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Denne undersøgelse viser, at man, når man har et varieret foder med gode råvarer, kan fjerne alle B-vitaminer og cholin, uden at det medfører mangelsymptomer hos minkene. I dette forsøg var der ikke forskel på tilvækst og skindkvalitet hos mink fodret med foder, hvor der ikke var tilsat B-vitamin. Der blev undersøgt urin- og blodprøver fra dyrene, og i urin var det muligt at genfinde både intakte vitaminer og nedbrydningsprodukter af vitaminer, som viste, at dyr fra alle hold havde haft tilstrækkelig B-vitamin i foderet. Undersøgelsen viser dog, at vitamin B9, folinsyre, som primært findes i vegetabilske foderemner, kræver yderligere forsøg, før der kan drages en konklusion.

Crosses between different mink lines from 3 Danish mink farms that use different breeding strategies were studied to estimate heterosis and variance components for litter size. The study was designed to analyze crosses between lines of the same color type, between different color types, and between animals originating from different farms. Effect of heterosis, color type, and variance components were estimated using Average information REML (AI-REML) algorithm implemented in the DMU package for analyzing multivariate mixed models. Females from 7 generations that gave birth to at least 1 offspring were analyzed and the effects of parity and production year were included in the analyses. Genetic trend and the proportions of the total variance explained by the effects of additive genetics (h2) , common environment (due to repeated litters from the same female; c2), and dam of the female (granddame of the born litter; d2) were estimated. The results showed that mink of the Black color type potentially produced smaller litters compared to mink of the other studied color types. We found significant general maternal effect of heterosis for litter size. Analyses of specific heterosis showed a significant positive effect of crossing between lines of the same color type. Estimates of variance components revealed h2 levels for farm A, B, and C of 0.15, 0.06, and 0.09, respectively; thus litter size could be selected for in the future. The effect of common environment on litter size was also considerable, with c2 values of 0.005, 0.11, and 0.15 at farms A, B, and C, respectively. In conclusion, we recommend genetic selection as a means of increasing litter size in farmed mink.

Mapping of quantitative trait loci (QTL) affecting fur quality traits (guard hair length, guard hair thikness, and density of woll) was performed in a 3-generation population (F2-design). In the parental generation, Nordic wild mink were crossed reciprocally with American short nap mink. Twenty one wild mink were mated to 25 short nap mink. In the F1-generation 103 mink were mated. 934 mink were obtained in the F2-generation. The mink were genotyped using 104 microsatellites covering all 14 autosomal chromosones. The marker spacing was approximately 11 cM. Recording of fur quality traits were wade on all genotyped mink by Kopenhagen Fur. The QTL analyses were performed by least square regression implemented in the software Grid QTL. Evidence was found for QTL for the fur quality on eight autosomal chromosomes (LOD score >3.0). QTL were detected for guard hair thickness on chromosomes 1, 2, 3, 4, 6, 11, and 13, for guard hair length on chromosomes 2, 3, and 6 and for wool density on chromosome 6, 7, and 13. Similar locations of QTL for guard hair length and guard hair thickness on chromosomes 2, 3, and 6 suggest that these traits are in part under the influence of the same genes