Abstract:
A systematic study involving the use of 85 does comprising 27 Malabari, 35 Alpine x Malabari and 23 Saanen x Malabari crosses reared and maintained at Mannuthy, Kerala, under All India Co – ordinated Research Project on Goats for Milk was carried out in order to ascertain the gestation length, process of parturition and placental details. In addition 583 breeding particulars gathered from the registers maintained at the Project also utilized for assessing the gestation length and frequency of occurrence of multiple births. The salient observations made and the valid inferences drawn are indicated below.
The average gestation length of different genetic groups of goats was found to be 146.66 + 0.53 days. There was no significant variation in the gestation period of does of different genetic groups both in single and multiple births. Parity had no influence on the gestation length in does. The variation in gestation length due to difference in the sex of kid was also not significant. Gestation period was not found to vary between seasons. The frequency of occurrence of single, twin and multiple births was found to be 50.75 per cent, 45.05 per cent and 4.19 per cent respectively.
Signs of approaching parturition was assessed based on the degree of manifestation of such symptoms as tumefaction of the vulva, udder engorgement and relaxation of the pelvic ligaments. The symptoms exhibited by the does were only moderate in the beginning but on nearing parturition there was conspicuous increase in the intensity of these changes. Colostrum was present in all the animals two days prior to parturition. Visible flow of cervical mucus was evident in 75 does two days prior to kidding and in all, 24 hours before parturition. There was no significant fluctuation of body temperature of does during prepartum period.
The total duration of parturition was 360.91 + 30.85, 358.20 + 16.67 and 395.42 + 40.09 minutes in single births and 359.12 + 26.15, 357.20 + 32.23 and 368.73 + 24.03 minutes in multiple births in Malabari, Alpine x Malabari and Saanen x Malabari goats respectively. The duration of parturition was not variance between genetic groups both in single and multiple births. The weight of kid was positively correlated to the weight of placenta, total number of cotyledone and to the number of large and medium sized cotyledons. There was negative correlation between weight of kid and the number of small sized cotyledons. The number of cotyledons in the gravid horn was significantly higher than that in non gravid horn in all the genetic groups. Weight of the placenta as well as the total number of cotyledone was found to be more in multiple pregnancy than in single pregnancy.