Composition of raw milk from conventional and organic dairy farming

Abstract

Possible differences between composition of raw milk due to dairy farming system (organic vs conventional) as well as seasonal variations were investigated. The samples were analysed during one year. A total of 6.782 samples of raw milk were collected (4.496 from organic farming). Dairy farms were located in the northern part of Republic of Serbia (Province of Vojvodina). The principle of analysis of raw milk samples was in accordance with the methodology by midinfrared spectrometry and flow cytometry. The fixed effect of system of farming and season (winter, spring, summer and fall) have shown a high statistical significance (P lt 0.01) on all examined milk parameters except fat, total solids and somatic cell count, where the impact was slightly lower (P lt 0.05). Significant difference wasn't found in number of bacterial colonies (P > 0.05). Composition of milk is also affected by a number of other factors, therefore it is recommended to involve factors such as nutrition of dairy cows, breed and farm management.

Cilj rada je bio da se ispitaju razlike između sirovog mleka dobijenog u različitim sezonama i sistemima proizvodnje (organska/ konvencionalna). Uzorci mleka su sakupljani u toku čitave godine. Ukupno je sakupljeno 6782 (od čega 4496 iz organske proizvodnje). Farme su bile locirane na severnom delu Srbije (AP Vojvodina). Sirovi uzorci mleka su analizirani u skladu sa metodologijom infracrvene spektometrije i protočne citometrije. Fiksni uticaji sistema proizvodnje i sezone (zima, proleće, leto i jesen) su pokazali visoku signifikantnu značajnost (P lt 0,01) na sve ispitivane parametre mleka osim na mlečnu mast, ukupnu suvu materiju i ukupan broj somatskih ćelija, gde je uticaj bio signifikantan na nivou (P lt 0,05). Statistički značajna razlika nije pronađena u ukupnom broju bakterija (kolonija) (P > 0,05). Na sastav mleka takođe utiče i veliki broj drugih faktora, stoga je za preporuku da se u ispitivanje uključe i faktori poput ishrane mlečnih krava, rase i farmskog menadžmenta.