MVSc

The aim of the present investigation was to study the gestation period and the process of parturition in crossbred cattle.
The materials used for the present study consisted of 40 crossbred cows of Jersey x Sindhi, Jersey x Local and Brown Swiss x Local cows maintained in the Livestock Farm attached to the Kerala Agricultural University. These animals were maintained under identical conditions of feeding and management. Duration of gestation was calculated from the breeding records maintained in the farm. Signs of approaching parturition were assessed by personal observations. The presentation, position and posture of foetus were studied by rectal and vaginal examinations.
The gestation length of Jersey x Sindhi, Jersey x Local and Brown Swiss x Local was 275.3 + 2.8, 279.3 + 2.5 and 280.5 + 2.6 days respectively. Breed of the dam and sex of the calf had no significant influence on the gestation length. Birthweight of calf was not significantly correlated to gestation length. Observation on the location of the foetus revealed a steadily increasing trend in the percentage of foetal extremities being presented in the pelvic cavity until a day prior to parturition. In all the animals observed, the foetuses were in anterior presentation. The position of the foetuses at the time of parturition were dorsosacral in all the cases. Changes in position and posture of the foetuses were noticed within 96 hours of parturition. In all the cows studied, there were progressive increase in vulval and udder enlargement, presence of coclostrum, relaxation of sacrosciatic ligaments and dilatation of cervix as parturitions were imminent. A significant drop in body temperature was noticed on the day prior to parturition.
The total duration of parturition was 34.68 + 68.75, 668.2 + 97.17 and 912.5 + 182.68 minutes respectively for Jersey x Sindhi, Jersey x Local and Brown Swiss x Local cows, the differences being statistically significant. It was also observed, that the differences in the duration of different stages of parturition were not at variance. Intensity of labour and sex of calf had no influence on the different stages of parturition in crossbred cows. Diurnal variation of calving was noticed with 60.53 per cent during day time and 39.47 per cent during night time. All the cows except one were recumbent at the time of expulsion of foetus.
Breed and sex of calf had no influence on the weight of placenta and number of cotyledons. The total number of cotyledons and large sized cotyledons were significantly higher in the gravid horn than in the nongravid horn. The small sized cotyledons were significantly lower in the gravid horn. No significant difference was observed in the number of medium sized cotyledons between gravid and nongravid horns. The weight of foetal fluids was found to range from 5.6 to 22.4 kg. with a mean of 15.214 + 2.25 kg.