Physiological and economic benefits of abandoning invasive surgical procedures and enhancing animal welfare in swine production

Investigating hair cortisol dynamics in German Shepherd Dogs throughout pregnancy, lactation, and weaning phases, and its potential impact on the hair cortisol of offspring

Pregnancy, lactation, and weaning are crucial physiological stages in the life of bitches, directly affecting the physiological health of bitches and the growth and development of newborn puppies. This study aims to investigate the physiological stress of bitches during pregnancy, lactation, and weaning, as well as the effects of these changes on newborn puppies, by analyzing the variations in hair cortisol concentrations (HCCs) of bitches and their newborn offspring during different stages. This study selected 24 female German Shepherd dogs aged 2-3 years who were pregnant and giving birth for the first time and their 118 surviving newborn offspring as experimental subjects. Hair samples were collected from the right shoulder and neck of the bitches and their offspring at four key time points: the day of mating (T0), the day of delivery (T1/NT1), the first day of weaning (T2/NT2), and the 60th day after weaning (T3/NT3). The HCCs was detected by enzyme-linked immunosorbent assay (ELISA) to assess their physiological stress. The results showed that the maternal HCCs significantly increased during pregnancy and lactation, reaching a peak during lactation. The HCCs of puppies also significantly increased during the weaning period. Meanwhile, there was a significant but moderate correlation between the cortisol levels in maternal hair and puppies' hair during pregnancy and lactation. In addition, the maternal HCCs during pregnancy and lactation were affected by the litter size, the higher the litter size, the higher the hair cortisol level, while the cortisol levels in the hair of puppies were not affected by the litter size. Bitches may face higher physiological and psychological pressures during reproduction and nurturing offspring, especially when the litter size is large. At the same time, the physiological status of bitches may have a certain impact on puppies. Therefore, care and attention during pregnancy, lactation, and puppy weaning periods should be strengthened to ensure that bitches and puppies receive good feeding management and environmental support, maintain their physiological and psychological health, and further enhance animal welfare.

Needle-free intradermal vaccination, an opportunity to improve commercial pig welfare

In-farm livestock production vaccinations are commonly delivered intramuscularly using needles. While there are alternative strategies these have been subject to little attention and limited commercialisation. One such alternative is needle-free vaccines and studies have focused on the immune response few have addressed the welfare implications. This study aims to compare the impact of intradermal needle-free vaccination and intramuscular injection in terms of the welfare of the piglets. A total of 179 piglets were divided into two treatments: intradermal needle-free delivery and intramuscular delivery of a vaccine. Measures of health and welfare included, vocalisations, behavioural observations, papule formation, and weight. Piglets vaccinated via the needle-free intradermal route vocalised less and displayed no significant behavioural differences but showed increased weight compared to piglets vaccinated intramuscularly. The use of a needle-free device to deliver a vaccine through an intradermal route revealed no adverse effects on piglet welfare and supports the use of alternative strategies to vaccinate livestock.

Impact of a natural rubber-based scratcher as an environmental enrichment on the scratching behavior, cortisol level, and semen quality of stable male goats

Background and Aim

Goats are valuable livestock because they can generate meat and milk for human consumption. Goat husbandry is becoming more intensive due to the growing demand for goat products, which may impact animal welfare and natural behavior. This study aimed to investigate the impact of natural rubber (para rubber)-based scratchers as an environmental enrichment on scratching behavior, cortisol levels, and semen quality in stable bucks (male goats/goats).

Materials and Methods

Nine male goats were used in this study. Scratching behavior and cortisol levels were used as welfare indicators, whereas semen quality was evaluated as an indicator of reproductive potential. These indicators were analyzed before and after scratcher installation.

Results

After installing the scratchers, the goats showed a significant increase in scratching behavior and a notable decrease in cortisol levels (p < 0.001). Notably, the goats exhibited a marked preference for scratching against the scratcher (p < 0.001) compared to the stable. They significantly preferred using their heads for scratching (p < 0.001) instead of other body parts. In addition, goats preferred to scratch on the softest rubber scratchers at specific installation locations (p < 0.001). Although there was a slight improvement in semen quality, there was no statistically significant difference (p > 0.05).

Conclusion

A natural rubber-based scratcher can increase scratching behavior and reduce cortisol levels, indicating its potential to improve the welfare of farm goats. Selecting an appropriate hardness and preferred location is essential to ensure that the scratcher effectively encourages animals to use it.

Determination of an Acclimation Period for Swine in Biomedical Research

Swine are widely used models in biomedical research due to their physiologic and anatomic similarities to humans. During transport from vendors to research facilities, pigs are subject to a number of stressors, including environmental, social, and stress as a result of deprivation from food and water. As stress can have a number of adverse psychologic and physiologic effects, an acclimation period, defined as the period of time that an animal has to adjust and stabilize in a new environment, is recommended. The literature indicates that swine should be conditioned to their new facility for 5 to 7 d prior to undergoing survival surgery; however, to date, there is no published scientific evidence to support this or any specific acclimation period for swine. To investigate whether a certain length acclimation period leads to decreased stress in swine, we measured 2 stress biomarkers, cortisol and chromogranin A (CgA), from the saliva of 12 naive Yorkshire swine (n = 6 males and 6 females) arriving at our facility for use in research protocols. Noninvasive saliva collection was performed on days 1, 3, 5, 7, 10, and 14 after arrival from the vendor (representing different acclimation periods). We hypothesized that longer acclimation periods would result in reduced levels of both cortisol and CgA, indicating reduced stress. Our data revealed that there was no statistical difference in cortisol levels over time (P = 0.8200), nor between the sexes (P = 0.9886) or individual animals (P = 0.6280). CgA, similarly to cortisol, showed no overall effect of time (P = 0.2017) or sex (P = 0.6598). For this analyte, individual animal was significant (P < 0.0001), which suggests high interanimal variation. Furthermore, there was a significant decrease (P = 0.0077) in salivary CgA from day 1 compared with day 14, suggesting that swine may benefit from an acclimation period of at least 14 d.

GnRH Immunocastration in Male Xizang Sheep: Impacts on Rumen Microbiome and Metabolite Profiles for Enhanced Health and Productivity

Castration is a prevalent and indispensable practice in sheep husbandry, aiding in enhancing meat quality, mitigating aggressive behavior, and managing unwanted reproduction. Nevertheless, the conventional surgical castration procedure poses several challenges, including heightened stress and pain, detrimental impacts on animal welfare, and diminished economic efficacy in farming operations. Consequently, immunocastration methods, serving as substitutes for surgical castration, are progressively finding application in livestock. The rumen, an essential and distinctive digestive and absorptive organ in ruminants, has been associated with enhanced meat quality and productive performance following castration in previous research studies, albeit fewer investigations have explored the potential impacts of GnRH immunization on the rumen's internal milieu in sheep post-de-escalation. Hence, the present study delved into evaluating the impact of GnRH immunocastration on the rumen microbiome and metabolomics in male Xizang sheep. This was achieved through the establishment of a GnRH immunocastration animal model and the collection of rumen fluid for microbiological and comprehensive metabolomics investigations. The outcomes of this investigation unveiled that the impact of GnRH immunocastration on body weight gain was more pronounced during the achievement of the castration objective. In addition, the Firmicutes-to-Bacteroidota ratio in the immune male (IM) group exceeded that of the control group (EM), suggesting that GnRH immunodeficiency may enhance the digestion and absorption of feed in male Xizang sheep. At the taxonomic level, the elevated presence of Prevotella and Quinella bacteria in the IM group compared to the EM group indicated that castration influenced a segment of the rumen microbiota in male Xizang sheep, thereby bolstering the digestive and metabolic efficacy of the rumen concerning nutrient utilization, particularly in the breakdown and absorption of proteins, carbohydrates, and lipids, ultimately expediting the fattening process and weight gain in male Xizang sheep following castration. Moreover, analysis of ruminal fluid metabolomics revealed that GnRH immunization had notable impacts on certain metabolites in the ruminal fluid of male Xizang sheep, with metabolites like 5-hydroxyindole acetic acid and 3-hydroxyindole acetic acid showing significant downregulation in the IM group compared to the EM group, while niacin and tyramine exhibited significant upregulation. These findings indicate a profound influence of GnRH immunization on the maintenance of ruminal equilibrium and ruminal health (including the health of ruminal epithelial cells). This study validates that GnRH immunocastration not only achieves the objectives of castration but also enhances ruminal health in male Xizang sheep, thus laying a foundational theoretical basis for the application and dissemination of GnRH immunocastration technology.

Effect of castration method on porcine skeletal muscle fiber traits and transcriptome profiles

This study examined the effects of immunocastration and surgical castration on the histomorphometric and transcriptome traits of the porcine skeletal muscle. We hypothesized that the differences in duration of androgen deprivation resulting from different castration methods influence skeletal muscle biology in a muscle-specific manner. This was tested by analyzing samples of m. longissimus dorsi (LD) and m. semispinalis capitis (SSC) from immunocastrated (IC; n = 12), entire male (EM; n = 12), and surgically castrated (SC; n = 12) pigs using enzyme/immunohistochemical classification and histomorphometric analysis of myofibers, quantitative PCR, and RNA sequencing. The results confirmed the distinctive histomorphometric profiles of LD and SSC and the castration method related muscle-specific effects at the histomorphometric and transcriptome levels. Long-term androgen deficiency (surgical castration) significantly reduced the proportion of fast-twitch type IIa myofibers in LD (P < 0.05), whereas short-term androgen deprivation (immunocastration) reduced the cross-sectional area of oxidative type I myofibers in SSC (P < 0.05). At the transcriptional level, glycolytic LD adapted to long- and short-term androgen deprivation by upregulating genes controlling myoblast proliferation and differentiation to maintain fiber size. In contrast, increased protein degradation through the ubiquitin ligase-mediated atrophy pathway (significantly increased TRIM63 and FBXO32 expression; P < 0.05) could underly reduced cross-sectional area of type I myofibers in the oxidative SSC in IC. Potential candidate genes (HK2, ARID5B, SERPINE1, and SCD) linked to specific metabolic profiles and meat quality traits were also identified in IC, providing a foundation for studying the effects of immunocastration on skeletal muscle fiber and carcass/meat quality traits.

Non-invasive methods for analysing pig welfare biomarkers

At present, the assessment of pig welfare quality has gained significant importance, prompting the exploration of novel biomarkers for this purpose. Traditionally, these biomarkers have been monitored in the blood; however, blood sampling is considered an invasive procedure. Currently, non-invasive methods for collecting samples are emerging as viable alternatives for assessing these biomarkers. This article aims to present the current knowledge regarding the use of non-invasive methods for analysing pig welfare biomarkers, specifically focusing on the saliva, hair, faeces, and urine as matrices to determine these biomarkers. The saliva analysis encompasses various biomarkers, such as cortisol, alpha-amylase, chromogranin A, the total esterase, oxytocin, acute phase proteins, adenosine deaminase, immunoglobulins and parameters of redox homeostasis. Cortisol, a specific biomarker, can be determined in the hair, urine and faeces, while urine samples allow for the analysis of catecholamines as non-invasive markers of pig welfare.

Hair cortisol concentration in finishing pigs on commercial farms: variability between pigs, batches, and farms

Hair cortisol is a stress indicator and could be used to assess the pigs' exposure to stressors in the weeks/months prior to non-invasive hair sampling. The main aim of this study was to describe the hair cortisol concentration (HCC) variability between individuals within a batch, between farms and between batches within a farm. The secondary aim was to determine how the number of sampled pigs influences the characterization of HCC within a batch. Twenty farrow-to-finish pig farms were recruited considering the diversity of their management practices and health status (data collected). Hair was sampled in two separate batches, 8 months apart. The necks of 24 finishing pigs were clipped per batch the week prior to slaughter. To describe the variability in HCC, an analysis of the variance model was run with three explanatory variables (batch, farm and their interaction). To identify farm clusters, a principal component analysis followed by a hierarchical clustering was carried out with four active variables (means and standard deviations of the two batches per farm) and 17 supplementary variables (management practices, herd health data). We determined how the number of sampled pigs influenced the characterization of HCC within a batch by selecting subsamples of the results. HCC ranged from 0.4 to 121.6 pg/mg, with a mean of 25.9 ± 16.2 pg/mg. The variability in HCC was mainly explained by differences between pigs (57%), then between farms (24%), between batches within the same farm (16%) and between batches (3%). Three clusters of farms were identified: low homogeneous concentrations (n = 3 farms), heterogeneous concentrations with either higher (n = 7) or lower (n = 10) HCC in batch 2 than in batch 1. The diversity of management practices and health statuses allowed to discuss hypotheses explaining the HCC variations observed. We highlighted the need to sample more than 24 pigs to characterize HCC in a pig batch. HCC differences between batches on six farms suggest sampling pigs in more than one batch to describe the HCC at the farm level. HCC variations described here confirm the need to study its links with exposure of pigs to stressors.

Saliva metabolome alterations after acute stress

Major stress has systemic effects on the body that can have adverse consequences for physical and mental health. However, the molecular basis of these damaging effects remains incompletely understood. Here we use a longitudinal approach to characterise the acute systemic impact of major psychological stress in a pig model. We perform untargeted metabolomics on non-invasively obtained saliva samples from pigs before and 24 h after transfer to the novel physical and social environment of a slaughterhouse. The main molecular changes occurring include decreases in amino acids, B-vitamins, and amino acid-derived metabolites synthesized in B-vitamin-dependent reactions, as well as yet-unidentified metabolite features. Decreased levels of several of the identified metabolites are implicated in the pathology of human psychological disorders and neurodegenerative disease, suggesting a possible neuroprotective function. Our results provide a fingerprint of the acute effect of psychological stress on the metabolome and suggest candidate biomarkers with potential roles in stress-related disorders.

Comparison of effects of a single dose of MHYOSPHERE® PCV ID with three commercial porcine vaccine associations against Mycoplasma hyopneumoniae (Mhyo) and porcine circovirus type 2 (PCV2) on piglet growth during the nursery period under field conditions

Pigs routinely undergo stressful vaccination procedures, which are often unavoidable given the unavailability of safer alternatives, challenging animal welfare. The available vaccines for Mycoplasma hyopneumoniae (Mhyo) or Porcine circovirus type 2 (PCV2) are mostly administered intramuscularly in association to prevent Porcine respiratory disease complex (PRDC). MHYOSPHERE® PCV ID is the first vaccine protecting from both agents by intradermal route. This randomized, blind-field trial aimed to compare the effects of MHYOSPHERE® PCV ID with those of three different intramuscular associations of commercially available vaccines. A total of 7072 21-day-old piglets from 12 consecutive batches in one farm were randomly vaccinated with MHYOSPHERE® PCV ID (G1) or Ingelvac CircoFLEX® + Hyogen® (G2), Porcilis® PCV + M + PAC® (G3), and Porcilis® PCV + Hyogen® (G4). Growth performance during the nursery period and adverse reactions (ARs) after vaccine administration were monitored. Average Daily Weight Gain (ADWG) during the first 7 days post-weaning in G1 was 10.92, 3.03, and 20.08 g/day higher than in G2, G3, and G4, respectively, and 0.65, 4.06, and 9.58 g/day higher than in G2, G3, and G4 during the entire nursery period, respectively. G1 ADWG was significantly higher than G4 during both periods and significantly higher than G2 during the first 7 days post-weaning. Incidence of systemic ARs in G2 and G4 was 0.03% and 0.32%, respectively; none were recorded in G1 and G3. Replacing the usual intramuscular vaccination with MHYOSPHERE® PCV ID results in higher growth performance during the first weeks after weaning with no systemic ARs.

Early Life Painful Procedures: Long-Term Consequences and Implications for Farm Animal Welfare

Farm animals routinely undergo painful husbandry procedures early in life, including disbudding and castration in calves and goat kids, tail docking and castration in piglets and lambs, and beak trimming in chicks. In rodents, inflammatory events soon after birth, when physiological systems are developing and sensitive to perturbation, can profoundly alter phenotypic outcomes later in life. This review summarizes the current state of research on long-term phenotypic consequences of neonatal painful procedures in rodents and farm animals, and discusses the implications for farm animal welfare. Rodents exposed to early life inflammation show a hypo-/hyper-responsive profile to pain-, fear-, and anxiety-inducing stimuli, manifesting as an initial attenuation in responses that transitions into hyperresponsivity with increasing age or cumulative stress. Neonatal inflammation also predisposes rodents to cognitive, social, and reproductive deficits, and there is some evidence that adverse effects may be passed to offspring. The outcomes of neonatal inflammation are modulated by injury etiology, age at the time of injury and time of testing, sex, pain management, and rearing environment. Equivalent research examining long-term phenotypic consequences of early life painful procedures in farm animals is greatly lacking, despite obvious implications for welfare and performance. Improved understanding of how these procedures shape phenotypes will inform efforts to mitigate negative outcomes through reduction, replacement, and refinement of current practices.

Effects of Wash Protocol and Contamination Level on Concentrations of Cortisol and Dehydroepiandrosterone (DHEA) in Swine Hair

Simple Summary

Quantifying the hormones cortisol and dehydroepiandrosterone (DHEA) in swine hair is of increasing interest to evaluate long-term stress and resilience. Because swine hair is often contaminated with varying amounts of excrement, it needs to be decontaminated with a solvent prior to hair hormone extraction to rid the hair of potential external contaminants. However, it is unknown how contamination influences hair hormone concentrations, and if current wash protocols are effective in removing contamination. The goals of this study were thus, to determine if wash solvents (methanol versus isopropanol), contamination level (none, mild, or severe), and the number of washes (one, three, or five) influenced hair cortisol and DHEA concentrations. This study showed that hair cortisol, but not DHEA concentrations were reduced when external contamination was present, and that methanol was more effective at removing external contamination compared to isopropanol. There were also decreasing concentrations of cortisol and DHEA within the hair and wash solvent with an increasing number of washes. Thus, it is recommended not to use contaminated hair for hormone analysis, and to wash swine hair with a minimum of three 3 min methanol washes prior to analysis.

Abstract

The effect of washing procedure and contamination level on the concentrations of cortisol and dehydroepiandrosterone (DHEA) in swine hair was explored over two studies. Hair shaved from finisher pigs (n = 8) and sows (n = 8, cortisol study 1 only) was split into two treatments (two hair samples/pig) to receive either three isopropanol or methanol washes, and two paired subsamples of hair were contaminated with feces and urine, mildly or severely. Samples were further subdivided and received one, three, or five methanol washes. Hormone concentrations were quantified from the hair and wash solvent, and the ratio of hormones in the solvent to that in the hair calculated. When grouping sow and grower hair together for analysis, hair cortisol concentrations were 13% greater after three isopropanol washes compared to methanol (22.84 ± 3.12 vs. 19.77 ± 2.64 pg/mg, respectively). When analyzing sow and grower hair separately, sow hair cortisol concentrations were 20% higher following three isopropanol washes compared to methanol washes (22.06 ± 5.21 vs. 27.72 ± 5.65 pg/mg), with no differences in grower pig hair concentrations. The solvent cortisol concentrations did not differ with wash solvent. No differences were seen for DHEA. Contamination level did not influence hormone concentrations. Hair cortisol concentrations were 24% higher after one wash compared to five washes (11.98 ± 1.47 vs. 9.05 ± 0.92 pg/mg), whereas the solvent cortisol concentrations were 80% and 84% higher after one wash compared to three and five washes, respectively (21.09 ± 4.04 vs. 4.21 ± 1.62 vs. 3.36 ± 1.32 pg/mg). The solvent–hair cortisol ratio was 65% and 73% higher following one wash compared to three and five washes (1.36 ± 0.80 vs. 0.47 ± 0.12 vs. 0.37 ± 0.14). Hair DHEA concentrations were 39% higher after one wash compared to five washes (42.39 ± 6.87 vs. 26.02 ± 5.69 pg/mg). The solvent DHEA concentrations, and the solvent–hair ratio for DHEA were 94% and 98% and 92% and 98% higher going from one wash to three and five washes, respectively (solvent: 5.07 ± 0.26 vs. 0.28 ± 0.12 vs. 0.12 ± 0.09 pg/mg and solvent–hair ratio: 0.13 ± 0.006 vs. 0.010 ± 0.004 vs. 0.003 ± 0.002). Following three methanol washes, the non-contaminated hair had 46% and 48% higher hair (17.47 ± 1.12 vs. 9.35 ± 0.80 vs. 9.05 ± 1.06 pg/mg) and a 76% and 72% higher solvent (16.31 ± 8.07 vs. 3.92 ± 0.50 vs. 4.50 ± 2.31 pg/mg) cortisol concentration compared to mild and severely contaminated hair, respectively. Wash solvent influences cortisol concentrations in swine hair, but not DHEA. Contaminated swine hair should be avoided in analyses when possible.

Do boars compensate for hunting with higher reproductive hormones?

The predation-stress hypothesis has been proposed as a general mechanism to explain the negative effect of predation risk on reproduction, through a chronic activation of the stress response. However, in some cases, stress appears to augment the reproductive potential of mammals. Wild boar (Sus scrofa) populations are on a rise worldwide, despite the high hunting pressure that they are exposed to. This hunting pressure instigates, among other effects, earlier sexual maturity in juvenile females, leading to the shortening of wild boars' generation time. The mechanism that underlies this earlier sexual maturity under high hunting pressure has not been examined to date. To explore the physiological effects that hunting has on the reproductive system and whether the stress response is involved, we examined steroid hormone levels in the hair of female wild boars in northern Israel, comparing populations exposed to high and low hunting pressure. Furthermore, we compared steroid levels in the hair of female wild boars that were roaming alone or as a part of a group. We found no hormonal signs of stress in the hunted boars. Cortisol levels were low in both the high and low hunting-pressure groups. Yet, progesterone levels were higher in females that were exposed to high hunting pressure. Females roaming in a group also had higher progesterone levels compared to females that were alone, with no distinguishable differences in cortisol levels. These elevations in reproductive hormones that were associated with hunting may lead to a higher reproductive potential in female wild boars. They further show that high hunting pressure does not necessarily lead to chronic stress that impairs the reproductive potential of female wild boars. This data suggests that a reproductive hormonal response may be one of the factors leading to the rapid wild boars population growth worldwide, despite the high hunting pressure.

Shortening sow restraint period during lactation improves production and decreases hair cortisol concentrations in sows and their piglets

Food animal welfare is an issue of great concern, as society has a responsibility for animals under human care. Pork is the most consumed meat worldwide, with more than a billion pigs being slaughtered globally every year. Still, in most countries, sows are restrained in farrowing crates throughout lactation. In these crates, sows are confined with bars to an area that is just slightly larger than their body. Thus, moving and turning around, grooming, or expressing other natural behaviors are typically impossible. In this study, we utilized a simple and practical modification of conventional farrowing crates to designed farrowing pens, by removable confinement bars, which provide the flexibility to change the housing system from one to another. Our objective was to examine the parameters of production and hair cortisol concentrations after different restraint periods during lactation. Analyses included data from 77 sows and their 997 piglets. Sows were housed in farrowing crates, but the confinement bars were removed after different periods, from 3 days post-farrowing to full restraint. For certain analyses, sows were grouped into Short or Long Restraint groups (3-10 days vs 13-24 days, respectively). Multiple linear regression revealed that for any additional day in restraint of the sows, piglets' weaning rate decreases by 0.4% (P < 0.05). Moreover, the total number of weaned piglets per litter was higher in the Short Restraint group as compared to the Long Restraint group (10.4 ± 0.3 vs 9.7 ± 0.3, respectively; P < 0.05). Accordingly, total litter weight on the weaning day tended to be higher in the Short Restraint group (68.8 ± 2.2 vs 64.9 ± 1.8 kg; P = 0.1210). The requirement for medical treatments during lactation (e.g., antibiotics, NSAID) tended to be less frequent in the Short Restraint group (Sows: 21.9% vs 40%; P = 0.1219. Piglets: 2.4% vs 17.1%; P = 0.0609). Hair cortisol as a marker for chronic stress during lactation decreased when the restraint period was shortened in both sows and piglets. Our analysis revealed that sows' hair cortisol is a significant mediator between the restraint of the sow and its piglets' hair cortisol (Sobel test; P < 0.05). For every day of sows' restraint, sows' hair cortisol increased by 0.5 pg/mg, and for any additional unit of sows' hair cortisol, piglets' hair cortisol increased by 0.36 pg/mg. In conclusion, sustainable swine farming management can be beneficial for both animals and farmers; limiting sow restraint during lactation is expected to reduce stress, enhance welfare and production, and potentially improve the economics of swine operations.

New technique of sex preselection for increasing female ratio in boar sperm model

In this study, we tried to optimize the porcine semen extender conditions to maximize the differences between live X chromosome-bearing (X) spermatozoa and to Y chromosome-bearing (Y) spermatozoa without a decline in the fertility rate at different pH conditions during storage. We observed the viability of X and Y boar spermatozoa in acidic (pH 6.2), original (pH 7.2), and alkaline condition (pH 8.2) for 5 days to investigate the effect of storage conditions on the X to Y spermatozoa ratio. The functional parameters of spermatozoa were also examined to evaluate sperm quality. Sperm motility was preserved at pH 7.2 and pH 6.2 for 3 days, while sperm motility at pH 8.2 decreased significantly after 2 days. Non-capacitated spermatozoa increased while capacitated spermatozoa decreased during storage. Sperm viability decreased significantly duration-dependent under all pH conditions, but there was no significant difference during storage at pH 6.2 and 7.2. The X: Y ratio of live spermatozoa in acidic condition was maximized (1.2:1) without affecting the sperm function and fertility-related protein expression after 2 days compared to original conditions. Moreover, insemination of sows using acidic extender increased the number of female pups on days 1 and 2 of preservation. These results indicate that the production of female offspring may increase when acidic BTS is used for 2 days without affecting the success rate of AI. Above all, this method is simple and economical compared to other methods.

Gender effects on pork quality and calpain-1 and calpastatin gene expression in male pig muscle

Studies that investigate the expression of genes related to the tenderness of meat from entire and immunocastrated male pigs have not yet been performed. The objective of this study was to investigate the association between gender (entire male and immunocastrated) and the meat quality of pigs, as well as to quantify the expression of calpain-1 and the calpastatin gene. Regarding carcass measurements and meat quality, boars presented lower values of muscle depth (P = 0.028), subcutaneous fat thickness (P = 0.046), L* value (P = 0.004) and cook loss (P = 0.008) than the immunocastrated pigs. The boars presented greater calpain-1 gene expression (P = 0.006) and lower calpastatin gene expression (P = 0.003) than immunocastrated pigs. This study shows that combined with other factors the gene expression can contribute to a tender meat from boars due to their higher calpain-1 expression and lower calpastatin expression than those of immunocastrated male pigs.

On the Road to End Pig Pain: Knowledge and Attitudes of Brazilian Citizens Regarding Castration

We explored the attitudes of Brazilians towards different methods to deal with boar taint in pork (surgical castration without pain control, SC; surgical castration with pain control, SC+PC; immunocastration, IC; raising entire males, EM). Two surveys (Sv1, n = 441 and Sv2, n = 768) containing closed and open questions were conducted. Nearly 70% of Sv1 and Sv2 participants were unaware that meat of entire males may have boar taint and that SC is widely used in pig production in Brazil. In Sv1, acceptability of SC+PC (63%) and IC (53%) was greater than of SC (15%). In Sv2, acceptability of IC (55%) and EM (52%) was greater than of SC (18%). Open-ended responses indicated that participants objected to inflicting pain to pigs to attain a production goal, and were concerned with organoleptic traits and risks of exogenous residues in pork. Participants' views regarding the potential increases in the cost of meat due to adoption of alternative methods varied; some argued that avoiding pain justifies an increase in the price of pork and others that this would impact especially lower income citizens. Our findings indicate that participants opposed surgical castration without pain control, and supported alternative methods. However, the concern with potential risks of presence of residues in meat, expressed by a few participants, may need to be addressed among consumers.

Optimal Methods of Documenting Analgesic Efficacy in Neonatal Piglets Undergoing Castration

Analgesic products for piglet castration are critically needed. This requires extensive animal experimentation such as to meet regulatory-required proof of efficacy. At present, there are no validated methods of assessing pain in neonatal piglets. This poses challenges for investigators to optimize trial design and to meet ethical obligations to minimize the number of animals needed. Pain in neonatal piglets may be subtle, transient, and/or variably expressed and, in the absence of validated methods, investigators must rely on using a range of biochemical, physiological and behavioural variables, many of which appear to have very low (or unknown) sensitivity or specificity for documenting pain, or pain-relieving effects. A previous systematic review of this subject was hampered by the high degree of variability in the literature base both in terms of methods used to assess pain and pain mitigation, as well as in outcomes reported. In this setting we provide a narrative review to assist in determining the optimal methods currently available to detect piglet pain during castration and methods to mitigate castration-induced pain. In overview, the optimal outcome variables identified are nociceptive motor and vocal response scores during castration and quantitative sensory-threshold response testing and pain-associated behaviour scores following castration.