Bente Krogh Hansen

The Effect of Cage Environment and Ad Libitum Feeding on the Circadian Rhythm, Behaviour and Feed Intake of Farm Mink

The effect of cage size and nest box environment on circadian rhythm and on stereotyped and non-stereotyped activities was measured for 66 farmed female mink fed ad libitum. The behaviour of the an...

Mink kit growth performance in the suckling period I. Environmental Factors Affecting Body Size of Kits

Growth performance was studied in 2918 standard black mink kits. The kits originated from a divergent selection experiment for body growth between two and four weeks. Growth was influenced by sex, litter size, age of dam, and production year. Sex dimorphism was found already at birth. Litter size had a negative effect on body weight and body length from birth to pelting. The age of the dam (yearlings vs. adults) had a positive influence on body weight, especially during the suckling period, and after weaning until September (age about 4.5 months) and even longer in female kits. The effect on body length was significant for female kits until July (age about 3 months).

Mink dam weight changes during the lactation period I. Genetic and Environmental Effects

Records from 570 scanblack mink dams with 786 lactations in the period 1989–94 were used to estimate genetic parameters for body weight and weight changes during the lactation period from parturition to 6 weeks post‐partum. Direct additive effects and effects of permanent environment were estimated using restricted maximum likelihood (REML) in univariate and bivariate models. During the first 6 weeks of lactation, the dam lost around 15% (169 g) of the body weight at parturition, the main part, 10% (112 g), during the last 2 weeks. Older dams lost more weight than yearling dams, especially during the late part of the lactation period. Dams fed ad libitum had a higher body weight during the last part of the lactation period. The litter size, the sex of the kits and the litter weight influenced weight loss of the dam, especially in the late part of the lactation period. The heritability of the direct additive effect was intermediate to high for body weight (h2 a ∼ 0.39–0.58), but lower for weight changes (h...

Response to selection and genotype–environment interaction in mink (Neovison vison) selected on ad libitum and restricted feeding

Nielsen, V. H., Møller, S. H., Hansen, B. K. and Berg, P. 2011. Response to selection and genotype-environment interaction in mink (Neovison vison) selected on ad libitum and restricted feeding. Can. J. Anim. Sci. 91: 231-237. Mink were selected for high November weight (AL line) and low feed conversion ratio (FC line) on ad libitum feeding and for high November weight on restricted feeding (RF line). After three generations of selection, the average estimated breeding value for November weight was 533, 326, and 150 g in males and 168, 82, and -85 g in females in the AL, RF, and FC lines. The breeding value for feed conversion ratio was -1.39, -0.84 and -0.68 kg feed kg-1 gain in males and -0.39, -0.31 and -0.23 kg feed kg-1 gain in females in the selection lines. In generation 4, the AL, RF and FC lines were tested on both ad libitum and restricted feeding. The estimated breeding value for November weight in males in the AL line (533 g) was significantly greater than that in the RF line (384 g) on ad libitum feeding. The corresponding values on restricted feeding were 297 and 326 g, respectively, which were not significantly different. This indicates genotype×environment interaction. In the AL line, selection improved feed conversion ratio by increased appetite. In the RF line, it was improved by increased feed utilization. Environmental sensitivity in males, estimated from breeding values for November weight was 236 g in the AL line and 58 g in the RF line suggesting that the RF line was more robust to changes in feeding conditions. A smaller litter size in the AL line (4.1) than in the RF line (5.6) indicates that selection for large weight affects reproduction.

Mink kit growth performance in the suckling period

Records of 4103 scanblack mink kits born in 1989–94 were used to estimate genetic parameters for body weight and body length during the growth season with special emphasis on the suckling period. Maternal additive and direct additive effects and effects of permanent maternal and specific litter environment were estimated, using restricted maximum likelihood (REML) in univariate and bivariate animal models. The maternal additive effect was constant during the first 4 weeks after parturition at h2 m ≈ 0.30 for weight, and decreased thereafter. The heritability estimate for direct additive effect for body weight decreased from h2 a ≈ 0.19 at birth to h2 a ≈ 0.12 at 4 weeks but increased to h2 a ≈ 0.50 in August to December. The maternal permanent environment was important only at 2 and 4 weeks, c2 p ≈ 0.10. The specific environment, common within the litter, increased from c2 s ≈ 0.24 at birth to c2 s≈ 0.40 at 2 and 4 weeks, but decreased thereafter to c2 s ≈ 0.10 in December. Estimates for body length showe...

Genetic parameters and effect of selection for body weight in lines of mink (Neovison vison) on ad libitum and restricted feeding

Abstract Selection was performed for high November weight on ad libitum (AL) and restricted feeding (RF) in mink in two generations. A farm fed line (FF) was maintained as a control. The estimates of heritability for November weight were large (0.62, 0.52, and 0.73 in males and 0.68, 0.51, and 0.60 in females in the FF-, AL-, and RF-line). The results indicate that selection on AL feeding increased appetite and thereby improved feed conversion ratio while selection on RF improved feed utilization. Furthermore, the results suggest that selection for August weight produces lean mink while selection for November weight produces fat mink.

Mink Dam Weight Changes During the Lactation Period: II. Energy Consumption and Plasma Concentrations of Thyroid Hormones and Insulin

Consumption of metabolizable energy (ME) and plasma concentrations of triiodothyronine (T3) and thyroxine (T4) were studied in lactating scanblack mink in the period from 1991 to 1994. In 1994, the plasma concentrations of insulin were also investigated. The objectives of the study were to describe the daily ME consumption and the plasma concentrations of T3, T4 and insulin during lactation and to evaluate the factors that influence ME consumption, and the concentrations of T3, T4 and insulin. The factors included were dam age, dam body weight, litter size and litter weight. The daily consumption was recorded from 72 dams in 85 lactations. Blood samples were collected at weekly intervals. Dam body weights were recorded before blood sampling and at days 14, 28, and 42 post partum. Kit body weights were recorded at parturition, and at days 14, 28, and 42 post partum. Between the first and the fourth weeks post partum, there was a steady increase in daily ME consumption from 1095 kJ to 1796 kJ. During the fi...

Stendomycin and Pantomycin Are Identical Natural Products: Preparation of a Functionalized Bioactive Analogue

The natural products pantomycin and stendomycin were both reported as antimicrobial agents. We demonstrate by gene cluster analysis, LC-MS analysis, and isolation that these polypeptides are identical, and we identify previously unknown congeners. We show that stendomycin can be chemically modified at its electrophilic dehydrobutyrine moiety yielding the first bioactive analogue of this natural product which can undergo additional functionalization. This compound may be a valuable starting point for molecular probe development, and we invite its distribution to the scientific community.

Catalytic Asymmetric [4+2]‐Cycloadditions Using Tropolones: Developments, Scope, Transformations, and Bioactivity

An organocatalyzed asymmetric [4+2]-cycloaddition between tropolones and electron-deficient dienophiles is presented. Complex and biologically interesting dihydrohomobarrelenone scaffolds are formed through a Diels-Alder reaction utilizing bifunctional Brønsted-base catalysis, affording the corresponding bridged bicyclic cycloadducts in up to quantitative yields with good enantio- (up to 92 % ee) and diastereoselectivity (up to >20:1 d.r.). The synthetic value of the obtained products is explored by downstream transformations, including photoisomerizations, and their biological relevancy by in vivo testing in MCF-7 cancer cells.