The analysis of foal productivity during the breedable period of light breed stallions
2008
Tsukada, T.(Tsukada Livestock Clinic, Hidaka, Hokkaido (Japan)) | Koyago, M. | Moriyosi, M. | Sawamukai, Y.
This study was conducted to determine the factors related to equine fertility using a total of 2,293 stallions, which serviced a total of 128,757 mares from 1965 to 2000 in Hidaka, Hokkaido. The age, number of services per breeding season, parturition rate of mares (production rate of stallions), breeds, breeding area, breeding farms and breeders were analyzed. The average age, number of services per breeding season and production rate of the stallions were 12.4+-4.2, 56.2+-26.9 and 70.6%, respectively. A significant correlation was found between the number of services and production rates of stallions. Of the total 2,293 stallions used in the study, 59 were serving 8 years or more and 20 or more services per breeding season. These stallions were divided into 5 groups based on the production rates as, (Group 1) stallion showing60% during the term of services (47 stallions: 79.6%), (Group 2)30% temporary drop (6 stallions: 10.1%), (Group 3)50% in first year but60% from second year (2 stallions: 3.4%), (Group 4) gradual drop in latter part (3 stallions: 5.0%) and (Group 5)60% in first two years then gradual drop in latter (one stallion: 1.9%). Significant differences were found in breeds, breeding area and breeders (p0.01). These results suggest that production and breeding management practices play an important role in influence production rates, thus the level of productivity of stallions could be maintained over 70% if proper breeding conditions were provided by breeders.
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