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As prenatal transportation stress altered behavior and adrenal glucocorticoid secretion of calves, we hypothesized that prenatal transportation stress would decrease ovarian reserve size and negatively impact female offspring fertility. The impact of prenatal transportation stress on ovarian follicle numbers in female offspring for three generations was studied. Brahman cows were transported for 2 h on day 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 of gestation. Ovaries were collected from offspring of transported or non-transported dams at multiple ages. Primordial, primary, secondary, and antral follicles were histologically analyzed. Antral follicle numbers were determined by ultrasound in a subset of offspring. Numbers of primordial, primary, secondary, and antral follicles were analyzed using the MIXED procedure, while the CORR procedure of SAS was used to determine the correlation between follicles observed by ultrasonography and histology. There were no differences (P > 0.05) in the number of primordial, primary, secondary, antral, or total follicles observed histologically due to treatment. Younger females had significantly greater numbers of follicles than older females (P < 0.0001). Antral follicles tended to be correlated with total histological ovarian follicles (P = 0.10). There was no difference in the number of antral follicles observed at ultrasound due to treatment (P = 0.3147), or generation (P = 0.6005) when controlling for age at observation. These results show that short-term transportation stress during early- to mid-gestation did not impact fertility as measured by ovarian follicle numbers in female Brahman offspring for three generations., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Calves from transported dams had greater concentrations of plasma cortisol when restrained and cleared plasma cortisol at a slower rate than calves from nontransported dams. Considering this hypothalamicpituitary-adrenal axis effect, investigation of other parameters influencing reproduction is warranted in offspring exposed to prenatal transportation stress. The purpose was to determine impact of prenatal transportation stress on offspring ovarian follicle count. Brahman cows were transported for 2 h on d 60, 80, 120, and 140 (± 5 d) of gestation. Offspring from transported (Stressed, n = 19) or non-transported (Control, n = 15) dams were slaughtered at 5 yr (Replication 1, n = 14) or ovariectomized at 8 yr (Replication 2, n = 20). A cross-section of ovary was collected, serially sectioned, and stained. Numbers of total, primordial, primary, secondary, and antral follicles were determined per section. Total ovarian follicle count for each stage was calculated using ovary dimensions. The MIXED procedure of SAS was used to analyze ovarian follicle count with treatment, replicate, and the interaction as fixed effects. Total ovarian follicle count decreased with age (P < 0.01; R1 = 383,663, R2 = 154,560); however, there was no difference in total ovarian follicle count between offspring due to treatment (P = 0.17; S = 221,813, C = 316,409). Similarly, there was no difference in primordial (P = 0.22; S = 127,300, C = 188,304), primary (P = 0.28; S = 58,610, C = 77,237), or antral (P = 0.48; S = 23,202, C = 28,695) follicle count between offspring due to treatment. Fewer secondary follicles were observed in Stressed offspring compared to Control offspring (P = 0.03). These results suggest that the ovarian follicular reserve, AFC, and potential fertility of cows may not be impacted by exposure to prenatal transportation stress. USDA is an equal opportunity provider and employer. [ABSTRACT FROM AUTHOR]