Supplementation of apple pomace with nonprotein nitrogen for gestating beef cows. IV. Pesticide accumulation in cows.

Abstract

Samples of fresh apple pomace were collected from 14 loads of apple pomace as delivered from the processing plant in October 1968 and from stored apple pomace that had been obtained in October 1967 and fed during a feeding trial from mid-November 1967 through April 1968. All samples were analyzed for dicofol (kelthane), tetradifon (tedion), DDT, DDD and DDE. For the pesticide residues in fresh apple pomace, the difference between the low and high load means was greater than 10-fold and these differences between loads were significant (P<01) for DDT, DDD and DDE. The pesticide residue content of stored apple pomace during a feeding trial ranged from .36 to 1.16 ppm for dicofol, .07 to .53 for tetradifon, 1.00 to 3.57 for DDT, .38 to .94 for DDD and .30 to .74 for DDE, which demonstrated potentially wide variation in pesticide intake during an apple pomace feeding period. Accumulation of pesticide residues in the fat depots of 28 pregnant beef cows was significant when apple pomace was fed for 160 days. Accumulation of residues was not affected by the type of nitrogen supplementation or by the inclusion of oil in the diet. Accumulation of residues appeared greater when pesticides were added to a simulated apple pomace diet than when apple pomace was fed. Tetradifon, DDT and DDD accumulated at a similar rate in fat tissue; 29% as fast as DDE. Dicofol accumulated 8% as fast as tetradifon. Total DDT residues (sum of DDT, DDD and DDE) were highest in heart fat, lowest in brisket and external rib fats and intermediate in internal rib, caul, kidney, ruffle and perianal fats of one trial, which indicated that depot location should be considered when obtaining samples for the determination of pesticide residue concentration in a carcass.