Urinary and plasma metabolome of farm mink (Neovison vison) after an intervention with raw or cooked poultry offal: a 1H NMR investigation.

The introduction of high amounts of cooked poultry offal in mink feed has been associated with health problems in growing mink. Cooking mink feed is a convenient way of reducing microbiological activity, but it may have a negative effect on raw material quality and animal welfare. This study investigates growth and health of mink fed raw or cooked poultry offal and describes urinary and blood plasma metabolic changes related to the feeding. A total of 65 male mink were divided in three feeding groups, two fed cooked offal and one group fed raw offal, and the plasma and urine samples were collected at 3 time points during the growth. Both bio-fluids and feed samples were measured by 1H NMR spectroscopy and resulted metabolomics data were analysed using univariate and multivariate statistical methods that revealed dominating effect of the mink growth stages and to a less extent the feeding regime. Metabolome differences in relation to low body mass index (BMI) and kidney lesions were observed in plasma. Disease and decrease in BMI was associated with high creatinine and dimethylglycine content in plasma. These molecules were also particularly indicative of the cooked feeds. Moreover, low urinary taurine levels were also associated with disease and low BMI. Individual mink appeared to show negative effects of the cooked feed diet, including impaired growth and gross pathological lesions involving the kidneys. This may be related to the absorption of essential metabolites such as amino acids and fats, necessary for mink growth, that are negatively impacted by the cooking process.

Absorption of α-tocopheryl acetate is limited in mink kits (Mustela vison) during weaning.

Bioavailability of α-tocopherol varies with source, dose and duration of supplementation. The effect of source and dose of α-tocopherol on response of α-tocopherol stereoisomers in plasma and tissues of mink kits during the weaning period was studied. Twelve mink kits were euthanised in CO2 at the beginning of the experiment, and 156 mink kits (12 replicates per treatment group) were randomly assigned to thirteen treatment groups: no added α-tocopherol in the feed (0 dose) or four different doses (50, 75, 100 and 150 mg/kg of diet) of RRR-α-tocopherol (ALC), RRR-α-tocopheryl acetate (ACT) or all-rac-α-tocopheryl acetate (SYN). Six mink kits per treatment group were euthanised 3 weeks after initiation of the experiment, and the remaining six were euthanised 6 weeks after initiation of the experiment. The RRR-α-tocopherol content in plasma, liver, heart and lungs was affected by interaction between source and dose (P < 0.01 for all). The highest RRR-α-tocopherol content in plasma (13.6 µg/ml; LS-means for source across dose and week), liver (13.6 µg/mg), heart (7.6 µg/mg) and lungs (9.8 µg/mg) was observed in mink kits fed ALC. The RRR-α-tocopherol content in plasma and tissues depended on source and dose interaction and increased linearly with supplementation. In conclusion, the interaction between source and dose reveals a limitation in hydrolysis of ester bond in α-tocopheryl acetate in mink kits around weaning as the likely causative explanation for the higher response of ALC at the highest doses. Thus, considerable attention has to be paid to the source of α-tocopherol during weaning of mink kits fed a high dose of α-tocopherol.

Association between Fur Animal Necrotizing Pyoderma in breeding farm mink (Neovison vison) and reduced fertility.

BACKGROUND: The disease Fur Animal Necrotizing Pyoderma (FNP) has since 2000 been reported in many fur producing countries including Canada, Finland and Denmark. Development of FNP is characterised by rapidly forming treatment-resistant wounds on paws and in the head region. Economic losses related to FNP have been associated with mortality and decreased fur quality as well as increased veterinary costs. Also it has been suggested that FNP may be associated with reduced production results for breeding mink. The aim of this study was to evaluate if there is an association between FNP lesions in breeding animals and reduced production results based on a retrospective cohort study. RESULTS: 1465 breeding animals (244 males and 1221 females) were followed during the breeding season 2019 on five Danish mink farms. Two farms were removed from the analysis since no occurrence of FNP appeared in the observation group. After exclusion, 846 breeding animals (148 males and 698 females) remained in the analysis and were divided into two groups: exposed (EXP) or non-exposed (N-EXP) depending on the disease history of the males during mating. Females exposed to FNP positive males during breeding in average produce 14% fewer kits (P = 0.032) and these females were also more than double as likely to produce small litters (N ≥ 3) than N-EXP females. Female's from the EXP group were introduced more times to males than females in the N-EXP group (P = 0.0001, 2.5 more times in average). Females in the EXP group did not have a statistically higher risk of becoming barren (P = 0.138) though the relative risk of becoming barren was 77% higher after encountering a FNP male. CONCLUSIONS: This study shows that FNP has more economic losses for the farms than direct loss of animals. Females in contact with males with FNP lesion during breeding have a higher risk of becoming barren, and produce significantly fewer kits compared to females whom haven't been in contact with a FNP positive male.

Familial disease history and fur color type are associated with urinary tract disease in farmed mink (Neovison vison).

Mink urinary tract disease (MUTD) and mink fatty liver disease (MFLD) constitute two important disease entities in the mink production associated with sudden mortality and economic loss. Genetic factors or heritability of the diseases have not previously been investigated. Since mortality associated with MUTD and MFLD mainly occurs in the young immature mink, a potential genetic predisposition would rarely be passed on by the mink itself but potentially by relatives. This study aimed to investigate familial aggregation of MUTD and MFLD based on data from four generations of mink on a research farm. The study included a total of 27,511 mink of brown and black color type with a post mortem prevalence of 0.8% for MUTD (n = 221) and 0.5% for MFLD (n = 138) within a year from birth. The prevalence in the color types brown and black were 0.6% and 1.6% for MUTD and 0.5% and 0.7% for MFLD. Family history of MUTD in breeding animals was found to be associated with a significantly higher probability of MUTD leading to mortality in offspring (p = 0.012, RR = 1.7; CI [1.1-2.4]), however this association was not significant for MFLD (p = 0.163, RR = 1.5; CI [0.9-2.7]). Mink of the color type black showed significantly higher risk of MUTD (RR = 2.6; CI [2.0-3.3]) and MFLD (R = 1.6; CI [1.1-2.2]) compared to brown mink. The results indicate that genetic factors may play a role in understanding MUTD and that selective breeding may contribute to reduce mortalities associated with this disease.

The microbiota of farmed mink (Neovison vison) follows a successional development and is affected by early life antibiotic exposure.

On many mink farms, antibiotics are used extensively during the lactation period to reduce the prevalence and severity of pre-weaning diarrhoea (PWD) in mink kits (also referred to as greasy kit syndrome). Concerns have been raised, that routine treatment of PWD with antibiotics could affect the natural successional development of the gut microbiota, which may have long lasting consequences. Here we investigated the effects of early life antibiotic treatment administered for 1 week (postnatal days 13-20). Two routes of antibiotic administration were compared to a non-treated control group (CTR, n = 24). Routes of administration included indirect treatment, through the milk from dams receiving antibiotics by intramuscular administration (ABX_D, n = 24) and direct treatment by intramuscular administration to the kits (ABX_K, n = 24). A tendency for slightly increased weight at termination (Day 205) was observed in the ABX_K group. The gut microbiota composition was profiled by 16S rRNA gene sequencing at eight time points between Day 7 and Day 205. A clear successional development of the gut microbiota composition was observed and both treatment regimens caused detectable changes in the gut microbiota until at least eight days after treatment ceased. At termination, a significant positive correlation was identified between microbial diversity and animal weight.

Distribution of α-tocopherol stereoisomers in mink (Mustela vison) organs varies with the amount of all-rac-α-tocopheryl acetate in the diet.

Synthetic α-tocopherol has eight isomeric configurations including four 2R (RSS, RRS, RSR, RRR) and four 2S (SRR, SSR, SRS, SSS). Only the RRR stereoisomer is naturally synthesised by plants. A ratio of 1·36:1 in biopotency of RRR-α-tocopheryl acetate to all-rac-α-tocopheryl acetate is generally accepted; however, studies indicate that neither biopotency of α-tocopherol stereoisomers nor bioavailability between them is constant, but depend on dose, time, animal species and organs. A total of forty growing young male mink were, after weaning, assigned one of the following treatments for 90 d: no α-tocopherol in diet (ALFA_0), 40 mg/kg RRR-α-tocopheryl acetate (NAT_40), 40 mg/kg all-rac-α-tocopheryl acetate (SYN_40) and 80 mg/kg feed all-rac-α-tocopheryl acetate (SYN_80). Mink were euthanised in CO2 and blood was collected by heart puncture. Mink were pelted and liver, heart, lungs, brain and abdominal fat were collected for α-tocopherol stereoisomer analysis. The proportion of RRR-α-tocopherol decreased in all organs and plasma with increasing amount of synthetic α-tocopherol stereoisomers in the diet (P≤0·05), whereas the proportion of all synthetic α-tocopherol stereoisomers increased with increasing amount of synthetic α-tocopherol stereoisomers in the diet (P≤0·05). The proportion of α-tocopherol stereoisomers in plasma, brain, heart, lungs and abdominal fat showed the following order: RRR>RRS, RSR, RSS>Σ2S, regardless of α-tocopherol supplement. The liver had the highest proportion of Σ2S stereoisomers, and lowest proportion of RRR-α-tocopherol. In conclusion, distribution of α-tocopherol stereoisomers differs with dose and form of α-tocopherol supplementation. The results did also reveal the liver's role as the major organ for accumulation of Σ2S α-tocopherol stereoisomers.

Short-term effect of oral amoxicillin treatment on the gut microbial community composition in farm mink (Neovison vison).

It is well documented that antibiotics have pronounced modulatory effects on the intestinal bacterial community of both humans and animals, with potential health consequences. The gut microbiota of mink has however attracted little attention due to low bacterial load and fast gastrointestinal transit time, questioning its relevance. In this study, we hypothesise that oral amoxicillin treatment affects the gut microbiota in mink. This was investigated in a controlled trial including 24 animals of which 12 were treated with amoxicillin for 7 days. By applying 16S rRNA gene sequencing, we found that the faecal microbiota was markedly altered already after 2 days of treatment, with a surprising increase in diversity to resemble the feed. The diversity within the mucosa at termination was however reduced, which indicates this compartment as an important colonisation site in mink. No impact on blood biochemistry, lipid metabolism, serum amyloid A, vitamins A and E and histomorphology of the gut and liver was found; however, a slight decrease in fat digestibility was observed. We suggest that early-life use of amoxicillin in mink production may be counteractive as dysbiosis of the microbiota during infancy is increasingly being recognised as a risk factor for future health.

The gastrointestinal tract of farmed mink (Neovison vison) maintains a diverse mucosa-associated microbiota following a 3-day fasting period.

Although it is well documented that the gut microbiota plays an important role in health and disease in mammalian species, this area has been poorly studied among carnivorous animals, especially within the mustelidae family. The gastrointestinal tract of carnivores is characterized by its short length and fast transit time, as compared to omnivores and herbivores, which is due to the low level of inherent fermentation. Mink represents an example of this, which have a GI tract only four times the length of the body and a transit time of approximately 4-5 hr. In this study, we used high-throughput 16S rRNA gene sequencing to explore the resident gut microbiota of the mink in terms of intra-and interindividual diversity. We report, for the first time, that the mucosa-associated bacterial community within the colon is diverse and dissimilar from the community found in the feed. We found large interindividual differences in bacterial composition between individual animals being dominated generally by the phylum Firmicutes, but in some cases also Proteobacteria or Fusobacteria. The bacterial load and community structure within the mucus was not severely impacted by 3 days of fasting, which implies that a resident and stable microbiota is hosted by these animals.

Anatomical distribution and gross pathology of wounds in necropsied farmed mink (Neovison vison) from June and October.

BACKGROUND: Wounds are regarded as an indicator of reduced welfare in mink production; however, information on the occurrence and significance of wounds is sparse. To provide a basis for assessment and classification of wounds in farmed mink, the distribution pattern and characteristics of wounds in farmed mink in June and October, respectively, is described. A total of 791 and 660 mink from 6 to 12 Danish mink farms, respectively, were examined. The mink were either found dead or were euthanized due to injury or other disease. Mink included from June were kits in the pre-weaning and weaning period (1-2 months old). Mink included from October were juveniles in the late growth period (approximately 5-6 months old) or older. Macroscopic pathology and wound location was systematically recorded. RESULTS: There was considerable variation in morphology as well as location of wounds between June and October. Wounds were primarily located on the front parts of the body and in the head in June (1-2 month old kits) and mainly on the rear parts of the body and on the tail in October (5-6 month old kits and older). Moreover, there were significantly more females than males with wounds for most wound types, and significant differences in occurrence of ear and tail base wounds between certain colour types. CONCLUSIONS: Wounds varied significantly from June to October with respect to morphology and anatomical location. Wounds in June were primarily located on the front parts of the body and in the head, while wounds in October were mainly present on the hind parts of the body and on the tail. The majority of the wounds were found in specific well defined skin areas and could therefore be grouped into categories according to anatomical location.

Interactions between retinol, α-tocopherol and cholecalciferol need consideration in diets for farmed mink (Mustela vison).

A sufficient but balanced vitamin supplementation is a prerequisite for a satisfactory growth pattern and an effective immune system in mink and all other species. The fat-soluble vitamins are very sensitive to over- or under-supply because they interact with each other with respect to dose-response and chemical form. The purpose of the present study was to investigate the effect of increasing the amount of retinol in combination with RRR-α-tocopherol or all-rac-α-tocopherol in the feed given to growing mink on their retinol, cholecalciferol and α-tocopherol concentrations in plasma and selected organs. The results showed that the mink met their retinol requirements from the basal diet, but there were no negative effects of supplying various amounts of retinol on their plasma α-tocopherol concentrations. On the other hand, the study showed that the cholecalciferol status in plasma, assessed as the 25-hydroxycholecalciferol concentration, was low when retinol was supplemented in the feed at high levels. In addition, supplementation with RRR-α-tocopherol in the feed negatively affected the plasma concentration of 25-hydroxycholecalciferol compared with supplementation with all-rac-α-tocopherol. In general, female mink had higher concentrations of fat-soluble vitamins in plasma than male mink.

Intestinal remodelling in mink fed with reduced protein content.

Low protein intake occurs in humans in relation to diseases, starvation and post-operatively. Low-protein diets may affect the gastrointestinal structure and mechanical function. The aim was to study the passive biomechanical properties and tissue remodelling of the intestine in minks on reduced protein diets. Twenty-seven male minks were divided into three groups receiving different protein level in the diet for 6 weeks: High protein level (group H, 55% energy from protein), moderate protein level (group M, 30% energy from protein) and low protein level (group L, 15% energy from protein) (n=9 for each group). Ten centimetre long segments from duodenum, jejunum and ileum were excised at the end of the study period. The mechanical test was performed as a ramp distension experiment. The intestinal diameter and length, wall thickness, wall area and opening angle were obtained from digitized images of the intestinal segments at pre-selected pressures, no-load and zero-stress states, respectively. Circumferential and longitudinal stresses (force per area) and strains (deformation) were computed. The layer thickness was measured from intestinal histological images. No difference in body weight was found between groups at the start of the experiment. However, at the end of the experiment the body weight was smallest in group L (P=0.0003 and 0.0004 compared with groups H and M). Similarly, the wet weight per unit length, wall thickness and area were smallest in group L (P<0.05, P<0.01). The lowest wall thickness was found in the jejunum and ileum in group L (P<0.05), mainly due to decreased mucosa and submucosa thickness. The smallest opening angle and absolute values of residual strain were found in the jejunal segment in group L (P<0.05). No difference was observed for duodenal and ileal segments among the three groups. Feeding the low-protein diet shifted the stress-strain curves to the right for the circumferential direction, indicating the wall become softer in the circumferential direction. However, no significant difference was observed in the longitudinal direction for any of the intestinal segments. In conclusion, this study demonstrated that low-protein diet in minks induce histomorphometric and biomechanical remodelling of the intestine.