Fruktsamhet och fruktsamhetsproblem hos chow-chow : en inledande studie över situationen i Sverige
Sammanfattning: The chow-chow breed is considered to have a low fertility and this report is an in depth study of the reproductive functions of this breed in Sweden. Only 53 % of the Chow-chow matings results in litters. Previous studies of other breeds in commercial kennels shows mating results around 85-90 %, but this has not been investigated in hobby kennels and most Chow-chows which are bred from in Sweden, are kept as family pets. Contrary to most other breeds, Chow-chows show a seasonal reproductive pattern and most litters are born in the autumn. The influence of the month of mating on pregnancy rate and litter size was found to be not significant, but can be considered a trend. Thirty-nine females with previous known fertility problems where studied. Some of them had reached puberty extremely early, at an age between 4-5 months, and many of the bitches showed great fluctuations in intervals between oestrus cycles. Some of the females showed abnormalities such as very short oestrus intervals of only 2-3 months, probably without ovulating. One bitch was mated between days 4-18 in the heat, which is extreme. One bitch varied in length of the heat with 1-4 weeks. Some of the bitches did not accept any male as mating partner, which is a primitive and natural behaviour for canines. The semen quality of four Chow-chow males was evaluated every third month during a year. No seasonal variation in semen quality was noted. However, the quality varied greatly in each individual male between the sampling occasions. Deviations from the normal reproductive pattern of both females and males in the study are exemplified and suggestions of measures and further investigations are given in the report.
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