Diurnal rhythm of blood biochemical plasma enzyme profile and minerals of sun exposed Martina franca jacks in semitropical desert climate

Abstract

Diurnal rhythm of blood biochemical profile and plasma minerals was studied in adult and apparently healthy male Martina Franca (Poitou) jacks (n=6). The jacks weighing between 270 to 350 kg were fed with standard ration for maintenance as per NRC (2007) from 10:00h to 14:00h. The donkeys remained exposed to solar radiation. Blood was collected for biochemical parameters at 07:00h, 10:00h, 14:00h and 16:00h on 1st, 4th and 7th day in a seven day experimental period during October 2016 heat stress period (HS). Thermal heat index (THI) =69.90 at7.00h and 80.14 at 14.00h) and on a single day in peak winter in December 2016 (control ‘C’, THI: 63.93 at 7.00h and 80.14 at 14.00h). Plasma enzyme activities (in U/l for ALP, γGT, AST, ALT and LDH) increased at 14:00h & 16:00h when compared to 07:00h and 10:00h during HS and remained higher than in C. The Mg values increased with diurnal progression of the day and were maximum at 14.00h than at 07.00 & 10.00h. Mg levels were higher in HS than in C. The Martina Franca jacks exhibited specific diurnal rhythm of several plasma biochemical constituents specifically related to heat stress. The impact was only transient and reduced when the climatic THI reduced, both with the diurnal time point in day as well as season.