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The objective of this study was to more fully define the surgical stress response to dehorning by heat cauterization in dairy calves by measuring behavioral, hormonal, inflammatory, and immunological markers of stress and to determine whether a nerve block of the surgical site with a concentrated solution of lidocaine (5%) reduces the degree of stress. Thirty-two 10- to 12-wk-old female Holstein calves were randomly allotted to 1 of 4 treatments: 5% lidocaine followed by dehorning, 2% lidocaine followed by dehorning, saline followed by dehorning, or 5% lidocaine followed by sham dehorning. Plasma cortisol concentration was measured in blood samples collected via a jugular catheter at -0.5, 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 9, 12, 24, 48, and 72 h. Various other blood constituents were measured in samples collected at -0.5, 12, 24, 48, and 72 h. Feeding, drinking, scratching, grooming, rubbing, licking, and inactivity behaviors were observed in the standing and recumbent positions using a 10-min scan sampling method analyzed on a time period and daily basis for 72 h following the dehorning procedure. The frequency of vocalization, kicking, and lying in the chute during the dehorning procedure were also assessed. The overall plasma cortisol concentrations were higher in calves subjected to dehorning than in control calves. Compared with the control group, the saline-treated calves had a higher cortisol concentration at 30 and 60 min postdehorning. Plasma cortisol concentrations were higher in all groups at 30 min postdehorning than at other sampling times. The percentage of circulating neutrophils and the neutrophil:lymphocyte ratio were increased in the saline and 2% lidocaine group. Total plasma protein, fibrinogen, and α1-acid glycoprotein concentrations were similar among treatments. The behavioral response to dehorning, as manifested by kicking while in the chute, was greater in the saline and 2% lidocaine group than in the control or 5% lidocaine treatment groups. In the postdehorning period, the percentage of time calves spent performing various maintenance behaviors did not differ among treatments. Thus, injection of 5% lidocaine may not provide any added comfort after the dehorning but may decrease the overall stress response during the procedure. [ABSTRACT FROM AUTHOR] more...

Plasma cortisol, porcine corticosteroid-binding globulin (pCBG), hepatic CBG expression, and other physiological and behavioral measures of stress were studied in pigs in response to elevated temperature in conjunction with establishing a social hierarchy. Twenty-four crossbred pigs were weaned at 25 d of age (three or six pigs from six sows) and housed in littermate groups at 23 ± 2°C. At 57 d of age (d 0), animals were weighed and placed under general anesthesia for collection of blood (10 mL) and liver (approximately 100 mg) samples. On d 1, three unacquainted pigs of similar BW (23 ± 1 kg) from different litters were allotted to each of eight nursery pens within two environmentally controlled rooms (12 pigs per room). From d 1 to 7, one room was maintained at 23 ± 2°C (CON) and the other at 33 ± 2°C (HEAT). Both rooms were kept at 23 ± 2°C from d 8 to 14. Animals were videotaped for 72 h beginning on d 1 and 8 to document behavioral changes in response to room temperature. The social hierarchy of pigs within each pen was based on fight activity recorded on d 1 to 3. Blood and liver tissue were collected again on d 7 and 14. The ADG for HEAT pigs increased (P < 0.05) over d 8 to 14 compared with d 1 to 7. In contrast to CON pigs, HEAT pigs displayed increased (P < 0.01) drinking but decreased feeding and lying in contact with other pigs from d 1 to 3, and similar drinking and feeding but increased (P < 0.01) lying with contact behaviors from d 8 to 10. With the exception of subordinate pigs exhibiting less (P < 0.05) frequent standing/walking behavior than the dominant or intermediate pigs on d 1 to 3, frequency of behaviors for both recorded time periods did not differ among pigs due to social status, regardless of treatment. The concentration of plasma haptoglobin in HEAT pigs on d 7 compared with d 0 increased (467 vs. 763 mg/L; P < 0.05), whereas cortisol and pCBG decreased (274 vs. 235 nmol/L and 11.4 vs. 9.9 mg/L, respectively; P < 0.05) as a result of treatment. The free cortisol index (total cortisol/pCBG) was greater (P < 0.05) in HEAT pigs on d 14 than on d 0 or 7. Hepatic CBG mRNA level was not affected by treatment. On d 14, HEAT pigs had plasma cortisol, pCBG, and haptoglobin concentrations similar to those of CON pigs. These results indicate that measured behavioral and physiological responses were not related to social status, and decreased circulating levels of cortisol and pCBG in pigs following a 7-d exposure to elevated temperature may not be determined by hepatic CBG mRNA expression. [ABSTRACT FROM AUTHOR] more...

Plasma cortisol, porcine corticosteroid-binding globulin (pCBG), hepatic CBG expression, and other physiological and behavioral measures of stress were studied in pigs in response to elevated temperature in conjunction with establishing a social hierarchy. Twenty-four crossbred pigs were weaned at 25 d of age (three or six pigs from six sows) and housed in littermate groups at 23 ± 2°C. At 57 d of age (d 0), animals were weighed and placed under general anesthesia for collection of blood (10 mL) and liver (approximately 100 mg) samples. On d 1, three unacquainted pigs of similar BW (23 ± 1 kg) from different litters were allotted to each of eight nursery pens within two environmentally controlled rooms (12 pigs per room). From d 1 to 7, one room was maintained at 23 ± 2°C (CON) and the other at 33 ± 2°C (HEAT). Both rooms were kept at 23 ± 2°C from d 8 to 14. Animals were videotaped for 72 h beginning on d 1 and 8 to document behavioral changes in response to room temperature. The social hierarchy of pigs within each pen was based on fight activity recorded on d 1 to 3. Blood and liver tissue were collected again on d 7 and 14. The ADG for HEAT pigs increased (P < 0.05) over d 8 to 14 compared with d 1 to 7. In contrast to CON pigs, HEAT pigs displayed increased (P < 0.01) drinking but decreased feeding and lying in contact with other pigs from d 1 to 3, and similar drinking and feeding but increased (P < 0.01) lying with contact behaviors from d 8 to 10. With the exception of subordinate pigs exhibiting less (P < 0.05) frequent standing/walking behavior than the dominant or intermediate pigs on d 1 to 3, frequency of behaviors for both recorded time periods did not differ among pigs due to social status, regardless of treatment. The concentration of plasma haptoglobin in HEAT pigs on d 7 compared with d 0 increased (467 vs. 763 mg/L; P < 0.05), whereas cortisol and pCBG decreased (274 vs. 235 nmol/L and 11.4 vs. 9.9 mg/L, respectively; P < 0.05) as a result of treatment. The free cortisol index (total cortisol/pCBG) was greater (P < 0.05) in HEAT pigs on d 14 than on d 0 or 7. Hepatic CBG mRNA level was not affected by treatment. On d 14, HEAT pigs had plasma cortisol, pCBG, and haptoglobin concentrations similar to those of CON pigs. These results indicate that measured behavioral and physiological responses were not related to social status, and decreased circulating levels of cortisol and pCBG in pigs following a 7-d exposure to elevated temperature may not be determined by hepatic CBG mRNA expression. [ABSTRACT FROM AUTHOR] more...

The objective was to evaluate the impact of hot iron branding on plasma cortisol and corticosteroid- binding globulin (CBG) concentrations of Senepol heifers and bulls (n = 15/sex; 14 mo of age). On d 1 and 14 calves were put in the chute and after applying squeeze a blood sample was collected by coccygeal vessel puncture (PRE). After 1 min to mimic the time it takes to brand a second blood sample was collected (POST). The calf was released from the chute. On d 7 calves were put in the chute and after applying squeeze to immobilize the calf a blood sample was collected by coccygeal vessel puncture (PRE). The calves were hot branded with a single digit (number 5) using an electric branding iron. A second blood sample was collected after branding was completed (POST). The calf was released from the chute and returned to the pen of same sex cohorts. Plasma was harvested from blood samples and stored at -20 °C until assayed for cortisol and CBG by RIA and ELISA, respectively. Free cortisol index (FCI) was determined as the ratio of total cortisol/CBG. Data was analyzed using SAS (9.3) with sex, week and time of sampling in chute as the main effects. Cortisol was higher (P < 0.0001) in heifers than in bulls (101.44 ± 3.99 vs. 74.88 ± 3.97 nmol/L, respectively). In bulls cortisol was lower on d 7 compared to d 1 and 14 (50.97 ± 6.88 vs. 87.19 ± 6.88 vs. 86.48 ± 6.88 nmol/L, respectively) but there was no difference (P > 0.10) in heifers over time. Cortisol was lower (P < 0.05) in the PRE than in the POST sample (82.45 ± 3.99 vs. 93.87 ± 3.97 nmol/L, respectively). Heifers had higher (P < 0.0002) CBG than bulls (0.81 ± 0.04 vs. 0.62 ± 0.04 mg/L, respectively). There was no difference in CBG across days or between PRE and POST samples (P > 0.10). On d 7 FCI of bulls was lower (P < 0.0005) than on d 1 and 14 (83.14 ± 17.54 vs. 157.64 ± 17.54 vs. 195.62 ± 17.54 nmol/mg, respectively). In heifers there was no difference (P > 0.10) in FCI across days or between PRE and POST. These results show that hot branding elicits a slight, acute cortisol response (13.8 % increase) in Senepol cattle but there was no residual impact 7 d after branding. [ABSTRACT FROM AUTHOR] more...

The objective was to evaluate the impact of hot iron branding on plasma cortisol and corticosteroid- binding globulin (CBG) concentrations of Senepol heifers and bulls (n = 15/ sex; 14 mo of age). On d 1 and 14 calves were put in the chute and after applying squeeze a blood sample was collected by coccygeal vessel puncture (PRE). After 1 min to mimic the time it takes to brand a second blood sample was collected (POST). The calf was released from the chute. On d 7 calves were put in the chute and after applying squeeze to immobilize the calf a blood sample was collected by coccygeal vessel puncture (PRE). The calves were hot branded with a single digit (number 5) using an electric branding iron. A second blood sample was collected after branding was completed (POST). The calf was released from the chute and returned to the pen of same sex cohorts. Plasma was harvested from blood samples and stored at -20 °C until assayed for cortisol and CBG by RIA and ELISA, respectively. Free cortisol index (FCI) was determined as the ratio of total cortisol/CBG. Data was analyzed using SAS (9.3) with sex, week and time of sampling in chute as the main effects. Cortisol was higher (P < 0.0001) in heifers than in bulls (101.44 ± 3.99 vs. 74.88 ± 3.97 nmol/L, respectively). In bulls cortisol was lower on d 7 compared to d 1 and 14 (50.97 ± 6.88 vs. 87.19 ± 6.88 vs. 86.48 ± 6.88 nmol/L, respectively) but there was no difference (P > 0.10) in heifers over time. Cortisol was lower (P < 0.05) in the PRE than in the POST sample (82.45 ± 3.99 vs. 93.87 ± 3.97 nmol/L, respectively). Heifers had higher (P < 0.0002) CBG than bulls (0.81 ± 0.04 vs. 0.62 ± 0.04 mg/L, respectively). There was no difference in CBG across days or between PRE and POST samples (P > 0.10). On d 7 FCI of bulls was lower (P < 0.0005) than on d 1 and 14 (83.14 ± 17.54 vs. 157.64 ± 17.54 vs. 195.62 ± 17.54 nmol/mg, respectively). In heifers there was no difference (P > 0.10) in FCI across days or between PRE and POST. These results show that hot branding elicits a slight, acute cortisol response (13.8 % increase) in Senepol cattle but there was no residual impact 7 d after branding. [ABSTRACT FROM AUTHOR] more...

Corticosteroid-binding globulin (CBG) is a transporter for cortisol and progesterone (P4) that acts to regulate their bioavailability. Little is known about bovine CBG and the mechanisms that regulate its biosynthesis. The objective of this study was to examine the impact of exogenous P4 released from a controlled internal drug release device (CIDR) on circulating concentrations of CBG in heifers undergoing synchronization of ovulation followed by fixed-time artificial insemination (TAI). Furthermore, P4 bioavailability was assessed between pregnant and non-pregnant heifers. Beef heifers (n = 67) from multiple herds were enrolled in the study and underwent synchronization of ovulation using the 7-day CO-Synch + CIDR protocol. Immediately prior to CIDR insertion on d -7, blood was collected from each heifer. Blood was collected again on d 0 immediately after CIDR removal and an additional blood sample was obtained upon pregnancy diagnosis on d 38. Concentrations of P4 and CBG were determined using a commercially available RIA and in-house ELISA, respectively. A free P4 index (FPI) was calculated by dividing total plasma P4 concentration by CBG concentration. Concentrations of P4 (ng/mL) were converted to nmol/L by a multiplicative conversion factor of 3.18. A mixed model ANOVA with repeated measures was performed (SAS 9.3). Progesterone, CBG, and FPI on d -7 and 0 did not differ (P > 0.05) between pregnant and non-pregnant heifers. Plasma P4, CBG, and FPI profiles were assessed over the three sampling points for heifers that became pregnant following TAI (n = 24). Samples collected on d 0 and -7 contained similar concentrations of P4 (8.27 nmol/L ± 2.63 vs. 10.77 nmol/L ± 2.96, respectively), but d 38 P4 was greater (P < 0.05) than that measured prior to CIDR insertion on d 0 (17.92 nmol/L ± 3.82 vs. 8.27 nmol/L ± 2.63, respectively). Similarly, CBG did not differ on d 0 and -7 (5.24 mg/L ± 0.53 vs. 4.59 mg/L ± 0.47), but was greatest (P < 0.05) at pregnancy diagnosis (6.61 mg/L ± 0.67). FPI was similar (P > 0.05) across all sampling time points. In summary, under the current methods, CIDR insertion did not impact CBG concentrations in heifers undergoing synchronization of ovulation. However, these data indicate that CBG may play a role in regulating P4 bioavailability during early gestation. [ABSTRACT FROM AUTHOR] more...

Dietary n-3 PUFA are precursors for lipid metabolites that reduce inflammation. Two experiments were conducted to test the hypothesis that enriching the sow diet in n-3 PUFA during late gestation and throughout lactation reduces stress and inflammation, and promotes growth in weaned pigs. A protected fish oil product (PFO; GromegaTM) was used to enrich the diet in n-3 PUFA. Experiment 1, time-bred gilts (n = 14) were fed a gestation and lactation diet supplemented with 0 (control; n = 5), 0.25 (n = 4), 0.5 (n = 4) or 1% (n = 5) PFO from 101 ± 2 d of gestation to d 16 of lactation. Adding 1% PFO to the diet increased the n-3:n-6 PUFA ratio in colostrum and milk compared to controls (P = 0.05). A subsequent experiment was performed to determine if supplementing the sows' diet with 1% PFO improved growth and reduced circulating markers of acute inflammation and stress in their offspring. Plasma was harvested from piglets (16 /treatment group) on d 0 (d of weaning) and d 1 and 3 postweaning. Pigs from the 1% PFO treatment group weighed more (P = 0.03) on d 3 postweaning and had a greater (P < 0.01) n-3:n-6 PUFA ratio in plasma on each day sampled compared to 0% PFO controls. There was an overall treatment effect (P = 0.02) on plasma total cortisol, with lesser concentrations in pigs on the 1% PFO diet. Plasma corticosteroid-binding globulin (CBG) concentrations were not different between treatment groups but were lesser (P < 0.001) on d 1 and 3 when compared to d 0. The resultant free cortisol index [FCI (cortisol/CBG)] was lesser (P = 0.02) on d 1 and 3 for pigs from the 1% treatment group compared to the controls. An ex vivo lipopolysaccharide (LPS) challenge of whole blood collected on d 0 and 1 was used to determine if 1% PFO attenuated release of inflammatory cytokines (IL-1β, IL-6, and TNF-α). Pigs from the 1% PFO treatment group tended (P = 0.098) to have a lesser mean concentrations of TNF-α in response to LPS compared to controls. These results suggest that providing a PFO supplement as 1% of the diet to sows beginning in late gestation and during lactation can increase the n-3:n-6 PUFA ratio in their offspring, which may improve growth and reduce the acute physiological stress response in the pigs postweaning. [ABSTRACT FROM AUTHOR] more...

The objective of the study was to evaluate the impact of hot branding on behavior of Senepol heifers and bulls (n = 15/sex; 14 mo of age). On d 1 and 14 calves were evaluated for pen score (PS; 1 = calm to 5 = aggressive) in same sex groups of 5 prior to being placed in the chute (PS1). Calves were held in the chute without catching their heads and no squeeze applied to record chute score (CS; 1 = calm to 5 = extremely agitated). After applying squeeze for 1 min to mimic the time it takes for branding calves were released from the chute and exit velocity (EV) was measured. A second PS was collected (PS2). On d 7 data was collected similar to d 1 with the addition of branding using a hot iron. On d 7 and 14 flight distance (FD) was measured with PS1 and PS2 (FD1, FD2) using a rangefinder. Data was analyzed using SAS (9.3) with sex, day and time relative to being in chute as the main effects. There was no difference in PS between bulls and heifers (1.2 ± 0.1 vs. 1.2 ± 0.1, respectively). Pen score on d 1 was higher than on d 7 or 14 (1.5 ± 0.1 vs. 1.1 ± 0.1 vs. 1.1 ± 0.1, respectively). On d 7 PS2 was higher (P < 0.03) than PS1 in bulls (1.3 ± 0.1 vs. 1.0 ± 0.1, respectively) but there was no difference (P > 0.10) in heifers. Heifers had higher (P < 0.002) CS than bulls on d 1 (2.1 ± 0.1 vs. 1.5 ± 0.1, respectively), but there was no difference (P > 0.10) on d 7 or 14. There was no difference (P > 0.10) in EV between bulls and heifers (2.03 ± 0.11 vs. 2.12 ± 0.11 m/s, respectively). Heifers had higher EV (P < 0.03) on d 7 than d 1 with d 14 being intermediate (2.48 ± 0.19 vs. 1.89 ± 0.18 vs. 1.98 ± 0.19 m/s, respectively) but there was no difference in bulls (P > 0.10). There was no difference in FD between bulls and heifers (2.29 ± 0.08 vs. 2.50 ± 0.08 m, respectively) or between day 7 and 14 (2.47 ± 0.08 vs. 2.32 ± 0.08 m, respectively). These results show that Senepol cattle have mild dispositions and the stress of branding does not alter their behavior. [ABSTRACT FROM AUTHOR] more...

The objective of the study was to evaluate the impact of hot branding on behavior of Senepol heifers and bulls (n = 15/sex; 14 mo of age). On d 1 and 14 calves were evaluated for pen score (PS; 1 = calm to 5 = aggressive) in same sex groups of 5 prior to being placed in the chute (PS1). Calves were held in the chute without catching their heads and no squeeze applied to record chute score (CS; 1 = calm to 5 = extremely agitated). After applying squeeze for 1 min to mimic the time it takes for branding calves were released from the chute and exit velocity (EV) was measured. A second PS was collected (PS2). On d 7 data was collected similar to d 1 with the addition of branding using a hot iron. On d 7 and 14 flight distance (FD) was measured with PS1 and PS2 (FD1, FD2) using a rangefinder. Data was analyzed using SAS (9.3) with sex, day and time relative to being in chute as the main effects. There was no difference in PS between bulls and heifers (1.2 ± 0.1 vs. 1.2 ± 0.1, respectively). Pen score on d 1 was higher than on d 7 or 14 (1.5 ± 0.1 vs. 1.1 ± 0.1 vs. 1.1 ± 0.1, respectively). On d 7 PS2 was higher (P < 0.03) than PS1 in bulls (1.3 ± 0.1 vs. 1.0 ± 0.1, respectively) but there was no difference (P > 0.10) in heifers. Heifers had higher (P < 0.002) CS than bulls on d 1 (2.1 ± 0.1 vs. 1.5 ± 0.1, respectively), but there was no difference (P > 0.10) on d 7 or 14. There was no difference (P > 0.10) in EV between bulls and heifers (2.03 ± 0.11 vs. 2.12 ± 0.11 m/s, respectively). Heifers had higher EV (P < 0.03) on d 7 than d 1 with d 14 being intermediate (2.48 ± 0.19 vs. 1.89 ± 0.18 vs. 1.98 ± 0.19 m/s, respectively) but there was no difference in bulls (P > 0.10). There was no difference in FD between bulls and heifers (2.29 ± 0.08 vs. 2.50 ± 0.08 m, respectively) or between day 7 and 14 (2.47 ± 0.08 vs. 2.32 ± 0.08 m, respectively). These results show that Senepol cattle have mild dispositions and the stress of branding does not alter their behavior. [ABSTRACT FROM AUTHOR] more...

Dietary n-3 PUFA are precursors for lipid metabolites that reduce inflammation. Two experiments were conducted to test the hypothesis that enriching the sow diet in n-3 PUFA during late gestation and throughout lactation reduces stress and inflammation, and promotes growth in weaned pigs. A protected fish oil product (PFO; Gromega™) was used to enrich the diet in n-3 PUFA. Experiment 1, time-bred gilts (n = 14) were fed a gestation and lactation diet supplemented with 0 (control; n = 5), 0.25 (n = 4), 0.5 (n = 4) or 1% (n = 5) PFO from 101 ± 2 d of gestation to d 16 of lactation. Adding 1% PFO to the diet increased the n-3:n-6 PUFA ratio in colostrum and milk compared to controls (P = 0.05). A subsequent experiment was performed to determine if supplementing the sows' diet with 1% PFO improved growth and reduced circulating markers of acute inflammation and stress in their offspring. Plasma was harvested from piglets (16 /treatment group) on d 0 (d of weaning) and d 1 and 3 postweaning. Pigs from the 1% PFO treatment group weighed more (P = 0.03) on d 3 postweaning and had a greater (P < 0.01) n-3:n-6 PUFA ratio in plasma on each day sampled compared to 0% PFO controls. There was an overall treatment effect (P = 0.02) on plasma total cortisol, with lesser concentrations in pigs on the 1% PFO diet. Plasma corticosteroid-binding globulin (CBG) concentrations were not different between treatment groups but were lesser (P < 0.001) on d 1 and 3 when compared to d 0. The resultant free cortisol index [FCI (cortisol/ CBG)] was lesser (P = 0.02) on d 1 and 3 for pigs from the 1% treatment group compared to the controls. An ex vivo lipopolysaccharide (LPS) challenge of whole blood collected on d 0 and 1 was used to determine if 1% PFO attenuated release of inflammatory cytokines (IL-1β, IL-6, and TNF-α). Pigs from the 1% PFO treatment group tended (P = 0.098) to have a lesser mean concentrations of TNF-α in response to LPS compared to controls. These results suggest that providing a PFO supplement as 1% of the diet to sows beginning in late gestation and during lactation can increase the n-3:n-6 PUFA ratio in their offspring, which may improve growth and reduce the acute physiological stress response in the pigs postweaning. [ABSTRACT FROM AUTHOR] more...

An experiment was performed to examine effects of exogenous porcine somatotropin (S) on physiological measures of health and well-being in weaned pigs with or without subsequent transport (T). We hypothesized that S may abrogate stress-related decreases in health and well-being in recently weaned and transported pigs. On d 17 of lactation pigs were were weighed and assigned to treatment groups (n=8/group): NS-NT (vehicle injection, no transport), S-NT (S injection, no transport), NS-T (vehicle injection, transport at weaning), and S-T (S injection, transport at weaning). Upon allocation, all pigs received daily intramuscular injections containing S (0.5 mg/kg) or vehicle for 5 d. On d 21, a blood sample was drawn immediately prior to injection (0800 h). At 1200 h on d 21, pigs were weighed and blood was collected. Pigs in the NT groups were then weaned into mixed nursery pens while pigs in the T groups were mixed and transported by truck for 3 h before being brought back to the nursery. All weaned pigs were fed a standard nursery diet. Blood samples and body weights were taken on d 22, 29 and 37. Data were analyzed by a mixed model procedure with a factorial design and repeated measures. Transport resulted in lower body weights (P<0.05) at all time points post-weaning, and weight gain within the 14-d window postweaning was less in T pigs (P=0.05). Transport increased circulating neutrophil numbers and overall white cell count (P<0.05). An S*Time interaction was observed (P<.05) such that S caused a sharp increase in circulating neutrophils 4 h after injection; however, neutrophil count returned to control levels within 24 h. Elevated concentrations of circulating cortisol were noted in all groups on d 22 (the morning after weaning; P<.0001). On d 22, a Time*S*T interaction was observed (P=0.05) such that cortisol was higher in S-NT and NS-T than in NS-NT pigs, with S-T pigs not different than NS-NT pigs. We conclude that treatment with S altered immune and hormonal profiles in weanling pigs but was not effective in abrogating the weight loss observed in transported pigs. [ABSTRACT FROM AUTHOR] more...

Exposing pregnant mammals to prenatal stress has been shown to alter the stress response of their resulting offspring. Research in rodents has shown that prenatal stress can modify aspects of gender behavior and morphology. Ano-genital distance is the distance between the anus and genital area. A decrease in ano-genital distance in males indicates a decrease in masculinization. Our objective was to determine if prenatal stress altered the ano-genital distance and pituitary gland of piglets. Sow treatments consisted of i.v. injections of adrenocorticotrophin (1 IU/kg BW) (ACTH, n=11), exposure to rough handling for a 10-min duration (RH, n=13), or no treatment (CONT, n=13) once a week during d 42 to d 77 of gestation. Ano-genital distance (a ratio of body length:ano-genital distance) was measured after birth in all male piglets. One male piglet per dam was sacrificed at 2-mo of age and the pituitary gland was collected for immunocytochemistry for analysis of growth hormone. Data were analyzed using the GLM procedures of SAS. Male piglets born to dams who received ACTH had a larger ano-genital ratio (a smaller ano-genital distance) compared to piglets from the roughly handled sows or the control sows (P < 0.0001; 2.01 ± 0.03; 1.91 ± 0.3; 1.87± 0.02 respectively). There were no differences (P > 0.10) among treatment groups in the number of immuno-positive cells for growth hormone in the pituitary gland. Adjusted weaning weight was found to be greater for pigs born to the CONT and RH handled sows as compared to piglets from sows who received ACTH (P < 0.05). These data indicate that prenatal stress may decrease masculinization during development and possibly decrease reproductive success later in life. The weight differences in the ACTH group at weaning may be due to the high level of prenatal stress activated by the ACTH injections. The differences in weight may imply that an increase in prenatal stress (ACTH) alters pre-weaning weight gain; however, a 2-mo period appears to be sufficient for the quantity of pituitary cells positive for growth hormone to recover from stress. [ABSTRACT FROM AUTHOR] more...

Adrenal responsiveness was tested in nonpregnant, lactating Holstein dairy cows fed diets supplemented with OmniGen-AF (OG; Phibro Animal Health Corp., Teaneck, NJ), an immune modulator, and in nonsupplemented control (CON) cows following bolus infusions of a combination of corticotropin-releasing hormone (CRH; 0.3 µg/kg of BW) and arginine vasopressin (VP; 1.0 µg/kg of BW) or ACTH (0.1 IU/kg of BW) in 2 environments: thermoneutral [TN; temperature-humidity index (THI) <60] for 24 h/d and heat stress (HS; THI >68 for 17 h/d). Cows (506) were initially fed OG (n = 254) or CON (n = 252) diets for 44 d before selection of a subgroup of cows (n = 12; 6 OG, 6 CON) for the study. The 2 subgroups were balanced for parity, milk yield, and days in milk. All cows were transported to and housed in 2 environmentally controlled rooms at the University of Arizona Agricultural Research Complex (Tucson). Cows were given 3 d to acclimate to the rooms and then underwent 12 d of TN conditions and then 8 d of HS conditions for a total of 24 d on experiment. Cows were infused with CRH-VP on d 9 of TN and on d 1 of HS and with ACTH on d 10 of TN and on d 2 of HS. Hormone infusions took place at 1000 h (0 h) on each infusion day. Blood samples, taken in 30-min intervals, were first collected at 0800 h (-2 h) and were drawn until 1800 h (8 h). Before infusion, serum progesterone was elevated in OG cows compared with CON cows. Infusion of releasing factors (CRH-VP or ACTH) caused increases in serum cortisol and progesterone, but cortisol release was greater in CON cows than in OG cows during HS, whereas progesterone did not differ between the 2 treatments. Serum ACTH increased following infusion of releasing factors, but this increase was greater following CRH-VP infusion than ACTH infusion. Serum bovine corticosteroid-binding globulin also increased following infusion of releasing factors in both treatment groups, but this increase was greater during HS in cows fed OG. The free cortisol index (FCI) increased following CRH-VP and ACTH and was higher in HS than in TN for both OG and CON cows. However, the FCI response was blunted in OG cows compared with CON cows during HS. Heat stress enhanced the adrenal response to releasing factors. Additionally, the adrenal cortisol and FCI response to releasing factors was reduced during acute heat stress in cows fed OG. Collectively, these data suggest that OG supplementation reduced the adrenal responsiveness to factors regulating cortisol secretion during acute HS., (Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.) more...

The aim of this study was to examine relationships among temperament, endocrinology, and reproductive parameters of bulls enrolled in an 84-day performance test. Angus bulls (n = 60) were housed in six pens grouped by age and weight. Pen scores (PS; 1 = docile to 5 = very aggressive) were assigned on Days -1, 27, 55, and 83 of the performance test. On the following day, blood and hair samples were collected, and body weight (BW) and exit velocity (EV) were recorded. Bulls were split into two categories based on; Day -1 PS (PScalm = PS 1 or 2; PSexcitable = PS 3 or 4) and Day 0 EV (EVcalm = slowest 20 bulls; EVexcitable = fastest 20 bulls). Cortisol and testosterone concentrations in serum and hair did not differ (P > 0.10) between PS or EV temperament categories. Sampling day differences (P < 0.01) occurred for serum testosterone, hair cortisol, and hair testosterone concentration; however, serum cortisol concentration did not differ (P > 0.10) over the sampling days. Serum testosterone concentration increased (P < 0.01) from Day 0 to 28, decreased from Day 28 to 56, but Day 84 did not differ from Day 0, 28, or 56. Hair cortisol concentration was greatest (P < 0.01) on Day 0, decreased from Day 28 to 56 but did not differ from Day 56 to 84. Hair testosterone concentration was greatest (P < 0.01) on Day 0 and remained constant from Day 28 to 84. Bulls categorized as PScalm had a greater (P < 0.01) percentage of normal sperm and secondary defects (P < 0.01) when compared with PSexcitable bulls. However, EVcalm bulls had fewer (P < 0.01) primary defects but more (P < 0.01) secondary defects than EVexcitable bulls. In conclusion, bulls exhibited physiological evidence of acclimation during the test as indicated by a reduction in hair cortisol concentration. In addition, the ability of the bulls to acclimate while residing at the testing center may have contributed to little differences observed during the breeding soundness examination portion of the performance test., (Copyright © 2016 Elsevier Inc. All rights reserved.) more...

Syndyphalin-33 (SD-33) increases feed intake in sheep and recently weaned pigs. To assess the effects of SD-33 on hypothalamic gene expression, hypothalami were collected from unweaned pigs (n=19; 21±3 d of age) on day 0. Remaining pigs received an intramuscular injection of 0.5 μmole/kg SD-33 (SD) or saline (VEH) and weaned into individual pens. On days 1, 4, and 7 after weaning, hypothalami were collected from subsets of pigs (n=8 or 9) within each treatment group. Expression of μ-opioid receptor (MOR) was less in SD pigs than in VEH pigs on day 1 and day 4, suggesting down-regulation of the receptor by SD-33. Expression of hypothalamic melanocortin 4 receptor (MC4R) at 1 d after weaning was increased in VEH pigs (but not SD pigs) relative to levels before weaning. Expression of AGRP was not significantly altered by weaning or treatment at 1 d after weaning. At 4 d after weaning, expression of AGRP was greater in SD pigs than in VEH pigs, but at day 7 expression was less in SD pigs than in VEH pigs. A strong positive correlation was noted between expression levels of MOR and MC4R across treatment and time. Treatment with SD-33 appeared to partially abrogate the effects of weaning on expression of two key appetite-regulating genes within 24 h. Effects of SD-33 appear to be mediated at least in part by the μ-opioid receptor and include actions on the melanocortinergic pathway., (Copyright © 2011 Elsevier Inc. All rights reserved.) more...

The objectives of this study were to develop an assay for the direct measure of porcine corticosteroid-binding globulin (pCBG) and to confirm age-related changes in plasma pCBG concentration. Isolation and purification of pCBG from plasma was performed by affinity chromatography and HPLC-DEAE anion exchange techniques. Analysis by SDS-PAGE revealed two polypeptides (54 and 59 kDa) having similar amino acid homology (>50%) to previously reported sequences of seven mammalian species for the first 33 amino acids. Porcine CBG (20 ng/well) was immobilized to microtiter plates and standards or samples added along with rabbit antiserum developed against the purified pCBG. Goat anti-rabbit IgG-alkaline phosphatase conjugate was added followed by p-NPP substrate. The resultant color development was read at 405 nm. Intra- and interassay coefficients of variation (n=26) of a pooled sample were 10 and 15%, respectively. Age-related changes (P<0.001) in plasma pCBG concentration (n=203) from day 3 through 168 of age confirmed that, in the pig, changes seen in the percent distribution of cortisol among protein bound and free forms around day 28 of age are associated with an increase in CBG concentration. more...

The objective of the present study was to evaluate the potential immunological benefit of adding menhaden fish oil to the diet of weaned pigs. Twenty-four crossbred male pigs were weaned at approximately 18 days of age and placed on a complex nursery diet containing 30% lactose and 7% plasma protein with 6% corn oil as the fat source (Cont, n=12) or with 5% menhaden fish oil and 1% corn oil as the fat source (MFO, n=12) for a period of 15 days. Body weights did not differ (P>0.78) between dietary groups either at the beginning or end of the 15 days feeding period. On day 15, all pigs were non-surgically fitted with an indwelling jugular catheter. On d 16, pigs received an i.v. injection of either saline (n=6/dietary group) or lipopolysaccharide (LPS; 150 microg/kg body weight; n=6/dietary group) and blood samples were collected at 30 min intervals for a period of 5h. Serum was harvested and stored at -80 degrees C for analysis of cortisol (CS), corticosteroid-binding globulin (CBG), tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). There was no significant effect of diet on basal concentrations (Time 0) of any of the blood parameters analyzed. A Time x Treatment x Diet interaction (P<0.03) was observed for serum CS such that those pigs which consumed the MFO diet followed by LPS treatment had a reduced CS response as compared to the LPS-treated pigs on the Cont diet. A Time x Treatment interaction (P<0.01) was observed for serum CBG such that LPS treatment reduced circulating CBG as compared to the saline-treated pigs. Time x Treatment x Diet interactions were also observed for serum concentrations of TNF-alpha (P=0.084) and IFN-gamma (P=0.022) such that both the TNF-alpha and IFN-gamma response to the LPS challenge was lower in those pigs receiving the MFO diet as compared to the LPS-treated pigs on the Cont diet. Overall, serum CS was negatively correlated with the CBG response (r=-0.40, P<0.001), however, the strongest negative correlation was observed in the LPS-treated pigs which consumed the MFO diet (r=-0.63, P<0.001). While further studies are needed to evaluate the immunological response of including MFO in the nursery pig diet, the present study demonstrates that supplementation with MFO does indeed alter the immunological response to an LPS challenge. more...

The purpose of this study was to develop a porcine CBG cDNA probe in order to examine the porcine CBG mRNA expression in major tissues from the postnatal pig. The reverse transcriptase-polymerase chain reaction (RT-PCR) was conducted to develop the porcine CBG cDNA probe using total RNA extracted from liver of 40-day-old pig. The RT-PCR product was subcloned into the pGEM vector (Promega, Madison, WI) and subjected to restriction enzyme treatments and DNA sequencing. Northern blot analysis was conducted using total RNA extracted from samples (approximately 200 mg) of liver, lung, kidney, and whole adrenal tissue that were collected from pigs on day 3 (n = 2) or day 40 (n = 2) postpartum. A 500 bp partial porcine CBG cDNA encoded 166 amino acids and had 83, 78, and 77% homology to a 494-nucleotide sequence of CBG from sheep, human, and rabbit, respectively. The deduced peptide sequence of the partial porcine CBG showed 77, 62, 60, and 51% homology to sheep, human, rabbit, and rat CBG sequences, respectively. An approximately 1.53 kb CBG mRNA was detected only in the liver tissue. In conclusion, the development of a partial CBG cDNA for swine makes it possible to study the ontogeny and the regulation of CBG synthesis at the molecular level and, based on tissues examined in this study, the liver appears to be the primary source of CBG biosynthesis in the postnatal pig., (Copyright 2002 Elsevier Science Inc.) more...

Thirty-five time-dated pregnant gilts were used to document plasma levels of total and free cortisol, corticosteroid-binding globulin (CBG) binding capacity, and percent distribution of cortisol among protein-bound (CBG and albumin) and free forms in the fetal pig during the last 24 days of gestation. Plasma from fetal pigs on days 110-114 of gestation (gestation length 114 days) had significantly higher levels of total cortisol (p < 0.01), percent albumin-bound and free cortisol (p < 0.10), and free cortisol concentration (p < 0.05) compared to samples on days 90, 100 and 105. Fetal plasma CBG binding capacity increased (p < 0.05) linearly from day 100 to 114. Fetal pigs located in the cervical region of the uterus had lower (p < 0.05) total and free cortisol and higher (p < 0.05) albumin and total protein concentrations compared to fetuses in the middle and oviductal regions. Total, percent free and free cortisol concentrations in maternal plasma on days 105-114 were greater (p < 0.10) than that measured on days 12-100 of gestation. These results suggest that the developmental patterns of plasma cortisol and CBG in the prenatal pig are directly related and highly similar to those of another precocious species, the sheep. more...