Phenotypic Exposure and Variability of Livestocks Lifetime Production of Milk and Dairy Fats

Abstract

An analysis of the phenotypic exposure and variability of lifetime milk production and milk fat and the content of milk fat of lifetime milk production was performed in 241 cows of Simental race distributed in three breeding areas (Čačak n = 67, Zlatibor n = 123 and Rudno n = 51). Descriptive statistical analysis found that the average lifetime milk production and milk fat in all three breeding areas was 16081 and 627.2 kg with a variability of about 40%. The average number of lactations during the productive life of cows was 3.73 and ranged from 4.31 in the area of Čačak to 3.45 in the Rudna area. The variability was high and on average it was about 35%, which resulted from a wide variation interval ranging from only 3 to 10 lactation per head. The average content of lifetime productions milk fat was 3.91%. The content of milk fat of lifetime milk production, unlike milk production of milk and milk fat, is more influenced by genetic factors, which is why it is characterized by a very low variability of only 2.30%.

Analiza fenotipske ispoljenosti i varijabilnosti životne proizvodnje mleka i mlečne masti i sadržaja mlečne masti životne proizvodnje mleka sprovedena je kod 241 krave simentalske rase raspoređenih na tri odgajivačka područja (Čačak n=67, Zlatibor n=123 i Rudno n=51). Deskriptivnom statističkom analizom ustanovljeno je da je prosečna životna proizvodnja mleka i mlečne masti na sva tri odgajivačka područja iznosila 16081 i 627,2 kg sa varijabilnošću od oko 40%. Prosečan broj laktacija u toku produktivnog života krava iznosio je 3,73 i kretao se od 4,31 na području Čačka do 3,45 na području Rudna. Varijabilnost je bila visoka i u proseku je iznosila oko 35%, što je posledica širokog intervala varijacije koji se kretao od svega 3 pa do 10 laktacija po grlu. Prosečan sadržaj mlečne masti životne proizvodnje mleka iznosio je 3,91%. Sadržaj mlečne masti životne proizvodnje mleka, za razliku od životne proizvodnje mleka i mlečne masti,više je pod uticajem genetskih faktora zbog čega se odlikuje dosta niskom varijabilnošću od svega 2,30%.