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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]

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]

Traditionally, molting was initiated by withdrawing feed. However, public criticism of feed deprivation, based on the perception that it inhumanely increases hunger, has led the poultry industry to ban the practice. Thus far, alternatives have not been demonstrated to ameliorate the increase in hunger that led to the ban on inducing molting by feed deprivation. Incorporating melengestrol acetate (MGA), an orally active progestin, into a balanced layer diet induces molting and increases postmolt egg quality. Hy-Line W-98 hens (n = 60) were randomly assigned to a balanced layer ration (control), a balanced layer ration containing MGA, or a 94% wheat middlings diet (wheat) for 20 d, or were feed deprived for 8 d. Hens were trained to peck a switch to receive a feed reward based on a progressive ratio reinforcement schedule. Motivation of hens to acquire feed was measured as the total number of pecks recorded in 15 mm on d 0, 4, 8, 12, 16, and 20. On d 20, abdominal fat pad and digesta-free gizzards were weighed. The number of pecks in the feed-deprived group was greater than controls by d 4 and remained greater at d 8, when these hens were removed from the experiment. Hens in the wheat group that were rewarded with a layer diet pecked more than controls from d 8 to 20. Hens in the MGA group pecked for a reward at the same rate as control hens throughout the experiment. Hens fed the wheat diet had heavier gizzards compared with control and MGA-fed hens. Hens fed MGA had greater abdominal fat pad compared with wheat and control hens. Hens molted using a diet containing MGA have a similar motivation to obtain feed as control hens; therefore, this alternative does not appear to increase hunger. However, hens molted with a wheat middling diet appear to be as motivated to obtain feed as did the feed-deprived hens. [ABSTRACT FROM AUTHOR]

Cattle are exposed to growth hormone stimulants and to stressors that cause cortisol release. Both of these hormones affect immune responses which may reduce disease resistance. Toll-like receptors are the pattern recognition molecules of pathogens that are on immune cells. They then orchestrate the induction of the appropriate acute phase cytokines of the early innate response. The objective of this study was to determine changes in toll-like receptors and acute phase cytokines following treatment with a synthetic glucocorticoid (dexamethasone) and growth hormone (GH). Twenty-eight calves were given the control (Cnt), dexamethasone (DEX), GH, or dexamethasone and GH (Both) treatments from 3 until 56 days of age. Blood was collected by jugular venipuncture on days 14, 28, 42, and 56. On day 56, a lung lavage was performed and spleen and thymus tissues collected. Total RNA was extracted from blood leukocytes, lung lavage cells, spleen and thymus cells. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to quantify interleukin-1 (IL-1), IL-1 receptor antagonist (IL-1Ra), tumor necrosis factor (TNF)-alpha, toll-like receptor 2 (TLR2), and toll-like receptor 4 (TLR4). Blood leukocytes had a time effect for IL-1Ra (P < 0.01), with a trend for a treatment effect (P = 0.07) and had a treatment by time interaction (P < 0.05). IL-1, TNF, and TLR2 and TLR4 were greatest (P < 0.05) for Cnt only at day 14. IL-1 expression of lung lavage cells was greatest (P < 0.05) for calves on the Both treatment compared to the other three treatments. However, IL-1Ra was not different among the treatments. Toll-like receptor 2 expression was enhanced with Both compared to either DEX (P < 0.05) or GH (P < 0.05) and tended to be greater than Cnt expression (P = 0.07). Expression of TLR4 tended to be reduced by Both compared to Cnt (P = 0.06). Tumor necrosis factor-alpha was greatly enhanced by Both compared to the other three treatments (P < 0.05). Spleen cell tended to have different IL-1 expression between GH and Both (P < 0.10). Interleukin-1 receptor antagonist and TLR2 and TLR4 were not different among treatments. However, TNF-alpha expression was enhanced by the DEX treatment alone compared to the GH treatment (P < 0.05), and tended (P < 0.10) to be greater than Cnt expression. None of the gene expressions were different among treatments for thymus cells. Lung lavage cell expression appears to be most susceptible to these hormones while blood leukocyte expression was only slightly affected, and thymus cells were not affected at all. These data demonstrate that TLR2 and TLR4 and acute phase cytokine expression can be altered by stress and growth hormones, which may decrease resistance of those animals to disease.