Investigation of some blood biochemical parameters changes in pregnant Lori-Bakhtiari ewes during different months of pregnancy

The aim of this study was to investigate the changes of some blood biochemical parameters in Lori-Bakhtiari ewes during different monthsof pregnancy and the influence of fetus numbers on these parameters. For this purpose, 20 ewes of Lori Bakhtiari breed were selected andmated with fertile rams. One month before mating and in the first to fifth months of pregnancy blood samples were collected from ewes andbiochemical and enzymatic parameters including calcium, phosphorus, magnesium, urea, creatinine, total bilirubin, AST, ALP and GGTwere measured. The concentration of calcium and AST activity were constant at the times of the study, but they increased in the last monthof pregnancy (P<0.05). Magnesium concentration increased in second month of pregnancy (P<0.05) and phosphorus concentration wasdecreased during pregnancy compared to the month before mating (P<0.05). Creatinine concentration decreased in the second and thirdmonths of pregnancy compared to other months of pregnancy (P<0.05). Total bilirubin and urea concentrations increased during fourthmonth and the second half of pregnancy, respectively (P<0.05). GGT activity was almost stable during study period but decreased in thefourth month of pregnancy (P<0.05), and ALP enzyme activity showed increasing trend during pregnancy period (P<0.05). The meanconcentration of the studied parameters in singleton ewes was not significantly different from twins (P <0.05). Based on the results of thisstudy, blood biochemical changes in Lori Bakhtiari ewes can be used to assess their physiological status during pregnancy.