[A.I. in pigs: breeding efficiency of one and two inseminations per heat (author's transl.)]

Breeding efficiency as expressed by the 30-60 days non-return percentage by one and two inseminations per heat was compared. Sows and gilts in a good heat (heat detection by stockmen) received only one insemination per heat, whereas females with a moderate/weal heat received two inseminations with an interval of approx. 24 hours, provided they were still in heat at the 2nd visit. The results have been set out in the tables I and II. A total of 89.1 and 90.8 percent non-returns by one and two inseminations per heat have been obtained (table I). The difference of 1.7 percentage units in favour of two inseminations is significant, (P less than 0.001). A variation within technicians of percentage of one insemination per heat from 10-97 was found, table II. 11 technicians had significant better results with two inseminations, one technician with one insemination, and by the rest of technicians no significant differences were found between one and two inseminations per heat. It is concluded that: 1) By effective heat detection, the breeding efficiency which can be obtained by one insemination per heat, is only two percentage lower than the breeding efficiency obtained by two inseminations per heat. 2) This loss in breeding efficiency is probably compensated by the economical advantage of one insemination per heat.