INFLUENCE OF SELECTED AMBIENT CLIMATIC FA CTORS ON PERFORMANCE OF INSEMINATED PRIMPAROUS SOWS UNDER LARGE FARM CONDITIONS

The influence of the ambient climatic factors average temperature, mea n resp. maximum daily highest temperature and average duration of suns hine on gravidity rate, litter size (total born piglets per litter) an d the number of total born piglets per 100 first inseminations able to evaluate (= piglet index) of primiparous sows has been followed up ov er an insemination period of 36 months. The mentioned climatic values were registred in two reproductive periods: I. from 20th day until fir st day before weaning of the sows from piglets of their first litters; II. from weaning of the sows until 6 days thereafter. A total of 25 2 15 first inseminations (F.I.) in 13 piglet producing units each of the m with 1000 sow places was interpreted. The units were situated in a c ircle up to 31 km to one of seven meteorological stations, that docume nted the climatic dates. The primiparous sows obtained a gravidity rat e of 78,1 %; a litter size of 10,72 +/- 3,14 total born piglets per li tter and a piglet index of 837. The following results were obtained: 1 . The temperature in reproductive period I had a lasting effective inf luence on the following insemination results. The maximum daily highes t temperature was best suitable from the tested parameters of ambient temperature to demonstrate the effect of temperature on the sow fertil ity. The highest piglet index of 892 total born piglets per 100 F.I. w as received following a maximum daily highest temperature of 10,1 to 1 5,0 degrees C. The index decreased to 830 piglets by excess of a limit value of 20 degrees C; to 774 piglets following a period with 25,1 to 30 degrees C and to 692 piglets by over 30 degrees C. 2. The influenc e of the maximum daily temperature in reproductive period I predominat ed that one in reproductive period II. 3. The average sunshine duratio n varied in reproductive period I from fewer than 2,5 hours until 11,5 hours. The maximum daily highest temperatures rised together with inc reasing sunshine duration. Considering both factors, high daily temper atures had a greater influence on gravidity rate and litter size of pr imiparous sows, however there was none evident effect by rise of daily sunshine duration;