EFECT OF SEASON ON AGE AT COMING INTO REPRODUCTION AND REPRODUCTIVE CAPABILITIES OF SWEDISH LANDRASE SOWS

Cilj ovog istraživanja, u tipično industrijskim uvjetimaa proizvodnje,bio je da se izuči utjecaj sezone rođenja nazimica na uzrast pri ulasku u reprodukciju i njihove reproduktivne sposobnosti u toku tri uzastopna praćenja.(G0 - G3). Obuhvaćeno je 525 plotkinja koje su rođene u različitim sezonama godine, pri čemu je praćen: uzrast kod pripusta, prvog, drugog i trećeg prašenja, plodnost i preživljavanje prasadi u prvom i prva tri praćenja. Ustanvljeno je da sezona rođenja kmača utiječe vrlo značajno (P<0,01) na njihov uzrast pri ulasku u reprodukciju, pri čemu su krmače rođene u zimskoj i proljetnoj sezoni za 15,1-20,7 dana kasnije ušle u prvu suprasnost, i približno za toliko kasnije donosile svoje prvo, drugo i treće leglo. Najplodnije su, u prva tri prašenja ukupno, krmače rođene u zimskoj sezoni (P<0,01), pa ljetnoj, dok su krmače rođene u proljeće i jesen međusobno slične. Broj uspiješno odgajene prasadi, u prva tri prašenja ukupno, veći je (P<0p5) u krmača rođenih u zimskoj i ljetnoj sezoni godine, nego u proljeće i jesen.The aim of our investigations was to study, in industrial production conditions, the effect of birth season of sows on their age at coming into reproduction and their reproductive capabilities in the course of three consecutive farrowings (G0-G3). 525 Swedish Landrase sows born in different seasons were included and their age at coming into reproduction, the first, the second and the third farrowing, fertility and the survival of piglets in the first and the first three farrowings were followed. It was foun that the season of the sows birth had a highly significant (P<0,01) effect on their age at coming into reproduction. The sows born in winter and spring had their first pregnancy 15.1-20.7 days later and bad their first, second and third litter approximately the same period later. Most fertile in all the three first farrowings were the sows born in winter (P<0,01), then those born in summer, while the sows born in spring and autumn were similar in this respect. The number of successfully reared pigs in all the three first farrowing was significantly higher (P