The net uptake and oxidation of glucose by leg muscle, pregnant uterus, and lactating mammary gland, together with the rate of irreversible loss and oxidation of glucose in the whole body of Merino ewes are reported. The ewes were fed on either chaffed oaten hay (OR), chaffed lucerne hay (L), or a mixture of chaffed oaten and lucerne hays (OHL). Measurements were made during five different physiological states: dry (nonpregnant), at 94 and 125 days of pregnancy, and at 20 and 50 days after lambing.

The factors affecting lipid absorption in unanaesthetized calves less than 24 hr old have been studied by comparing the output of lipid in the thoracic duct lymph of calves fed one of the following diets: (1) colostrum, in which the colostral fat was replaced with milk fat globules; (2) milk; (3) colostral whey containing milk fat globules; (4) isotonic saline containing milk fat globules. The animals were fed after they had recovered sufficiently from the operation to stand and suck from a nipple feeder.In calves fed diets 1 and 2 the maximum output of lipid in lymph occurred 12 and 6 hr after feeding respectively. In contrast, lipid absorption in calves fed the casein-free diets 3 and 4 was rapid, the maximum output of lipid in lymph occurring at 2-3 hr. It is apparent from these results that newborn calves are capable of absorbing large quantities of lipid and that the delayed absorption associated with colostrum and milk feeding was a function of casein concentration.The lipid in all diets was absorbed with equal efficiency. It was evident from a comparison of the rate and efficiency of lipid absorption in calves fed diets 3 and 4 that factors in colostrum known to be associated with enhanced protein absorption do not significantly influence lipid absorption.Immediately prior to feeding, lymph flow had reached comparatively stable values of 536±5·4 ml/hr (mean ± S.E.) for 13 calves. Flow increased almost twofold within the first 2-3 hr after feeding colostrum and remained elevated for a further 3-4 hr. This occurred in the absence of significant lipid absorption but it was associated with an increase of up to threefold in globulin concentration of lymph. In contrast there was little change in flow over the first 4 hr after feeding milk, although lymph flow increased up to 1· 5-fold at 5-6 hr, corresponding with the peak of lipid absorption.