Effects of early selection and body conditioning of young blue fox Alopex lagopus females on breeding result, a field study

• Main Authors: Koskinen, Nita, Sepponen, Juhani, Kupsala, Kirsi, Rekilä, Teppo
• Other Authors: Maa- ja elintarviketalouden tutkimuskeskus (MTT) / KEL Kotieläintuotannon tutkimus / Turkistalous TTA / Turkistalous (TUR), NJF Subsection for fur animals
• Format: Conference Object
• Language: English
• Published: dk 2007
• Subjects: Ko; sinikettu; turkiseläimet; jalostus; valinta; furbearing animals; breeding; selection; blue fox; Alopex lagopus; fur animals
• Online Access: http://jukuri.luke.fi/handle/10024/464880

The aim of the field study was to determine if the season, when blue fox females are selected for breeding and body conditioning have an effect on the breeding result and to clarify connection of body weight of artificially inseminated blue fox female with breeding result and the litter size. A field study with 231 blue fox females at the beginning of the trial was carried out in a private blue fox farm 2005-2006. Young blue fox females were selected for breeding in September (Early group) or late in November (Late group). The females in Early group were fed on a restricted breeder's diet during growing-furring season and before artificial insemination. The females in group Late were fed as ad libitum during growing-furring season and the feeding was strongly restricted after selection for breeding. Commercial fox feed was used and the feed consumption was not registered due to the practical field conditions. The females of the Early group were weighed when selected for breeding, in January and at the time of artificial insemination. The females in group Late were weighed in January, in February and also at the time of artificial insemination. Breeding result (litter size/inseminated female) was calculated when litters were 25 days old. The season for selecting the first year blue fox breeders was important. There was statistically significant difference in the average weight of females between groups in January and at the time of artificial insemination (p<0.0001). At insemination time the average weights were 8848±83 g and 11052±158 g in groups Early and Late, respectively. The breeding result was 5.21 cubs per inseminated female in group Early and 2.37 cubs per inseminated female in group Late (p<0.0001). The selection in early autumn improved the breeding result. The weight of blue fox female at the time of artificial insemination had an effect to the litter size. The litter size was significantly lower in the weight category over 11 kg at insemination time, 1.74 cubs per inseminated female ...