Groups Of Mink Research Articles

Evaluation of genome stability, haematological and productivity performance of young mink when using dried palm fat

The article presents of the results on estimation genome stability, haematological and productive indices of young heads standard short-haired black mink, bred for pelts, when using in a diet supplement of dry palm fat during the period winter hair of formation (October-November). The control group of mink received a general farm diet without the additive. The palm fat additive was added to the feed mixture of the experimental group in an average amount of 0.75 g per 100 g of the feed mixture per day. It was found out that the composition the minks of the leukoformulas studied was within the physiological norm. Since four months of age, the young mink had a stable neutrophilic blood profile. Determination of the erythrocytes frequency containing micronuclei in the peripheral blood of young mink allowed to evaluate the stability (instability) of the genome during the introduction of dry palm fat to the diet. It was found that elevated frequency of erythrocytes containing micronuclei in the blood of males at the age of 7 months above the level of 7.7±1.84‰ (ppm) is connected with changes of diet composition and correlates with increase of live weight gain at conservation of morphophysiological characters and directed for realization of youngsters productivity - increase of area and good quality of skins.

Effect of intensity and duration of anthropic noises on European mink locomotor activity and fecal cortisol metabolite levels.

Human activities involving noise emission can affect wild animals. European mink was exposed to road noise and human voice playbacks to analyze how sound intensity level and duration of both noises altered the time that individuals were active and if their fecal cortisol metabolite (FCM) levels varied. A Hierarchical Analysis Cluster was performed to establish 2 mink groups with respect to both noise source type: short duration/low intensity (SL) and long duration/high intensity (LH). We performed general linear mixed models to evaluate the variation in locomotor activity duration (s) and FCM (nanogram per gram) levels, respectively. The results showed both road noise and human voices decreased locomotor activity duration in SL more sharply compared with LH, and human voices were the triggers that induced the most pronounced response to both exposure conditions. FCM (ng/g) levels increased in SL compared with LH during road noise while the opposite happened during human voices. Differences based on sex and age of individuals were observed. In conclusion, noise characteristics given by the sound type determined the variations in locomotor activity duration while noise exposure level determined the variations in FCM (ng/g) levels. Attention should be paid to noisy activities (e.g., recreational activities for visitors in protected natural areas) and loud groups of people to conserve wildlife, especially noise sensitive species.

Relaxer feed additive as a natural tranquilizer for farmed mink (Neovison vison) in stress situations

Mink, as carnivorous fur animals, are especially exposed to stress factors during mating, gestation, parturition, and rearing of the young that manifests as aggressive behaviour. So far, preparations applied on mink farms to relieve stress have shown low efficacy. Therefore, we aimed at determining whether the Relaxer feed supplement, prepared from valerian (Valeriana officinalis L.) and passionflower (Passiflora incarnata) extracts, can be applied to reduce the negative effects of stressors. The study was conducted on mink (Neovison vison) of the brown variety on a fur farm (Poland). The study was divided into two stages investigating the effect of the Relaxer additive on adult mink during the mating season (1%, 1.5%, 2% additive) and on young mink weaned from their mothers (1.5%). For all mink groups basic haematological and morphological blood parameters were determined. The animals’ condition and health were observed, and behavioural observations were made using a temperament test. The results of blood parameters of mink showed no negative impact of the additive on the animals’ health. Statistical differences were observed in red blood cell counts. Analysing the white blood cell count parameters from the first stage of the study, a decrease in white blood cell (WBC) count was observed in the blood of animals of groups K and D1 in successive intakes. In this stage, the lowest cortisol levels were obtained in groups D1 and D2. Analysing the red blood cell parameters of animals at stage II, statistically significant differences were observed. Smaller differences were observed for the studied parameters of the protein-cell image of mink blood. A lower percentage of animals with extreme behavioural types (aggressive and fearful) was found in the experimental group. The feed addition of a mixture of herbs significantly influenced the stress behaviour of mink. Improved behaviour was observed which resulted in improved animal welfare and optimised production parameters. The optimal proportion of the additive in the feed was set at 1.5%.

Pathogenicity comparison of the SMPV-11 and attenuated mink enteritis virus F61 in mink

Mink enteritis virus (MEV) is a major pathogen inducing acute hemorrhagic enteritis in mink. This study aims to determine the pathogenicity of the isolated MEV strain (SMPV-11) compared with the attenuated MEV strain (MEV-F61) in the mink. The two MEV strains were inoculated in the two mink groups, respectively. Then the clinical symptom, hematological, serological, and histopathological change were evaluated. Our findings showed that there were differences in the clinical features and pathological changes of the SMPV-11 and MEV-F61 in the mink. It indicates that SMPV-11 is a virulent strain, and it can be the potential MEV vaccine strain in the mink.

Experimental Infection with T. Canis and T. Leonina in Farm Mink (Neovison Vison).

IntroductionFarm mink (Neovison vison) can be naturally exposed to T. canis and T. leonina pathogens on the farm. If mink were hosts, it would imply some veterinary public health as well as animal welfare issues. For this reason, the aim of the study was to determine whether mink might be definitive or paratenic hosts of these parasites.Material and MethodsFour groups of mink were infected with both parasite species using larvated eggs or feed containing mouse tissue previously infected with the parasites. Following inoculation, the infections were monitored in vivo by faecal examination for 14 weeks p.i., and then western blotting and ELISA were performed.ResultsCoprology did not reveal any canine roundworm eggs, neither were nematodes found in mink intestines during post mortem examination. The specific IgG antibodies recognising excretory/secretory (ES) antigens of both parasite species were identified in mink sera. Single T. leonina tissue larvae were found in digested organs.ConclusionsOur results confirm that farm mink may contribute both T. canis and T. leonina infections. It was proved that farm mink were not their definitive hosts, and therefore mink faeces need not be considered a source of canine roundworm eggs in any soil it fertilises. Nonetheless, as farm mink may be a paratenic host for both parasite species, this may have some impact on the health and welfare of infected animals.

Addition of Dried Blood Plasma to Feed of Minks During Lactation and Rearing of Kits

Abstract Studies on the effects of dried blood plasma on certain health parameters of mink (of the pastel variety) were conducted during lactation and the rearing of the kits. The study included two groups of mink (control group and experimental group). Animals in the experimental group received 0.5 % of dry blood plasma and the control group did not receive the plasma supplement. From the whole blood of both groups the direct and indirect haematological indices were recorded. Also, in both groups, the histopathological and immunohistochemical studies were performed on the: liver, kidneys, lymph nodes, spleen, and intestinal segments. From the experimental group some of the organs examined demonstrated slightly altered histopathology.

Relationship between body weight and leptin concentrations in mink dams and the birth parameters of kits

The aim of this study was to assess the impact of the leptin concentration and body weight of mink females on the birth parameters of their kits. Blood samples were collected 3 times during preparation for reproduction, 7±2 days before mating. Total leptin concentration in serum was measured using commercial RIA kits (Millipore, St. Charles, Missouri USA). Research was conducted on 20 clinically healthy scanbrown female minks (Neovison Vison) aged 2-3 years. To evaluate their body condition, the females were divided into two groups based on the BCS scoring system. In the first group, referred to as BCS 2, lean females were included, and the second group (BCS 4) consisted of obese females. In mink dams belonging to BCS 2, the average leptin values were one-fourth of those in the BCS 4 group. The results obtained indicate the influence of the body mass of minks during preparation for reproduction on serum leptin concentration. The results of the Mann-Whitney U test showed a statistically significant difference between weights and leptin concentrations in groups BCS 2 and BCS 4. Among the other traits, such differences were not found. The analysis of results obtained in the two mink groups did not reveal a clear relationship between leptin in the serum of mothers before mating and the birth parameters of their kits.

Necrotizing and Eosinophilic Masticatory Myositis in Farmed Mink: a Preliminary Description

This report describes necrotizing and eosinophilic myositis affecting the masticatory muscles of a group of mink. Affected animals demonstrated sudden death with marked subcutaneous oedema over the dorsal head. The temporalis and masseter muscles were pale, swollen and friable. Histologic changes consisted of varying degrees of myodegeneration, myonecrosis and inflammation. Eosinophils were prominent in the inflammatory infiltrate. Similar to dogs, masticatory muscles in mink were found to contain unique type 2M fibres, suggesting a possible target for an immune response. Aerobic and anaerobic tissue cultures of the affected musculature revealed no significant pathogens. Histological and nutritional analyses were not typical of vitamin E/selenium deficiency. This case series supports the existence of a novel disease entity in mink with some features comparable with masticatory muscle myositis in dogs.

Tissue Pathomorphology and Immunohistochemistry in Mink (Neovison Vison) Fed Blood Plasma Supplemented Diet in the Period of Preparation for Breeding

Abstract The research carried out at a mink farm aimed to determine the effect of blood plasma supplemented diet applied at the period preparing mink for reproduction on the animal organism. The studies included four groups of mink. The control group received a non-supplemented diet, while the experimental groups had feed with additive of 0.5%, 1.5%, and 2.5% of beef-pork plasma in the daily feed ration. The pathomorphological and immunohistochemical evaluation was performed on the liver, kidneys, lymph nodes, spleen, and bowel from all the groups. Pathomorphological and immunohistochemical changes of various intensity were observed in the examined organs from all experimental groups.

RAPD Genetic Analysis on Etiological Factor of Mink Self-biting Disease

Self-biting is a chronic disease, which causes wound to effect mink growth and pelt quality. In this study, we first adopted the RAPD (random amplification polymorphism DNA) technique based on the reproducible 26 polymorphism primers screened from 100 random primers to analyze the hereditary constitution of the samples from healthy minks and self-biting minks, respectively, at molecular level with the aim to discuss the causes of self-biting. The results showed that 29 straps showed polymorphism among the amplified 105 straps, of which the polymorphism rate is 27.62%. Between healthy and sick mink groups, the amplified DNA fragment through different primers indicated different distribution frequency. The similarity coefficient of mink groups is 0.8471 and the genetic distance (variation) index is 0.1529. Through primer S356, we amplified different straps between healthy and sick mink. The amplified 1000 bp DNA fragment in the sick mink groups can preliminarily serve as molecular genetic label to distinguish between healthy and sick mink groups to gradually remove the mink individual of self-biting, to achieve purification of mink groups and reduce economy loss of the mink breeding industry. This study might provide the theoretical basis for further researches on molecular breeding and disease prevention of mink.

Mercury and stable isotopes of carbon and nitrogen in mink

Total Hg concentrations and values of stable isotopes (delta(15)N, delta(13)C) in tissues of mink (Mustela vison) captured in Rhode Island (USA) during winters of 1999 to 2004 were statistically distinct based on location. Mink captured in salt marsh environments (salt marsh group mink [SMGM]) had significantly lower mean Hg concentrations in liver and muscle tissue, and significantly higher delta(15)N and delta(13)C values in muscle, than those in corresponding samples of mink from upland freshwater locations (upland group mink [UPGM]). Stomach content samples obtained from the mink carcasses showed that fish, frogs, and crayfish were the dominant food items in UPGM, but in SMGM, fish predominated. Significant correlations were found for total Hg concentrations and stable isotope values between stomach contents and tissues. Comparisons of increases in Hg concentrations and delta(15)N values from stomach contents to muscle tissue showed nonsignificant differences between UPGM and SMGM for Hg concentrations (SMGM, factor of 4.2; UPGM, factor of 3.9) and delta(15)N values (SMGM, difference of 3.9 per thousand; UPGM, difference of 3.1 per thousand). These results suggest that the length of the trophic step and the extent of accumulation of Hg were approximately equal in both mink groups despite the differences in dietary composition and possible differences in accumulation of organic and inorganic Hg. The correspondence of stable isotope values and Hg concentrations between mink tissues and their stomach contents indicates that use of stomach content analysis to identify major prey items, followed by collection and analysis of appropriate field prey, may represent an approach for estimating Hg exposure to mink.

Efficacy of imidacloprid, imidacloprid/permethrin and phoxim for flea control in the Mustelidae (ferrets, mink)

Farmed mink (Mustela vison), a close relative of the domestic ferret (Mustela putorius furo), naturally infested with the squirrel flea (Ceratophyllus sciurorum) were included in a study to investigate three compounds for flea control. The test products were imidacloprid in a 10% (w/v) solution, an imidacloprid 10% (w/v)/permethrin 50% (w/v) solution, and phoxim; all three are well-known compounds for the control of different ectoparasites in a wide range of animals. Two groups of mink received 0.1 ml per animal of the imidacloprid or the imidacloprid/permethrin combination at days 0 and 28, respectively. Two groups of mink were sprayed with 25 ml of a 0.1% phoxim solution at day 0 and either 1x25 ml or 2x25 ml, respectively, of a 0.05% phoxim solution at day 28. One group of mink served as an untreated control. At assessment on day 56 the efficacy was 91.9% in the imidacloprid group, 89.3% in the imidacloprid/permethrin group, 92.2% in the phoxim 1x25-ml group and 99.3% in the phoxim 2x25 ml group, respectively. In the untreated control group an average of 757 fleas per mink nesting material was recorded.

DNA vaccination with the Aleutian mink disease virus NS1 gene confers partial protection against disease

Aleutian disease virus (ADV) causes severe losses in mink. This happens in nature as well as in farms. In spite of several attempts to provide an efficient protective protein based vaccine, experiments have failed so far. Only partial protection has been obtained. The aim of this work was to construct and test a protective DNA vaccine based on the gene encoding for the ADV non-structural protein 1 (NS1) and to test this construct as a potential vaccine candidate against ADV infection or disease. First, the vaccine construct was tested by in vitro transfection studies. NS1 protein expression was found by immunofluorescent studies and the expected size of translated protein confirmed by Western blot. Then, 18 female mink were divided into three groups: a control group, a DNA vaccinated group, and a group which received DNA vaccine plus a boost with recombinant NS1 protein in the last immunization. After virus challenge, the two DNA vaccinated groups induced higher antibody levels in the first 23 weeks of the 32 week observation period. One month after virus challenge, the most interesting finding was, that the “DNA + protein” group exhibited a significantly higher percentage of CD8 + cells, when compared to the levels in the two other groups. This, we believe, indicate a memory CTL response created by the vaccination. Most CD8 + cells were found to contain interferon gamma as measured by FACS intracellular staining. Severity of Aleutian disease was judged by quantification of plasma gammaglobulin levels and mink death statistics. The findings let us to conclude, that the two DNA vaccinated groups of mink did show milder disease characteristics, but that the vaccine effect also in this trial could only be characterized as partial.

Ecological risk assessment in a large river-reservoir: 8. Experimental study of the effects of polychlorinated biphenyls on reproductive success in mink

As a component of an ecological risk assessment of Poplar Creek (located on the Oak Ridge Reservation [ORR]) and the Clinch River (a large river–reservoir system), fish from Poplar Creek, the Clinch River, and Atlantic Ocean were fed to ranch mink to evaluate reproductive success. Five diets, each composed of 75% fish and 25% normal ranch mink chow, were prepared. Two diets served as reference diets and contained 75% Atlantic Ocean fish or 75% Clinch River fish collected above the ORR. The fish portion of the remaining three diets contained 25, 50, and 75% fish collected from Poplar Creek and 50, 25, and 0% ocean fish, respectively. Five mink groups (eight females and two males each) were each fed one of the prepared diets for 196 days. Polychlorinated biphenyl concentrations were determined in diets and various mink tissues, ethoxyresorufin-O-deethylase (EROD) activity was determined in liver tissue, and reproductive success was evaluated. Concentrations of PCB were greatest in the diet composed of 75% Poplar Creek fish and in tissues from mink fed this diet and their offspring. There was a trend toward decreased adult female and kit weights and reduced mean litter size in mink fed diets containing 75% Poplar Creek fish; however, at 6 weeks of age, kit survival was similar among diet groups. Liver EROD activity significantly increased in adult female mink fed 50 and 75% Poplar Creek fish diets. Estimated dietary concentrations of PCBs were similar to or slightly lower than concentrations associated with adverse effects in experimentally dosed mink. Mercury (Hg) concentrations previously reported in these same mink were below that associated with adverse effects, and there was no indication of additive or synergistic effects from exposure to PCBs plus Hg. It is unlikely that population-level reproductive effects would be observed in mink consuming fish from Poplar Creek on the ORR.

The development of the endotheliochorial mink placenta: light microscopy and scanning electron microscopical morphometry of maternal vascular casts.

The development of the mink endotheliochorial placenta has been studied by means of light microscopy and scanning electron microscopy of maternal vascular corrosion casts. The placental blood vessels of three groups of mink, representing early, intermediate and near-term gestational ages were either perfusion fixed for histology, or instilled with liquid plastic in order to prepare vascular casts, which were examined qualitatively and/or quantitatively. The maternal component of the placental vascular system evolves from preimplantation blood vessels between the endometrial glands, into which the initial feto-maternal contact is made. The influence of highly invasive syncytiotrophoblast provokes a transition of the maternal capillaries into extensively anastomosing sinusoids with a subsequent modification of their endothelial cells into large cells with luminal protrusions. Three-dimensionally, the sinusoids are arranged as vascular crypts. This implies a villous-crypt type of interdigitation for the mink, but since the fetal capillaries surround the maternal sinusoids as a dense network a labyrinth is formed. The vascular crypts are supplied by very short arterioles, branching from maternal stem arteries, which arise from branches of the uterine artery and move straight to the surface of the endometrium. Venous outlets of the sinusoids converge onto venules and large stem veins in the deepest portion of the endometrium. This architectural pattern persists until term. Morphometry was used to confirm the qualitative observations in vascular casts. The diameter of maternal vascular crypts significantly increased from 137.3+/-21.9 microm in early gestation up to 217.8+/-80.9 microm in the intermediate stage and 431.8+/-119.5 microm near-term, when compared to the paraplacental zone in early gestation (82.2+/-19.5 microm). The capillary or sinusoidal diameter also increased significantly from intermediate stage (42.9+/-11.8 microm) to near term (60.1+/-16.7 microm), whereas the difference in the paraplacental zone (7.3+/-2.1 microm) and early gestation (13.0+/-3.2 microm) was not statistically significant.

Reproductive efficiency in mink (Mustela vison) treated with the pesticides lindane, carbofuran and pentachlorophenol

Mink are carnivores of agroforestry fringe habitats and are exposed to pesticides that biomagnify within the food chain. Some pesticides are thought to disrupt reproductive and endocrine functions. In Expt 1, four groups of mink (n = 10) were fed either a control diet, or diets treated with lindane (1 mg kg-1 day-1), carbofuran (0.05 mg kg-1 day-1) or pentachlorophenol (1 mg kg-1 day-1) from before breeding until weaning. Mink were mated twice, at 7-8 day intervals. The treatments had no effect on the proportion of mink accepting the first mating; however, lindane and pentachlorophenol caused a decrease in the percentage of females accepting the second mating. Lindane and pentachlorophenol caused a decrease in whelping rate, although litter size was not affected. Carbofuran had no effect on fertility. Mink that mated only once had a lower whelping rate than mink that mated twice; therefore, it could not be determined whether the decreased whelping rates were due to the lack of a second mating or to increased embryo loss. In Expt 2, two groups of mink (n = 15) were fed a control diet or a diet treated with lindane (1 mg kg-1 day-1) from before mating until weaning. Mink were mated twice on two consecutive days. Lindane did not affect mating response at either mating. Whelping rate, but not implantation rate, was decreased by the lindane treatment. The proportion of embryos lost after implantation (implantation scars not represented by kits at whelping) was increased by the lindane treatment. In conclusion, both lindane and pentachlorophenol decreased fertility in mink, and the lindane effect was primarily a result of embryo mortality after implantation.

Urinary protein excretion of semidomesticated mink in a chronic methylmercury study.

A model using semidomesticated mink was set up to study the effects of chronic oral methylmercury exposure in piscivorous mammals. Three groups of mink were fed daily with diets containing approximately 0.1, 0.5, and 0.9 micrograms/g of total mercury. Piscivorous and non-piscivorous fish, naturally contaminated with methylmercury, were used to prepare diets. Renal injury was evaluated using total urine protein/creatinine ratio and differentiation of urinary low-molecular-weight and high-molecular-weight proteins on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The significance of the total urine protein/creatinine ratio data was assessed by comparing the results to a 95% group-based reference interval. The values for total urine protein/creatinine ratio did not reveal any significant increased excretion, and no dose-related trends were observed within the reference interval. Overall the total urine protein data did not suggest renal damage. Analysis of the SDS-PAGE electrophoretograms did not suggest the presence of any persistent glomerular damage in any group. High-molecular-weight proteins were not detected more frequently for any of the dose groups. During the adaptation phase, the B2M-like protein band was not remarked during the visual analysis of the gels. The B2M-like protein band was remarked during the gel analysis only several weeks into the exposure phase. This B2M-like protein band was more prevalent in urine samples taken from minks in the 0.5 and 0.9 micrograms/g groups than in the 0.1 microgram/group. These latter data, however, did not allow an evaluation of a quantitative dose-response excretion with time. The B2M-like data are suggestive of very minor renal injury.

Histopathology of postpartum placental sites in mink (Mustela vison) exposed to polychlorinated biphenyls or fractions thereof.

Polychlorinated biphenyls (PCB) cause reproductive failure in mink. Ovulation and nidation occur, but the fetuses die during gestation. The toxicity of different chlorinated biphenyl (CB) congeners differs markedly. Dioxin-like congeners with no (0-ortho CBs) chlorine in the ortho position to the biphenyl bond are considered to be highly toxic. Altogether, 13 groups of 10 female mink (Mustela vison) were exposed to PCB or CB fractions thereof during the reproductive season of 1988 and 1989. In 1988, one group of mink received 2 mg/day of Clophen A50 and five groups received single fractions thereof or synthetic 0-ortho CB in their diet. In 1989, one group received 1.64 mg/day of Aroclor 1254 and six groups received combinations of fractions thereof. The daily amounts of the fractions administered per animal were equivalent to those present in 2 mg of Clophen A50 or 1.64 mg of Aroclor 1254. After administration for 3 months in both experiments, the animals were killed 5 days after parturition. Histological examination focused on the placental sites. The most involuted placental sites were those of early fetal death in primiparous, non-whelping animals in the 1989 experiment. The least involuted placental sites, displaying a hyperplastic and pleomorphic uterine luminal epithelium, in which proliferating cell nuclear antigen (PCNA) was present, were those of late fetal death in biparous, non-whelping animals in the 1988 experiment. The survival of the fetoplacental unit was related to PCB exposure. The histology of the placental sites seemed only to be related to the survival time of the fetuses and to the number of former reproductive seasons.

Experimental infection of mink with bovine spongiform encephalopathy

To determine whether the aetiological agent of bovine spongiform encephalopathy (BSE) is pathogenic for mink, standard dark mink were inoculated with coded homogenates of bovine brain from the U.K. Two homogenates were from cows affected with BSE. The third was from a cow that came from a farm with no history of having had BSE or having been fed ruminant-derived, rendered by-products, the proposed vehicle for introduction of the BSE agent. Each homogenate was inoculated intracerebrally into separate groups of mink and a pool of the three was fed to a fourth group. Signs of neurological disease appeared in mink an average of 12 months after intracerebral inoculation and 15 months after feeding. Decreased appetite, lethargy and mild to moderate pelvic limb ataxia were the predominant clinical signs, quite unlike the classic clinical picture of transmissible mink encephalopathy (TME). Microscopic changes in brain sections of most affected mink were those of a scrapie-like spongiform encephalopathy. Vacuolar change in grey matter neuropil was accompanied by prominent astrocytosis. Varying greatly in severity from one mink to another, the degenerative changes occurred in the cerebral cortex, dorsolateral gyri of the frontal lobe, corpus striatum, diencephalon and brainstem. Although resembling TME, the encephalopathy was distinguishable from it by less extensive changes in the cerebral cortex, by more severe changes in the caudal brainstem and by sparing of the hippocampus. The results of this study extend the experimental host range of the BSE agent and demonstrate for the first time the experimental oral infection of mink with a transmissible spongiform encephalopathy agent from a naturally infected ruminant species.

Variation between and within Populations of Mink: I. Weight and Skin Length

Abstract Genetic and non-genetic sources of variation were estimated within and between populations in a progeny testing scheme with approximately 200 paternal progeny groups of mink. Animals from several populations were housed at a central test station and corresponding full-sibs were kept at the farm of origin. Body weight was recorded in the production period, and the length of the dried skins was measured after pelting. Significant environmental and genetic population differences were found accounting for 20–30% of the total variation. Environmental and genetic differences were on average up to 1.9 and 1.6 phenotypic standard deviations, indicating a potential for improved breeding schemes. Most heritability estimates varied between 0.2 and 0.4, lower than earlier estimates within populations. Maternal effects accounted for 10–40% of the variation in most cases. There was a large difference between sexes, and males and females were found to react differently to environmental effects. Furthermore, an ...