serums was 0.64 à ± .27 ppm. There were 211 cattle with less than 0.5 ppm copper and 67 will less than 0.25 ppm. Future supplementation trials and additional sampling are planned.North Dakota State UniversityAnimal physiologyArticle