Veterinary/zoology session

The number of mammary glands (glandulae mammaria) of breeding sows is important maternal trait. Pigs usually have five to nine teats (mammillae) on each side. Traditionally, sows had 2.5 more teats than the number of piglets in their average litter.

As for the number of teat canals (ductus papillares), there is not uniform standpoint in the reference books and different publications. Majority of them claims to be 2 or 2-3 teat canals in each teat. No scientific evidence can be found in the literature for the functional significance for the number of teat canals.

A study was conducted to characterize the number of mammary glands and the numerical evaluation of teat canals of randomly selected teat samples in slaughtered culled breeding sows was also done. The pathological conditions were not recorded.

The data of 1507 breeding sows (number of mammary glands/number of animals) is as follows: 10/2 (0.1%); 11/89 (5.9%); 12/211 (14%); 13/352 (23.4%); 14/560 (37.1%); 15/193 (12.8%); 16/73 (4.8%); 17/27 (1.7%); 18/0 (0%). The number of sows involved in this sudy comprises approximately 0.7 per cent of the total number of breeding sows in Hungary.

The number of teat canals based on 901 samples collecting randomly (0-3 samples/animal) from mammary glands of different anatomical position were recorded and summarized: 1 canal in 130 teats (14.4%); 2 canals in 753 teats (83.6%); 3 canals in 18 teats (2.0%).

The distribution of 1, 2 or 3 teat canals in the mammary glands being in different anatomical location is not statistically different by Kruskal-Wallis test in the case of the 5 anterior (throracic and abdominal) pairs of mammary glands - producing more milk yield – as well as those of the 2-4 posterior (inguinal) ones discriminated by producing less milk.

*A poster presentation and abstract based on the present study was:
Kertész, A.M., Bíró, H., Sótonyi, P.: The Number of Mammary Glands and Teat Canals in Culled Breeding Sows. In: Proceedings of 1st European Symposium on Porcine Health Management, Copenhagen, Denmark, August 27th – 28th 2009. p. 56.