M. J. U. Sarder
Department of Animal Husbandry and Veterinary Science, Faculty of Agriculture, University of Rajshahi, Rajshahi-6205, Bangladesh
Spermatozoa, Abnormalities, Bull, genetic group, AI, Conception rate
Dairy Farm (CCBSDF), Savar, Dhaka; Rajabarihat Dairy Cattle Improvement Farm ( RDCIF), Rajshahi, and District Artificial Insemination Centre, Rajshahi,
Variety and Species
The study was conducted on morphological abnormalities of spermatozoa in different breeds of 71 AI bulls at three AI centres I stations ( Central Cattle Breeding Station and Dairy Farm, Savar, Dhaka; Rajabarihat Dairy Cattle Improvement Farm, Rajshahi, and District Artificial Insemination Centre, Rajshahi ) and 40 AI Sub-centres I Points on 20,936 cows for first insemination under District AI centre, Rajshahi during the period from January 1997 to March 2002. The experimental AI bulls were divided into 6 ( six ) groups ( A to F ) according to their genetic composition; Group A= 100% Friesian ( 100% F, n = 11 ), Group B = 100% Sahiwal ( 100% SL, n = 11 ), Group C = 75% Friesian x s 25 %Local ( 75% F x S25 % L, n = 14 ), Group D == 50% Sahiwal x $50% Friesian (50% SL x 50% F, n = 11 ), GroupE= 50% Friesian x 50% Local (50% F x 50% L, n = 14) and Group F = 100% Local ( 100% L, n = 10 ). A total of 676 ejaculates of semen for tail abnormities and 714 ejaculatt!s of semen for head abnormalities from 71 AI bulls were obtained over a period of 5 years considered as the basic materials for the study. The following support chemical reagents viz. basic fucshin, alcohol, phenol, bluish eosin, chloramine for William's stain and disodium hydrophosphate, potassium di-hydrogen phosphate, sodium chloride and formaldehyde for formal saline . used as fixative were used. The bulls of three centres I stations were regarded as clinically healthy and free from any significant abnormalities. The bulls received routine vaccination against anthrax, haemorrhagic septicemia, blackleg, foot and mouth disease and anthelmintics against fascioliasis and round worm infections. Bulls were tested for fertility before putting them in the breeding herd. The feeding and management systems of bulls were more or less same but environmental condition was different. The bulls were trained to ejaculate in artificial vagina (AV) at homosexual mount using at three AI centres. After collection, semen samples were kept at 35°C in water-bath until the media and reagents were added to the samples. Semen was collected from bulls generally interval once in a week of all the AI centres. After routine semen examination and two types of seme A (chilled semen and frozen semen ) were produced for AI. For chilling, the semen was diluted with egg yolk-citrate extender at a rate of 20 x 106 actively motile spermatozoa in an insemination dose of 1 mi. The diluted semen was preserved in aliquots (1 ml) at 4 to 8 °C until used. Only the semen showing 50% motility after processing was selected for AI. For freezing semen, CCBSDF, Savar, and RDCIF. Rajshahi, routinely used egg yolk-tris-fructose-citric acid-glycerol extender. The final concentration of spermatozoa was 30 x I06 I 0.25 mi. According to the AI centres, only semen that showed 40% post-thaw motility was adopted for AI. Morphological examination was done by staining the smear of semen with William's method (Williams, 1920). A thin smear of fresh semen was prepared on a grease free slide for the study of morphological abnormalities of sperm head after staining with William's stain. The smear was air dried and fixed in flame and some information like bull ID and date of semen collection were marked on slide at any end with the help of permanent marker pen. Then the smear was treated with absolute alcohol for 3-4 minutes and washed with 0.5% chloramine for 1-2 minutes until it appeared fairly clear and then washed in distilled water followed by rinsing in 95% alcohol and finally stained with Carbol fllcshin eosin for 8-10 minutes. After staining, the slides were washed in running tap water, then dried off and examined under light microscope with oil emersion at 1000X. The proportion of sperm with normal head morphology included only those were free from any detectable abnormalities. The head abnormalities in spermatozoa were classified as per description of Williams (1920) such as pear shape head, narrow at the base head, narrow head, broad, big and little short head, abaxial position of the mid piece, undeveloped head, abnormal contour and others abnormal head. At least 500 spermatozoa from individual smears were examined. The proportion of spermatozoa with abnormal head morphology included only those, which were any detectable abnormalities.
Bangl. J. Vet. Med. (2004). 2 (2): 129-135
Journal