Investigation of the effect of certain paragenetic factors on fertility traits of bull dams of Simmental breed

Abstract

Investigation included bull dams of Simmental breed selected on farms of agricultural producers on the territory of the Republic of Serbia. Method of Least Squares - LSMLMW (Harvey 1987) was used for analysis of the effect of region and order of lactation on reproductive traits. Obtained results indicate the justification for investigation of paragenetic factors, since the knowledge of their effect can contribute to more objective evaluation of random effects. Regions had highly significant effect (P (lt) 0,01) on age at first conception, duration of service period and interval between calvings whereas no significant effect on duration of pregnancy was registered (p>0.05). The effect of region of breeding many factors are included and most important one is nutrition. Order of lactation as second factor investigated in this research had no effect on any of the fertility traits (p>0.05). General average of mean values of least squares for fertility was: for age at first conception 517.61 days, duration of pregnancy 285.51 days, duration of service period 108.98 days, interval between calving 395.34 days.

U radu su detaljno ispitani uticaji odgajivačkog područja i laktacije po redu na uzrast pri prvoj oplodnji, trajanje bremenitosti, trajanje servis perioda, trajanje intervala između dva telenja. Ispitivanja su se odnosila na bikovske majke simentalske rase odabrane na imanjima poljoprivrednih proizvođača na teritoriji Republike Srbije. Za analizu uticaja odgajivačkog područja i laktacije po redu na reproduktivne osobine korišćen je Metod najmanjih kvadrata-LSMLMW (Harvey 1987). Odgajivačko područje imalo je visoko znacajno dejstvo na uzrast pri prvoj oplodnji, trajanje servis perioda i na dužinu međutelidbenog intervala (p (lt) 0.01), dok na dužinu bremenitosti nije imalo značajnijeg uticaja (p>0.05). Laktacije po redu nije imala značajnijeg uticaja ni na jednu od ispitivanih osobina (p>0.05).Srednje vrednosti opšteg proseka iznosile su za uzrast pri prvoj oplodnji 517.61 dana; trajanje bremenitosti 285.51 dana; trajanje servis perioda 108.98 dana;trajanje međutelidbenog intervala 395.34 dana.