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Improving piglet survivability rates is of high priority for swine production as well as for piglet well-being. Dysfunction in the serotonin (5-HT) system has been associated with growth deficiencies, infant mortalities, or failure to thrive in human infants. The aim of this research was to determine if a relationship exists between infant mortality and failure to thrive (or unthriftiness), and umbilical 5-HT concentration in piglets. Umbilical blood was collected from a total of 60 piglets from 15 litters for analysis of 5-HT and tryptophan (Trp; the AA precursor to 5-HT) concentrations. Behavior was scan sampled for the first 2 days after birth. Brain samples were also taken at 8 h after birth from healthy and unthrifty piglets (n = 4/ group). The raphe nucleus was dissected out and analyzed for 5-HT and dopamine concentrations as well as their major metabolites 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA), respectively. Data were analyzed by ANOVA. Piglets that died within 48 h of birth (n = 14) had significantly lower umbilical blood 5-HT concentrations at the time of their birth compared to their healthy counterparts (n = 46, P = 0.003). However, no difference in Trp was detected (P 0.38). Time spent under the heat lamp and sleeping were positively correlated with umbilical 5-HT levels (P - 0.004 and P = 0.02, respectively), while inactivity had a negative correlation with 5-HT levels (P = 0.04). In the raphe nucleus, the center for brain 5-HT biosynthesis, unthrifty piglets had a greater concentration of 5-HIAA (P = 0.02) and a trend for higher concentrations of 5-HT (P = 0.07) compared with healthy piglets. Dopamine levels did not differ between thrifty and unthrifty piglets (P = 0.45); however, its metabolite HVA tended to be greater in unthrifty piglets (P = 0.05). Our results show evidence of serotonergic dysfunction, at both the central and peripheral levels, accompanying early piglet mortalities. These data suggest a possible route for intervention, via the 5-HT system, to improve piglet survivability. However, further research is required to validate this hypothesis. [ABSTRACT FROM AUTHOR]

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 b]) of alternative methods for performing 1) teeth resection: [a] clip vs. [b] grind, 2) identification: [a] ear tag vs. [b] ear notch, 3) iron administration: [a] inject vs. [b] oral, 4) castration: [a] cords cut vs. [b] cords torn, and 5) tail docking (TD): [a] cold clip vs. [b] hot clip. 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, grants, 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 (Z3 <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. [ABSTRACT FROM AUTHOR]

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 mm, 4 h, 48 h, 1 wk, and 2 wk postprocedure and assayed for cortisol and ~3-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 f3-endorphin concentrations at 45 mm 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. [ABSTRACT FROM AUTHOR]

The effects of piglet processing procedures on behavior, growth and cortisol. Soon after birth, piglets undergo procedures that are a likely source of stress. Our aim was to evaluate stress responses evoked by two alternative methods for performing the following processing procedures: 1) teeth resection (TR) - clip vs. grind; 2) tail-docking (TD) - cold- vs. hot-clip; 3) identification (ID) - ear notch vs. tag; 4) iron administration (FE) - inject vs. oral; 5) castration (CA) - cords cut vs. torn. Ten litters of eight 2-3 day-old piglets were assigned to each procedure. Within each litter a male and a female piglet were assigned to one of 4 possible procedures: the two alternative methods, a sham procedure, and a sham procedure plus blood sampling. Piglets were balanced for weight. Blood was sampled before processing and at 45 min, 4h, 48h, 1wk, and 2wks post-procedure and assayed for cortisol. Procedures were video-taped and analyzed to evaluate time taken to perform the procedure and the number of squeals, grunts and escape attempts exhibited. Piglets were weighed before the procedure and at 24h, 48h, 1wk and 2wks afterwards. Lesions were scored on a 0 to 5 scale on ID, TD and CA pigs at 24h, 1 wk and 2wks post-procedure. Statistical analysis was performed using Proc GLM of SAS. For TR, grinding took about 20s longer than clipping and resulted in higher cortisol levels overall, poorer growth rates and more escape attempts (P < 0.05). For TD, hot clipping took longer (P < 0.05) and resulted in more squealing (P < 0.001). For FE, oral delivery took longer and resulted in more squealing (P < 0.05). For ID, notching took longer, resulted in higher lesion scores (P < 0.05), more squealing (P < 0.001), more escape attempts (P < 0.01) and tended to result in higher cortisol concentrations (P < 0.1). For CA, tearing took longer and resulted in more squealing and escape attempts (P < 0.05). In general, procedures which took longer to perform resulted in the occurrence of more pronounced stress-related responses. [ABSTRACT FROM AUTHOR]