Changes in some blood constituents of Barki ewes during pregnancy and lactation under semi arid conditions.
A study based on 12 pregnant and six dry Barki ewes was carried out to examine the changes in blood constituents during pregnancy and lactation periods. The blood parameters were blood hemoglobin, packed cell volume percent (PCV%), mean corpuscular hemoglobin concentration (MCHC), glucose, aspartate aminotransaminase (AST or GOT), alanine aminotransaminase (ALT or GPT), total plasma protein, albumin, globulin, albumin to globulin ratio (A/G), urea and creatinine. During pregnancy all these parameters started to increase significantly, but in different stages, reaching maximum values at parturition. In contrast, dry ewes showed almost stable values during the experimental period. From 10th week to parturition, PCV% and MCHC increased (P<0.01) in pregnant ewes, which resulted in increased (P<0.01) blood hemoglobin. Blood glucose increased from the 4th week of pregnancy to reach its maximum at parturition (60.15-90.08mg/dl). The two transaminases increased significantly from the 2nd week (52.23-65.02IU for AST and 8.02-15.12IU for ALT). Plasma protein with its two components, albumin and globulin, increased significantly at the 6th week, but dropped throughout the 16-18th week of pregnancy. Urea and creatinine began to increase significantly after 10-12 weeks of pregnancy (from 54.73 to 72.11mg/dl for urea and from 0.882 to 2.475mg/dl for creatinine). During the first month of lactation, PCV decreased sharply in lactating ewes and was significantly lower than in dry ewes at the 3rd week of lactation (24.25 versus 27.17%), which resulted in a drop in blood hemoglobin at the 4th week (68.42 versus 74.00g/l). However, lactating ewes maintained significantly higher values of MCHC (30.01-31.19% for lactating versus 29.87-27.48% for dry). In lactating ewes, levels of glucose, ALT, urea and creatinine returned to levels comparable to those in dry ewes. The same occurred with total plasma proteins, mainly due to a sharp decrease in globulin, while albumin remained higher than in dry ewes with a slow decline, which resulted in higher values of A/G ratio during lactation. Aspartate aminotransferase remained higher than in dry ewes.