Research Article

Analysis of litter sizes at birth and at 7 days of nursing in mink (Neovison vison) of Black Velvet, Hedlung White, and Silverblue color types

Beata Seremak, Lidia Felska-Błaszczyk, Marta Dworecka, Małgorzata Dziadosz-Styś, Bogdan Lasota

1. Acta Sci. Pol. Zootechnica, 12(2), 2013, 39‒48

Abstract. The aim of this study was to evaluate the effect of litter size at birth on offspring raising and an attempt to establish the litter size that would be optimal for the nursing process. We analysed litters of 390 one-year-old females of three color types: Black Velvet (or short NAP), Hedlund White, and Silverblue. Each study group comprised 130 mink. Within each group, we analysed the litter size and birth and the number of pups that survived until the age of seven days. Also percentage proportion of various classes of litter sizes is given and survival rate (in percentage) of pups in each litter has been calculated. The analysis reveals that if litter sizes comprise 10-11 pups, most of them will not be properly nursed, and as few as 2 to 6 pups have a chance to survive in many of such large litters; only in Black Velvet femals, the decline in litter size was to 9 pups, on average. An interesting fact also is that females that give birth to a single pup often do not raise it at all. The presented analysis leads to a conclusion that litters of 2 to 9 pups are best in terms of nursing success, with apparent differences resulting from the color type.

Keywords: litter size, Neovison vison, nursing, reproduction