Effects on Chickens of Chronic Exposure to Mercury at Low Levels Through Dietary Fish Meal

Abstract

The effects of ingestion of low levels (0.014 and 0.018 p.p.m.) of mercury over prolonged periods by male and female birds of one broiler strain and three White Leghorn strains were studied. The sources of mercury were herring meals manufacutured from fish caught off the Pacific and Atlantic coasts of Canada and containing 0.22 and 0.17 p.p.m. respectively of mercury.The difference in concentrations of mercury in the two meals was reflected in differences in tissue concentrations of mercury of the birds fed the respective meals. Genetic differences in tissue accumulation of mercury were evident both in tissues which accumulated higher concentrations of mercury (feather, claw, kidney) as well as in muscle which accumulated relatively little. There was no apparent relationship between the incidence of mortality and tissue accumulation of mercury. Egg production and egg quality were unaffected by the source of herring meal in the diet. Most of the mercury in the eggs was present in the albumen and the overall average concentrations of 47 and 40 p.p.b. in the albumen and 16 and 15 p.p.b. in the yolks of the eggs from the hens fed the respective meals reflected the difference in the mercury concentration in the meals. The concentration of mercury in the eggs did not increase with the length of time during which the herring meals were fed. Fertility and hatchability of eggs were not affected by the source of herring meal fed. ABSTRACTTwo herring meals containing 0.17 and 0.22 p.p.m. of mercury respectively were fed to broilers at dietary levels of 5, 10 and 17.1%. The amounts of mercury present in the diet from this source thus varied from 0.0085 to 0.0376 p.p.m. Growth rate and mortality to eight weeks of age were unaffected by the level or source of herring meal in the diet. The amount of mercury ingested by the birds fed any of the diets resulted in negligible effects on the concentration of mercury present in breast or leg muscle. There was, however, significant accumulation of mercury in liver, kidney, claw and feather tissue, which reflected the dietary concentration of mercury. The amount present in the feathers was high as 0.845 p.p.m. This amount may be sufficiently high to warrant concern when feathers are processed into meal.

Relationship Between Trace Element Content in the Brain of Bony Fish Species and Their Food Items in the Southwest of the Caspian Sea Due to Anthropogenic Activities

“…Injection of estrogen resulted in an increased Cu level and also elevated serum ceruloplasmin in many mammals (69,70). Furthermore, serum Cu levels increased in patients using contraceptive pills (71,72).…”

Tissue Residues of Mercury in Broilers Fed Fish Meals Containing Different Concentrations of Mercury

“…The two meals were from the same manufacturing lots as were used in the separate study with adult birds mentioned above (March et al, 1974) and contained 0.17 and 0.22 p.p.m. The meals were manufactured from fish caught off the Atlantic and the Pacific coasts of Canada.…”

“…Mercury analyses were carried out as described previously (March et al, 1974). Samples of each tissue from males and females were pooled separately.…”

“…POULTRY SCIENCE 53: 2185-2192, 1974 by guest on June 14, 2015 http://ps.oxfordjournals.org/ Downloaded from…”

Genetic and Nongenetic Factors Affecting the Elemental Composition of Human and other Animal Tissues — A Review

“…Most that are known concern the trace elements Cu and Zn. Breed differences in the mineral composition of tissues of animals are numerous and appear to be under some measure of genetic control (Lucis and Lucis, 1969;March et al, 1974a). Marked differences between animal species in the tissue concentration of Cu, Mn, F and Si are known (Underwood, 1977).…”