Reference interval of biochemical parameters of lactating sheep in the tropics

Abstract

The objective was to estimate the reference intervals of biochemical parameters of lactating ewes in the tropics. Information on up to 290 lactating ewes was compiled from 2006 to 2017. All animals were healthy and were not subjected to forced malnutrition. Animals were raised in different management systems (pasture, total confinement, partial confinement, collective and/or individual confinement). The biochemical profile consisted of information on cholesterol, triglycerides, fructosamine, HDL (high density lipoprotein), VLDL (very low-density lipoprotein), total protein (TP), uric acid, urea, albumin, creatinine, calcium, phosphorus and magnesium, AST (aspartate aminotransferase), GGT (gamma-glutamyl transferase) and alkaline phosphatase (ALP). Reference values were estimated using the Dixon test, when parametric, and by boostrap, when non-parametric, with a 95% confidence interval. Estimated intervals were 36.3 - 94; 262.22 - 450.66; 7 - 43; 18.6 - 69.4; 1.4 - 8.4; 0.61 - 1.66; 5.4 - 11; 0 - 1.4; 8.4 - 61.5; 1.9 - 3.57 for cholesterol, fructosamine, triglycerides, HDL, VLDL, creatinine, TP, uric acid, urea and albumin, respectively. For enzymes and mineral profile, 59 - 160; 37.9 - 127.8; 30 - 190; 8.23 - 12.45; 3.7 - 8.5; 1.7 - 3.8 for AST, GGT, ALP, Ca, P, and Mg, respectively. It can be concluded that the biochemical parameters of lactating ewes in the tropics are different from those determined in the literature.