Effect of Feeding Methoxychlor–Treated Alfalfa Hay to Dairy Cows

Summary Methoxychlor did not appear in measurable amounts in the blood, milk or tissues of six dairy cows consuming alfalfa hay that had been dusted in the field with methoxychlor. Two cows receiving untreated alfalfa hay likewise had no methoxychlor in their milk, blood or tissues. There was no effect on milk or butterfat production or on feed consumption as a result of feeding methoxychlor-treated hay. The methoxychlor residue on the hay was 0, 7, 9.5 and 14 ppm. for the alfalfa treated with 0, 1, 2 and 2.8 lb., respectively, of methoxychlor per acre. There was no apparent effect of consuming the methoxychlor-treated hay upon the health of the cows. Good economic control of alfalfa weevil larvae was obtained in the plots of alfalfa dusted with methoxychlor. The treated plots gave a somewhat greater yield of hay than the untreated plots.