Influence of berseem as beta-carotene source on growth and circulatory levels of vitamin A in crossbred calves

Abstract

An experiment was conducted to study the effect of feeding different levels of B-carotene through berseem fodder on growth and circulatory vitamin A levels in crossbred calves. Crossbred calves (15), 193 ± 15day-old, were fed on a Pcarotene deficient diet consisting of wheat straw and a concentrate mixture for 9 weeks so that their plasma vitamin A concentration dropped to the deficient level of less than 20 mg/100ml. Thereafter, the calves were divided into 3 equal groups. Body weight and plasma vitamin A at the start of the experiment averaged 103.6±6.4, 102.4 ± 7.5, 100.0 ± 8,9 kg and 13.3 ± 0.5, 17.3 ± 3.0, 16.3 ± 1.3 mg/100ml in groups 1, 2 and 3 respectively. All the calves were fed as per NRC requirements and their ration included 0, I, and 2 kg berseem fodder daily to approximately supplement 0, 40 and 80 mg p-carotene to 3 respective groups. OM intake was slightly increased due to p-carotene supplementation. The growth rate of calves was significantly (P<0.01) higher in fodder supplemented groups. Plasma vitamin A level was also increased (P<0.01 in groups 2 and 3 over group I calves. Higher beta-carotene supply as in group 3 was not converted to vitamin A. It is therefore evident that 1 kg of berseem supplementation is sufficient to provide required amount of p-carotene to fulfill the vitamin A needs of growing crossbred calves.