Seasonal effect on viability and morphology of spermatozoa in Karan Fries (Holstein Friesian×Tharparkar) bulls under tropical climatic condition
Submitted Date : 10-08-2015
Accepted Date : 17-10-2015
Availability of morphologically normal and higher percentage of live spermatozoa throughout the year is highly demanded to fulfilment the demand of dairy cattle. There may be deterioration of semen quality during summer season in crossbred bulls in tropical climatic condition. Therefore the present study was designed to observe the seasonal effect on viability and morphology of spermatozoa in Karan Fries bulls. Five adult healthy bulls (n=5) were selected from Animal Breeding Research Centre (ABRC) of ICAR-NDRI, Karnal, Haryana (India). Six ejaculates from each bull were collected using artificial vagina (42-45 °C) during winter (December to Middle February), spring (Middle February to April), hot-dry (May to June) and hot- humid (July to August) seasons. Immediately of collection, the ejaculates were placed in a water bath (37 °C). Eosin-nigrosin vital stain was used for assessing live, dead and sperm abnormalities. The percentage of live spermatozoa were significantly (p<0.05) lowered during hot humid season and the major abnormalities were significantly (p<005) higher during hot-dry (8.66 ± 0.22 %) and hot-humid (10.74 ± 0.18 %) seasons. It can be concluded that hot-dry and hot-humid seasons are stressful to Karan Fries bulls. Therefore, sufficient measures should be taken to ameliorate the effect of heat stress on Karan Fries bulls.