Biopsy of mammary gland in sows: A tool for studying colostrum production

Mortality and health of newborn piglets are related to colostrum intake which is mainly limited by the colostrum yield of the sow and highly variable between animals. There is a need for studies focusing on factors affecting colostrum yield. One method that could be used is next‐generation sequencing of mammary gland tissue which would allow to gain an understanding about the difference between mammary glands that produce a low and high amount of colostrum. The purpose of this study was to test different biopsy needles, evaluate the amount and composition of obtained tissue, and observe whether sows develop complications such as hematoma or abscess. The most suitable needle was an automatic one with a diameter of 14 gauge, a length of 10 cm and a penetration depth of 22 mm (Monopty, Bard Finland Oy, Finland). Biopsies were taken from eight sows three days before expected farrowing from the lateral‐caudal part of three different mammary glands. Before the biopsy, glands were disinfected three times with a povidone‐iodine solution (7.5% Betadine, Leiras OY, Finland). During the biopsy, food was provided to the sows. The needle was inserted through the skin, about one centimeter into the tissue and triggered. After the biopsy, the tissue was placed in formalin and later transferred to paraffin for histological examination. The size of obtained tissue was about 30 mm2 and the composition homogenous. Sows showed no reaction during the biopsy. Minor local bleeding occurred but no pathological changes were observed afterwards. The experiment shows that biopsy of the mammary gland is feasible and does not affect the health and welfare of the animal and therefore can be used as a tool for studying colostrum yield in sows.