Multiphasic Growth Curves in Mink (Mustela vison) Selected for Feed Efficiency

Abstract

Growth of mink from 1 to 28 weeks of age was modelled, using weekly body weights, and effects on model parameters of selection lines for high and low feed efficiency, sex and interaction were tested. From results on average growth curves, individual growth curves were modelled using a multiphasic logistic growth function with three phases. Individual growth curve parameters were tested for effects of selection line, sex, and interaction by analysis of variance.

Selection for feed efficiency affected the growth curve of mink. Selection lines differed for time of maximum increase (center) for each phase; the high feed efficiency line was centered later than the low line, the growth curve being shifted to the right. Males gained more weight in phases 2 and 3 than females; phase 2 was centered later for males than for females; males had a shorter duration for phase 3 than females. There was no line–sex interaction.

Keywords:

• body weight
• selection
• sex effects

Acknowledgments

The authors thank the staff of the Danish Fur Breeders Research Centre (PFR), Research Farm ‘SYD,’ for collecting and recording the data. We thank Peter Sandbøl and PFR Board Members for allowing Kristin Sorensen the opportunity to work at Wageningen University. The Danish Academy of Technical Sciences (ATV) and PFR provided funding for this research. The Animal Production Systems Group at Wageningen University generously provided Michael Grossman an opportunity to conduct research while on sabbatical leave.