Tove N. Clausen

Effect of dietary protein levels on growth performance, mortality rate and clinical blood parameters in mink (Mustela vison)

Effects of dietary protein levels ranging from 35% to 15% of metabolizable energy (ME) and dietary fat levels ranging in a reciprocal fashion from 47% to 67% of ME, and a constant dietary carbohydrate level of 18% of ME were investigated in male mink kits in the growing‐furring period. Growth performance, mortality rate, hepatic fatty infiltration, weights of body and liver, relative weight of liver, haematocrit values, plasma activities of alanine‐aminotransferase (ALAT), aspartate‐aminotransferase (ASAT) and creatine‐kinase (CK), and plasma concentrations of chemical parameters were studied. A protein supply of 30% of ME supported normal growth performance and ensured a low mortality rate. Plasma ALAT and hepatic fatty infiltration increased with decreasing ME from protein. Alanine‐aminotransferase was found to be a useful tool in estimation of the incidence of hepatic fatty infiltration. The haematocrit values and the plasma values of total protein, urea, creatinine and bile acids were influenced by th...

Effects of dietary supplement of essential amino acids on mortality rate, liver traits and blood parameters in mink (mustela vison) fed low‐protein diets

A low‐protein diet supplemented with essential amino acids to meet the estimated requirements for essential amino acids in growing mini and with a total amino acid nitrogen content of 65–75% of the requirement, was fed to male mink kits during the growing period from weaning to pelting. The effects on mortality rate, liver fat content, liver weights, growth performance, plasma activities of alanine‐aminotransferase (ALAT), plasma concentrations of total protein, urea, creatinine and bile acids and haematocrit values were studied. The results showed that the mink has a high requirement of dietary protein besides essential amino acids, especially glucogenic amino acids. Feeding a low‐protein diet caused increased mortality rate, liver lipidosis, increased plasma activity of ALAT and reduced growth performance compared with control feeding. A dietary supplement of essential amino acids to the low‐protein diet did not improve the health status, but had a positive effect on growth performance compared with the...

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.

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.

Fatty fish and defatted fish products for male mink (Mustela vison) in the growing-furring period. II. Effects on haematological and clinical-chemical parameters, vitamin E status and fatty acid composition.

The effects of different dietary levels of marine lipids in the diets with a constant distribution of metabolizable energy (ME) on protein, fat and carbohydrate were investigated in male mink kits in the growing-furring period during 2 consecutive years. The physiological investigations included 15 males per experimental group, each consisting of about 75 males. Fat herring and mackerel scrap were used in amounts resulting in levels of marine lipids of 30, 50 and 70% of total dietary lipid, respectively. Defatted herring scrap was used in proportions of 12, 23 and 32% in the diets. Haematocrit value, haemoglobin concentration, number of erythrocytes, leucocytes and platelets, plasma activities of alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT) and creatine kinase (CK), concentrations of tocopherols in plasma, liver and adipose tissue, composition of fatty acids (FA) in liver and adipose tissue, body weight, weight of liver and heart in relation to body weight, and liver fat content were studied. The number of platelets decreased with an increasing proportion of marine lipids of total content of dietary lipids. A high intake of fatty fish products had no influence on the health status of the animals evaluated by haematological and clinical-chemical analyses, vitamin E status and FA composition in growing-furring male mink. No negative effects on the health of the animals were demonstrated when feeding with defatted herring scrap.

Fatty and defatted herring scrap fed to mink (Mustela vison) in the reproduction and nursing periods

The use of fatty herring scrap and defatted herring scrap products for female mink in the reproduction and nursing periods was investigated in two experiments. In exp. 1, diets with 27% fatty herring scrap with 60 vs. 120 mg vitamin E kg−1 feed, and 10 vs. 19% defatted herring scrap ensiled with formic and acetic acids were compared with a control diet without fatty herring scrap or defatted herring scrap silage. Each dietary group consisted of 137 females. In exp. 2, diets with 20% fatty herring scrap with 63 vs. 78% of the dietary fat originating from fish, and diets containing 20 vs. 29% defatted herring scrap were compared with a control diet without fatty herring scrap or defatted herring scrap. Each dietary group consisted of 90 females. The results showed that fatty herring scrap, defatted herring scrap and defatted herring scrap silage can be used at these levels during the winter and reproduction periods until parturition, without any negative effects on the number of kits per female at parturiti...

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.

Fatty Fish and Defatted Fish Products for Male Mink (Mustela vison) in the Growing-Furring Period: I. Effects on growth and pelt characteristics

Investigations on the use of fatty herring (Clupea harengus) scrap and mackerel (Scomber scombrus) (whole and scrap), and defatted herring scrap for male mink kits in the growing-furring periods were carried out in two consecutive years. Each year, three diets containing fatty herring scrap and three diets containing fatty mackerel, supplying 30, 50 or 70% of the dietary fat were compared with a control diet supplying only 20% of dietary fat as marine fat. In one of the experiments, another three groups were fed 12, 23 or 32% of defatted herring scrap in the diet. Each experimental group consisted of ∼75 male Scanglow mink kits. The energy content of the feed was 8.5 MJ kg-1 and there was ∼360 g crude protein per kg dry matter in all diets. When supplying up to a level of 50% of the fat from marine fat, the same or better weight gain, pelt length and fur quality in male mink kits were found compared with the control group. Increasing the proportion of dietary fat from herring scrap or mackerel up to 70% r...