Ultrasonography and computer-assisted assessment of postpartum uterine echotexture and its relationship with peripheral oxidative stress biomarkers in goats

The postpartum (PP) period is a crucial factor for the resumption of reproductive capacity and the regular cycling of goats. Until now, there is a lack of information on monitoring the PP uterine involution using morphological assessment of uterine echotexture by ultrasonography. This study aimed to use ultrasonography and computer software analysis for morphometrical evaluations of postpartum uterine involution in 30 pleuriparous Egyptian Balady goats from Day zero (kidding day) till Day 21 PP. Uterine echotexture (pixel intensity; PI and integrated density; ID) was assessed by the computer-assisted image analysis software. In addition, the changes in peripheral oxidative stress biomarkers were monitored by measuring superoxide dismutase (SOD; U/mL), glutathione peroxidase (GPx; U/mL) activities, and malondialdehyde (MDA; nmol/mL) levels in the sera during the PP period. Results revealed a significant (P < 0.001) reduction in the transverse uterine diameter from 8.05 ± 0.58 cm at Day zero to less than 2 cm at Day 16 PP onward. The uterus returned to its apparently normal non-pregnant state with the absence of lochia by Day 16.6 ± 1.35 PP. There were significant (P ˂ 0.0001) increases in the PI and ID of the endometrium with the progression of the PP days [Day 0: PI: 86.99 ± 8.61; ID (×1000): 82.09 ± 1.47 versus Day 12 PP: PI: 186.73 ± 5.62; ID (×1000): 355.17 ± 38.63]. Gradual elevations in the levels of SOD (0.33 ± 0.02 U/mL) and MDA (11.81 ± 0.21 nmol/mL) were found from Day 0 and reaching the maximum levels (SOD: 0.48 ± 0.12 U/mL; MDA: 15.31 ± 0.13 nmol/mL) at Day 6–7 PP. Concentrations of GPx increased gradually from Day 0 (65.23 ± 2.09 U/mL) till Day 21 PP (145.81 ± 2.99 U/mL). In conclusion, assessment of the changes in morphometrical and echotextural parameters of the uterus by ultrasonography as well as the oxidative stress biomarkers provided useful information in the progress and completion of the normal physiological PP uterine involution in goats.