Subclinical Pregnancy Toxemia Affects Blood Parameters of Ewes and Impairs Postnatal Growth and Development of Lambs

Abstract

Pregnancy toxemia (PT) is a common metabolic disorder that occurs in the last trimester of pregnancy. This study aimed to detect the effects of subclinical PT (SPT) on serum biochemical parameters of ewes and postnatal growth and development of lambs in Romanov sheep. A total of 40 ewes and 69 lambs were included in the study. Blood samples of ewes were collected at the time of parturition to evaluate serum beta-hydroxybutyric acid (βHBA), serum nonesterified fatty acid (NEFA), cholesterol, and triglyceride. Live weight and body measurements of lambs were recorded at birth (0th day), 30th day, and 60th (weaning) day. In the diagnosis of SPT serum βHBA concentrations were taken into account. A cut-off value of 0.8 mmol/L for βHBA was a critical concentration and ewes with 0.8-1.6 mmol/L βHBA were evaluated as SPT. There were no ewes with ΒHBA value higher than 1.6 mmol/L (clinical PT) in the study. There was no significant difference in serum βHBA, NEFA and cholesterol concentrations between ewes regarding birth type (single, twin, and triplet). However, triglyceride concentrations were higher (p < 0.001) in ewes giving birth to triplets compared to ewes giving birth to single lamb. Serum βHBA and triglyceride concentrations were higher (p < 0.01) in ewes with SPT (n = 14) compared to healthy ewes (n = 26). There was no significant difference between ewes with SPT and healthy ewes in serum NEFA and cholesterol. Repeated measures ANOVA results indicated that SPT negatively affected 0th, 30th, and 60th body weights of twin (p < 0.01) and triplet born lambs (p < 0.05). The effect of time on body weights was also found to be significant (p < 0.001). Similarly, most of the body measurements of twin and triplet born lambs were lower (p < 0.05) in the SPT group compared to healthy group. Overall results indicate that SPT may negatively affect postnatal growth and development in Romanov lambs. Because a decline in growth performance has many negative outcomes affecting production traits in sheep, these findings may be valuable for the veterinary field.