Gestational length in Carthusian broodmares: effects of breeding season, foal gender, age of mare, year of parturition, parity and sire.

The research investigated the impact of various factors such as the breeding season, foal gender, age of the mare, year of parturition, parity, and sire on the gestational length of Carthusian broodmares. The results of the research revealed that these factors do significantly affect the gestational period of these mares.

Research Methodology and Data Collection

• The gestational length of Carthusian broodmares was evaluated using data from 339 spontaneous full-term deliveries that occurred between 1998 and 2005. The deliveries were from 158 broodmares and 29 stallions at a large Spanish horse farm that specialized in the Carthusian strain.
• An ultrasonography technique was used to determine the first day of pregnancy and to confirm conception. The average gestational length was discovered to be approximately 332.4 +/- 12.1 days with a normal range of 297-358 days for this particular breed.
• The gestational length records were categorized based on the sex of the foal (colt or filly), the month of mating, the age of the mare, the particular year of breeding, the stallion, and parity (first-time mother or not).

Research Findings

• The study discovered that mares mated between the months of May and July had shorter gestational lengths, 12.9 days, compared to those mated between November and January; and 15.3 shorter days for those mated between February and April.
• There were gestational length variations observed related to the age of the mare. Mares in the age range of 8-12 years had 5.3 shorter gestational days compared to those aged 13-17 years.
• When considering foal gender, the study found that pregnancies tended to be 5.7 days longer when the mares gave birth to colts versus fillies.
• Primiparous mares (those giving birth for the first time) had gestational periods that were 14.5 days longer than multiparous mares.
• No statistical differences were observed concerning gestational length when viewing data based on the specific years involved in the study.
• The study also provided evidence suggesting that the choice of specific stallions for breeding could have an impact on gestational length.