Influence of paragenetic factors on production and chemical composition of Paška sheep milk

Budući se proizvedeno mlijeko paških ovaca u cijelosti prerađuje u Paški sir, od izuzetne važnosti je osigurati ujednačenu proizvodnju mlijeka propisanog kemijskog sastava i higijenske kvalitete. Uz genotip, kao najvažniji čimbenik, na proizvodnju i kvalitetu ovčjeg mlijeka utječu brojni fiziološki čimbenici, pa je stoga svrha istraživanja bila utvrditi utjecaj stadija i redoslijeda laktacije na dnevnu količinu i kemijski sastav mlijeka (udio suhe tvari, mliječne masti, proteina, kazeina, laktoze i suhe tvari bez masti) paških ovaca. Slučajnim odabirom odabrana su 3 gospodarstva s područja Kolana i Caske, a istraživanje je provedeno na ukupno 213 paških ovaca. Stadij laktacije bio je podijeljen na: početak (do 50.-og dana), sredinu (od 51. do 100.-og dana) i kraj (od 101. dana do zasušenja) laktacije. Ovisno o redoslijedu laktacije, ovce su grupirane u pet razreda (1., 2., 3., 4., 5. i ostale laktacije). Istraživanjem je utvrđen značajan utjecaj stadija i redoslijeda laktacije na prosječnu dnevnu količinu mlijeka i analiziran kemijski sastav mlijeka. Paške ovce vrh dnevne proizvodnje mlijeka ostvarile su sredinom laktacije (773 g), odnosno u 3. laktaciji (712 g). Krajem laktacije udio suhe tvari, mliječne masti, proteina, kazeina i suhe tvari bez masti u mlijeku, bio je značajno viši u odnosu na početak i sredinu laktacije. Najviši udio suhe tvari, mliječne masti, proteina i kazeina utvrđen je u mlijeku paških ovaca u 5. i ostalim laktacijama. Između pojedinih parametara utvrđeni su značajni koeficijenti korelacija.Since the produced Paška sheep milk is entirely processed in Pag cheese, it is of great importance to ensure a uniform milk production of prescribed chemical composition and hygienic quality. In addition to genotype, as the most important factor, the production and quality of sheep milk is affected by numerous physiological factors, so the aim of this research was to determine the influence of paragenetic factors (stage and number of lactation) on daily milk yield and chemical composition (total solids, milk fat, protein, casein, lactose, total solids non fat) of Paška sheep milk. Three herds were chosen by random selection within the areas of Kolan and Caska, and survey was conducted on a total of 213 Paška sheep. Stage of lactation was divided to: the beginning (to 50th-day), the middle (from 51st till 100thday) and the end (101st -day till dry out) of lactation. Depending on the number of lactation, sheep were grouped into five groups (1st, 2nd, 3rd, 4th, 5th and others). A significant influence of stage and number of lactation on average daily milk yield and analysed chemical composition parameters was determined. The Paška sheep had the highest daily milk production in the mid lactation (773 g), and the third lactation (712 g) recorded. At the end of lactation, total solids, milk fat, protein, casein, total solids non fat in milk were significantly higher than at the beginning and middle of lactation. The highest share of total solids, milk fat, protein and casein was determined in Paška sheep milk at 5th lactation and other lactations. Between the individual parameters significant correlation coefficients were determined