Influence of quebracho tannins administration on some blood metabolites in sheep and goats

Eight Merino sheep (49.4±4.23 kg LW) and eight Alpine goats (53.2±2.51 kg LW) were used in two experiments to study the effect of quebracho tannins (Q) on some plasma metabolites. Four sheep and four goats were fed daily 20 g DM of alfalfa hay (3-5 cm) per kg LW (A), whereas the other animals were given the same amount of hay treated with 50 g of Q. Blood samples were taken after 5, 34, and 64 days of starting the administration of the Q diet, to assay some plasma metabolites [i.e. alkaline phosphatase (ALP), gamma glutamyltransferase (GGT), glutamic oxaloacetic transaminase (GOT), and creatinin] as indicators of liver and kidney function. The concentration of the above mentioned plasma metabolites was unaffected by the inclusion of quebracho in the diet for the three sampling times being the mean values for sheep: ALP (IU/l) 56.97 vs 58.26 (sed 6.710), GGT (IU/l) 44.45 vs 44.48 (sed 4.857), GOT (IU/l) 40.93 vs 46.47 (sed 10.682) and creatinin (mg/dl) 0.94 vs 1.05 (sed 0.023) for the A and Q diet, respectively; and for goats: ALP (IU/l) 161.64 vs 190.12 (sed 47.461), GGT (IU/l) 30.51 vs 29.82 (sed 3.426), GOT (IU/l) 41.25 vs 44.16(sed 4.218) and creatinin (mg/dl) 0.76 vs 0.77 (sed 0.029) for the A and Q diet, respectively. Thus, it appears that the level of tannins used in these experiments does not cause any ill effect either in sheep or in goats even after 64 days of consumption of the Q diet.