The aim of this study was to evaluate stress responses evoked by 2 alternative methods for performing the following processing procedures: 1) teeth resection-clipping vs. grinding; 2) tail docking-cold vs. hot clipping; 3) identification-ear notch vs. tag; 4) iron administration-injection vs. oral; 5) castration-cords cut vs. torn. Eight to 10 litters of 8-, 2-, and 3-d-old piglets were assigned to each procedure. Within each litter, 2 piglets were assigned to 1 of 4 possible procedures: the 2 alternative methods, a sham procedure, and a sham procedure plus blood sampling. Blood was sampled before processing and at 45 min, 4 h, 48 h, 1 wk, and 2 wk postprocedure and assayed for cortisol and beta-endorphin. Procedures were videotaped and analyzed to evaluate the time taken to perform the procedure and the number of squeals, grunts, and escape attempts. Vocalizations were analyzed to determine mean and peak frequencies and duration. Piglets were weighed before the procedure and at 24 h, 48 h, 1 wk, and 2 wk afterward. Lesions were scored on a scale of 0 to 5 on pigs in the identification, tail docking, and castration treatments at 24 h, 1 wk, and 2 wk postprocedure. For teeth resection, grinding took longer than clipping and resulted in greater cortisol concentration overall, poorer growth rates, and longer vocalizations compared with pigs in the control treatment (P<0.05). For tail docking, hot clipping took longer, and hot-clipped piglets grew slower than cold-clipped piglets (P<0.05). Hot clipping also resulted in longer and higher frequency squealing compared with pigs in the control treatment (P<0.01). For identification, ear notching took longer than tagging, and ear-notched piglets had worse wound scores than tagged piglets (P<0.05). Cortisol concentrations at 4 h also tended to be greater for ear-notched piglets (P<0.10). Ear notching evoked calls with higher peak frequencies than the control treatments. For iron administration, oral delivery took numerically longer than injecting, but there were no significant differences between injecting and oral delivery for any of the measures. For castration, tearing took longer than cutting the cords (P<0.05), but beta-endorphin concentrations at 45 min postprocedure were greater for cut piglets. When measures of behavior, physiology, and productivity were used, the responses to teeth resection, tail docking, and identification were shown to be altered by the procedural method, whereas responses to iron administration and castration did not differ. The time taken to carry out the procedure would appear to be an important factor in the strength of the stress response.

After birth, piglets undergo procedures likely to cause stress. The aim of this study was to evaluate stress responses evoked by 2 combinations (More Stressful [all a] or Less Stressful [all a] or More Stressful [all b]) of alternative methods for performing the following processing procedures: 1) teeth resection (TR) – [a] clip vs. [b] grind; 2) identification (ID) – [a] ear tag vs. [b] ear notch; 3)iron administration (FE) – [a] inject vs. [b] oral; 4) castration (CA) – [a] cords cut vs. [b] cords torn; 5) taildocking (TD) – [a] cold clip vs. [b] hot clip [corrected]. Ten litters of eight 2- and 3-d-old piglets were assigned to each procedure. Within each litter 1 male and 1 female piglet was assigned to 1 of 4 possible procedures: the 2 combinations, sham procedures, and sham procedures plus blood sampling. Blood was collected before processing and at 45 min, 4 h, 48 h, 1 wk, and 2 wk afterward and assayed for cortisol and β-endorphin concentrations. Procedures were videotaped and analyzed to evaluate the time taken to perform the procedure and the number of squeals, grunts, and escape attempts. Vocalizations were analyzed to determine mean and peak frequencies and duration. Piglets were weighed before the procedure and at 24 h, 48 h, 1 wk, and 2 wk afterward. Identification, tail docking, and castration lesions were scored on a 0 to 5 scale at 24 h, 1 wk, and 2 wk postprocedure. Both combinations of methods took longer to carry out than sham procedures and resulted in more squeals, grunts, and escape attempts during the procedures and higher peak frequencies of vocalizations compared with the control treatments (P < 0.05). Cortisol concentrations 45 min after processing were also higher in the 2 combination treatments than in the sham treatments (P < 0.05). Comparing between procedure treatments, the More Stressful combination of methods took longer to carry out, resulted in higher β-endorphin concentrations at 1 wk, had higher peak frequency of vocalizations, and increased ear (P < 0.05) and tail wound (P < 0.1) lesion scores at 1 wk than the Less Stressful combination. Growth during d 2 to 7 postprocedure was lower in More Stressful piglets than control piglets (P < 0.05) but by 2 wk, growth was unaffected. Using measures of behavior, physiology, and productivity, the More Stressful combination of procedures decreased welfare relative to the Less Stressful combination; however, both combinations decreased welfare relative to controls. The time taken to carry out the procedure would appear to be an important factor in the strength of the stress response.

Lameness in breeding-age gilts and sows is a major cause of culling, resulting in increased economic losses and welfare concerns. This study determined if exercise during gestation would affect the musculo-skeletal system, production variables, and behavior. Gilts were blocked by BW and assigned to 1 of 3 treatment groups: control (n = 10; no exercise), low exercise (n = 14; 122 m/d for 5 d/wk), and high exercise (n = 14; 122 m/d for 2 d/wk and 427 m/d for 3 d/wk). All gilts were stall-housed during gestation, and gilts were exercised between d 35 and 110 of gestation. Lameness score, BCS, BW, and blood were taken at multiple points before gestation, and during gestation and lactation. Blood serum was analyzed for carboxy-terminal telopeptide of type I collagen. Sow lying behavior was recorded for 3 d after farrowing. Farrowing data included litter weight and size at birth and weaning, and preweaning mortality. After weaning, 38 sows were slaughtered and muscles and the bones of the left fore- and hind-limbs were harvested. Bone density and quality were determined by computed tomography (CT) scans, dual energy x-ray scans, and bone-breaking force tests. The control group took longer to lie down than both exercise groups, and the low exercise group took longer to lie down than the high exercise group (P < 0.05). The number of pigs weaned was greater in the high exercise group than the control group (P < 0.05). Piglet preweaning mortality was greatest in the control group compared with both exercise groups (P < 0.05). The low exercise treatments exhibited a greater bone density (CT) in the humerus, radius, and tibia compared with that of the control group (P < 0.05). The bone density (CT) of the humerus in the low exercise group was greater than that of the high exercise group (P = 0.03). Breaking force in the humerus and femur was greater (P < 0.05) in the low exercise group than the control group. Breaking force in the tibia of the high exercise group was greater than the control group (P = 0.01). The tibia of both the low and high exercise groups had a greater breaking force (P < 0.05) than the control group. Although there was no benefit of exercise on lameness, differences in bone density and quality, lying behavior, and piglet survivability may provide useful insight into alternative housing for sows.

Sows subjected to prenatal stress have been found to produce offspring that have altered responses to stress. Our objective was to determine if exposing a sow to stress would alter the response of the offspring to lipopolysaccharide (LPS) at 2 mo of age or their response to mixing stress at 4 mo of age. Sow treatments consisted of intravenous injections of ACTH (1 IU/kg of BW), exposure to rough handling for a 10-min duration (rough), or no treatment (control) once per week from d 42 to 77 of gestation. At 2 mo of age, pigs from each treatment, 1 per litter (n = 21, 17, and 15 for the ACTH, rough, and control treatments, respectively), were challenged with 2 μg of LPS/kg of BW or saline, or served as a noninjected control. Their behavioral response to a human approach test and salivary cortisol were measured. At 4 mo of age, 1 pig from each treatment (n = 14, 14, and 15 for the ACTH, rough, and control treatments, respectively) was taken from its home pen and placed in a pen of unfamiliar pigs. At this time, a punch biopsy wound (6 × 6 mm) was created to measure the ability of the pig to heal the wound. At this same time, each pig received a 1-mL intramuscular injection of 20% ovine red blood cells (oRBC), and then a second injection of oRBC at 21 d postmixing. Blood samples were collected 3 times per week for 2 wk and then once a week for 4 more weeks. Blood samples were analyzed for cortisol, porcine corticosteroid-binding globulin, antibody response to oRBC, and nitric oxide production by macrophages. Behavior was recorded during the first 5 d after mixing. All pigs in the LPS challenge responded with characteristic sickness behavior; however, pigs in the rough treatment showed less sickness behavior than those in the other 2 treatments (P < 0.05). Maternal stress treatment did not affect (P < 0.43) salivary cortisol. Pigs from all treatments responded similarly to mixing stress with regard to cortisol, porcine corticosteroid-binding globulin, antibody titers, nitric oxide production, and hematology measures, and all pigs experienced the same amount of aggression in response to mixing. Without altering peripheral measures of stress responsivity, prenatal stress enhanced the ability of pigs to cope with a simulated immune challenge, which could prove to be an adaptation to challenging environments.

Exposing a pregnant sow to stress has been shown to affect the resulting offspring. Our objective was to determine if rough handling of pregnant sows altered the physiology of her offspring and if these alterations were different from an experimentally induced model of prenatal stress. Sow treatments consisted of i.v. injections of ACTH (1 IU/kg of BW), exposure to rough handling for 10 min (Rough), or no treatment (Control) once a week during d 42 to 77 of gestation. To determine the plasma cortisol response to treatments, blood (5 mL) was collected from 30 sows after treatment administration. To conduct the prenatal stress study, a separate group of 56 sows was used in 1 of 4 replicates. At birth, production data were collected for each litter, including birth weight, number born, anogenital distance, and pig viability. At weaning, pigs were blocked by BW and sex, and placed in a nursery pen of 6 pigs, with 2 pigs from each treatment group. To assess the effect of treatments on cortisol, corticosteroid-binding globulin (CBG), and hematological cell profiles, blood was collected every other day for 10 d after weaning. Application of treatments caused plasma cortisol concentrations to be greatest in ACTH sows compared with Control sows (P < 0.001), with Rough sows having intermediate values (P = 0.07). Treatments did not affect the number of pigs born, number of stillborn, or pig viability (P > 0.40). The ratio of cortisol to CBG did not differ between treatments (P = 0.09). Hematological variables did not differ between treatments (P > 0.19). Pigs born to ACTH sows had a smaller anogenital distance compared with controls (P < 0.03), with pigs from Rough sows being intermediate. Our data indicate that swine exposed to prenatal stress (ACTH injection) can have alterations in sexual morphology without effects on growth or the immune cell populations measured in this study.