Abstract :
This study describes the fluctuations in serum energy-related metabolites during a period
of 2 weeks before, to 2 weeks after parturition in Lori-Bakhtiari ewes. The effect of parity
was also studied. Blood profiles were determined in 60 healthy pregnant ewes with single
(n = 30) and twin (n = 30) lambings. Blood was collected from each ewe on days 14 and 7
prepartum, and days 7 and 14 postpartum to determine the serum non-esterified fatty acid
(NEFA), -hydroxybutyrate (BHBA), glucose, cholesterol, blood urea nitrogen (BUN) and
calcium (Ca) levels. The age of the ewes had no significant effect on the energy metabolism
indicators. Serum NEFA, BHBA, glucose, BUN and calcium concentrations recorded peak
levels 7 days before parturition. However, NEFA and BHBA recorded significant changes
(P < 0.05) during the peri-parturition period. All metabolites changed significantly in ewes
carrying twin-bearing ewes, compared to single-bearing ewes. Serum BHBA concentrations
recorded positive correlations with the serum NEFA (P < 0.01) and cholesterol (P < 0.05),
while blood glucose had negative correlations (P < 0.01) with NEFA, BHBA and Ca. Blood
NEFA and BHBA recorded positive correlations (P < 0.05) with the BUN levels and negative
correlations (P < 0.05) with Ca. The results showed that blood NEFA and BHBA levels are
sensitive indicators of the energy balance during the peri-parturition period in ewes
