Factors Affecting the Semen Production and Semen Quality of Bulls Used for Artificial Insemination

Abstract

The present study was to evaluate the semen production and semen quality in relation to bull ID, breed, age, body weight, body condition, libido, testicular circumference, season and Artificial Insemination (AI) centres from 16 bulls used for AI programme in Bangladesh. The study was conducted at District AI Centres (DAIC), Rajshahi and Rajshahi Dairy & Cattle Improvement Farm (RDCIF) Rajabarihat, Rajshahi, AI sub centres / points under the Rajshahi district and Dept. of Animal Husbandry and Veterinary Science, University of Rajshahi duration from July, 2011 to June, 2013. The average values of semen production such as volume of ejaculate, color, mass activity, density, sperm concentration, sperm motility, total number of sperm cells /ejaculate, number of semen doses per collection were 7.67±2.17ml, 3.06±0.98 (scale:1-4), 2.91±0.74 (scale:1-5), 3.56±0.77 (scale:1-4), 1330.46±313.32 million/ml, 62.94±5.32%, 10112.88±3521.12 million/ejaculate 337.10±117.37 respectively. Individual bull had significant effect (P<0.05) on only volume of ejaculate and color of semen. Six breeds of the bull such as L×F×SL×F×F, SL×F, L×F×F, L×F, (L×F)2, L×F(L×F×F) had significant (P<0.05) effect on all the semen characteristics. The significant (P<0.05) highest volume (8.23±2.47 ml) was found in L×F×SL×F×F breed and lowest (5.97±2.36 ml) in L× F×(L×F×F) breed. Significantly (P<0.05) highest values of sperm motility (63.48±5.12%), total number of sperm cells/ejaculate (10523.03±3607.45million/ml) and the number of semen doses (350.70±120.25) were found in (L×F)2 breed of bull. The semen quality was tested by using three type of extenders to evaluate sperm motility %, various duration of preservation of semen in relation to conception rate of cows. A total 189 cows were artificial inseminated in different AI sub centre/points of District AI centre and average conception rate was observed 50.77%. The three extenders of Egg Yolk Citrate (EYC), Cornell University Extender (CUE) and Coconut Milk Extender (CME) had significant effect (P<0.05) on sperm motility % and conception rate. The highest conception rate was found at EYC (57.82±7.00%) and lowest in CME (43.71±3.59%). A total 64 semen sample was studied for the determination of sperm abnormalities in association to non return rate (NRR). The average head and tail abnormalities were obtained 4.29% and 13.90% respectively and total sperm abnormalities was observed 18.13 ±6.78%. A total of 1600 cows inseminated by that 16 bull semen were observed for NNR within 60 days. The overall NRR was obtained 78.50±11.95%. Bull ID, breed, testicular circumference, libido had significant effect (P<0.05) on sperm abnormalities and NR%. It was concluded that the overall semen production performance was found better in (L×F)2 breed, young age, 500-<600 body weight, very good body condition, >38 cm testicular circumference, good libido, spring season and AI centre’s of RDCIF. Semen quality was suitable in the EYC extender for chilled semen preservation under field condition as well as L×F×F breed had shown satisfactory performance of sperm morphology and NR%.