Castrated Males Research Articles

The effect of castration on home range size and activity patterns of domestic cats living in a natural area in a protected area on a Brazilian island

The presence of domestic cats (Felis silvestris catus) in natural areas can generate several environmental problems, such as competition with other species, disease transmission, and predation. Male cats generally tend to be more territorial than female cats. Male cats also tend to have larger home ranges than female cats. In this study, we used radio-telemetry monitoring to demonstrate the significant effect of the castration of males in reducing the home range of cats living in semi-domiciliary conditions that have access to natural areas. The home range was calculated based on the minimum convex polygon method (we use 100 % of the location points collected in each period: before and after castration), and the kernel method fixed points (95 % of the locations in each period). We also determine the size of the activity centers for each individual using the fixed kernel method (including 25 or 50 % of each animal's location points collected in each period). As a consequence of this reduced home range (by 79.32 %), a reduction in the overlap between domiciliary and natural areas was also observed. The male cats’ activity patterns also decreased significantly (28.72 %). Thus, the castration procedure, in addition to its potential effects on population control, may be a possible strategy for wildlife conservation.

Hair as an alternative noninvasive matrix: sources of variation in testosterone levels

Hair is one widely used alternative matrix for endocrine studies. Not only can it maintain hormone content during storage for long periods of time, but its collection also induces little to no stress. Noninvasive techniques have broadened the opportunities for endocrine research, particularly regarding wild animals. Despite its advantages, many sources of variation may affect the steroid concentration found in hair, such as body location harvested, fur color, reproductive status, and sex. Thus, domestic species, such as the dog, are an excellent and approachable model for understanding this variability. For such, we addressed diverse sources of variation in testosterone concentrations from 24 domestic dogs (Canis lupus familiaris) of the Poodle breed of various colors and neuter status, and from both sexes. The variation comprised the comparison between 2 different matrices (blood vs hair); 2 different extraction storage methods (refrigerator vs freezer); 3 body regions (head, torso, and limbs); 3 coat colors (black, brown, and white); different neuter status (intact vs castrated males) and, finally, sex. Our results showed no correlation between blood and hair testosterone concentrations. Additionally, we did not find differences related to the storage method, body region, or coat color. There were differences in concentration between males and females, but not between females and castrated males. We discuss hair testosterone levels exhibited reasonable stability, and we present practical applications for both domestic and wildlife animals.

Pgc1a is responsible for the sex differences in hepatic Cidec/Fsp27β mRNA expression in hepatic steatosis of mice fed a Western diet.

Hepatic fat-specific protein 27 [cell death-inducing DNA fragmentation effector protein C (Cidec)/Fsp27] mRNA levels have been associated with hepatic lipid droplet extent under certain circumstances. To address its hepatic expression under different dietary conditions and in both sexes, apolipoprotein E (Apoe)-deficient mice were subjected to different experimental conditions for 11 wk to test the influence of cholesterol, Western diet, squalene, oleanolic acid, sex, and surgical castration on Cidec/Fsp27 mRNA expression. Dietary cholesterol increased hepatic Cidec/Fsp27β expression, an effect that was suppressed when cholesterol was combined with saturated fat as represented by Western diet feeding. Using the latter diet, neither oleanolic acid nor squalene modified its expression. Females showed lower levels of hepatic Cidec/Fsp27β expression than males when they were fed Western diets, a result that was translated into a lesser amount of CIDEC/FSP27 protein in lipid droplets and microsomes. This was also confirmed in low-density lipoprotein receptor (Ldlr)-deficient mice. Incubation with estradiol resulted in decreased Cidec/Fsp27β expression in AML12 cells. Whereas male surgical castration did not modify the expression, ovariectomized females did show increased levels compared with control females. Females also showed increased expression of peroxisome proliferator-activated receptor-γ coactivator 1-α (Pgc1a), suppressed by ovariectomy, and the values were significantly and inversely associated with those of Cidec/Fsp27β. When Pgc1a-deficient mice were used, the sex differences in Cidec/Fsp27β expression disappeared. Therefore, hepatic Cidec/Fsp27β expression has a complex regulation influenced by diet and sex hormonal milieu. The mRNA sex differences are controlled by Pgc1a.

Prevalence and risk factors of feline lower urinary tract disease in Chiang Mai, Thailand

Feline lower urinary tract disease (FLUTD) is a common problem in cats. The objectives of the study were to determine the prevalence, clinical signs, and causes of FLUTD and the risk factors for FLUTD. The medical records of 3486 cats visiting Chiang Mai University Small Animal Veterinary Teaching Hospital (VTH) between November 2016 and October 2017 were reviewed. An age-matched case-control study was performed to determine the risk factors for FLUTD by comparing 78 cats with FLUTD and 78 clinically normal age-matched cats. For each animal, potential risk data were obtained from medical records and cat owner interviews; these were analysed for associations with FLUTD. Multivariable logistic regression analysis was performed to estimate the odds ratios and to adjust for expected confounding factors. The prevalence of FLUTD in cats visiting the Chiang Mai University Veterinary Teaching Hospital was 2.2%. The most common clinical signs identified were urethral obstruction (55.1%) and haematuria (23.1%). The most common diagnoses were feline idiopathic cystitis (FIC) (57.7%) and urolithiasis (struvite) (18%). The multivariable logistic regression analysis results indicated that FLUTD was most likely to be diagnosed in castrated male cats. FIC and urolithiasis were the most common diagnoses in cats with FLUTD, and male sex and castration increased the risk of FLUTD.

Experimental and clinical justification of male orchidectomy under local anesthesia in combination with xylazine and subanesthetic doses of zoletil

The objective of our study was to establish the possibility of safe and painless castration of males using only sedatives together with local anesthesia. Animals, before appropriate fixation, were intramuscularly injected with xylanit (active substance xylazine) at a minimum dose of 1 mg/kg of live weight and zoletil at a subanesthetic dose of 1 mg/kg of animal weight, the testes and scrotal skin were infiltrated with 2% lidocaine solution according to the generally accepted method in veterinary surgery. Before, during, and after surgery, nociception indicators were evaluated: blood pressure; heart rate and respiration rate; degree of pain relief depth (presence of pain and spontaneous movement). During the surgery, the heart rate decreased, on average, by 40-50 beats/minute from baseline values, the respiratory rate decreased, on average, by 10 breaths/minute, and there was a decrease in blood pressure. We found that pre-sedation of animals with xylanite and subanesthetic doses of zoletil followed by tissue infiltration with lidocaine allowed humanely performing orchidectomy, as well as minimizing the cost of general anesthesia and the duration of anesthesia aftereffect on the body.

PPARγ inhibition boosts efficacy of PD-L1 Checkpoint Blockade Immunotherapy against Murine Melanoma in a sexually dimorphic manner.

Immune checkpoint blockade-based immunotherapy has become standard of care for multiple cancer types. However, the overall response rates among various cancer types still remain unsatisfactory. There is a pressing clinical need to identify combination therapies to improve efficacy of anticancer immunotherapy. We previously showed that pharmacologic inhibition of PPARγ by GW9662 boosts αPD-L1 and αPD-1 antibody efficacy in treating murine mammary tumors. In addition, we defined sexually dimorphic αPD-L1 efficacy in B16 melanoma. Here, we show a sexually dimorphic response to the combination of GW9662 and αPD-L1 immunotherapy in B16 melanoma. Combination effects were observed in female, but not male hosts. Neither female oöphorectomy impairs, nor does male castration rescue the combination effects, suggesting a sex hormone-independent response to this combination therapy. In diet-induced obese females, melanoma growth remained responsive to the combination treatment, albeit less robustly than lean females. These findings are informative for future design and application of immunotherapy-related combination therapy for treating human melanoma patients by taking gender and obesity status into consideration.

Testosterone replacement causes dose-dependent improvements in spatial memory among aged male rats

Testosterone has been shown to have dose-dependent effects on spatial memory in males, but the effects of aging upon this relationship remain unclear. Additionally, the mechanism by which testosterone regulates memory is unknown, but may involve changes in brain-derived neurotrophic factor (BDNF) within specific brain regions. We tested the effects of age and testosterone on spatial memory among male rats using two spatial memory tasks: an object-location memory task (OLMT) and the radial-arm maze (RAM). Castration had minimal effect on performance on the RAM, but young rats (2 months) performed significantly fewer working memory errors than aged rats (20 months), and aged rats performed significantly fewer reference memory errors. Both age and castration impaired performance on the OLMT, with only the young rats with intact gonads successfully performing the task. Subsequent experiments involved daily injections of either drug vehicle or one of four doses of testosterone propionate (0.125, 0.250, 0.500, and 1.00 mg/rat) given to castrated aged males. On the RAM, a low physiological dose (0.125 mg) and high doses (0.500–1.000 mg) of testosterone improved working memory, while an intermediate dose (0.250 mg) did not. On the OLMT, only the 0.250 mg T group showed a significant increase in exploration ratios from the exposure trials to the testing trials, indicating that this group remembered the position of the objects. Brain tissue (prefrontal cortex, hippocampus, and striatum) was collected from all subjects to assay BDNF. We found no evidence that testosterone influenced BDNF, indicating that it is unlikely that testosterone regulates spatial memory through changes in BDNF levels.

Technical note: novel delivery methods for an enterotoxigenic Escherichia coli infection model in MUC4-locus sequenced weaner pigs1.

An infection model with enterotoxigenic Escherichia coli (ETEC) harboring the F4 fimbriae can be used to assess the impacts that various challenges associated with weaning (e.g., dietary, psychological, environmental) have on the expression of postweaning diarrhea. The objective of this study was to develop a novel inoculation method for administering an ETEC culture that would induce a higher proportion of ETEC-F4 diarrhea, in pigs that genetically showed ETEC-F4 susceptibility or resistance. The study was designed as a factorial arrangement of treatments with the factors being 1) partially susceptible or resistant to ETEC-F4 based on genetic testing, and 2) 4 challenge treatments, being a) a conventional liquid broth method using a drenching gun [Positive control (PC)], b) a Syringe method, c) a Capsule method, and d) Negative control [pigs not challenged (NC)]. At 21 ± 3 d of age (mean ± SEM), 48 male castrate pigs (Large White × Landrace) weighing approximately 7.0 ± 1.18 kg were allocated to 4 treatment groups in 2 replicate pens (6 pigs per pen). Initial ETEC-F4 susceptibility was based on a DNA marker test and each treatment group had 9 partially susceptible and 3 resistant pigs. On days 7 and 8 after weaning, pigs were challenged with ETEC (serotype O149:K88; toxins LT1, ST1, ST2, and EAST). On each inoculation day the PC pigs were orally dosed with 9 mL 7.12 × 109 colony-forming unit (CFU), the Syringe pigs with 0.8 mL 6.72 × 109 CFU, the Capsule pigs were orally administered 2 capsules containing 0.8 mL 3.28 × 109 CFU, and the NC pigs 1 mL of phosphate-buffered saline (PBS) solution. Approximately 72 h after infection, 44, 22, 78, and 0% of partially susceptible pigs in the PC, the Syringe, the Capsule, and the NC group had developed ETEC-F4 diarrhea (P = 0.007). Partially susceptible pigs had a higher diarrhea index (DI) compared to resistant pigs (31.5 vs. 4.8, P < 0.001). The NC group had a lower DI compared to the PC and Capsule pigs (3.9, 38.1, and 40.3, respectively, P < 0.005). Following infection, genetically resistant pigs in the Capsule group had a DI of zero and the partially susceptible pigs had a DI of 55.6 (P = 0.014). This study showed that genetically screening pigs and using a Capsule to deliver ETEC-F4 can increase cases of diarrhea and the efficiency of the challenge model. Taken together, these methods have the potential to reduce the number of pigs needed in future experimental infection studies.

Interactive effects of feed allowance and ractopamine supplementation on growth performance and carcass traits of physically and immunologically castrated heavy weight pigs

One experiment was conducted to investigate the impact of feed allowance and ractopamine supplementation on growth, carcass and meat quality traits in barrows and immunocastrated male pigs. Eighty finishing male pigs (95.79 ± 1.71 kg) were allocated in a 2 × 2 × 2 factorial treatment design with two castration methods (CM) (physically (BA) x immunologically (IM) castrated pigs), two ractopamine supplementation programs (RAC) (0 vs 10 ppm in the feed) and two feeding allowance schemes (FA) (restricted (RT) vs ad libitum (AL)) from 131 to 160 days of age. RAC-fed pigs were heavier (P < 0.01) and RT pigs were lighter (P < 0.001) at the end of the evaluation period. Average daily weight gain was higher in IM (P < 0.05) and pigs fed diets without RAC and RT showed lower daily weight gain (P < 0.05). RAC improved feed efficiency regardless of CM and FA (P < 0.001). BA were fatter at 131 days of age (P < 0.001). RAC deaccelerated backfat deposition (P < 0.001) and improved lean muscle deposition (P < 0.01) after the 29-day duration of the trial. RAC increased slaughter weight (P < 0.01), hot carcass weight (P < 0.05) and lean muscle weight (P < 0.05). RT pigs showed decreased slaughter weight (P < 0.001) and backfat thickness was increased in BA fed diets without RAC (P < 0.01). BA pigs fed diets with 0 ppm RAC showed the highest backfat thickness and IM pigs fed diets with 0 ppm showed the lowest backfat depth (P < 0.01). IM AL pigs fed diets with 0 ppm showed the highest percentage of muscle and BA RT and BA AL pigs fed diets with 0 ppm showed the lowest lean muscle percentages (P < 0.01). Loin muscle area was reduced in RT pigs (P < 0.001) and increased by RAC (P < 0.05). Feeding RAC increased meat shear force (P < 0.01). In conclusion, our results confirm that rearing immunologically castrated males is a profitable alternative for pork producers and that feed restriction after the second vaccination negatively influences growth and carcass parameters, which can be partially compensated by ractopamine supplementation.

Evaluation of routine procedures in swine production as estimative methods of stress through the application of vocalization and speed of handling

Vocalization and behavior are non-invasive methods of animal welfare analysis. The objective of this study was to evaluate the welfare of piglets during Australian ear notching, tooth wear and castration, from vocalizations and behavioral aspects of pigs. For this, 281 piglets were used, with measurements of the maximum and minimum intensity of the noise emitted by the piglets and the time of accomplishment. The behavior of the piglets was obtained according to the activity performed during handling and containment. For behavioral analysis a specific etogram was used. The comparison of means was performed by T-test and PDIFF. The castration was the practice with the highest average of time of accomplishment, followed by the wear of teeth and ear notching. The highest mean values of minimum and maximum intensity were found for male castration in the slow process. It was observed that sex did not influence the time when the ear notching and tooth wear were performed, but at the same time the avoidance behavior was the most observed (P <0.05), with low frequency in castration. Therefore, it can be concluded that the procedures caused pain, characterized by vocal demonstrations and negative behavior.

Morphometric study of red blood cells in non-descriptive cattle with respect to age and sex

The present study was conducted to investigate the influence of age (calf, young and adult) and sex (female and castrated male) on the morphometry (mean length and mean breadth) of red blood cells (RBCs) of non-descriptive cattle. Blood samples were collected from each non-descriptive cattle with respect to age and sex by jugular venipuncture and collected in EDTA vials. Then, blood smears were prepared on grease-free microscopic slides then air-dried, fixed on methanol, and stained with Giemsa stain for morphometric study. The morphometric study was done with the help of the ocular micrometer and stage micrometer under 40X objective. Since there was no previous report on comparative morphometrical analyses of castrated males and female ND cattle of Odisha, an attempt has been taken to undertake this particular study. For both mean length and breadth, no significant difference was there among the different age groups of female cattle. Highly significant differences (p < 0.001) were observed between the mean length of RBCs of male calves with young castrated males and adult males. For mean breadth of RBCs, a highly significant difference (p < 0.01) was there between the male calves and male adults. A highly significant difference (p < 0.01) was there between the mean length of RBCs of the male calves with the mean length of RBCs of the young females. Therefore, age and sex have a profound effect on the morphometry of RBCs in non-descriptive cattle. Therefore, careful attention must be done in studying and interpretation of anemic conditions on the basis of size.

Effect of surgical or immune castration on postprandial nutrient profiles in male pigs

ABSTRACTTo avoid boar taint before slaughtering, late castration by immunisation against gonadotrophin releasing hormone or immunocastration has been developed. The current study aimed at determining whether differences in feed efficiency between castrated male (CM), immune castrated (IM) and entire male pigs (EM) can be explained by differences in nutrient plasma profiles after a meal. In this study, 24 male pigs (n = 8/type) were enrolled between 14 to 19 weeks of age. Entire and IM pigs ate less and were more feed efficient than CM pigs (p < 0.05). The postprandial plasma profiles of glucose, insulin, urea and amino acids (AA) were determined before (d –6), just after (d 8) and well after (d 16) the decrease in testicular hormones in IM pigs. For each test day, pigs were fasted overnight and subsequently fed a small meal (400 g). On d –6, postprandial profiles of plasma glucose of IM pigs did not differ from the two other types of pigs. On d 8, EM pigs had a greater average plasma glucose concentration than IM and CM pigs (p < 0.05) but the profiles did not differ. On d 16, the differences between profiles of glucose suggest a lower clearance of glucose in EM compared with IM and CM pigs. Plasma insulin did not significantly differ between the three types. Plasma urea profiles did not differ between CM, EM and IC pigs on d –6 whereas CM pigs showed higher plasma urea concentrations than EM and IM thereafter (p < 0.01). Among AA, Lys plasma concentrations were greater in CM than in EM and IM pigs on d –6, d 8 and d 16 (p < 0.05), whereas on d 16 plasma Hypro concentrations were lower in CM than in EM and IM pigs (p < 0.05). The finding that plasma glucose profiles were modified by immunocastration much faster and earlier than urea and AA profiles, suggest that the decrease in testicular hormones impacted energy metabolism more rapidly than protein metabolism.

Behavioral analysis and productive performance of piglets in the post-weaning phase in enriched environments

This study aimed to assess the effect of environmental enrichment on the behavior and productive performance of castrated piglets, both males and females, from 21 to 35 days of age. For this, 45 animals were randomly distributed in three treatments (control, environmental enrichment with pet bottle, and suspended rope), five replicates, and three animals per experimental unit. The experiment lasted 14 days, with 30 minutes of daily observation, and the observations were performed by the focal animal and behavior relative sampling. The data were recorded about the interactions with the objects, stereotypes, social and agonistic interactions, and animal activities. The productive performance was assessed by weighing three animals of the experimental unit, and their feed at the beginning and at the end of the experiment. We evaluated the daily weight gain, daily feed intake, and feed conversion. A descriptive analysis of the behavioral data was performed. The performance data were evaluated by analysis of variance. The comparison between the treatments was performed by Tukey test at 5% probability. Animals that received either the pet bottle or the suspended rope did not show a significant difference in social, agonistic, and physiologist interactions, but the results showed a significant difference in ludic interactions. Animals that did not receive any environmental enrichment displayed higher rates of stereotypes and aggressive behaviors. There was no effect (p > 0.05) of the treatments on the daily weight gain, daily feed intake, and feed conversion. Environmental enrichment improves the welfare of piglets by increasing physiological, social, and playful behaviors (positive), and decreasing stereotypy and agonistic behaviors (negative), but it does not influence the productive performance of animals.

Boar taint and meat quality characteristics of entire male and castrated male pigs

Abstract. The aim of the present research was to study the chemical composition, technological traits and intensity of boar taint of meat in entire male (EM) and surgically castrated male (CM) pigs. The study included 46 male pigs, cross F1 (Landrace x Danube White), fattened to average live weight 90 kg. In terms of chemical composition, the higher water and lipid content of the meat of entire male pigs, compared to the meat of surgically castrated male pigs was not statistically significant. A significant difference in the meat’s technological traits – pH values, water-holding capacity, cooking losses and tenderness between the two groups of male animals ware not found. The influence of the factor “castration” was reported in trait marbling of meat (p&lt;0.001). There were statistically significant differences in the values of L*, b* and Hue angle, defining the color characteristics of the meat.

ENDOCRINE HISTORY: The history of discovery, synthesis and development of testosterone for clinical use.

As the most important male hormone, testosterone has an impact on almost all organs and body functions. The biological effects of testosterone and the testes have been known since antiquity, long before testosterone was identified as the active agent. Practical applications of this knowledge were castration of males to produce obedient servants, for punishment, for preservation of the prepubertal soprano voice and even for treatment of diseases. Testes were used in organotherapy and transplanted as treatment for symptoms of hypogonadism on a large scale, although these practices had only placebo effects. In reaction to such malpractice in the first half of the 20th century science and the young pharmaceutical industry initiated the search for the male hormone. After several detours together with their teams in 1935, Ernst Laqueur (Amsterdam) isolated and Adolf Butenandt (Gdansk) as well as Leopold Ruzicka (Zürich) synthesized testosterone. Since then testosterone has been available for clinical use. However, when given orally, testosterone is inactivated in the liver, so that parenteral forms of administration or modifications of the molecule had to be found. Over 85 years the testosterone preparations have been slowly improved so that now physiological serum levels can be achieved.

Adipocyte PD-L1 Modulates PD-1/PD-L1 Checkpoint Blockade Cancer Immunotherapy Efficacy

Abstract PD-L1 expression in both tumor and host cells correlates with antitumor therapeutic efficacy, but the specific contribution of PD-L1 in various cell compartments to antitumor immunity remains to be fully elucidated. Here we show that PD-L1 expression is significantly elevated in human and mouse mature adipocytes versus preadipocytes. When co-cultured with mouse splenocytes, adipocytes reduce αPD-L1 antibody-mediated CD8+T cell activation. Genetic ablation of adipose PD-L1 obliterates, while enforced PD-L1 expression in preadipocytes confers, the immune-inhibitory effect of adipocytes. Pharmacologic inhibition of adipogenesis by the PPARγ antagonist GW9662 reduces adipose PD-L1 expression and enhances the antitumor efficacy of αPD-L1 and αPD-1 immunotherapies in female mice bearing syngeneic melanoma or mammary tumors. Combo treatment with GW9662 and αPD-L1 increased antitumor lymphocytes infiltration versus control or single agent treatment. In diet-induced obese female mice, combo treatment elicited suppressed melanoma growth, although less effectively versus lean females. In contrast to females, melanomas in either lean or obese male mice exhibited no applicable response to combo treatment. More strikingly, obese males lost αPD-L1 single treatment response versus lean males, with lower CD45+and CD3+T cell infiltration in tumors. However, castration in lean males rescued efficacy of combo treatment. These data suggest an antagonistic effect of male hormones in this combination. The potential impact of sex and obesity warrants consideration in future development of immunotherapy-related combination therapy.

Gender-Related Effect of Sodium Dichloroacetate on the Number of Hassall's Corpuscles and RNA NKCC1 Expression in Rat Thymus.

The aim was to investigate the effect of dichloroacetate (DCA) on thymus weight, Hassall's corpuscle number (HCs), and NKCC1 RNA expression in Wistar rats aged 4–5 weeks. They were investigated in the controls and DCA-treated gonad-intact and castrated males and females. The treatment lasted 4 weeks with DCA 200 mg/kg/day. At the end of the experiment, rat thymus was weighted, and its lobe was taken for the expression of NKCC1 RNA determined by the PCR method and of Hassall's corpuscles by immunohistochemistry. DCA caused a thymus weight decrease in DCA-treated gonad-intact rats of both genders as compared with their controls (p < 0.05), and no such impact was found in castrated DCA-treated males and females. DCA caused an increase of the HCs in gonad-intact males (p < 0.05), and no such increase in the DCA-treated gonad-intact females was found. There was gender-related difference in the HCs when comparing DCA-treated gonad-intact males and females: males showed significantly higher HCs (p < 0.05); no gender-related differences were found in the castrated DCA-treated groups. The Slc12a2 gene RNA expression level was found to be significantly decreased only in gonad-intact and in castrated DCA-treated males. The authors discuss the gender-related DCA effects on the thymus.

Acceptability of Dry-Cured Belly (Pancetta) from Entire Males, Immunocastrates or Surgical Castrates: Study with Slovenian Consumers.

Abandoning of male piglets castration in the European Union is a challenge for the pork production sector in particular for high-quality dry-cured traditional products. The information on consumer acceptability of dry-cured products from alternatives is limited, so the objective was to test the consumer acceptability of unsmoked traditional dry-cured belly (Kraška panceta) processed from three sex categories, i.e., surgical castrates (SC), entire males (EM) and immunocastrates (IC). Consumers (n = 331) were asked to taste dry-cured bellies from EM, IC and SC and to score the taste appreciation on a 9 cm unstructured scale. After tasting the pancetta of three sex categories, the consumers attributed the lowest acceptability scores to SC, whereas IC and EM received similar scores. Only about a quarter of consumers attributed the lowest score to EM, mainly when boar taint compounds were present. The results of this study indicate that a certain share of consumers was sensitive to taste deficiencies and that the leanness of this product is very important for consumers.

Regulatory role of metallothionein-1/2 on development of sex differences in a high-fat diet-induced obesity

AimsTo evaluate the role of metallothionein (MT) in sex differences of obesity, we examined the effect of MT on regulation of lipid accumulation in female and male wild type (WT) and MT1/MT2-null (MT-KO) mice. Main methodsMale and female WT and MT-KO mice fed standard diet (SD) or high-fat diet (HFD) for 35 weeks. Surgical castration in male mice was also performed to examine the effects of androgen on fat accumulation under HFD condition. Key findingsThe fat mass and size of adipocytes in white adipose tissue (WAT) was greater in adult MT-KO mice than in WT mice after 35 weeks of SD feeding without gender differences, suggesting a role of MT in limiting WAT development during normal growth in both sexes. In female mice fed HFD, weights of WAT and body were greater in MT-KO mice than in WT mice, indicating that MT had a preventive role against excess fat accumulation. In male mice fed HFD, WAT weight hardly increased in MT-KO mice compared to the increase in WT mice. Surgically castrated WT males fed HFD had lower WAT weight compared with sham-treated mice, although castrated MT-KO males fed HFD had greater increases in WAT weight compared with sham-treated mice and castrated WT males. SignificanceThese data suggest that MT could enhance the preventive action of estrogen against excess fat accumulation, on the contrary, MT augmented the ability of androgen to increase fat accumulation. MT may act to modify the susceptibility to obesity under sex hormones.

Challenges and opportunities to livestock breeding programmes in India.

Animal breeding in India has a long and chequered history. High pressure on agricultural land and increasing human population opened a new opportunity for the livestock and poultry sector as a promising food industry. Productivity of livestock in India is low due to less coverage of livestock under structured breeding programmes, inadequate nutrition and its entanglement with several socio-economic issues. A bottom-up approach to breeding policy formulation addressing local needs is required with assured flow of investments. Cattle slaughter is banned in India; hence, a legal policy to curb widespread indiscriminate mating is required which may incur substantial financial and infrastructural burdens for castration of stray males and strengthening of cow rehabilitation centres. Genetic evaluation of indigenous cattle with progeny testing (PT) requires substantial financial support, without affecting the already existing PT for exotic cattle breeds used in the local cross-breeding programmes and PT of new genotypes obtained from crosses of exotic and local breeds of cattle and for purebred buffaloes. Small ruminants need special attention due to their socio-economic importance in rural and often highly disadvantaged communities and because they are the second most important meat-producing species after poultry. Genetic improvement of small ruminants should be accompanied by attention to shrinking grazing resources which would require strong political will together with financial support. The outreach of breeding programmes for small ruminants is currently limited; there is also a lack of linkage between the market and producers that discourages farmers from adopting clear breeding objectives like improvement in growth rate, as animals are seldom sold on weight basis. Apart from government agencies, involvement of private sector, non-government organizations, local co-operatives, self-help groups and self-sustainable community-based breeding programmes can strengthen market linkages. Strengthening of the existing infrastructure along with technical input and skilled manpower is essential for achieving the breeding objectives.