Studies on the production of beef from zebu cattle in East Africa IV. Variation in blood haemoglobin and its response to the feeding of dicalcium phosphate

Abstract

Lactating Boran type zebu cows had high haemoglobin levels during the week after calving, after which these levels dropped sharply and then continued to decline more gradually until their calves were weaned. Some recovery was made during the subsequent dry period.Cows fed 1 oz. dicalcium phosphate daily were constantly lower in blood haemoglobin level than their controls, and significantly so between the 14th and 20th weeks of the lactation. No differences were observed in weekly weight changes or in estimated milk yields.Calf haemoglobins decreased gradually with age until relatively adult levels were reached at about a year of age. Initial content during the week of birth was lower than at a few weeks old. There was no difference in the blood haemoglobins of calves suckling on treated and untreated cows.Individual variation was high in all groups. Some implications of seasonal effects and altitude are discussed.