The team of the researchers at the Sheep, Goats and Fur Covered Animals Breeding Department of the Agricultural University of Poznan has created a subspecies of dairy sheep, 05. The research was conducted at the Experimental Farm in Złotniki and the subspecies presents a meaningful share of both East-Fresian (13/16) and Polish Merino (3/16) sheep genotype. The ewes of the subspecies in the Z³otniki herd are milked for 16 weeks in two seasons: spring-summer (March till June) and summer-autumn (July till October). The milking is carried out on selected ewes having clinically healthy udders and being after two months of lambs feeding (60 ± 22 days). The sheep are machine-milked in the milking hall produced by Westfallen company and prepared for 14 sheep. 161 ewes of 05 dairy sheep were examined in both milking seasons of 2000-2002. The examination of the milkiness of ewes was conducted with monthly breaks and the yield was defined in ml from both morning and evening milking. During the examination of milkiness, before the morning milking, after a few milk streams, cleaning and drying of the teats, about 50 ml of milk was collected from udder halves (preserved with CC preparation) in order to evaluate the percentage content of fat, protein and lactose, as well as the somatic cell count. The examinations of milk samples were carried out in the Milk Evaluation Laboratory in Krotoszyn. The basic milk composition was described applying MilkoScan apparatus, while the somatic cell count was evaluated by the assistance of Fossomatic apparatus. The somatic cell count was transformed to a decimal logarithm (log SCC) in order to obtain a distribution being close to normal. The numerical data referring to the daily milk production, the number of somatic cells (log SCC), as well as the percentage content of fat, protein and lactose was defined with an application of the multifactor analysis of variance. The following sources of changeability were taken into consideration: the year, ewes. milking season, successive lactation and stage of lactation, type of ewes birth-giving and the number of lambs both born and bred. Environmental conditions (the time of year), as well as successive lactation and the stage, and type of birth-giving influenced the quantitative and qualitative level of ewes. milkiness. The somatic cell count and the basic milk composition were significantly varied in both milking seasons. As far as the milk of multi-lamb ewe mothers is concerned, there was an observable tendency for them to produce more milk per day, increase the somatic cell count and percentage of milk content and protein, as well as the simultaneous decrease in the content of lactose. The obtained results can be helpful while selecting ewes for machine milking, focusing on those coming from multiple litters and those which have bred more than one lamb. The ewes should be utilized for milking up to the fourth lactation, mainly due to the significant decrease of the level of milkiness (10%) and nearly 60% increase in the number of the somatic cell count in milk in the fifth and successive lactations (from log 5.168 to log 5.363, i.e. from 145 × 103 cells/ml to 230 × 103 cells/ml).
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