Castrated Males Research Articles

Age and Sex-Dependent Differences in the Neurochemical Characterization of Calcitonin Gene-Related Peptide-Like Immunoreactive (CGRP-LI) Nervous Structures in the Porcine Descending Colon.

Neurons of the enteric nervous system (ENS) may undergo changes during maturation and aging, but knowledge of physiological stimuli-dependent changes in the ENS is still fragmentary. On the other hand, the frequency of many ENS-related intestinal illnesses depends on age and/or sex. The double immunofluorescence technique was used to study the influence of both of these factors on calcitonin gene-related peptide (CGRP)—positive enteric nervous structures—in the descending colon in young and adult female and castrated male pigs. The influence of age and gender on the number and neurochemical characterization (i.e., co-localization of CGRP with substance P, nitric oxide synthase, galanin, cocaine- and amphetamine-regulated transcript peptide and vesicular acetylcholine transporter) of CGRP-positive nerve structures in the colonic wall has been shown. These observations strongly suggest the participation of CGRP in adaptive processes in the ENS during GI tract maturation. Moreover, although the castration of males may mask some aspects of sex-dependent influences on the ENS, the sex-specific differences in CGRP-positive nervous structures were mainly visible in adult animals. This may suggest that the distribution and exact role of this substance in the ENS depend on the sex hormones.

Porcine Breed, Sex, and Production Stage Influence the Levels of Health Status Biomarkers in Saliva Samples.

In this study, the influence of several factors such as breed, sex, and production stage over the normal range values of salivary biomarkers of health status was evaluated in pigs. A total of 409 pigs of 2 different breeds (conventional Large White × Duroc and Iberian pigs) were included in the study. Animals were divided into different groups according to their sex (male or female) and the stage of the production cycle they were in (post-weaning, nursery, fattening, and finishing). The levels of an inflammatory marker, adenosine deaminase (ADA), and two acute phase proteins, C-reactive protein (CRP) and haptoglobin (Hp) were measured in saliva samples. Moreover, the total antioxidant capacity level (TAC) was quantified for the first time in porcine saliva; therefore, an analytical validation and stability analysis during storage at −80°C were also performed. Differences according to breed were observed for all the markers studied; thus, the influence of age and sex on the normal range values were studied separately for conventional and Iberian pigs. In Large White × Duroc pigs the overall median values of ADA, CRP, Hp and TAC were 282 U/L, 10.49 ng/mL, 0.88 μg/mL, and 21.73 μM Trolox equivalents, respectively. However, higher values of inflammatory marker and acute phase proteins were observed in males at the initial stages of the production cycle, while females presented higher values when they had reached sexual maturity. In Iberian pigs the overall median values observed were 585 U/L, 4.81 ng/mL, 0.63 μg/mL, and 21.21 μM Trolox equivalents for ADA, CRP, Hp, and TAC respectively with slight differences in the influence of the studied factors. Sex differences were not observed in the levels of acute phase proteins in Iberian pigs, probably due to the castration of males during the first days of life; however, ADA levels were found to be higher in male pigs at the end of the production cycle. It could be concluded that breed, sex, and production stage influence the range values of salivary markers of health status in pigs and should be taken into account to further establish reference intervals.

Effects of gonadectomy on scent-marking behavior of shelter dogs

In male domestic dogs, castration appears to reduce frequency of sexually dimorphic behaviors, such as mounting and roaming, but results for urine-marking, another highly dimorphic behavior, are less clear. Using two different experimental designs, I studied effects of gonadectomy on scent-marking behavior during leash walks of dogs at two animal shelters in NY (Cortland Community SPCA and Tompkins County SPCA). In the between-dog study, I compared intact males and females and gonadectomized males and females with respect to rate of urination (a highly sexually dimorphic behavior), likelihood of ground-scratching (a somewhat sexually dimorphic behavior), and likelihood of defecation (a sexually monomorphic behavior). In my within-dog study, I compared rate of urination before and after gonadectomy in a subset of males and females. For the between-dog study, I found that castrated males urinated at lower rates than intact males and that spayed females and intact females urinated at similar rates; this pattern characterized dogs at both shelters. Gonadectomy did not influence likelihood of ground-scratching by either males or females at either shelter. For males and females at the Tompkins shelter and females at the Cortland shelter, gonadectomy did not influence likelihood of defecation. However, intact males were more likely to defecate than castrated males at the Cortland shelter. For dogs observed both before and after gonadectomy in the within-dog study, overall rates of urination decreased after castration in males but did not significantly change after spaying in females (sample sizes sufficient for analysis at the Cortland shelter only). Individual differences characterized male behavioral response to castration: while one male showed a very slight increase in mean rate of urination after castration (4%), the remaining sixteen males differed in degree of response, with percentage decreases in mean rate of urination after castration ranging from 14% to 72%. The source of this individual variation remains to be identified. In summary, spaying did not influence urination, ground-scratching, or defecation by female dogs. For male dogs, I found the most robust effects of castration on urine-marking, the most sexually dimorphic of the three scent-marking behaviors studied. This study is the first research based on direct observations of individual dogs to find decreased urine-marking by males after castration.

The Effects of Chemical Castration with Degarelix on Bone Turnover: Densitometric and Biomechanics Bone Properties of Male Rats.

BackgroundGonadotropin releasing hormone (GnRH) antagonists may cause chemical castration in males by suppressing the pituitary-gonadal axis, hence reducing testosterone level. There are limited data on the effects of degarelix, a newer series of potent and long acting GnRH antagonist on bone.ObjectivesThe current study aimed at determining the effects of degarelix on bone turnover, bone densitometry, and bone mechanical strength in male rats.MethodsEighteen male Sprague-Dawley rats were randomly divided into sham (SHAM), orchidectomized (ORX), and degarelix-induced (DGX) groups. Chemical castration was performed by subcutaneous degarelix injection (2 mg/kg) at the scapular region. The rats were scanned for baseline bone mineral area (BMA), bone mineral content (BMC), and bone mineral density (BMD) using dual-energy x-ray absorptiometry (DXA). Following six weeks of experimental period, BMA, BMC, and BMD were measured again with DXA and blood was collected for testosterone and bone biomarkers (osteocalcin and C-terminal of type I collagen crosslink (CTX-1)) measurements. The rats were euthanized and femora were dissected for bone biomechanical strength analysis.ResultsBilateral orchidectomy and degarelix administration significantly lowered serum testosterone level, decreased whole body BMC, femoral BMA, femoral BMC, and femoral BMD (P < 0.05) compared with the SHAM group. However, no significant changes were observed in bone biochemical markers and bone mechanical strength in all experimental groups.ConclusionsIn conclusion, degarelix administration had comparable effects on bone as bilateral orchidectomy. Administration of degarelix provides an alternative method of inducing testosterone deficient-osteopenia in male rats without need for removing the testes.

Male lifespan extension with 17-α estradiol is linked to a sex-specific metabolomic response modulated by gonadal hormones in mice.

SummaryLongevity in mammals is influenced by sex, and lifespan extension in response to anti‐aging interventions is often sex‐specific, although the mechanisms underlying these sexual dimorphisms are largely unknown. Treatment of mice with 17‐α estradiol (17aE2) results in sex‐specific lifespan extension, with an increase in median survival in males of 19% and no survival effect in females. Given the links between lifespan extension and metabolism, we performed untargeted metabolomics analysis of liver, skeletal muscle and plasma from male and female mice treated with 17aE2 for eight months. We find that 17aE2 generates distinct sex‐specific changes in the metabolomic profile of liver and plasma. In males, 17aE2 treatment raised the abundance of several amino acids in the liver, and this was further associated with elevations in metabolites involved in urea cycling, suggesting altered amino acid metabolism. In females, amino acids and urea cycling metabolites were unaffected by 17aE2. 17aE2 also results in male‐specific elevations in a second estrogenic steroid—estriol‐3‐sulfate—suggesting different metabolism of this drug in males and females. To understand the underlying endocrine causes for these sexual dimorphisms, we castrated males and ovariectomized females prior to 17aE2 treatment, and found that virtually all the male‐specific metabolite responses to 17aE2 are inhibited or reduced by male castration. These results suggest novel metabolic pathways linked to male‐specific lifespan extension and show that the male‐specific metabolomic response to 17aE2 depends on the production of testicular hormones in adult life.

Hormone-responsive genes in the SHH and WNT/β-catenin signaling pathways influence urethral closure and phallus growth.

Environmental endocrine disruptors (EEDs) that affect androgen or estrogen activity may disrupt gene regulation during phallus development to cause hypospadias or a masculinized clitoris. We treated developing male tammar wallabies with estrogen and females with androgen from day 20-40 postpartum (pp) during the androgen imprinting window of sensitivity. Estrogen inhibited phallus elongation but had no effect on urethral closure and did not significantly depress testicular androgen synthesis. Androgen treatment in females did not promote phallus elongation but initiated urethral closure. Phalluses were collected for transcriptome sequencing at day 50 pp when they first become sexually dimorphic to examine changes in two signaling pathways, sonic hedgehog (SHH) and wingless-type MMTV integration site family (WNT)/β-catenin. SHH mRNA and β-catenin were predominantly expressed in the urethral epithelium in the tammar phallus, as in eutherian mammals. Estrogen treatment and castration of males induced an upregulation of SHH, while androgen treatment downregulated SHH. These effects appear to be direct since we detected putative estrogen receptor α (ERα) and androgen receptor (AR) binding sites near SHH. WNT5A, like SHH, was downregulated by androgen, while WNT4 was upregulated in female phalluses after androgen treatment. After estrogen treatment, WIF1 and WNT7A were both downregulated in male phalluses. After castration, WNT9A was upregulated. These results suggest that SHH and WNT pathways are regulated by both estrogen and androgen to direct the proliferation and elongation of the phallus during differentiation. Their response to exogenous hormones makes these genes potential targets of EEDs in the etiology of abnormal phallus development including hypospadias.

An increase in estradiol facilitates the onset of paternal behavior in the dwarf hamster (Phodopus campbelli)

In the dwarf hamster (Phodopus campbelli), activational effects of testosterone (T) and estradiol (E2) in the regulation of paternal behavior have been repeatedly rejected because peripheral concentrations of E2 do not change across the reproductive cycle of males. Further, castration no affected paternal behavior despite that both T and E2 concentrations decreased significantly. However, the role of these hormones has not been evaluated in models of castration and hormonal replacement in virgin males. Here, we analysed the effects of E2 and T in paternal behavior in virgin male dwarf hamster (Phodopus campbelli). Thirty paternal (PAT) males were bilaterally castrated; of them, 10 were implanted with T, 10 with E2 and 10 males received no treatment. Other 10 PAT males underwent sham-castration. Seventeen aggressive (AGG) males were also bilaterally castrated; of these, 10 AGG received E2 replacement, 7 were not treated. Other 7 AGG males were submitted to sham-castration. Following treatments, paternal behavior tests were conducted again. T and E2 levels in plasma were quantified by radioimmunoassay (RIA). The results showed that the treatments did not affect the paternal behavior of males that were initially paternal. Neither castration nor sham-castration surgery affected the behavior of AGG males. However, when these males were treated with E2 and the concentrations of this hormone increase significantly they became paternal. Our data suggest that an increase in E2 levels shifted infanticidal behavior to paternal behavior in dwarf hamster.

Adaptación de la inmunocastración a la montanera del macho de cerdo Ibérico: efectos en órganos reproductivos y características de canal.

Voluntary end of male pig castration is expected in the EU in the near future, but standard immunocastration (IC) protocols need to be adapted for Iberian (IB) pig males due to their long life cycle. Our team developed 3-dose protocol that needs further adjustment to suit montanera (MT; free-range acorn feeding) chronology. Our hypothesis is that improving homogeneity of body condition at the start of MT will enhance and homogenize testicular atrophy. Pure IB males (n=35) reared in extensive system were feed-restricted during the growth phase (pre-montanera) as usual. Of these animals, Control pigs (C; n=18) were immunized against GnRH at 10.5, 12 and 13.5 months (m)of age. Treated pigs (T; n=17) were immunized at 10.5, 11.5 and 13 m, with 15-day ad libitum (AL) feeding period starting at the 3rd dose. Both groups started the MT period at 13.5 m, coinciding with the 3rd dose of C and the end of the AL period of T, and both were slaughtered at 16 m. To further validate the effect of nutritional level, an additional group was fed ad libitum during growth and finishing phases with commercial feedstuff in regular outdoor rearing system (Adlib; n=15 IB x Duroc males), with the vaccinations taking place at 8, 9 and 11 m and slaughter at 13 m (earlier, due to genotype and unrestricted feeding). Testes and epidydimides were significantly smaller in Adlib and T than C pigs. Similarly, bulbourethral glands were significantly smaller in T than C pigs. Testes parenchyme color a (green to red) was highly correlated (r=0.87) with testes weight. Backfat androstenone and skatole were below detection limits for all the animals. Foreleg, loin and prime-cut yields were significantly greater for Adlib than for C and T pigs. In conclusion, nutritional level can be used to improve the efficacy of male IC, and testes colorimetry can be used to monitor this efficacy.

Public opinion towards castration without anaesthesia and lack of access to pasture in beef cattle production.

Recent publications have shown that citizens in developing nations are gaining interest in farm animal welfare. The aims of this study were to assess the opinion of Chilean citizens about surgical castration without anaesthesia and lack of access to pasture in beef cattle production, to investigate how involvement in livestock production influences opinions, and to evaluate if different types of information would affect their opinion towards these management practices. The study was carried out in the Metropolitan Region of Santiago, Chile, and consisted of two surveys with 400 participants in each study. The first one used an online, self-administered questionnaire and the second one used a face to face questionnaire. The second questionnaire had four information treatments assigned randomly to survey participants (no information; negative information; negative and positive information; positive information). Most participants were aware that the two management practices are common in beef production systems and were opposed to them. Involvement in animal production was associated with greater acceptance of both management practices and participants that had visited a beef production farm before the study were more likely to support castration without anaesthesia in Survey 1. Belonging to any socioeconomic group and providing negative or positive information had no impact on participants’ opinion. The results show a disconnection between the views of participants recruited for this study and beef production systems that do not provide pain control for male cattle surgical castration or provide little or no access to pasture.

Age castration of Nellore males on the profile of fatty acids of meat

This study aimed to evaluate the cholesterol content, ?-tocopherol and fatty acids in the meat of Nellore young bulls or steers castrated at different ages, 13 or 18 months. The animals were confined for 100 days and slaughtered at 22 months of age. The experimental design was completely randomized with three treatments, using 12 repetitions. The levels of palmitic acid (26.39%), stearic (24.39%), myristic (3.01%) and total saturated fatty acids were not altered by sexual condition or castration age. Oleic was the fatty acid with the highest average participation in the meat (34.54%), and lower content in the meat of young bulls in relation to the castrated. The content of total unsaturated fatty acids was lower in the young bulls in relation to castrated at 18 months, which did not differ from castrated at 12 months. The content of total polyunsaturated fatty acids was increased by elevation of the castration age, being similar between young bulls and castrated at 18 months. The ratio ?6/?3 was not altered by sexual condition or castration age. Castration at the beginning of the finishing period increases the content of beneficial fatty acids to health in relation to castrated in the first third of backgrounding.

Sex differences in behavioral and neurochemical effects of gonadectomy and aromatase inhibition in rats

Aromatase inhibitors, which are widely used for the treatment of estrogen-dependent cancers, have been associated with psychiatric side effects ranging from mania to depression. In the present study, we investigated sex differences in the behavioral and neurochemical effects of aromatase inhibition on male and female, sham-operated or gonadectomized adult rats. Three weeks after surgery, rats received chronic treatment with the aromatase inhibitor letrozole or vehicle and were then subjected to the open field test, which assesses general activity. Half of the subjects were subsequently exposed to the stressful procedure of the forced swim test (FST), which is also a test of antidepressant activity. Aromatase activity was analyzed in the hypothalamus and testosterone and corticosterone were assayed in the blood serum of all rats. The hippocampus and prefrontal cortex (PFC) were analyzed for monoamine (noradrenaline, dopamine and serotonin), as well as amino acid (GABA, glutamate, glycine, taurine, alanine and histidine) levels. The observed decrease in hypothalamic aromatase activity confirmed the efficacy of letrozole treatment in both sexes. Moreover, letrozole enhanced testosterone levels in sham-operated females. In the open field test, females were overall more active and explorative than males and gonadectomy eliminated this sex difference. In the FST, females exhibited overall higher immobility than males and gonadectomy further enhanced this passive behavior in both sexes. However, sustained aromatase inhibition had no effect on open field and FST behaviors. Head shakes during FST, which were fewer in females than in males, were reduced by castration in males and by letrozole treatment in ovariectomized females, suggesting a role of testosterone and extra-gonadal estrogens in the expression of this behavior. Sustained aromatase inhibition also decreased noradrenaline and the dopaminergic turnover rates [DOPAC/DA, HVA/DA] in the hippocampus and PFC of male and female rats, irrespectively of gonadectomy. Moreover, letrozole treatment enhanced the serotonergic turnover [5HIAA/5HT] rate in the hippocampus of males and females, irrespectively of gonadectomy. Amino acid levels were not influenced by letrozole, but sex differences were demonstrated with higher levels in the PFC of females vs. males. Present findings suggest that the neuropsychiatric effects of aromatase inhibition can be attributed to the inhibition of extragonadal estrogen synthesis, presumably in the brain, and could be further associated with serotonergic and catecholaminergic changes in brain regions involved in mood and cognition. Importantly, present data could be linked with the neurobiology of affective side-effects in post-menopausal women receiving aromatase inhibitors.

Effect of castration on social behavior and hormones in male Japanese macaques (Macaca fuscata)

Population control is essential for animal welfare and human safety in free-ranging or captive settings, especially when resources are limited. As an alternative to lethal control, contraceptive methods such as castration in males can be a practical solution, because the testicles are a visual cue to determine which males have been sterilized. However, careful analyses should be carried out to ensure no disruption in the social structure of the population. Japanese macaques (Macaca fuscata) live in a society centered around dominance rank and matrilineal kin relationships. Testosterone and glucocorticoids have been correlated with dominance rank in humans and other species, but previous studies in Japanese macaques were inconclusive. This study aimed to investigate behavioral and physiological differences between castrated and intact male Japanese macaques, and to examine the effect of season and behavior in hormonal concentrations in intact males. Our subjects were six intact males from Jigokudani Monkey Park (Japan) and 13 castrated males from Born Free Primate Sanctuary (USA). We collected behavioral data using both focal and ad libitum sampling, and fecal samples for determination of testosterone (fT) and glucocorticoids (fGC) by enzyme immunoassay. We found that castrated males exhibited a social hierarchy, but not a linear hierarchy, as was the case in intact males. Castrated males were less aggressive than intact males, probably because fT concentrations were lower in the castrated males. Age was positively correlated with fGC levels, while fT concentrations were lower in old males than younger adult males. Fecal T levels correlated with both rank and atmospheric temperature. In intact males, both fGC and fT levels were elevated during the mating season. We found a negative correlation between fGC levels and the amount of grooming received. Our findings indicate that castration had a minimal impact on sociality, with season, temperature, and rank all influencing male sex steroid levels in intact males. Our study indicates that castration can be adopted as a population control mechanism without drastically altering the social relationships of males.

Two complementary methods to control gonadotropin-releasing hormone vaccination (Improvac®) misuse in horseracing: Enzyme-linked immunosorbent assay test in plasma and steroidomics in urine.

Since the availability on the European market of the vaccine Improvac® dedicated to male pig immunological castration, the risk of misuse of this product in horses is now considered as a threat for the horseracing industry. Immunological castration is not allowed by the racing codes (immune system, Article 6). Indeed, this vaccination against the hypothalamic hormone luteinizing hormone-releasing hormone or gonadotropin-releasing hormone (GnRH) will prevent the release from the anterior pituitary of luteinizing hormone and follicle stimulating hormone, which are required for the development and activity of gonads in males (testes) and female (ovaries) and therefore all their subsequent physiological functions. This treatment will induce a strong hormonal variation resulting in a behaviour modification of the animals. In this work, four male standardbreds treated with Improvac® vaccine (two intramuscular injections within 4weeks) were studied. Monitoring of the total scrotal width showed a decrease of the scrotum size (37%) and production of anti-GnRH antibodies was detected up to 200days after the first injection. Anti-GnRH antibodies were detected in plasma after caprylic acid precipitation followed by an enzyme-linked immunosorbent assay (ELISA) as a rapid and efficient screening method applicable to routine analysis. These results were correlated to a switch of the sexual status from male group to gelding/female group obtained by a steroidomic approach with urine based on ten endogenous compounds. Copyright © 2017 John Wiley & Sons, Ltd.

Early weaning stress induces chronic functional diarrhea, intestinal barrier defects, and increased mast cell activity in a porcine model of early life adversity.

Early life adversity (ELA) is a risk factor for development of gastrointestinal disorders later in life. The underlying mechanisms through which ELA and sex interact to influence disease susceptibility remains poorly understood. Utilizing a porcine early weaning stress (EWS) model to mimic ELA, we investigated the long-term effects of EWS on functional diarrhea, ileal permeability, mast cell activity and mast cell relationship with enteric ganglia. Juvenile and adult EWS pigs exhibited chronic, functional diarrhea (EWS 43.6% vs late wean control(LWC) 4.8%, P<.0001), increased intestinal permeability (2 fold increase EWS vs LWC, P<.0001), and mast cell numbers (at 7weeks and 20weeks ~1.6 fold increase EWS vs LWC, P<.05). Compared with EWS male castrates (Male-C), females EWS pigs exhibited more frequent diarrhea (58.8% vs 29.9%, P=.0016), and increased intestinal permeability (1-2 fold higher in EWS females, P<.001). Increased mast cell numbers and their enhanced co-localization with neuronal ganglia were observed in both Male-C and female EWS pigs; however, female pigs exhibited greater release of mast cell tryptase upon activation with c48/80 (~1.5 fold increase, P<.05), compared with Male-C pigs. These data demonstrate that pigs exposed to ELA exhibit increased vulnerability to functional diarrhea, intestinal permeability and mast cell activity. Further, these studies also showed that EWS female and Male-C pigs exhibited dimorphic responses to EWS with female piglets exhibited greater susceptibility and severity of diarrhea, intestinal permeability and mast cell tryptase release. Together, these findings mimic some of the key pathophysiologic findings in human functional GI disorders functional gastrointestinal disorders (FGIDs) suggesting that the EWS porcine model could be a valuable preclinical translational model for FGID research associated with ELA.

Comparison of meat quality characteristics, growth, and feed efficiency of intact and castrated post-pubertal bovine males

Yearling Red Angus or Black Angus bulls (n = 24; initial BW = 1,336 ± 25.1 lb; (606 ± 11.4 kg); average 16 mo of age) were used to evaluate the effects of castration and use of growth promoting technology (STR) on performance, carcass traits, and meat quality characteristics when compared to intact (BULL) post-pubertal male cattle. The STR treatment included administration of a combination 120 mg trenbolone acetate + 24 mg estradiol growth-promoting implant on d 0 and feeding ractopamine hydrochloride the last 28 d on feed. Cattle were individually fed a corn-based finishing diet for 62 d and harvested at a commercial abattoir. Intact bulls had greater average daily gain (4.08 vs 3.19 lb or 1.85 vs 1.45 kg/d; P = 0.02) and feed:gain ratio (8.54 vs 10.97; P = 0.02) than STR. There were no treatment differences for dry-matter intake, quality or yield grade, hot carcass weight, back-fat thickness, or dressing percent (P &lt; 0.05). Longissimus muscle area was greater in BULL compared to STR carcasses (16.6 vs 15.0 in2 or 106.9 vs 96.8 cm2; P &lt; 0.01). Warner-Bratzler Shear Force was not affected (P &gt; 0.05) by treatment. Intact bulls had improved performance with no differences in carcass characteristics, tenderness, or sensory panel measurements compared to STR treatment.

Growth of total fat and lean and of primal cuts is affected by the sex type

Knowledge of tissue and cuts growth depending on the sex could be used to improve performance and efficiency. Computed tomography (CT) is a non-invasive technology that enables the study of the body composition of live animals during growth. The aims of the present study were (1) to evaluate variation in the body composition of four sex types (SEX) of pigs (castrated males (CM), immunocastrated males (IM), entire males (EM) and females (FE)) at the live weight of 30, 70, 100 and 120 kg, assessed using CT; (2) to model the growth of the main tissues and cuts; and (3) to predict the mature BW (MBW) of the four SEX and establish the relationships between the growth models and the MBW. There were significant phenotypic differences in the allometric growth of fat and lean among SEX. For the lean tissue, FE and EM showed higher values of the b coefficient than CM and IM (1.07 and 1.07 v. 1.00 and 1.02, respectively) all of them close to unity, indicating a proportional growth rate similar to live weight and that this tissue developed faster in FE and EM than in CM and IM. However, these differences were not related to differences in estimated MBW. There were significant differences in estimated MBW among SEX, being higher in IM and EM than in CM and FE (303 and 247 v. 219 and 216 kg), however, the MBW may have been overestimated, especially for the IM. The poorer accuracy of the MBW estimate for the IM could be due to a maximum live weight of 120 kg in the experiment, or to the fact that this particular SEX presented two clear behaviours, being more similar to EM from birth to the second injection of the vaccine (130 days) and comparable with CM from that point to the final BW.

The effects of male and female immunocastration on growth performances and carcass and meat quality of pigs intended for dry-cured ham production: A preliminary study

A total of 48 Duroc×(Landrace×Large White) pigs, 24 males and 24 females, with 85±3 d of age were used to study the effect of sex and immunocastration on growth performances and carcass and pork quality. There were 4 experimental treatments; surgical castrated males (SCM), immunocastrated males (ICM), entire females (EF) and immunocastrated females (ICF). The surgical castration had been carried out in 12 males when were 5±3 d of age. The immunocastration consisted in two vaccinations with Improvac®, in 12 boars and in 12 gilts, at the beginning of the trial and 28 d later (45.4 and 70.6kg body weight as average, respectively). Pigs were intended for dry-cured ham elaboration; therefore, heavy body weight (126kg and 167 d of age as average) and a minimum of carcass fat depth (20mm) were required. During the overall period (from days 0–82), SCM were less efficient converting feed into gain than the rest of the treatments (P=0.049). At slaughter, ICM were heavier than SCM and ICF with EF being intermediate (P=0.05) and ICF were fatter, as much at 10th rib (P=0.05) as at level of Gluteus medius muscle (P=0.043), than EF with males (SCM and ICM) in an intermediate position. As a consequence, EF had the leanest carcasses (P=0.048) and 25% of them were rejected for lack of fatness vs 0% in the other treatments (P=0.02). Pork from ICF was redder (higher a*) than that from ICM (P<0.001) and meat from SCM showed a more intense color (higher C*) (P=0.03) and tended to have lower level of oxymyoglobin (P=0.061) and metmyoglobin (P=0.082) than that from EF. The intramuscular fat content was not affected. The inmunocastration of males or females had limited influence on major fatty acids of subcutaneous or intramuscular fat. It can be concluded that immunocastration could be interesting in pigs intended for dry-cured ham elaboration because in males improved the feed conversion ratio with no penalization of carcass or meat quality, in comparison to surgical castration, and in gilts increased backfat thickness of carcass reducing to 0% the rejections at slaughterhouse for lack of fatness.

Estrogen-mediated downregulation of AIRE influences sexual dimorphism in autoimmune diseases.

Autoimmune diseases affect 5% to 8% of the population, and females are more susceptible to these diseases than males. Here, we analyzed human thymic transcriptome and revealed sex-associated differences in the expression of tissue-specific antigens that are controlled by the autoimmune regulator (AIRE), a key factor in central tolerance. We hypothesized that the level of AIRE is linked to sexual dimorphism susceptibility to autoimmune diseases. In human and mouse thymus, females expressed less AIRE (mRNA and protein) than males after puberty. These results were confirmed in purified murine thymic epithelial cells (TECs). We also demonstrated that AIRE expression is related to sexual hormones, as male castration decreased AIRE thymic expression and estrogen receptor α-deficient mice did not show a sex disparity for AIRE expression. Moreover, estrogen treatment resulted in downregulation of AIRE expression in cultured human TECs, human thymic tissue grafted to immunodeficient mice, and murine fetal thymus organ cultures. AIRE levels in human thymus grafted in immunodeficient mice depended upon the sex of the recipient. Estrogen also upregulated the number of methylated CpG sites in the AIRE promoter. Together, our results indicate that in females, estrogen induces epigenetic changes in the AIRE gene, leading to reduced AIRE expression under a threshold that increases female susceptibility to autoimmune diseases.

Predicting the carcass chemical composition and describing its growth in live pigs of different sexes using computed tomographys

The aims of this study were (1) to evaluate the ability of computed tomography (CT) to predict the chemical composition of live pigs and carcasses, (2) to compare the chemical composition of four different sex types at a commercial slaughter weight and (3) to model and evaluate the chemical component growth of these sex types. A total of 92 pigs (24 entire males (EM), 24 surgically castrated males (CM), 20 immunocastrated males (IM) and 24 females (FE)) was used. A total of 48 pigs (12 per sex type) were scanned repeatedly in vivo using CT at 30, 70, 100 and 120 kg and slaughtered at the end of the experiment. The remaining 44 were CT scanned in vivo and slaughtered immediately: 12 pigs (4 EM, 4 CM and 4 FE) at 30 kg and 16 pigs each at 70 kg and 100 kg (4 per sex type). The left carcasses were CT scanned, and the right carcasses were minced and analysed for protein, fat, moisture, ash, Ca and P content. Prediction equations for the chemical composition were developed using Partial Least Square regression. Allometric growth equations for the chemical components were modelled. By using live animal and carcass CT images, accurate prediction equations were obtained for the fat (with a root mean square error of prediction (RMSEPCV) of 1.31 and 1.34, respectively, and R2=0.91 for both cases) and moisture relative content (g/100 g) (RMSEPCV=1.19 and 1.38 and R2=0.94 and 0.93, respectively) and were less accurate for the protein (RMSEPCV=0.65 and 0.67 and R2=0.54 and 0.63, respectively) and mineral content (RMSEPCV from 0.28 to 1.83 and R2 from 0.09 to 0.62). Better equations were developed for the absolute amounts of protein, fat, moisture and ash (kg) (RMSEPCV from 0.26 to 1.14 and R2 from 0.91 to 0.99) as well as Ca and P (g) (RMSEPCV=144 and 71, and R2=0.76 to 0.66, respectively). At 120 kg, CM had a higher fat and lower moisture content than EM. For protein, CM and IM had lower values than FE and EM. The ash content was higher in EM and IM than in FE and CM, while IM had a higher Ca and P content than the others. The castrated animals showed a higher allometric coefficient for fat and a lower one for moisture, with IM having intermediate values. However, for the Ca and P models, IM presented higher coefficients than EM and FE, and CM were intermediate.

Deficiency of sex hormones does not affect 17-ß-estradiol-induced coronary vasodilation in the isolated rat heart.

The relaxation of coronary arteries by estrogens in the coronary vascular beds of naive and hypertensive rats has been well described. However, little is known about this action in gonadectomized rats. We investigated the effect of 17-ß-estradiol (E2) in coronary arteries from gonadectomized rats, as well as the contributions of endothelium-derived factors and potassium channels. Eight-week-old female and male Wistar rats weighing 220-300 g were divided into sham-operated and gonadectomized groups (n=9−12 animals per group). The baseline coronary perfusion pressure (CPP) was determined, and the vasoactive effects of 10 μM E2 were assessed by bolus administration before and after endothelium denudation or by perfusion with NG-nitro-L-arginine methyl ester (L-NAME), indomethacin, clotrimazole, L-NAME plus indomethacin, L-NAME plus clotrimazole or tetraethylammonium (TEA). The CPP differed significantly between the female and sham-operated male animals. Gonadectomy reduced the CPP only in female rats. Differences in E2-induced relaxation were observed between the female and male animals, but male castration did not alter this response. For both sexes, the relaxation response to E2 was, at least partly, endothelium-dependent. The response to E2 was reduced only in the sham-operated female rats treated with L-NAME. However, in the presence of indomethacin, clotrimazole, L-NAME plus indomethacin or L-NAME plus clotrimazole, or TEA, the E2 response was significantly reduced in all groups. These results highlight the importance of prostacyclin, endothelium-derived hyperpolarizing factor, and potassium channels in the relaxation response of coronary arteries to E2 in all groups, whereas nitric oxide may have had an important role only in the sham-operated female group.