Intact Males Research Articles

Feeding behavior in nursery pigs affected with gastric ulcers

Gastric ulcers are a common pathological finding at slaughterhouses, with a prevalence of up to 65% in finishers and 35% in nursery pigs. Pigs’ eating behavior is a dynamic process that can be adapted to feed supply, social pen interactions, and disease status. However, evidence addressing the effect of gastric ulceration on feeding behavior in nursery pigs is limited.This study aimed to identify key differences in the diurnal feeding behavior of nursery pigs with no lesions in the pars oesophagea and pigs with severe ulcers in pars oesophagea and fed pelleted feed ad libitum by assessing: (1) differences in the duration of feeding time per visit to the feeder (minutes/visit); (2) differences in the total feeding time per day (minutes/day); (3) differences in the number of feeding visits per day (visits/day).In total, 199 intact male (n = 105) and female (n = 94) nursery pigs were assessed for gastric lesions 6 weeks after weaning observing an overall prevalence of 84%. Based on a gastric health assessment, pigs were characterized as either NLPO “no lesions in the pars oesophagea” (only healthy and parakeratosis scores) or LPO “lesions in the pars oesophagea” (erosions, ulcers, scars, and oesophageal stenosis). The LPO group was further divided into a subgroup: POU “severe ulcers in pars oesophagea” (ulcers with oesophageal stenosis). Diurnal feeding behavior was retrospectively assessed for 30 nursery pigs (15 NLPO and 15 POU) using video recordings from 06:00 AM to 10:00 PM (16 h) for 7 days before the stomachs were collected.The regression model showed that the POU nursery pigs had a tendency to eat for a longer period (+1.3 min) each time they visited the feeder (p = 0.055), but had significantly (p = 0.044) fewer feeding visits (-2.3 visits) during the day compared to NLPO nursery pigs. Both NLPO and POU pigs spent the same amount of feeding time at the feeder per day. Furthermore, it was observed that intact males spent significantly (p = < 0.05) less time per feeding visit to the feeder, had more feeding visits per day, and spent longer feeding time per day compared to females.In conclusion, this study showed that feeding behavior in nursery pigs 6 weeks after weaning was weakly associated with severe gastric ulceration. However, severe gastric ulceration did not have an effect on the total feeding time per day. Moreover, it was found that feeding behavior in nursery pigs is strongly associated with sex.

SEX DIFFERENCES IN AORTIC STENOSIS PROGRESSION IN A MURINE MODEL

<h3>BACKGROUND</h3> Sex differences in stenosed aortic valve have been recently demonstrated, however sex-specific progression of aortic stenosis (AS) remains unstudied. This study aims to examine the impact of sex and sex hormones on the progression of AS in a murine model of AS. <h3>METHODS AND RESULTS</h3> LDL-/- ApoB100/100 IGF-II+/- mice fed with high fat/sucrose/cholesterol diet were divided in 6 groups: intact males (IM), intact females (IF), castrated males (CM), ovariectomized females (OF), CM with testosterone supplementation (CMT) and OF with estrogen supplementation (OFE). Echocardiographic evaluation of AS and valve tissue histological analysis were performed at 12 and 36 weeks. Among male mice, IM had the fastest progression of peak aortic jet velocity (Vpeak) (24.2±5.7 cm/s; p < 0.001) compared to CM (6.2±1.4; p=0.42) who did not progress significantly, and CMT had a significant intermediate progression of Vpeak (15.1±3.5; p=0.002; p for interaction=0.02 - Figure). Accordingly, indexed aortic valve area (AVAi) decreased significantly in the IM and CMT groups, while the decrease in AVAi was smaller and did not reach statistical significance in the CM group (IM: -0.68±0.21cm2/m2; p < 0.001 vs. CMT: -0.40±0.20 cm2/m2; p < 0.001 vs. CM: -0.15±0.28 cm2/m2; p=0.07; p for interaction < 0.001). Among female mice, Vpeak progression was significant and similar in all groups (IF: 25.8±5.3; p < 0.001; OF: 12.8±2.6; p=0.03; OFE: 18.5±3.4; p=0.003; p=0.29 - Figure). Accordingly, AVAi decreased in the three female groups (IF: -0.60±0.22cm2/m2; p < 0.001, OFE: -0.66±0.19 cm2/m2; p < 0.001, OF: -0.43±0.22 cm2/m2; p < 0.001; p for interaction < 0.001). Aortic valve leaflets were thicker at 36 weeks compared to 12 weeks (median [IQR]: 0.143[0.120-0.188] vs.0.103[0.056-0.120] mm; p < 0.001). The largest decrease of leaflet fibrosis was seen in CMT (-13.76±4.53%), compared to CM (-8.67±4.53%) and IM (-5.18±7.22%) (p=0.02). Leaflet fibrosis increased among female groups (OF: 14.43±7.04; IF: 5.31±14.41; OFE: 9.21±17.04%; p=0.46). At 12 weeks, we found no evidence of leaflet calcification. At 36weeks, female mice had lower amounts of calcification than male mice (IF: 0.00[0.00-0.43], OF: 0.40[0.17-1.38], OFE: 0.45[0.07-1.85], IM: 6.01[1.87-40.7], CMT: 4.00[0.00-7.05], CM: 1.66[0.06-21.80] %; p=0.02). <h3>CONCLUSION</h3> In this murine model of AS, testosterone played an important role in hemodynamic AS progression in male mice unlike estrogen on hemodynamic AS progression in female mice. Despite valve thickness increasing in all groups, the composition of the valve leaflet was different between male and female mice, and testosterone presence was associated with higher calcification of the valve.

Влияние глипролинов на уровень сывороточных каспаз в условиях «социального» стресса

Objective. To investigate the effect of glyprolines on the levels of initiating and effector caspases in the serum of white rats under "social" stress. Materials and methods. The study was conducted on 90 white male rats of 6 months of age. All manipulations with animals were carried out in accordance with international and domestic requirements for working with laboratory animals. When modeling "social" stress, groups of animals with aggressive and submissive behavior were formed. Laboratory animals, taking into account the types of behavior, were divided into groups (n=10): a group of intact males (control); a group of animals exposed to" social " stress for 20 days (stress); groups of individuals who received intraperitoneal Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro), Pro-Gly-Pro, Pro-Gly-Pro-Leu at doses of 100 mcg/kg / day from the 1st day of stress exposure within a 20- day course. The effect of neuropeptides on the activity of apoptosis processes was evaluated by determining the level of initiating and effector caspases (caspase-8 and caspase-3) (ELISA Kit for Caspase-8 and ELISA Kit for Caspase-3; USA) in the blood serum of white rats by enzyme immunoassay. Results. According to the results of the study, it was found that under conditions of "social" stress, an increase in apoptotic processes was observed, accompanied by an increase in the level of caspase-3 and caspase-8 in the blood serum of white rats. The introduction of the studied compounds against the background of stress contributed to a decrease in the level of the studied indicators, which is most likely due to the presence of antiapoptotic action in glyprolins due to inhibition of the caspase-dependent cascade of apoptosis reactions, as a result of which the destruction of cellular structures occurs by hydrolysis of nuclear lamina, cleavage of adhesive proteins, destruction of the cytoskeleton. Conclusion. Thus, the conducted study established the presence of Thr-Lys-Pro-Arg-Pro-Gly-Pro (Selank), Pro-Gly-Pro and Pro-Gly-Pro-Leu under conditions of stress-induced antiapoptotic activity due to inhibition of the caspase-dependent cascade of apoptosis reactions.

Non-therapeutic male circumcision in infancy or childhood and risk of human immunodeficiency virus and other sexually transmitted infections: national cohort study in Denmark

Whether male circumcision in infancy or childhood provides protection against the acquisition of human immunodeficiency virus (HIV) or other sexually transmitted infections (STIs) in adulthood remains to be established. In the first national cohort study to address this issue, we identified 810,719 non-Muslim males born in Denmark between 1977 and 2003 and followed them over the age span 0–36 years between 1977 and 2013. We obtained information about cohort members’ non-therapeutic circumcisions, HIV diagnoses and other STI outcomes from national health registers and used Cox proportional hazards regression analyses to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) associated with foreskin status (i.e., circumcised v. genitally intact). During a mean of 22 years of follow-up, amounting to a total observation period of 17.7 million person-years, 3375 cohort members (0.42%) underwent non-therapeutic circumcision, and 8531 (1.05%) received hospital care for HIV or other STIs. Compared with genitally intact males, rates among circumcised males were not statistically significantly reduced for any specific STI. Indeed, circumcised males had a 53% higher rate of STIs overall (HR = 1.53, 95% CI: 1.24–1.89), and rates were statistically significantly increased for anogenital warts (74 cases in circumcised males v. 7151 cases in intact males, HR = 1.51; 95% CI: 1.20–1.90) and syphilis (four cases in circumcised males v. 197 cases in intact males, HR = 3.32; 95% CI: 1.23–8.95). In this national cohort study spanning more than three decades of observation, non-therapeutic circumcision in infancy or childhood did not appear to provide protection against HIV or other STIs in males up to the age of 36 years. Rather, non-therapeutic circumcision was associated with higher STI rates overall, particularly for anogenital warts and syphilis.

The Role of Reproductive Hormones in Sex Differences in Sleep Homeostasis and Arousal Response in Mice.

There are various sex differences in sleep/wake behaviors in mice. However, it is unclear whether there are sex differences in sleep homeostasis and arousal responses and whether gonadal hormones are involved in these sex differences. Here, we examined sleep/wake behaviors under baseline condition, after sleep deprivation by gentle handling, and arousal responses to repeated cage changes in male and female C57BL/6 mice that are hormonally intact, gonadectomized, or gonadectomized with hormone supplementation. Compared to males, females had longer wake time, shorter non-rapid eye movement sleep (NREMS) time, and longer rapid eye movement sleep (REMS) episodes. After sleep deprivation, males showed an increase in NREMS delta power, NREMS time, and REMS time, but females showed a smaller increase. Females and males showed similar arousal responses. Gonadectomy had only a modest effect on homeostatic sleep regulation in males but enhanced it in females. Gonadectomy weakened arousal response in males and females. With hormone replacement, baseline sleep in gonadectomized females was similar to that of intact females, and baseline sleep in gonadectomized males was close to that of intact males. Gonadal hormone supplementation restored arousal response in males but not in females. These results indicate that male and female mice differ in their baseline sleep–wake behavior, homeostatic sleep regulation, and arousal responses to external stimuli, which are differentially affected by reproductive hormones.

Оценка репродуктивной способности самцов крыс при остром токсоплазмозе

Toxoplasmosis is a parasitic disease of humans and animals caused by Toxoplasma gondii. Toxoplasma is an intracellular parasite that belongs to the simplest and has a complex development cycle. Infection with Toxoplasma is possible orally, transplacentally, percutaneously (if the integrity of the skin is damaged). This invasion is often the cause of problems with bearing pregnancy, as well as the development of congenital anomalies in children. The purpose of the study was to study the reproductive ability of male rats in acute toxoplasmosis. Materials and methods. The experiment was performed on 90 female and 45 male Wistar rats with a body weight of 180-200 g. The intact control males were orally injected with 2 ml of 0.2% starch gel. Experimental groups of males were infected with an invasive Toxoplasma gondii culture at a dose of 25 tachyzoites per 1 g of body weight (5000 tachyzoites per rat) and 50 tachyzoites per 1 g of body weight (10000 tachyzoites per rat). Then the males of all groups were coupled with the females for 3 days. The effect of toxoplasmas on the reproductive ability of male rats was assessed by the development of pregnancy and changes in the levels of pre- and post-implantation embryo death in female rats on the 7th, 14th, and 21st days after pregnancy. To account for changes in the pre- and post-implantation death of embryos in female rats after removal from the experiment, the uterus and ovaries were isolated, the uterine horns were opened, the number of implantation sites, the total number of embryos, the number of living and dead embryos, the number of resorption, and the number of yellow bodies in the ovaries were determined. Results and discussion. In the females of the 4th, 5th and 6th groups (coupling with males infected at the dose of 25 tachyzoites per 1 g of body weight), a decrease in the number of implantation sites in the uterus, the total number of embryos and the number of live embryos was recorded by 1.8-1.9 times compared to the control parameters. In female rats of the 7th, 8th and 9th groups (coupling with males infected at the dose of 50 tachyzoites per 1 g of body weight), there was a decrease in the number of implantation sites in the uterus, the total number of embryos and the number of live embryos by 5.6-6.8 times compared to the control. When compared to the results obtained from the females of the 4th, 5th and 6th groups, a decrease in these indicators was recorded by 3.1-3.5 times. Conclusion. Toxoplasma gondii has an effect on reproductive capacity in male rats expressed in changes of the levels of preimplantation mortality in female rats. The obtained effect depends on the dose of infection and the period of parasitosis development in males

Differential expression of urinary volatile organic compounds by sex, male reproductive status, and pairing status in the maned wolf (Chrysocyon brachyurus).

The maned wolf (Chrysocyon brachyurus) is an induced ovulator. Though the mechanism of ovulation induction remains unknown, it is suspected to be urinary chemical signals excreted by males. This study assessed volatile organic compounds (VOCs) in weekly urine samples across 5 months from 13 maned wolves (6 intact males, 1 neutered male, 6 females) with the goal of identifying VOCs that are differentially expressed across sex, reproductive status, and pairing status. Solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used to extract and separate VOCs that were identified via spectral matching with authentic standards, with spectral libraries, or with new software that further matches molecular fragment structures with mass spectral peaks. Two VOCs were present across all 317 urine samples: 2,5-dimethyl pyrazine and 2-methyl-6-(1-propenyl)-pyrazine. Fifteen VOCs differed significantly (Adj. P < 0.001 and |log2 fold change| >2.0) between intact males and females. Using partial least squares-discriminant analysis, the compounds with the highest importance to the sex classification were delta-decalactone, delta-dodecalactone, and bis(prenyl) sulfide. Sixty-two VOCs differed between intact males and the neutered male. Important classifier compounds were 3-ethyl 2,5-dimethyl pyrazine, 2-methyl-6-(1-propenyl)-pyrazine, and tetrahydro-2-isopentyl-5-propyl furan. Several VOCs established as important here have been implicated in reproductive communication in other mammals. This study is the most robust examination of differential expression in the maned wolf thus far and provides the most comprehensive analysis of maned wolf urinary VOCs to date, increasing the sample size substantially over previous chemical communication studies in this species. New data analysis software allowed for the identification of compounds in the hormone-producing mevalonate pathway which were previously unreported in maned wolf urine. Several putative semiochemicals were identified as good candidates for behavioral bioassays to determine their role in maned wolf reproduction, and specifically in ovulation induction.

Sex Differences and Estradiol Effects in MAPK and Akt Cell Signaling across Subregions of the Hippocampus

Introduction: Rapid effects of estrogens within the hippocampus of rodents are dependent upon cell-signaling cascades, and activation of these cascades by estrogens varies by sex. Whether these pathways are rapidly activated within the dentate gyrus (DG) and CA1 by estrogens across sex and the anatomical longitudinal axis has been overlooked. Methods: Gonadally intact female and male rats were given either vehicle or physiological systemic low (1.1 µg/kg) or high (37.3 µg/kg) doses of 17β-estradiol 30 min prior to tissue collection. To control for the effects of circulating estrogens, an additional group of female rats was ovariectomized (OVX) and administered 17β-estradiol. Brains were extracted, and tissue punches of the CA1 and DG were taken along the longitudinal hippocampal axis (dorsal and ventral) and analyzed for key mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) cascade phosphoproteins. Results: Intact females had higher Akt pathway phosphoproteins (pAkt, pGSK-3β, and pp70S6K) than males in the DG (dorsal and ventral) and lower pERK1/2 in the dorsal DG. Most effects of 17β-estradiol on cell signaling occurred in OVX animals. In OVX animals, 17β-estradiol increased cell signaling of MAPK and Akt phosphoproteins (pERK1/2, pJNK, pAkt, and pGSK-3β) in the CA1 and pERK1/2 and pJNK DG. Discussion/Conclusions: Systemic 17β-estradiol treatment rapidly alters phosphoprotein levels in the hippocampus, dependent on reproductive status, and intact females have greater expression of Akt phosphoproteins than that in intact males in the DG. These findings shed light on underlying mechanisms of sex differences in hippocampal function and response to interventions that affect MAPK or Akt signaling.

Disentangling digesta passage rate in the gastrointestinal tract of male and female growing goats fed varying feeding levels using multivariate and metanalytical approaches

Digesta passage rate (kp) in ruminants is a very dynamic and complex process and is related to digestion, methane emission, and microbial growth. The objectives of this study were to identify variables related to kp in gastrointestinal tract (GIT) segments by creating latent variables using multivariate factor analysis and access the important sources of variation (i.e., goats’ growth, sex, or feeding levels) of each created latent variables. Two data set were used from three studies with Saanen goats. Data set Growth was composed of individual records of castrated males (n = 36), females (n=34), and intact males (n=33) fed ad libitum and slaughtered at 15 (16.62 ± 0.96 kg body weight (BW)), 22 (23.09 ± 1.33 kg BW), 30 (30.67 ± 2.25 kg BW), 37 (38.02 ± 1.61 kg BW), or 45 (44.12 ± 1.95 kg BW) kg BW. Data set Feeding Level was composed of individual records of castrated males (n=38), females (n=33), and intact males (n=36) fed ad libitum (26.82 ± 2.54 g/kg BW), 75% (22.90 ± 1.99 g/kg BW) or 50% (20.44 ± 2.05 g/kg BW) of ad libitum, over 109 ± 10 days. Four orthogonal latent variables were extracted from each data set, and they explained around 61% of the original variability of each data set. Digesta passage rate had different responses whether evaluated in growing goats or goats fed varying feeding levels in the long term. Growing goats had kp of solutes in reticulorumen, omasum, and colon-rectum positively related to DM intake level and chews/kg DM intake and negatively related to GIT sections capacity and BW growth. Moreover, DM intake level, reticulorumen kp of particles, and large intestine kp of solutes and particles were all positively related in growing goats. Goats fed varying feeding levels had kp of solutes in all GIT segments positively related to feeding level and capacity of GIT segments and negatively related to chews/kg DM intake. Reticulorumen kp of particles was not associated with any of the selected factors of the data set Feeding Level. In conclusion, DM intake level is the driving force of GIT kp of solutes in growing goats and goats fed varying feeding levels in the long term. Also, the GIT kp of solutes is negatively affected by GIT capacity and positively affected by chews/kg DM intake only in growing goats. Moreover, kp of particles in reticulorumen and kp of particles and solutes in large intestine of growing goats are positively related among them and positively related to DM intake level. However, reticulorumen kp of particles is constant in goats fed varying feeding levels in the long term. Sex effect on GIT kp seemed to depend on chews/kg DM intake, however, further investigations are needed to fully understand sex effects on kp.

17-α-Estradiol Has Sex-Specific Effects on Neuroinflammation That Are Partly Reversed by Gonadectomy.

17-α-Estradiol (17aE2) treatment from 4 months of age extends life span in male mice and can reduce neuroinflammatory responses in the hypothalamus of 12-month-old males. Although 17aE2 improves longevity in males, female mice are unaffected, suggesting a sexually dimorphic pattern of life-span regulation. We tested whether the sex-specific effects of 17aE2 on neuroinflammatory responses are affected by gonadal removal and whether hypothalamic changes extend to other brain regions in old age. We show that sex-specific effects of 17aE2 on age-associated gliosis are brain region specific and are partially dependent on gonadectomy. 17aE2 treatment started at 4 months of age protected 25-month-old males from hypothalamic inflammation. Castration before 17aE2 exposure reduced the effect of 17aE2 on hypothalamic astrogliosis in males. In contrast, sex-specific inhibition of microgliosis generated by 17aE2 was not significantly affected by castration. In the hippocampus, gonadectomy influenced the severity of gliosis and the responsiveness to 17aE2 in a region-dependent manner. The male-specific effects of 17aE2 correlate with increases in hypothalamic estrogen receptor alpha expression, specifically in gonadally intact males, consistent with the idea that 17aE2 might act through this receptor. Our results indicate that neuroinflammatory responses to 17aE2 are partially controlled by the presence of sex-specific gonads. Loss of gonadal function and age-associated neuroinflammation could, therefore, influence late-life health and disease onset, leading to sexual dimorphism in both aging and in response to drugs that modify the pace of aging.

Castration delays epigenetic aging and feminizes DNA methylation at androgen-regulated loci.

In mammals, females generally live longer than males. Nevertheless, the mechanisms underpinning sex-dependent longevity are currently unclear. Epigenetic clocks are powerful biological biomarkers capable of precisely estimating chronological age and identifying novel factors influencing the aging rate using only DNA methylation data. In this study, we developed the first epigenetic clock for domesticated sheep (Ovis aries), which can predict chronological age with a median absolute error of 5.1 months. We have discovered that castrated male sheep have a decelerated aging rate compared to intact males, mediated at least in part by the removal of androgens. Furthermore, we identified several androgen-sensitive CpG dinucleotides that become progressively hypomethylated with age in intact males, but remain stable in castrated males and females. Comparable sex-specific methylation differences in MKLN1 also exist in bat skin and a range of mouse tissues that have high androgen receptor expression, indicating that it may drive androgen-dependent hypomethylation in divergent mammalian species. In characterizing these sites, we identify biologically plausible mechanisms explaining how androgens drive male-accelerated aging.

Sex-related response in mice after sub-acute intraperitoneal exposure to silver nanoparticles

Silver nanoparticles (AgNPs) are among the most commercialized nanomaterials in biomedicine due to their antimicrobial and anti-inflammatory properties. Nevertheless, possible health hazards of exposure to AgNPs are yet to be understood and therefore raise public concern in regards of their safety.In this study, sex-related differences, role of steroidal hormones and influence of two different surface stabilizing agents (polymer vs. protein) on distribution and adverse effects of AgNPs were investigated in vivo. Intact and gonadectomised male and female mice were treated with seven AgNPs doses administered intraperitoneally during 21 days. After treatment, steroid hormone levels in serum, accumulation of Ag levels and oxidative stress biomarkers in liver, kidneys, brain and lungs were determined.Sex-related differences were observed in almost all tissues. Concentration of Ag was significantly higher in the liver of females compared to males. No significant difference was found for AgNP accumulation in lungs between females and males, while the lungs of intact males showed significantly higher Ag accumulation compared to gonadectomised group. Effect of surface coating was also observed, as Ag accumulation was significantly higher in kidneys and liver of intact females, as well as in kidneys and brain of intact males treated with protein-coated AgNPs compared to polymeric AgNPs. Oxidative stress response to AgNPs was the most pronounced in kidneys where protein-coated AgNPs induced stronger effects compared to polymeric AgNPs. Interestingly, protein-coated AgNPs reduced generation of reactive oxygen species in brains of females and gonadectomised males. Although there were no significant differences in levels of hormones in the AgNP-exposed animals compared to controls, sex-related differences in oxidative stress parameters were observed in all organs.Results of this study highlight the importance of including the sex-related differences and effects of protein corona in biosafety evaluation of AgNPs exposure.

Testosterone Increases the Emission of Ultrasonic Vocalizations With Different Acoustic Characteristics in Mice.

Testosterone masculinizes male sexual behavior through an organizational and activational effects. We previously reported that the emission of ultrasonic vocalizations (USVs) in male mice was dependent on the organizational effects of testosterone; females treated with testosterone in the perinatal and peripubertal periods, but not in adults, had increased USV emissions compared to males. Recently, it was revealed that male USVs have various acoustic characteristics and these variations were related to behavioral interactions with other mice. In this regard, the detailed acoustic characteristic changes induced by testosterone have not been fully elucidated. Here, we revealed that testosterone administered to female and male mice modulated the acoustic characteristics of USVs. There was no clear difference in acoustic characteristics between males and females. Call frequencies were higher in testosterone propionate (TP)-treated males and females compared to control males and females. When the calls were classified into nine types, there was also no distinctive difference between males and females, but TP increased the number of calls with a high frequency, and decreased the number of calls with a low frequency and short duration. The transition analysis by call type revealed that even though there was no statistically significant difference, TP-treated males and females had a similar pattern of transition to control males and females, respectively. Collectively, these results suggest that testosterone treatment can enhance the emission of USVs both in male and female, but the acoustic characteristics of TP-treated females were not the same as those of intact males.

Surgical sterilization impacts on behavior of coyote pairs

Coyotes (Canis latrans) involved in depredation of livestock, an act frequently resulting in human-wildlife conflict, often do so out of necessity for provisioning pups. Surgical sterilization methods such as vasectomy that preserve gonadal hormones have been successful in reducing depredation by free-ranging coyotes while allowing individuals to maintain territoriality and mate fidelity. However, use of these methods remain costly and ineffective for wide-scale use. Given the alternative proposal of using chemical sterilization techniques, we investigated whether the use of hormone-altering sterilization methods impacted behavior of captive coyote pairs (i.e., male-female pair bonds). Our objective was to evaluate behavior and reproductive hormones of mated coyote pairs that had received different surgical sterilization treatments. We assigned mated pairs of captive coyotes to different sterilization treatment groups (vasectomy, spay, neuter, ovary-sparing spay, and intact) and coded their behavior as the time spent in resting versus active (i.e., walking, running, scent communication, and aggressive interactions) behaviors. Additionally, hormone concentrations were analyzed to determine effectiveness of hormone-altering treatment, given the potential role of gonadal hormones in regulating behavior. The study was repeated across three breeding seasons. The top model comparing time spent active versus resting was the null model, although the model that included whether sterilization type altered hormones and year also had a ΔAIC of < 2.0. Testosterone concentrations between neutered and vasectomized or intact males was significantly different, indicating sterilization treatment was successful and the different sterilization techniques impact hormones differently; there were no statistical difference for estradiol or progesterone levels among female treatment groups. No sterilized pairs produced pups, but the intact pairs did. Although there are potentially some differences in behavior across sterilization treatment types, our results suggest sterilization of coyotes holds potential as a future management strategy as behavior did not differ among different treatments. Potential difference across years suggest further research is necessary to determine potential extraneous factors influencing behavior and the effect of treatment on territoriality on free-ranging coyotes.

The effect of pyriproxyfen on the concentration of circulating metabolic fuel molecules and chemical elements in the hemolymph of Acraea horta L. (Lepidoptera: Nymphalidae): A quantitative analysis

Many pollinating insects expand their niche to adjacent agricultural areas and are, therefore, exposed to chemical insecticides. Acraea horta L. (Lepidoptera: Nymphalidae) is a pollinator butterfly widely distributed in the Southern African region. The objectives of this work were to evaluate carbohydrate, lipid and chemical elements in the hemolymph of A. horta exposed to pyriproxyfen, a juvenile hormone analog (JHA). Last instar larvae (L6: day 1 or day 2) were topically exposed to an aqueous solution of pyriproxyfen (100 μg of the active ingredient per insect) or to diluent (control group). Hemolymph was collected after adult eclosion to determine total carbohydrate and lipid concentrations: in the control group lipids were present in lower concentrations than carbohydrates and there was no significant difference in metabolite levels between sexes; a similar pattern with similar levels were measured in the treated group, except that lipid concentrations in treated males were lower, and carbohydrate concentrations in treated females were lower than the control values. Morphologically intact adult males from treated larvae were subjected to free flight; their hemolymph carbohydrate levels were significantly reduced and did not recover to starting levels in a 30 min rest period following the exhaustive flight episode. To assess the effect of pyriproxyfen on a different stage of development, 48 h old butterflies were treated in the same way as described for the L6 larvae above; hemolymph samples were taken 48 h later for metabolite measurements and for quantification of chemical elements: carbohydrate levels decreased significantly after pyriproxyfen exposure, while lipid levels increased; inorganic elements measured in untreated adults were more abundant in females, with a general decrease in concentration following pyriproxyfen exposure, except for an increase in Fe levels in males and Cl levels in females. The quantitative changes measured in A. horta hemolymph via biochemical and chemical element analyses may indicate distinct physiological interferences beyond the main mode of action of pyriproxyfen on JH activity. In conclusion, the use and quantification of pyriproxyfen should be carefully evaluated prior to application in areas where A. horta and other pollinator species occur.

Macromineral and trace element requirements for Santa Ines sheep

Minerals play an important role in animal metabolism. Knowledge of mineral requirements allows well-formulated diets to be provided, which is the main factor that affects performance. To determine the macromineral and trace element requirements for growth and maintenance, thirty-eight 2-month-old Santa Ines lambs with initial body weight (BW) of 13.0 ± 1.49 kg were distributed in a factorial design with feeding levels (ad libitum, 30% and 60% feed restriction) and sex classes [castrated (CM) and intact males (IM)]. The net mineral requirements for gain were higher (P < 0.05) with increasing BW and average daily gain, except for Ca and Na, which remained constant as the empty BW (EBW) increased. The macromineral net requirement for maintenance (g/kg EBW0.75) and the true retention coefficient (k; %) were 0.0784 and 65.2 for Ca, 0.0926 and 80.0 for P, and 0.0379 and 59.0 for K, respectively. The k of Mg was higher (P < 0.05) for IM (11.3 for IM and 7.9 for CM). Sex did not affect (P > 0.05) the maintenance requirement of the trace elements Co, Cu, Zn and Cr which were 0.0015, 0.037, 0.698, and 0.0055 (mg/kg EBW0.75), respectively. Our study indicated that the Santa Ines net mineral requirements are different from the main nutritional requirements established by committees for sheep, which may result in unbalanced diets.

Hyperprolactinemia in a male pituitary androgen receptor knockout mouse is associated with female-like lactotroph development.

Circulating prolactin concentration in rodents and humans is sexually dimorphic. Oestrogens are a well-characterised stimulator of prolactin release. Circulating prolactin fluctuates throughout the menstrual/oestrous cycle of females in response to oestrogen levels, but remains continually low in males. We have previously identified androgens as an inhibitor of prolactin release through characterisation of males of a mouse line with a conditional pituitary androgen receptor knockout (PARKO) which have an increase in circulating prolactin, but unchanged lactotroph number. In the present study, we aimed to specify the cell type that androgens act on to repress prolactin release. PARKO, lactotroph-specific, Pit1lineage-specific and neural-specific conditional androgen receptor knockout male mice were investigated using prolactin ELISA, pituitary electron microscopy, immunohistochemistry and qRT-PCR. Lactotroph-specific, Pit1lineage-specific and neural-specific conditional AR knockouts did not duplicate the high circulating prolactin seen in the PARKO line. Using electron microscopy to examine ultrastructure, we showed that pituitary androgen receptor knockout male mice develop lactotrophs that resemble those seen in female mice. Castrated PARKO males have significantly reduced circulating prolactin compared to intact males. When expression of selected oestrogen-regulated anterior pituitary genes was examined, there were no differences in expression level between controls and knockouts. The cell type that androgens act on to repress prolactin release is not the lactotroph, cells in the Pit1-lineage, or the dopaminergic neurons in the hypothalamus. PARKO males develop a female-specific lactotroph ultrastructure that this is likely to contribute to the increase in circulating prolactin. Castrated PARKO males have significantly reduced circulating prolactin compared to intact males, which suggests that removal of both circulating oestrogens and androgens reduces the stimulation of pituitary prolactin release. Further investigation is needed into prolactin regulation by changes in androgen-oestrogen balance, which is involved sexual dimorphism of development and diseases including hyperprolactinemia.

Characteristics and trait preferences of West African Dwarf goat keepers in Ghana.

A study was conducted to evaluate the characteristics of West African Dwarf (WAD) goat keepers and their trait preferences as part of a broader phenotypic characterisation work with the aim of providing information for improving the household management, conservation and productivity of the breed in Ghana. A total of 384 respondent households were selected from four agro-ecological zones in the middle belt and southern part of the country for questionnaire administration and direct observation of animals under field conditions. The results showed that there are slightly more women (54.2%) keeping WAD goats than men (45.8%) and fall within the economically active population of youthful and middle age categories (53.9%). A majority of these goat keepers were married (73.8%) and educated (87.3%) in one way or the other. They obtained their starter or foundation stock mainly from neighbours (80.5%) and the open market (16.0%). The average flock size from the households sampled was 7.9 ± 1.5, whereas the flock structure constituted 56.1% adult females, 27.5% adult intact males, 1.2% castrates and 15.2% kids of both sexes. Survivability, fast growth rate and larger litter size were the farmers' most preferred quantitative traits, whereas most of these respondents preferred to keep WAD goats which do not have qualitative traits such as horn, wattle and beard. From the findings of the research, it was concluded that the favourable socio-economic characteristics of WAD goat keepers could sustain intensification and increase the productivity of the breed when given the necessary input assistance along the goat value chain. The primary objective of WAD goat farmers is to produce matured animals for various purposes and the breeding goal for a WAD goat breeding programme would be to increase survival, growth rate and litter size of light coat (white, grey and light brown) goats. Finally, most farmers lack knowledge on the significance of tropically beneficial qualitative traits such as horn, wattle, beard and light coat colouration on the survivability, climate adaptability or resilience and productivity of their goats. Educating farmers on the importance of conserving and inclusion of animals possessing such traits in their selection practices under the Government's Rearing for Food and Jobs Initiative is therefore suggested.

Metabolizable Protein: 2. Requirements for Maintenance in Growing Saanen Goats.

This study aimed to estimate the protein requirements for the maintenance of growing Saanen goats of different sexes from 5 to 45 kg of body weight (BW) using two methods and applying a meta-analysis. For this purpose, two datasets were used. One dataset was used to evaluate the effects of sex on the protein requirements for maintenance using the comparative slaughter technique. This dataset was composed of 185 individual records (80 intact males, 62 castrated males, and 43 females) from six studies. The other dataset was used to evaluate the effects of sex on the protein requirements for maintenance using the N balance method. This dataset was composed of 136 individual records (59 intact males, 43 castrated males, and 34 females) from six studies. All studies applied an experimental design that provided different levels of N intake and different levels of N retention, allowing the development of regression equations to predict the net protein requirement for maintenance (NPM) and the metabolizable protein (MP) requirements for maintenance (MPM) in Saanen goats. The efficiency of MP use for maintenance (kPM) was computed as NPM/MPM. The efficiency of MP use for gain (kPG) was calculated using the equation of daily protein retained against daily MP intake above maintenance. A meta-analysis was applied using the MIXED procedure of SAS, in which sex was considered a fixed effect, and blocks nested in the studies and goat sex were considered as random effects. The NPM did not differ between sexes, irrespective of the approach used. The daily NPM estimated was 1.23 g/kg0.75 BW when using the comparative slaughter technique, while it was 3.18 g/kg0.75 BW when using the N balance technique for growing Saanen goats. The MPM estimated was 3.8 g/kg0.75 BW, the kPM was 0.33, and the kPG was 0.52. We observed that the NPM when using the comparative slaughter technique in growing Saanen goats is lower than that recommended by the current small ruminant feeding systems; on the other hand, the MPM was similar to previous reports by the feeding systems. Sex did not affect the protein requirements for maintenance and the efficiencies of use of metabolizable protein.

Evaluation of the ability of haemodynamic variables obtained with minimally invasive techniques to assess fluid responsiveness in endotoxaemic Beagles

ObjectiveTo examine the ability of different haemodynamic variables recorded by minimally invasive monitoring techniques to assess fluid responsiveness (FR) in endotoxaemic Beagles. Study designProspective terminal experimental study. AnimalsA group of six healthy, purpose-bred Beagle dogs (three intact females and males), age 5–9.8 years (range) and weighing 11.4–17.9 kg. MethodsEndotoxaemic shock was induced by injecting 1 mg kg–1Escherichia coli lipopolysaccharide (LPS) intravenously in six sevoflurane-anaesthetized mechanically ventilated Beagles for another project. After 10 minutes, three Ringer’s acetate boluses (10 mL kg–1) were administered each over 10 minutes with collection of haemodynamic data immediately before and after each bolus. Thereafter, arterial hypotension was treated with noradrenaline ± dexmedetomidine until arterial pressures increased to a target value. After a wash-out period of 20 minutes another three boluses of fluid were administered and measurements were repeated equally. For each fluid bolus, FR was considered positive when change (Δ) in stroke volume measured by pulmonary artery thermodilution was ≥15%. To test predictive accuracy for FR, we recorded heart rate, invasive arterial, right atrial and pulmonary capillary wedge pressures, pulse wave transit time with haemodynamic monitors, calculated pulse pressure, shock index and rate over pressure evaluation (ROPE) and measured stroke distance and corrected flow time (FTc) with oesophageal Doppler monitoring. ResultsA total of 35 measurements (19 positive and 16 negative responses) were evaluated. A FTc < 330 ms, Δ pulse pressure ≥20%, Δ shock index ≤–14% and ΔROPE ≤–17% were the most significant indicators of positive FR with an area under the receiver operating characteristics curve between 0.72 and 0.74. Conclusions and clinical relevanceIn endotoxaemic Beagles, none of the assessed haemodynamic variables could predict FR with high sensitivity and specificity.