Search

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 search for alternative methods to euthanize piglets is critical to address public concern that current methods are not optimal. Scientific evidence supports that blunt force trauma is humane when performed correctly, but most people find it visually difficult to accept. The use of C09 is often recommended; at the same time, it is criticized as being aversive to pigs. This research sought to 1) identify a method of scientifically determining if piglets find a gas aversive, using an approach-avoidance test, which relies on the perspective of the piglet, and 2) test different gas mixtures to determine if they are effective and humane for neonatal piglet euthanasia. Pigs were allowed to walk freely between 1 chamber filled with air and another chamber either gradually filled with gas mixtures (Exp. 1) or prefilled with gas mixtures (Exp. 2). Experiment 1 tested C02 (90%) and air (10%), N20 (60%) and CO, (30%), Ar (60%) and C02 (30%), and N2 (60%) and C02 (30%). Because piglets had to be removed when they started to flail, the test was shortest (P <0.01) for the pigs in the C02 treatment compared with pigs in the N2O/C02, Ar/CO2, and N2/C02 treatments, 3.1 ± 0.2, 8.5 ± 0.6, 9.6 ± 0.4, and 9.9 ± 0.1 min, respectively. Nonetheless, all gas mixtures adversely affected the pigs, causing the pigs to leave the test chamber. In Exp. 2, piglets were allowed to enter a chamber prefilled with N2/C02 orN2O/C02 (both 60/30%). Pigs exposed to the prefill chambers started to flail in fewer than 20 s, much faster in comparison with the gradual fill method, which supports that this method was more aversive. In Exp. 3, piglets were euthanized using a 2-step procedure. Pigs were first placed in a gradual fill chamber with 1 of 4 gas mixtures: 90% C02, N2/C02, N2O/C02, orN2O/02 (the last 3 mixtures at 60/30%) followed by placement into a 90% CO? prefill chamber when the pigs started to flail or were anesthetized. All 3 gas treatments that contained C02 killed pigs more quickly than N2O/02 (P < 0.05). However, N2O/02 was the only treatment that anesthetized the pigs instead of causing squeals or flailing although requiring about 12 min longer. Although longer, a 2-step procedure in which pigs are anesthetized with a mixture of N2O and 02 before being euthanized by immersion in C02 may prove to be more humane than CO2 alone. [ABSTRACT FROM AUTHOR]

A pure form of salbutamol has the poten-tial to deliver positive production benefits to the swine industry. The aim of this experiment was to determine the effects of salbutamol on growth, carcass measures, and health of finishing pigs. The study used 192 pigs (89 ± 1 kg BW) housed in groups of 6 in 32 pens and assigned to 1 of 4 treatments: 1) control (CTL), 0 mg/kg salbutamol; 2) 2R, control diet with 2 mg/kg of the pure R-enantiomer of salbutamol; 3) 4R, control diet with 4 mg/kg of pure R-salbutamol; or 4) 8RS, control diet with 8 mg/kg of a 50:50 mixture of the R- and S-enan-tiomers. All diets were offered ad libitum for 4 wk. All pigs were weighed and pen feed intakes were recorded weekly. At slaughter, individual HCW and measure-ments of the lOth-rib loin muscle area (LMA), color, marbling, firmness, and back fat, last lumbar, and mid-line back fat depths were collected. Data were analyzed using Proc GLM of SAS, with pen as the experimental unit. Overall, 2R and 4R pigs had greater ADG than CTL pigs (P < 0.05) and, at slaughter, were heavier than CTL pigs (P < 0.01). Overall, 8RS pigs had decreased ADFI {P < 0.05), and CTL pigs had poorer G:F (P < 0.001) than the other 3 treatments. All salbutamol-fed pigs had 5 to 6 kg greater HCW (P < 0.001), 2% to 3% increased carcass yield (P < 0.001), 5.6 cm2 larger LMA CP < 0.01), 3 to 4 mm less lOth-rib back fat (P < 0.01), and 2 mm less lumbar back fat (P < 0.05) than CTL pigs. However, control pigs had greater loin muscle color scores (P < 0.05) and marbling scores (P < 0.001) than all salbutamol-treated pigs. Taken together, these data indicate that as little as 2 mg/kg R-salbutamol has a positive effect on pig growth and carcass composition. However, the effects of salbutamol on meat quality re-quire further research. [ABSTRACT FROM AUTHOR]

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. [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]

Lameness in breeding-age guts 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. [ABSTRACT FROM AUTHOR]

Salbutamol has potential for use as a repartioning agent in swine. The aims of this experiment were to determine effects of salbutamol on behavior and physiology of finishing pigs. The study used 192 pigs (88.8 ± 0.9 kg of BW) housed in groups of 6 in 32 pens and assigned to 1 of 4 treatments: 1) control—0 mg/kg of salbutamol, 2) 2R—control diet with 2 mg/kg of the pure R-enantiomer of salbutamol, 3) 4R—control diet with 4 mg/kg of pure R-salbutamol, or 4) 8RS—control diet with 8 mg/kg of a 50:50 mixture of the R- and S-enantiomers. All diets were offered ad libitum for 4 wk. Salbutamol diets were replaced with control diets 24 to 48 h before slaughter. Behavioral responses to handling during weighing were recorded immediately before assignment to the treatments (wk 0) and at weekly intervals over the next 4-wk period. Behavioral and heart rate (HR) responses to a 10-min human presence test in the home pen were measured during wk 0, wk 1, and wk 3. Heart rate responses to a 36-min transportation were recorded. One pig from each pen had blood collected 4 times: during wk 0, 2, 4, and at exsanguination. Blood was analyzed for NEFA, creatine kinase, glucose, lactate, blood urea nitrogen, ammonia, insulin, cortisol, norepinephrine, and epinephrine. Data were analyzed using PROC GLM of SAS, with pen as the experimental unit. Treatment had no effect on time spent lying laterally, overall activity, or time spent alert. Treatment had no effect on handling measures (P> 0.05) or on behavioral responses to human presence (P> 0.05), with all pigs willing to spend similar amounts of time close to and touch- ing the human. However, during the human presence test in wk 1 and wk 3, control pigs had HR around 10 peats per minute less (P < 0.05) than pigs in the other 3 treatments. During transport, overall HR were similar across treatments (P> 0.05). However, at certain 1-min time points, control pigs had greater HR than salbutamol-treated pigs (P < 0.05). There were no treatment differences in lactate, epinephrine, or norepinephrine concentrations at any point. During wk 4, control pigs had less creatine kinase (P < 0.02) and greater blood urea nitrogen (P< 0.005) compared with pigs fed all the salbutamol treatments. The home pen behavior, handling, human presence test, and transport results indicate that salbutamol-treated pigs do not show marked differences in home pen time budgets and behavioral and HR responses to handling and transportation compared with control pigs. Thus, salbutamol did not have a negative effect on finishing pig well-being during this study. [ABSTRACT FROM AUTHOR]

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 lU/kg of BW), exposure to rough handling for 10 mm (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. [ABSTRACT FROM AUTHOR]

Pig processing procedures can cause distress to pigs. Alternatives exist for each procedure, thus our objective was to compare a combination of five different procedures. Least aversive procedures compared to the most aversive procedures were determined by previous research. Comparisons were made between processing pigs with the 'most' aversive methods (Most): teeth grinding, tail docking with a hot iron, oral administration of iron, ear notching, and castration with cord tearing, as compared to the 'least' aversive methods (Least): teeth clipping, tail docking with a cold iron, injection of iron, ear tagging, and castration with cord cutting. Two control groups were included, one which was blood sampled (Control) and another that served merely as a behavioral control and was not blood sampled or processed but was handled. A total of 8 pigs from each of 10 litters were used - one male and one female pig per treatment. Body weights were recorded prior to bleeding, at 24 h, 1 wk and 2 wk relative to application of treatments and blood was collected at 0 h, .75 h, 4 h, 48 h, 1 wk, and 2 wk in order to measure plasma cortisol. Behavioral data were collected to record escape attempts, squeals, and grunts. Body weight did not differ between treatments (P > 0.10). Females did not differ in their plasma cortisol response to processing (P > 0.10). In contrast, male pigs in both the Most and Least treatments exhibited elevated plasma cortisol at .75 h after processing as compared to Control pigs (P < 0.0001). Pigs in the Most treatment performed more squeals as compared to the Least (P < 0.01) and the two control treatments (P < 0.001). Pigs in the Least treatment performed more squeals than in the two control treatments (P < 0.07). However, when adjusted for the amount of time required to perform the two treatments, no treatment differences were noted (P > 0.10). These data indicate that both the Most and Least processing approaches reported in this study result robust stress responses as measured by plasma cortisol. In addition, the time required to perform procedures contributes significantly to the stress experienced by the pigs. [ABSTRACT FROM AUTHOR]

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]

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]