Prenatal transportation stress alters temperament and serum cortisol concentrations in suckling Brahman calves12

Abstract

This experiment examined the relationship between prenatal stress and subsequent calf temperament through weaning. The prenatal stressor used was repeated transportation of pregnant Brahman cows for 2 h at 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 d of gestation. Prenatally stressed calves ( = 41) were compared with controls ( = 44; dams did not undergo transportation during pregnancy) from 2 wk of age until weaning (average age at weaning = 174.8 ± 1.3 d). Temperament was defined by pen score (PS; 1 = calm and 5 = excitable), exit velocity (EV; m/sec), and temperament score (TS; (PS + EV)/2) and was recorded for each calf on d -168, -140, -112, -84, -56, -28, and 0 relative to weaning (d 0 = weaning). Cortisol concentrations were determined in serum samples obtained on d -168, -140, -28, and 0 relative to weaning. Birth weight and weaning weight were not different between treatment groups (> 0.1). Pen score was greater ( = 0.03) in prenatally stressed calves (2.84 ± 0.21) relative to controls (2.31 ± 0.21). Exit velocity was greater ( < 0.01) in prenatally stressed calves (2.1 ± 0.14 m/sec) than in controls (1.61 ± 0.14 m/sec). Exit velocity was affected by a treatment × calf sex interaction ( = 0.04) and was greater in prenatally stressed females. Exit velocity was also affected by day ( < 0.0001). Temperament score was greater ( = 0.01) in prenatally stressed calves (2.45 ± 0.16) than in controls (1.95 ± 0.16). Temperament score was affected by day ( < 0.01). Basal cortisol concentrations were greater ( = 0.04) in prenatally stressed calves (15.87 ± 1.04 ng/mL) than in controls (13.42 ± 1.03 ng/mL). Basal cortisol concentrations were greater ( < 0.01) in females (16.61 ± 1.06 ng/mL) than in males (12.68 ± 1.02 ng/mL). Cortisol concentrations were positively correlated ( < 0.01) with PS ( = 0.55, < 0.01), EV ( = 0.4, < 0.01), and TS ( = 0.55, < 0.01). Overall, suckling Brahman calves that were prenatally stressed were more temperamental and had greater circulating serum concentrations of cortisol than control calves.

Prenatal transportation stress alters genome-wide DNA methylation in suckling Brahman bull calves1,2

“…"Dopamine-DARPP32 Feedback in cAMP Signaling and Dopamine Receptor Signaling" pathways were activated in PNS bull calves ( Supplementary Table S1). Alterations in methylation of genes and canonical pathways related to behavior, stress response, and neural function agree with increased HPA axis activity and more excitable temperaments observed in calves in the larger population from which bull calves in this study were derived (Littlejohn et al, 2016). Previous reports suggest an influence of prenatal stress on dopamine regulation, especially at the level of COMT (Thompson et al, 2012) and dopamine receptors (Berger et al, 2002).…”

“…These studies support the potential influence of prenatal stress on the ADCYAP1 gene in this study and suggest altered behavioral effects due to prenatal stress. Behavioral alterations were previously observed in PNS calves (Littlejohn et al, 2016).…”

“…Multiparous Brahman cows were assigned to 1 of 2 treatment groups (Transported: n = 48 and Control: n = 48) according to age, parity, and temperament (Littlejohn et al, 2016). Transported cows were hauled for a 2-h duration at 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 d of gestation (Price et al, 2015).…”

“…Control cows were maintained in the same manner as Transported cows with the exception of being transported. The 2 groups were housed in the same pasture (at the Texas A&M AgriLife Research and Extension Center at Overton, TX) and fed the same diet (Littlejohn et al, 2016). From these cows, 26 male and 18 female calves (Control group) were born to Control dams, while 20 male and 21 female calves [prenatally stressed (PNS) group] were born to Transported dams.…”

Impact of Maternal High Stocking Density during the Dry Period on Dairy Calf Health, Behaviour, and Welfare

“…Lay and colleagues reported that repeated transportation of cows throughout pregnancy altered the offspring's physiological response to stress [22]. More recent studies also reported that repeated transportation of pregnant cows resulted in higher basal cortisol levels and more temperamental traits in offspring [23]. The findings from these studies would suggest that it is possible that certain maternal factors can affect foetal development in cattle.…”