INFLUENCE OF LITTER SIZE ON ULTRASOUND ESTIMATED FETAL GROWTH CURVE, MATERNAL STEROIDS, OXIDATIVE STRESS AND SERUM FREE RNA IN GOATS

This study aimed at evaluating the litter size influence on fetal growth (marked by biparietal diameter), steroid hormones (estradiol and progesterone), oxidative stress markers [Total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx), and malondialdehyde (MDA)], total proteins, and serum-free RNA. Goats (n=150) were blood sampled and assessed ultrasonographically during the mid-stage of pregnancy (6th to 14th week) and were classified into non-pregnant (n=64), single (n= 55) twine (n= 25), and triple (n= 6) pregnancy according to a number of feti. The correlation coefficient of caprine fetal growth was R² = 0.9609, 0.9418, and, 0.928 in single, twin, and triple feti, respectively. The area under the curve of the fetal growth was 286.2, 282.1, and 263.4 for single, twin, and triple caprine fetuses. The mean reduction rate in fetal growth compared to singleton pregnancy was 1.65±1.03 and 8.32±2.41 % in twine and triple feti, respectively. Estradiol significantly (P< 0.05) decreased, while progesterone (P< 0.01) and serum-free RNA (P< 0.001) increased in pregnant animals compared to non-pregnant. TAC and MDA increased in multiple pregnancies compared to non-pregnancy in association with the decrease of SOD and catalase activities. GPx activity and total proteins substantially decreased in triple pregnancy than non-pregnancy. Cell-free RNA negatively correlated with estradiol, CAT, GPx, and total proteins, and positively correlated with P4, TAC, and MDA. In conclusion, litter size greatly impacted fetal growth, maternal steroids, and serum-free RNA, and preload to oxidative stressmediated health disorders in pregnant goats.