EN
The study was conducted on 4-year-old Kamieniec ewes, 12 suckling single lambs and 12 suckling twin lambs. The course and consequences of lactation in ewes nursing singles and twins were compared based on daily milk yield, blood hematological indices, blood mineral concentrations and wool quality traits. Milk yield was found to be significantly higher in ewes nursing twins - by 21.46% at the peak of lactation, and by as much as 27.40% towards the end of lactation. Blood hematological indices were not affected by the number of suckling lambs. A significant decrease in Ca concentration observed in all ewes at peak milk yield was followed by an increase. There was a tendency towards a gradual decrease in Mg levels during lactation, but significant differences were reported only with respect to ewes nursing twins. The process of uterine involution at first proceeded faster in ewes suckling twins, but starting from day 30 p.p. no differences were noted between the groups. Lactation had a negative influence on wool quality in both groups, but the decrease in wool growth rate as well as in staple thickness and strength was much more significant in ewes nursing twins.