Effect of High Dietary Levels of Manganese on the Performance and Blood Constituents of Calves

Abstract

Fifty-two Holstein male calves were used in two experiments to determine the minimum dietary toxic level of manganese and the effect of high levels of dietary manganese on performance and blood constituents. A basal ration containing 12 ppm of manganese was used in both experiments with manganese sulfate added to give the desired manganese levels. In Experiment I levels of added manganese were 0, 820, 2460 and 4920 ppm with seven individually-fed calves per treatment. Body weights were taken and blood was sampled at 14-day intervals throughout the 84-day experimental period. Body weight gains and feed intake were depressed at the high dietary levels of manganese. No significant differences were found between treatments in feed efficiency, hemoglobin, serum calcium, serum inorganic phosphorus, serum magnesium or serum alkaline phosphatase activity. In Experiment II levels of added manganese were 0, 1000, 2000 and 3000 ppm with six calves per treatment fed for 100 days. The four calves comprising each replication received equal amounts of feed. No significant difference was found in average daily gain or feed efficiency. A significant depression in blood hemoglobin level was noted with increasing dietary manganese. No differences were found between treatments in any of the serum constituents measured. A brief study was conducted in which graded levels of manganese were added to incubation flasks containing washed cell suspensions of micro-organisms from fistulated cows fed no manganese or 5000 ppm of dietary manganese. Depressed volatile fatty acid production, especially propionate, and marked changes in the rumen flora were observed at high levels of dietary manganese. Copyright © 1966. American Society of Animal Science . Copyright 1966 by American Society of Animal Science