Influence of the age of the first insemination on some reproductive indexes in sows

The aim of the study was to establish the influence of the month and the year of birth of gilts from the hybrid combination ?Y? ((Tai Zumu x Landrace) x Large White), as well as of the age of the first insemination on the age of the first mating, the first farrowing, the duration of pregnancy, and the total number of born piglets. The experimental animals were divided into three groups depending on the age of the first insemination (by the 249th day (n=71), from the 250th to the 271st (n=42), and after the 272nd one (n=20). The average age of the first insemination and the first mating was respectively 258.8?0.78 and 276.71?3.54 days, on average. The age of the first farrowing was 391.56?3.54 on average, and the duration of pregnancy - 115.03?0.2 days. The total number of born piglets in a litter was 11.87?0.32 pigs on average. The age of the first insemination has a reliable influence on the age of the first mating and the first farrowing (p<0.001), as well as on the number of born piglets (p<0.05). The month (p<0.001) and the year of birth of the gilt pigs (p<0.05) have reliable influence on the age of the first insemination.