Study on Semen Quality and Field Efficiency of AI Bulls Kept at the National Artificial Insemination Center
No Thumbnail Available
Date
2005-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
A laboratory based semen quality study was carried out at the National Artificial Insemination Centre, located at southeast outskirt of Addis Ababa, with the objective of evaluating the semen quality of AI bulls of the Centre. In addition, a field study was carried out to evaluate AI efficiency at field level in Girar Jarso Wereda of the North-Shewa Zone of the Oromia Regional State. The study was undertaken from October 2004 to April 2005. 16 AI bulls were included for the semen quality at the NAIC. A total of 93 postpartum dairy cows and heifers which came to the veterinary clinic in Girar Jarso wereda to get AI service were included in the sample to study AI field efficiency using the semen of 8 bulls among the 16 involved in the semen quality study. Semen was collected from each of the 16 bulls included in the sample once per week for eight weeks using artificial vagina and evaluated for volume, color, concentration, mass activity, individual motility, morphological abnormalities and percentage of alive spermatozoa. According to the results, the average volume ranged from 6.18 ml in the Friesian bulls to 7.18 ml in the crossbred bulls and the average concentration ranged from 1143.1 million/ml in crossbred animals to 1270.3 million/ml in Friesian bulls. Comparable means of mass activity score (3.17 in crossbred and 3.18 in Friesian bulls) and individual motility (71.67 % in crossbred and 71% in Friesian bulls) were recorded. The average proportion of total morphological defects was 18.17% in crossbred bulls and 16.10% in Friesian bulls. The proportion of alive cells was 74.67% in crossbred bulls while it was 76.60% in Friesian bulls. The results of independent t-test to see the effect of different factors on semen quality parameters indicated that only age (p<0.05) and scrotal circumference (p<0.01) of bulls had significant effect on semen volume. The results of Pearson’s correlation analysis showed that mass action had positive correlation with individual motility (p<0.01) and concentration (p<0.05).
In the field study of the efficiency of AI, a minimum of 10 cows were served by the semen of each of the 8 bulls included in the field efficiency trial. The inseminated animals were checked for pregnancy by rectal palpation after 60 days of first
x
insemination. The results revealed that the overall pregnancy rate was 55.9% and only body condition score of cows or heifers affected pregnancy rate significantly (p<0.05).
Description
Keywords
Semen quality, AI, Bulls, Post partum Cows, Field efficiency