Intact Males Research Articles

DIFFERENCES IN CARCASS COMPOSITION OF MALE, CASTRATED, AND IMMUNOCASTRATED PIGS: A narrative literature review

The quality of pork is dependent on factors of retail and consumer interest, including appearance, shelf life, as well as tenderness and flavor. One of the factors determining the quality of the animal concerns its castration. Castration of pigs is a procedure carried out to control the odor of the meat and to guarantee the complete quality of the animal for consumption. Therefore, understanding its effects on pig production is essential to have a quality animal and increasingly higher production levels. In this sense, the general objective of this study is to carry out an analysis of the differences in the composition of the pig carcass: male, castrated and immunocastrated through a bibliographical review. The specific objectives were to elucidate the carcass characteristics of male, castrated and immunocastrated pigs and verify the impact of castration on the quality of the animal carcass. Through this study it was possible to conclude that immunocastrated pigs stand out in terms of carcass yield compared to surgically castrated males and intact males, due to the sexual odor, the quality of the meat, the thickness of the bacon and in its entirety.

PSXII-19 Influence of dietary copper concentration and liver sampling location on liver copper concentrations in three breeds (Gulf Coast Native, Suffolk x Hampshire, and Jacob) of sheep

Abstract Male sheep (n = 27) from three different breeds: 1) Gulf Coast Native (GCN; n = 9 wethers), 2) Suffolk x Hampshire (SHC; n = 9 wethers), and 3) Jacob (JCB; n = 9 intact males) approximately 9 mo of age, [body weight (BW) = 38.16 ± 2.43 kg) were stratified by BW and breed into 3 treatment groups to examine the impact of breed, supplemental copper (Cu) dose, and liver sampling location on liver Cu concentrations. On d 0 of the experiment, liver biopsies were collected from 5 sheep per breed and analyzed for Cu concentrations. Animals were housed in individual pens and received 2% of BW of a pelleted concentrate containing the appropriate Cu treatment once daily and hay in amounts to allow ad libitum access to hay over a 24 h period. Treatments consisted of 1) low Cu (LCu; 15.3 mg Cu/kg DM), 2) moderate Cu (MCu; 17.7 mg Cu/kg DM), and 3) high Cu (HCu; 23.8 mg Cu/kg DM) from CuSO4∙5H2O. On d 50 of the experiment, all animals were weighed and transported to an USDA inspected abattoir and harvested. Following harvest, samples were obtained from the left and right lobes of the liver and thoroughly washed with phosphate-buffered saline. All liver samples were dried, ashed, and reconstituted in 5 mL of 1.2 N HCl for Cu analysis. Data were analyzed as a randomized block design using the MIXED procedure in SAS with individual animal as the experimental unit. There was a three-way interaction between breed x treatment x liver lobe (P < 0.04). The right liver lobe in HCu JCB sheep had greater (P < 0.05) Cu concentrations compared with the left liver lobe. Both the left and right lobes of the liver had greater (P < 0.001) Cu concentrations compared with the initial liver Cu concentration in MCu JCB sheep. The right liver lobe of HCu GCN sheep tended (P < 0.07) to have greater liver Cu concentrations compared with the left liver lobe. The Cu concentration in the right liver lobe tended (P < 0.09) to be greater in MCu sheep compared with the left liver lobe. Liver Cu concentrations within the right lobe of HCu GCN sheep were greater (P < 0.05) than liver Cu concentrations in the right and left liver lobe samples in LCu GCN sheep. Liver Cu concentrations in SHC sheep were not influenced by treatment. Future research examining the impact of breed and Cu supplementation on the molecular mechanisms associated with Cu absorption, storage, and excretion is warranted.

PSLBII-20 Estimation of genetic parameters for methane emissions and residual feed intake in Nellore cattle

Abstract The objective of this study was to obtain (co)variance components, heritability, and genetic correlation estimates for enteric methane emissions, residual feed intake, growth, carcass and reproductive indicator traits. Data from 43 feed efficiency trials conducted over a 13-yr period on a single purebred Nellore herd in Central Brazil, comprising 3,400 intact males and 2,167 females, were analyzed. Trial data along with diet NDF content were used to estimate the methane emission (g CH4/kg carcass gain) for each individual, using an equation developed by Medeiros et al., 2014: CH4 (g/d) = -0.1011 + 0.02062*DMI (kg/d) + 0.001648*NDF (% of DMI). Other data included pedigree information, body weight (BW), carcass traits, and reproductive indicator traits. Continuous traits were analyzed using a linear animal model, and threshold traits were analyzed using a threshold animal model. Two-trait analyses were performed using the restricted maximum likelihood to estimate the variance components, heritabilities and genetic and phenotypic correlations among traits. The estimated heritability of methane emissions was 0.136 ± 0.0314. The genetic correlations of methane emissions with growth and carcass traits were low and not different from zero: BW at 450 d (0.064 ± 0.140), scrotal circumference at 365 d (0.188 ± 0.155), longissimus muscle area (-0.090 ± 0.132), 12th-13th rib fat (-0.122 ± 0.142), rump fat (0.080 ± 0.119), intramuscular fat % (-0.108 ± 0.152), BW at 210 d (-0.077 ± 0.168). By contrast, there were the low genetic correlation of methane emissions with early calving probability (-0.260; -0.504 – 0.026); moderate genetic correlations of methane emissions with age at first calving (0.519 ± 0.202) and DM intake (0.512 ± 0.116); and the high correlation of methane with residual feed intake (RFI; 0.832 ± 0.073). Thus, selection to improve weaning and yearling weights, and carcass traits would not affect methane emissions. Genetic selection to reduce methane emissions is feasible and would also reduce DMI and RFI, as well as female sexual precocity traits. Conversely, selection to improve RFI can be used to identify animals with decreased methane emissions. Medeiros, S. R, L. G. Baioni, A. Berndt, M. C. Freua, T. Z. Albertini, C. Costa Jr., e G. B. Feltrin (2014) Modeling enteric methane emission from beef cattle in Brazil: A proposed equation performed by principal component analyses and mixed modeling multiple regression. Proceedings, Livestock, Climate Change and Food Security Conference, Madrid.

440 The effects of reducing dietary nutrient density after the second dose of GnRF immunization (Improvest) on growth performance and carcass characteristics of gilts and intact males

Abstract Objectives were to determine the effects of reducing dietary nutrient density after the second dose of GnRF immunization (Improvest; Zoetis Inc.) on growth performance and carcass characteristics. Pigs (n = 1,008) were fed in five diet phases during the 102-d grow-finish period. Diets were formulated to meet 100% of recommended SID Lys to net energy established by PIC (2021) for physically castrated (PC) barrows/non-immunized gilts (regular diet), while diets for GnRF-immunized pigs were formulated with 120% SID lysine than PC barrows/ non-immunized gilts (nutrient-dense diet). During diet phase-4 (2 d after the second GnRF analogue dose), SID lysine and vitamins/trace minerals for the nutrient-dense diet were either maintained at 100% or reduced to 95% or 90%. During diet phase-5 (18 d after second GnRF analogue dose), SID lysine and vitamins/trace minerals nutrient-dense diet were either maintained at 100% or reduced to 90% or 80%. The study consisted of six pen replications (21 pigs/pen) of the following eight treatments: CON-NEG: traditional mixed-sex pigs (PC barrows and non-immunized gilts) that received the regular diet; CON-POS: traditional mixed-sex pigs that received the nutrient-dense diet; I-MALE-100: immunized males (I-MALES) that received the nutrient-dense diet with 100% density; I-MALE-95/90: I-MALES that received the nutrient-dense diet with 95% density during diet phase-4 and 90% density during diet phase-5; I-MALE-90/80 I-MALES that received the nutrient-dense diet with 90% density during diet phase-4 and 80% density during diet phase-5; I-FEM-100: immunized females (I-FEM) that received the nutrient-dense diet with 100% density; I-FEM-95/90: I-FEM that received the nutrient-dense diet with 95% density during diet phase-4 and 90% density during diet phase-5; I-FEM-90/80: I-FEM that received the nutrient-dense diet with 90% density during diet phase-4 and 80% density during diet phase-5. Data were analyzed with PROC MIXED of SAS, with pen serving as the experimental unit. In addition, linear effects of diet dilution for I-MALE and I-FEM pigs were tested using contrast statements. There were not significant linear effects of diet dilution for gain:feed or hot carcass weight in either the I-MALE (P > 0.28) or I-FEM (P > 0.78) pigs. For the overall period, gain:feed was improved by 7.4% for I-MALE pigs compared with the CON-NEG pigs and was improved by 1.6% for the I-FEM pigs compared with the CON-NEG pigs. Hot carcass weight was 3.6 kg greater for the I-MALE pigs compared with the CON-NEG pigs and 1.6 kg greater for the I-FEM pigs compared with the CON-NEG pigs. The results would suggest that removing nutrients during the post-second dose period of GnRF immunization does not negatively affect growth performance or carcass characteristics, while both I-MALE and I-FEM pigs are more efficient and heavier when compared with traditional mixed sex pigs.

Courtship performance, not ornamentation, predicts mating success in two sister-species of wolf spider with divergent phenotypes

Mate choice is posited to explain the evolution and maintenance of numerous secondary sexual traits, including ornamentation. This study explores the role of ornamentation in the mating success of two sister-species of wolf spider with divergent ornamentation. Mature male Schizocosa crassipalpata lack ornamentation while males of its closest living relative, S. bilineata, express both dark pigmentation and foreleg brushes. Following phenotypic manipulations of foreleg ornamentation – i.e. adding ornamentation in the form of dark pigment to non-ornamented males (S. crassipalpata, Aim 1) and removing ornamentation in varying degrees from highly ornamented males (S. bilineata, Aim 2 – shaving brushes; Aim 3 – shaving brushes and painting over dark pigment in vibration present/absent environments) – we found no evidence that ornamentation alone improves male mating success in either species, regardless of the vibratory signaling environment. In both S. bilineata experiments, however, higher courtship rates resulted in higher mating success, suggesting selection for courtship performance. Furthermore, females were more likely to turn, a presumed receptivity display, in response to males that courted at a higher rate. Also, similar to findings in another relative (S. stridulans), we found indications that ornamentation may function to ease a male’s reliance on courtship performance – i.e., at low courtship rates, only ornamented males can secure a mating. Our phenotypic manipulations also influenced courtship behavior in S. bilineata. Shaved males began courting earlier and courted more often over a longer time than intact males, yet ultimately acquired similar matings. This increased courtship effort likely compensated for reduced ornamentation. Finally, the vibratory environment appears crucial for female–male dialogue in S. bilineata, as vibratory absent environments resulted in increased female attacks and decreased male courtship rates. Together, our data suggest that S. crassipalpata females do not possess a preference for ornamentation and that S. bilineata females do not use ornamentation alone in mating decisions. Instead, our results are consistent with a hypothesis that ornamentation in Schizocosa evolved, and is likely maintained, due to its interactions with dynamic movement displays (i.e. leg movements), which can themselves be plastically altered based on the signaler’s phenotype as well as the signaling environment.

Characterization and economic losses caused by bruis in bovine carcasses in the state of Acre

The objective of this study was to characterize the injuries caused by bruises and evaluate the economic losses in carcasses of cattle slaughtered in a slaughterhouse, in the municipality of Rio Branco, Acre. The period from july 2020 to february 2021, two monthly visits were carried out, on random days, where 4,526 carcasses were analyzed. The presence of bruises was visually checked; the age, degree and size of the lesions, in addition, at the end of each slaughter, the distance between the municipality of origin of the animals and the slaughterhouse was verified. These lesions were later removed and weighed to quantify the damage caused. Among the carcasses analyzed, only 957 (21.12%) showed any lesion. The female category was the one that recorded the most injuries proportionally, with 172 (41%) of the 442 animals slaughtered, while 343 (25%) of the 1388 castrated males and 442 (16%) of the 2724 intact males had some injury. There was an average loss of 0.10443 kg per animal, extrapolating to the total number of cattle slaughtered in the state during the period, a loss of R$ 1.82 or U$ 0.33 per animal is estimated. Despite the low incidence, most bruises appear in the last 24 hours before slaughter, suggesting problems in pre-slaughter management. Therefore, improving animal welfare at this stage is essential to reduce these injuries and improve profitability in beef production.

Taylorella equigenitalis in Icelandic intact males compared with other horse breeds using natural cover.

Contagious equine metritis (CEM) is caused by Taylorella equigenitalis. It is a venereal disease that is detected in some breeds more than others and can cause temporary infertility with substantial costs for regular testing, sanitation and retesting. There was a perceived increase in T. equigenitalis-positive cases in Icelandic intact males where natural cover is common. We aimed to investigate the prevalence of T. equigenitalis in Icelandic intact males and compare to draught horse and Haflinger intact males. We hypothesised that prevalence of T. equigenitalis is higher in Icelandic compared with draught and Haflinger intact males. Cross sectional. Swabs from 76 Icelandic, 35 Haflinger, and 51 draught horse intact males were collected on 38 different farms and analysed by qPCR. Animals were further stratified into active breeding and non-breeding animals and age groups (1.5-7.0 and 8.0-26.0 years). Fisher's exact tests and mixed effect logistic regression with 'farm' as random effect were used to estimate differences in odds for T. equigenitalis-positive test results. The overall prevalence of T. equigenitalis in included intact males was 16.7% (27/162). The odds for T. equigenitalis-positive intact males were significantly higher in Icelandic compared with draught and Haflinger intact males (Odds ratio [OR] = 6.42, 95% confidence interval (CI) = 1.43-28.8, p = 0.02). Odds for T. equigenitalis-positive intact males were significantly lower in active breeding compared with non-breeding animals (OR = 0.09, 95% CI = 0.01-0.54, p = 0.009). Age had no significant influence on test results. Convenience sampling with regional restrictions to Southern Germany and Austria, small sample size. Significantly higher odds for T. equigenitalis-positive intact males were found within Icelandic over draught and Haflinger and within non-breeding animals compared with active breeding animals. Findings suggest that non-breeding animals could be a reservoir for T. equigenitalis. Testing for CEM should therefore be routinely performed in Icelandic horses prior to breeding and investigations into epidemiology and reservoirs on affected farms should be initiated.

Developmental exposure to environmentally relevant doses of phthalates alters the neural control of male and female reproduction in mice

The present study aims to analyze the effects of developmental exposure to phthalates at environmentally relevant doses on the neural control of male and female reproduction. For this purpose, C57Bl/6J mice were exposed to di-(2-ethylexyl) phthalate (DEHP) alone (5 or 50 μg/kg/d), or DEHP (5 μg/kg/d) in a phthalate mixture. Exposure through diet started 6 weeks before the first mating and lasted until weaning of litters from the second gestation (multiparous dams). Analyses of offspring born from multiparous dams exposed to DEHP alone or in a phthalate mixture showed that females experienced a delayed pubertal onset, and as adults they had prolonged estrous cyclicity and reduced Kiss1 expression in the preoptic area and mediobasal hypothalamus. Male littermates showed a reduced anogenital distance and delayed pubertal onset compared with controls. However, in adulthood the weight of androgen-sensitive organs and hypothalamic Kiss1 expression were unaffected, suggesting normal functioning of the male gonadotropic axis. Developmental exposure to DEHP alone or in a phthalate mixture reduced the ability of intact males and ovariectomized and hormonally primed females to attract a sexual partner and to express copulatory behaviors. In addition, females were unable to discriminate between male and female stimuli in the olfactory preference test. Social interaction was also impaired in females, while locomotor activity and anxiety-like behavior in both sexes were unaffected by the treatment. The sexual deficiencies were associated with reduced expression of the androgen receptor in the preoptic area and progesterone receptor in the mediobasal hypothalamus, the key regions involved in male and female sexual behavior, respectively. Thus, the neural structures controlling reproduction are vulnerable to developmental exposure to phthalates at environmentally relevant doses in male and female mice. Adult females had an impaired gonadotropic axis and showed more affected behaviors than adult males.

High circulating concentrations of estradiol are anabolic for bone mass and strength in an adult male to female transgender mouse model

The effects of gender affirming hormone therapy (GAHT) on bone microarchitecture and fracture risk in adult transgender women is unclear. To investigate the concept that skeletal integrity and strength in trans women may be improved by treatment with a higher dose of GAHT than commonly prescribed, we treated adult male mice with a sustained, high dose of estradiol. Adult male mice at 16 weeks of age were administered ~1.3 mg estradiol by silastic implant, implanted intraperitoneally, for 12 weeks. Controls included vehicle treated intact females and males. High-dose estradiol treatment in males stimulated the endocortical deposition of bone at the femoral mid-diaphysis, increasing cortical thickness and bone area. This led to higher stiffness, maximum force, and the work required to fracture the bone compared to male controls, while post-yield displacement was unaffected. Assessment of the material properties of the bone showed an increase in both elastic modulus and ultimate stress in the estradiol treated males. Treatment of male mice with high dose estradiol was also anabolic for trabecular bone, markedly increasing trabecular bone volume, number and thickness in the distal metaphysis which was accompanied by an increase in the histomorphometric markers of bone remodelling, mineralizing surface/bone surface, bone formation rate and osteoclast number. In conclusion, a high dose of estradiol is anabolic for cortical and trabecular bone in a male to female transgender mouse model, increasing both stiffness and strength. These findings suggest that increasing the current dose of GAHT administered to trans women, while considering other potential adverse effects, may be beneficial to preserving their bone microstructure and strength.

From “Husky” to “Bulldog”– behavioural correlates between castration and breed groups in the domestic dog (Canis lupus familiaris)

Neutering dogs is a widespread method and is carried out for various behavioural and husbandry reasons. This study’s main objective is to investigate the behavioural correlations between neutering and the breed of male dogs. In order to possibly find breed-dependent differences in the behaviour of intact and castrated dogs, a differentiation between two clades - the “Huskies“(chow chow, shar pei, akita/shiba inu, alaskan malamute, siberian/alaskan husky) and the “Bulldogs” (german boxer, english/french bulldog, old english mastiff, boston terrier, english bull terrier, staffordshire bull terrier, american staffordshire terrier), based on Parker et al. [1], was made.Using an online questionnaire,, 31 neutered and 37 intact male dogs from the clade “Huskies“ and 30 neutered and 38 intact male dogs from the clade “Bulldogs”, participated in the study (N = 136).The survey included detailed questions on the dogs’ personality and any associated issues as well as a behavioural anamnesis. Further questions relating to four of the “big five” personality dimensions based on the “Budapest questionnaire” by Turcsán et al. from 2011 [2] were also added.The results show, that neutered males from both breed clades more frequently displayed aggression toward humans than intact males (multinomial logistic regression, p = 0.002). When it came to aggression towards other dogs, it was the “Huskies” that differed significantly from the “Bulldogs“(multinomial logistic regression, p = 0.04) with being more aggressive. There were also significant differences in stress-related behaviour depending on castration status and breed (multinomial logistic regression, p < 0.001; Cramer’s V = 0.33) and only the castration status had an impact on the significance (multinomial logistic regression, p < 0.001). The analysis also revealed significance for stress-indicating behaviour with dependence on neutering status (multinomial logistic regression, p < 0.001) and showed that stress as well as uncertainty are significantly more common in neutered dogs depending on breed and neutering status (multinomial logistic regression, p < 0.001; Cramer’s V = 0.42), in that only neutered “Bulldogs“ were stressed, but more “Huskies“ overall.According to the Budapest questionnaire data, the “Bulldog” clade had considerably greater extraversion scores overall (ordinal regression, p < 0.001) than the “Huskies“.Our findings highlight the risks and potential negative effects of neutering. Gonadectomy in no way substitutes for the dog receiving the necessary socialization, training, or bonding. Although in some circumstances it might have a favourable impact on the dog’s behaviour, it should not be seen as a panacea for unwanted behaviour. Given that not all behaviours are influenced by sex hormones, every castration decision must be weighed up individually.

Is There a Difference in the Prevalence of Gastric Ulcers between Stallions Used for Breeding and Those Not Used for Breeding?

Equine gastric ulcer syndrome (EGUS) is a worldwide disease, and includes two different syndromes, Equine Squamous Gastric Disease (ESGD), affecting the squamous mucosa, and Equine Glandular Gastric Disease (EGGD), affecting the glandular mucosa. These two diseases are present in different categories (different activities, ages, etc.) and breeds of horses. The effect of sex on gastric health is not clear: some studies found a higher prevalence of ESGD in geldings and stallions, while others found no influence of sex on the squamous mucosa. The few studies conducted on glandular diseases failed to identify sex as a risk factor. The only study on breeding horses, focused on Thoroughbred mares at pasture, found that 70% of them were affected by gastric ulcerations especially in the squamous mucosa. The aim of this study was to determine the prevalence of EGUS, ESGD, and EGGD in intact males while also investigating the potential influences of breeding and exercise activity on the occurrence and severity of the diseases. A total of 101 intact males were admitted for gastroscopic examination. Comprehensive data regarding their breeding and sports history, management, and presence of clinical signs were recorded. A statistical analysis was performed. Within this equine population, no discernible relationship was found between breeding activity and occurrence and severity of ESGD or EGGD. Exercise and a combination of exercise and breeding activities were found to be associated with the occurrence of EGGD. The presence of clinical signs was correlated only with the grade of ESGD in this cohort of horses.

An ovine model for investigation of the microenvironment of the male mammary gland.

The specific biology of the male breast remains relatively unexplored in spite of the increasing global prevalence of male breast cancer. Delineation of the microenvironment of the male breast is restricted by the low availability of human samples and a lack of characterisation of appropriate animal models. Unlike the mouse, the male ovine gland persists postnatally. We suggest that the male ovine mammary gland constitutes a promising adjunctive model for the male breast. In this study, we evaluate the male ovine mammary gland microenvironment, comparing intact and neutered males. Assessment of the glandular histo-anatomy highlights the resemblance of the male gland to that of neonatal female sheep and confirms the presence of rudimentary terminal duct lobular units. Irrespective of neutered status, cell proliferation in epithelial and stromal compartments is similarly low in males, and cell proliferation in epithelial cells and in the intralobular stroma is significantly lower than in pubertal female sheep. Between 42% and 72% of the luminal mammary epithelial cells in the male gland express the androgen receptor and expression is significantly reduced by neutering. Luminal epithelial cells within the intact and neutered male gland also express oestrogen receptor alpha, but minimal progesterone receptor expression is observed. The distribution of leukocytes within the ducts and stroma is similar to the mammary gland of female sheep and females of other species. Both macrophages and T lymphocytes are intercalated in the epithelial bilayer and are more abundant in the intralobular stroma than the interlobular stroma, suggesting that they may have a protective immunological function within the vestigial glandular tissue of the male sheep. Mast cells are also observed within the stroma. These cells cluster near the glandular tissue and are frequently located adjacent to blood vessels. The abundance of mast cells is significantly higher in intact males compared to neutered males, suggesting that hormone signalling may impact mast cell recruitment. In this study, we demonstrate the utility of the male ovine mammary gland as a model for furthering our knowledge of postnatal male mammary biology.

23 The effects of dietary net energy level on grow-finish performance and carcass characteristics of intact male market pigs managed with Improvest

Abstract Improvest is a gonadotropin releasing factor (GnRF) analogue-diphtheria toxoid conjugate product approved for temporary suppression of testicular function and reduction of boar taint in intact male pigs (Zoetis Canada Inc.). Objectives for this study were to determine the effects of dietary net energy (NE) level during the grow-finish period on live performance and carcass characteristics of intact male pigs managed with Improvest/immunological castration (IC) when compared with physically castrated (PC) male pigs. The 101-d study began when 1,008 pigs (504 intact male pigs and 504 PC male pigs; 10 wk old) were allocated by body weight to 48 pens with 21 intact males or 21 PC males per pen. Three dietary NE treatments were fed to pigs using five dietary phases to provide an average of 2,212 kcal/kg (Low NE), 2,337 kcal/kg (Medium NE), or 2,462 kcal/kg (High NE). Dietary programs were formulated according to standardized ileal digestible lysine requirements of IC males or PC males. The experiment was designed and analyzed as a 2 × 3 factorial with main effects of Improvest management and NE. For the overall study period, there were no significant interactions between Improvest management and NE (P ≥ 0.19) for average daily feed intake (ADFI), average daily gain (ADG), or gain to feed ratio (G:F; Table). There were also no significant interactions between Improvest management and NE (P ≥ 0.06) for carcass characteristics. Immunologically castrated male pigs consumed less feed (5.3% less ADFI; P &amp;lt; 0.01), grew faster (5.1% greater ADG; P &amp;lt; 0.01), and were more efficient (11.2% greater G:F; P &amp;lt; 0.01) compared with PC male pigs. Hot carcass weight (HCW) did not differ (P = 0.16) between IC males and PC males (attributed to 1.6 percentage unit less dressing percentage for IC males; P &amp;lt; 0.01); however, IC males were leaner (0.9 mm less backfat and 0.65% greater predicted lean yield; P &amp;lt; 0.01) compared with PC males. For the overall study period, pigs fed Low NE and Medium NE diets consumed more feed than pigs fed High NE diets, and pigs fed Low NE diets grew slower than pigs fed Medium NE and High NE diets. This resulted in pigs fed Low NE diets having 4.4% less G:F than pigs fed Medium NE and 8.6% less G:F than pigs fed High NE diets (P &amp;lt; 0.01). Pigs fed Low NE had 3.0 kg lighter (P &amp;lt; 0.01) HCW compared with Medium NE, while High NE had intermediate HCW that did not differ from the other two treatments. Overall, typical Improvest response levels were sustained for each of the NE treatments in this study; however, consideration should be provided to the known production impacts of low NE diets when male market pigs are managed with Improvest.

Interplay of hormones and metabolite excretion with fern pattern prove saliva as a potent indicator of male reproductive status in Kangayam breed cattle.

Kangayam cattle are one of the drought breeds in India with distinct attributes. Agricultural transformation has led to a decline in many pure-breed indigenous cattle, including the Kangayam breed. Hence, a study on the reproductive physiology of male Kangayam breed cattle is necessary to disentangle problems in the area of livestock improvement. In this study, we investigated the relationship between serum hormones and bio-constituents and ascertained the potential of saliva as an indicator of the reproductive status of Kangayam cattle (Bos indicus). The present study confirms that cholesterol was higher in intact males and lower in prepubertal and castrated males. Testosterone levels were also higher in intact males than in castrated or prepubertal males. Hence, it can be inferred that high cholesterol levels contribute to active derivatization of testosterone in intact males. In contrast, reduced cholesterol availability leads to decreased testosterone synthesis in castrated and prepubertal males. Furthermore, it is reasonable to speculate that testosterone could have influenced salivary fern patterns in intact males, and thus, fern-like crystallization in the saliva was apparent. The unique salivary compounds identified through GC-MS across various reproductive statuses of Kangayam males may advertise their physiological status to conspecifics. In addition, the presence of odorant-binding protein(OBP) in saliva further supports its role in olfactory communication. This study attested to a posssible interlink between gonadal status and serum biochemical profiles. The salivary fern pattern revealed in this study can be used as a predictive tool, and the presence of putative volatiles and OBP adds evidence to the role of saliva in chemical communication.

Effects of Cross-Sex Hormone Therapy on Metabolic Parameters and Aortic Relaxation in Castrated Male Rats

With the rising awareness, the number of individuals identifying themselves as transgender in the US is increasing over the years. Cross-sex hormone therapy (CSHT) may alter numerous cardiometabolic parameters leading to the increased risk of cardiovascular diseases (CVD) in transgender population. Epidemiological studies suggest that transgender females (male to female, MtF) on estrogen therapy develop higher risk of CVD compared to transgender males (female to male, FtM) taking testosterone. Underlying mechanisms of impaired cardiovascular functions in MtF are not well documented. This study was undertaken to examine the effects of 17β-estradiol (E2) on certain cardiometabolic parameters and aortic reactivity in castrated (CAS) male Sprague Dawley (SD) rats. The 8-10-weeks old CAS rats were subcutaneously implanted with either 1.5 mg of E2 (CAS+E2) or placebo (CAS+PL) containing pellets for ~35 days. The age-matched SD intact male (IM) rats were also included in the experimental groups. After performing the glucose tolerance test, animals were sacrificed, and the blood was collected for later measurements of the HbA1C and triglyceride (TG) levels. Endothelium-dependent vasorelaxation (EDV) to acetylcholine (ACh) in aortic rings pre-contracted with phenylephrine (PE) was measured before and after treatment with indomethacin (a cyclooxygenase inhibitor), followed by L-NAME [a nonselective nitric oxide (NO) synthase (NOS) inhibitor]. Contractile responses to PE before and after L-NAME in aortic rings and sodium nitroprusside (SNP)-induced relaxation responses in endothelium-denuded rings were also measured. Here, we report the decreased body weight and visceral white adipose tissue, and improved HbA1C and glucose tolerance in E2-treated CAS rats. However, the E2-treated CAS rats exhibited elevated plasma level of TG. Furthermore, the vascular relaxation to ACh was significantly impaired in aortas from this group compared to those in CAS+PL and IM rats. The impairment of ACh responses in CAS+E2 rats was accompanied by a significant decrease in NO contribution to ACh vasorelaxation. The basal NO levels and the smooth muscle sensitivity to NO were not altered, whereas the maximum contractile responses to PE were enhanced in aortas of CAS+E2 group compared to IM. In conclusion, our data suggests that the glucose homeostasis was improved in CAS+E2 rats. Regardless, this group exhibited increased level of TG in plasma and decreased aortic vasorelaxation to ACh. The impairment of EDV in E2-treated CAS rats might be due to reduced NO-mediated vasorelaxation or increased contractile responses observed in this group. Additional studies are needed to document the underlying mechanisms for improvement of glucose homeostasis and impairment of EDV in CAS+E2 rats. NIDA/NIGMS, 1SC1DA052120-01 to MF and Bridge Grant from University of the Pacific to RR. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Potential of different strategies to increase intramuscular fat deposition in sheep: A meta-analysis study

We evaluated the potential of different strategies to increase intramuscular fat (IMF) deposition in sheep meat through meta-analytical methods. Additionally, this study aimed to investigate the interrelationship among diet composition, performance, carcass traits, meat quality, marbling score and IMF in sheep. The dataset was composed by 102 peer-reviewed publications. The strategies to increase IMF deposition in sheep meat were evaluated by examining the weighted mean difference (WMD) between control treatment and increased-IMF treatment (beta-agonist; glycerin; essential oil; vitamin E; lipids; tannins; feeding system and sex class). The interplay between factors such as dietary composition, performance, carcass and meat quality traits highlights how the intensification of production systems, characterized by a high grain content in the diet and shorter finishing periods, reduces IMF content of meat. The IMF content was greater in females (WMD = 0.52%; P<.0001) and castrated males (WMD = 0.53%; P = 0.001) compared to intact males. Lambs finished in feedlots exhibited a 19.23% higher IMF content (WMD = 0.74%; P <.0001) compared to those finished in pasture systems. The inclusion of lipids sources to the diets increased in IMF content (WMD = 0.11%; P = 0.008), while tannins sources decrease in IMF (WMD = −0.07%; P = 0.029). Marbling score did not prove to be an adequate indicator of IMF deposition in sheep meat, potentially due to biases in subjective marbling assessments. In conclusion, our findings suggest that the most effective strategy for enhancing IMF in lambs involves utilizing female or castrated males rather than intact males followed by finishing lambs on high concentrate diets in a feedlot. Genetics did not impact IMF in the evaluated studies while other dietary strategies to alter IMF deposition had mixed effects on IMF deposition. Tannin marginally decreased IMF, vitamin E had no effect, and lipid supplementation had varied effects on IMF deposition depending on the lipid source.

Anatomical and topographic substantiation of various accesses to the proximal epiphysis of the tibia

One of the most frequently performed accesses in the practice of an orthopedic veterinarian is access to the proximal epiphysis of the tibia. Access to the proximal epiphysis of the tibia is necessary in many cases of treatment of pathologies of the musculoskeletal system in cats and dogs and can be used in such surgical pathologies. The aim of the study was to consider options for surgical access to the proximal epiphysis of the tibia to perform osteosynthesis of fractures according to the Salter–Harris type, and osteotomy leveling the slope of the tibial plateau (TPLO) with anatomical and topographic justification. The study was conducted in the Network of veterinary centers "Kotonai" and the Department of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine. The object of the study was dogs of small and medium breeds in the number of twelve individuals. The average age of the patients ranged from 6 months to 12 years. The study involved 5 intact females and 7 intact males. The average weight at the time of the study ranged from 2.5 to 21.0 kg. In the process of collecting the life history of all patients, the presence of chronic diseases, allergies and infectious diseases is excluded. The initial examination of the animal included: collection of anamneses of life and illness, general clinical examination, thermometry, neuroorthopedic examination, auscultation of the heart and lungs, X-ray examination under sedation. General clinical examination, thermometry and auscultation of the heart and lungs did not reveal pathological changes in all cases. According to the results of the study, it was found that there were no severe postoperative complications requiring repeated treatment in the studied patients. With the observance of clear anatomical and topographic landmarks in the formation of accesses, a good understanding of the anatomy of the medial and cranial surfaces of the tibia, visualization in the wound during surgical interventions (osteosynthesis of SalterHarris fractures, TPLO osteotomy) in the area of the proximal epiphysis of the tibia is convenient and safe.

Ponies, miniatures, and younger equids are at higher risk of fecalith obstruction compared to a general colic population.

To determine breed, age, and sex predispositions for fecalith obstruction and to evaluate short-term survival and prognostic factors following surgical treatment of fecalith intestinal obstruction in equids. 151 equids. Medical records of equids undergoing surgery for fecalith obstruction from 2000 to 2020 were reviewed. Signalment, history, presenting clinicopathological data, surgical findings, complications, and short-term survival were recorded and compared between survivors and nonsurvivors. Signalment of the fecalith population was compared to a contemporaneous colic population. Clinical factors were assessed for association with outcome. 64 females, 53 castrated males, and 31 intact males were included. Three equids presented twice. Miniature horses, ponies, and miniature donkeys/mules represented 48% (71/148) of fecalith population and full-sized breeds represented 52% (77/148). Miniature horses and ponies were overrepresented and equids ≤ 1 year of age were overrepresented in the fecalith population compared to the colic population. One hundred thirty-nine equids (92%) survived to discharge, 6% (9/148) were euthanized intraoperatively, and 2% (3/148) were euthanized during hospitalization. Nonsurvivors showed more severe colic signs on admission, tachycardia on admission, and hyperlipemia. Equids with postoperative colic (P = .01) and complications (P = .002) were less likely to survive. Miniature horses and ponies were overrepresented compared to the colic population; however, full-sized breeds were also affected. Surgical treatment had an excellent short-term prognosis. Severe colic signs, tachycardia, hyperlipemia, postoperative colic, and surgical complications negatively affected short-term survival.

Causes of Sex Differences in Serum Cholesterol and Triglyceride Levels in Meishan Pigs.

To clarify the causes of sex differences (male < female) in the serum total cholesterol (TCHO) and triglyceride (TG) levels in Meishan pigs, we examined the sex differences in mRNA levels of key hepatic enzymes involved in the biosynthesis/metabolism of cholesterol and TG using real-time RT-PCR. There were no sex differences in mRNA levels of 3-hydroxy-3-methylglutaryl-CoA reductase and CYP51A1 for cholesterol biosynthesis, or of the rate-limiting enzyme CYP7A1 for bile acid synthesis from cholesterol. By contrast, sex differences (male < female) were observed in mRNA levels of glycerol-3-phosphate acyltransferase 1 (GPAT1), a rate-limiting enzyme for TG biosynthesis. However, the sex differences in mRNA levels of carnitine palmitoyltransferase 1A (CPT1A) and acyl-CoA dehydrogenase long chain (ACADL), key enzymes for the oxidation of the fatty acids that are structural components of TG, were the opposite (male > female). Castration of male pigs led to an increase in the mRNA level of GPAT1 and decreases in those of CPT1A and ACADL. Furthermore, testosterone propionate (TP)-treatment of castrated males and intact females restored and changed, respectively, these mRNA levels to those of intact males. Notably, castration and TP-treatment increased and decreased, respectively, serum and hepatic TG levels. These findings suggest that sex differences in the serum and hepatic TG levels in Meishan pigs are closely correlated with differences in testosterone-associated mRNA expression levels of the key enzymes (GPAT1, CPT1A, and ACADL) involved in the TG biosynthesis process, although no causes of sex differences in serum and hepatic TCHO levels could be found.

An In-Depth Look at Fonni's Dog Behavior under Different Outdoor Conditions.

This study aimed to investigate the common social and communicative behaviors of the Fonni's Dog under different outdoor conditions. For this study, 70 adult dogs (3-7 years; 32 intact males, 38 intact females) belonging to the Fonni's breed were used. A total of 35 dogs were kept in kennels and 35 were free-ranging dogs in their sheep/goat livestock units. A behavioral repertoire was adapted from the literature and an ethogram was filled in for each dog. All dogs were evaluated in the presence of the owner. Fisher's exact test, following Bonferroni's correction, was used to test possible differences in the categorical variables (presence or absence of the behavior) between free-ranging dogs and dogs kept in kennels. The study revealed that several categories of the dogs' body language were associated with the management condition. However, the breed motivations (guarding and defense of the territory) were satisfied both in kennel and in the animals who were free in the property. The current study suggests a good behavioral balance of the Fonni's Dogs which could be attributed to correct communication between dogs and owners.