Abstract
An experiment is described wherein each of 105 cows was exposed to one of three levels of winter feeding from November to April for 9 consecutive years. The present report covers the period from 1954 to 1957 when they were at ages 6 to 9, and during which observations of cancer eye were made at six-month intervals. Differences in level of nutrition affected cancer eye importantly. The higher level of feeding increased the average number of sites on the eyes affected by lesions and their rate of increase with age, increased the number of affected animals, and increased the stage of pathogenesis of the lesions. Moreover, the survival rate of animals on the high level was lower than that on the medium and low feeding levels. Possibly the higher nutritional level hastens the aging process so that the animals on such regimes reach an older physiological age at a younger chronological age than animals on lower feeding levels. Lesions on the lids apparently occur earlier than those on the eyeball, though the latter are more prevalent and show faster rates of increase with age.