Die Bodenkultur - Journal for Land Management, Food and Environment

J. Schlederer, W. Schneeberger, S. Vogel:

Return to oestrus rates in pig breeding units of an Austrian producer group


This study is focused on the average occurrence of return to oestrus rates per month and year in pig breeding units of an Austrian producer group. The data were collected in the year 2006 from the 635 pig operations keeping a total of approximately 37,000 breeding sows, on the average per farm 58 sows (minimum 8, maximum 272). In the year 2006 on average the return to oestrus rate of all pig units was 17.4 %. In July, August and September the return to oestrus rates were significantly higher as compared to the other month in the years 2004 until 2006. The so called “summer infertility syndrome” as reported in the literature could be confirmed by the data of all pig breeding units of the producer group. Based on the annual return to oestrus rates in the year 2006 the farms were grouped into quartiles. On farms with high annual return to oestrus rates the “summer infertility syndrome” is quite more evident as compared to farms with low return to oestrus rates. However on farm basis a comparison of the return to oestrus rates on average of July, August and September with the average of the remaining months of the year 2006 shows that the “summer infertility syndrome” did not appear on 32 % of the pig units analysed.

Key words: Breeding sows, return to oestrus rates, summer infertility syndrome, producer group, Austria.