Relationship of stage and number of lactation with somatic cell count in milk of Paška sheep

S obzirom da se mlijeko paških ovaca prerađuje u istoimeni sir, važna je higijenska ispravnost proizvedenog mlijeka. Osim genetskih čimbenika, na proizvodnju i kvalitetu mlijeka utječe i velik broj okolišnih čimbenika, s obzirom na navedeno cilj istraživanja bio je utvrditi utjecaj stadija (rani, srednji i kasni) i redoslijeda laktacije (1., 2., 3., 4., 5. i ostale), na promjene dnevnih količina mlijeka i promjene broja somatskih stanica u mlijeku paških ovaca. Odabrana stada uzgajana su na području Kolana i Caske, a istraživanje je obuhvatilo ukupno 213 paških ovaca. Stadij laktacije bio je podijeljen na rani (do 50. dana), srednji (od 51.-100. dana) i kasni (>101. dana do kraja laktacije). S obzirom na redoslijed laktacije, ovce su bile razvrstane u 1. laktaciju (A), 2. laktaciju (B), 3. laktaciju (C), 4. laktaciju (D) i 5. i ostale laktacije (E). Istraživanjem je utvrđen značajan utjecaj stadija i redoslijeda laktacije na prosječnu dnevnu količinu mlijeka i broj somatskih stanica. Paške ovce vrh dnevne proizvodnje mlijeka (750 g) ostvarile su sredinom laktacije, odnosno u 3. laktaciji (690 mL). Najviši broj somatskih stanica (log10) bio je na početku (5,21), a najniži sredinom laktacije (5,04). Dnevna količina mlijeka nakon laktacijskog vrha (3. laktacija) postupno se smanjivala, a povećanje broja somatskih stanica zabilježeno je do 4. laktacije nakon čega je slijedilo smanjenje njihovog broja. Između pojedinih parametara utvrđeni su značajni koeficijenti korelacija.Considering Paška sheep milk is entirely processed in Pag cheese, it is importance hygienic quality to milk production. In addition to genetic factors, as the most important factor, the production and quality of sheep milk is affected by numerous environmental factors, so the aim of this research was to determine the influence of stage (the beginning, the middle, the end) and number of lactation (1st, 2nd, 3rd, 4th, 5th and others) on changes in daily milk quantities and changes in somatic cell count of Paška sheep milk. Herds were 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 (A), 2nd (B), 3rd (C), 4th (D), 5th and others (E). A significant influence of stage and number of lactation on average daily milk yield and number of somatic cells. The Paška sheep had the highest daily milk production (750 g) in the mid-lactation, and the third lactation (690 mL) recorded. The highest somatic cell counts (log10) were at the beginning (5.21) and the lowest at the middle (5.04) of lactation. Daily milk yield after the lactation peak (3rd lactation) gradually decreased, while an increase in the proportion of somatic cells up to the 4th lactation was observed, followed by a decrease. Between the individual parameters significant correlation coefficients were determined