Light control methods in mink farming

The mink is an important fur-bearing animal, and its growth and development are closely related to light. In production, if attention is paid to controlling light and making full use of the beneficial effects of light on its growth, development and reproductive performance, production costs can be effectively reduced and economic benefits improved.

So-called light control means using artificial or modern electronic technology to simulate changes in the natural light cycle, providing suitable light duration and intensity for mink reproduction and molting, so that mink production can develop faster in the direction of meeting human needs.

During the long process of evolution, the growth, development and breeding of mink have formed an inseparable connection with changes in the natural photoperiod. Under natural conditions, as the seasons change, that is, with changes in the natural photoperiod, mink reproduce once a year and molt twice. Under artificial light-control conditions, however, mink can reproduce at any time of the year, and the reproductive cycle can be effectively shortened, achieving three litters in two years. At the same time, the winter fur of mink can be brought to maturity earlier, allowing earlier slaughter, saving feed expenses and management costs, and greatly reducing production costs.

The artificial light-control scheme is unrelated to the date on which shortening the daylight begins. Even in the hot summer, giving mink short daylight can promote the growth of winter fur in summer. However, in production, attention should be paid to the fact that the growth of winter fur in mink has a refractory period. After the winter fur matures, extending the light duration can accelerate the development of the sexual organs, but it does not cause the growth of summer fur; summer fur does not begin to grow until the animal enters the gestation period. If light is extended before the winter fur matures, it will prevent the development of the winter fur and inhibit the growth of the sexual organs. Therefore, farms and households should pay attention to grasping the optimal period for artificial light control.

In production, light-controlled feeding generally begins on December 21, starting with 1 hour of light per day, extending to 8 hours per day by January 1, then increasing by 15 minutes to 30 minutes every 5 days, until May 1 of the following year, when the sunshine duration reaches 15 hours and 25 minutes. Using this method can significantly increase the mating conception rate of mink. If the aim is to promote winter fur maturity, light-controlled feeding generally begins on June 21 in production, mostly using 40-watt fluorescent lamps for illumination. The artificial photoperiod changes at twice the speed of the local natural photoperiod, adjusted once a week, so that the light duration rapidly shortens and the winter fur develops rapidly. Generally, by October 6 the winter fur can mature.

After mating ends, 7 days to 8 days later, electric lights are used to extend the light, with the daily light duration reaching 14 and a half hours. During the lighting period, the small chamber cover of the light-control shed is opened so that the mink can fully receive light, until the start of farrowing, when the supplementary lighting is stopped. Using this method, newborn mink kits are lively and strong, and the survival rate of the kits is relatively high.