Blood Plasma Urea and Ammonia Concentrations of Grazing and Grazing-Supplemented Ruminants in a Humid Tropical Environment

Abstract

The concentration of blood plasma urea nitrogen (BUN) and blood ammonia nitrogen (BAN) was determined using 8 each of West African dwarf sheep, West African dwarf goats, Boran cattle, Ndama cattle, and Muturu cattle. Each group of 8 animals was further divided into two sub-groups of 4 animals; one subgroup was maintained by grazing only while the other was grazed and supplemented with concentrate. This procedure was adopted in both experiments 1 and 2. In Experiment 1, sheep had the highest BUN with values of 3.21 and 2.66 mg/1oo ml for unsupplemented and supplemented animals respectively, followed by goats (2.92, 2.43), Boran (2.65, 1.63), Ndama (2.54, 1.60) and Muturu (2.44, 1.42). The BUN concentrations were significantly depressed (P < 0.05) in supplemented animals. Values of BUN were generally lower in Experiment 2 than in Experiment 1 and the order was also altered; goats had the highest, followed by sheep, Ndama, Boran and Muturu cattle. The BAN followed almost the same pattern as the BUN and BAN values were depressed on supplementation with concentrate. The generally low values for BUN indicate inadequacy of dietary nitrogen for the animals.