Carotene Requirements for the Maintenance of a Normal Spinal Fluid Pressure in Dairy Calves

Abstract
The results of these experiments indicate that measurement of the spinal fluid pressure of calves is a fairly critical index of adequacy or inadequacy of carotene intake. An intake of 66 μg. per kilogram of body weight during the winter months is about the minimum requirement for carotene for Holstein and Ayrshire calves when spinal fluid pressure is used as a criterion. Because of individual characteristics, plasma vitamin A or carotene values will not distinguish between variations of carotene intake of 62 to 75 μg. per kilogram of body weight.