Effects of Defaunation and Dietary Nitrogen Source on Sodium, Potassium, Iron and Zinc in the Rumen Fluid, Plasma and Wool of Lambs

This study was conducted to investigate the effects of defaunation, and the addition of urea and sulfur in the replacement of plant protein (PP) sources on concentrations of Na, K, Zn and Fe in the ruminal fluid, blood plasma and wool of lambs. Forty male Ramlic lambs, 2.70 ± 0.30 months of age, and weighing approximately 16.44 ± 0.41 kg, were used. Lambs were divided into 4 groups as follows: faunate + control diet (FC), defaunate + control diet (DC), faunate + experimental diet (FE), and defaunate + experimental diet (DE). The control diet contained plant protein as a N source, whereas the experimental diet was supplemented with urea and sulfur, both at 3% of BW per day. The forage portion of the diet was 350 g of alfalfa hay per lamb per day. Diets were fed twice daily in equal amounts. Defaunation, or feeding a diet supplemented with urea and sulfur in place of plant protein sources, had no effect on ruminal fluid Na concentrations but there was an interaction on Na concentration in the rumen fluid. Ruminal K concentration was lower (P < 0.021) in the experimental diet versus the control diet, while it was not affected by defaunation. There was an interaction effect on Zn concentration in rumen fluid. Plasma Na, K and Zn concentrations were not affected by treatments, whereas defaunation significantly decreased (P < 0.048) plasma Fe concentration. Defaunation or N source had no effect on Na, K, Zn and Fe concentrations in wool. We concluded that both defaunation and feeding a diet supplemented with urea and sulfur in place of plant protein sources did not affect blood plasma, except for Fe, and wool Na, K, Zn and Fe concentrations despite differences in their ruminal concentration.