Factors Affecting Days to Conception, Litter Size and Litter Weight of Intensively Managed Canarian Hair Sheep

In order to assess the effect of month of breeding, year and sire on days to conception, litter size and litter weight, records on 605 lambings by 350 ewes and 13 rams were used. Days to conception were higher (P<0.01) for spring and summer breeding than mating in fall and winter. Sixty-nine percent of ewes became pregnant within 10 d of ram exposure in winter compared with 24% in spring (P<0.01). Litter size at birth tended (P=0.08) to be higher for spring breeding and lower in winter matings. Mean litter weights at birth were influenced by year of lambing and ram (P<0.01), but not by breeding season. It was concluded that the Canarian hair sheep can be used in accelerated lambing systems under intensive conditions found in the Canary Islands, because this breed presents only a mild reproductive seasonality, which allows multiple season lambings.