Morphological sperm abnormalities of different breeds of AI bull and its impact on conception rate of cows in AI programme

Abstract

The main objective of this study was to evaluate the effect of genetic groups of bulls on morphological characteristics of spermatozoa in relation to conception rate of first inseminated cows. For this purpose, 1390 ejaculates of semen were collected from 71 bull of six genetic groups at Central Cattle Breeding Station and Dairy Farm (CCBSDF), Savar, Dhaka; Rajabarihat Dairy Cattle Improvement Farm (RDCIF), Rajshahi, and District Artificial Insemination Centre, Rajshahi, from January 1997 to March 2002. A total of 20936 cows were inseminated by 40 technicians of different AI Sub-centre or points under the District Artificial Insemination Centre, Rajshahi, and pregnancy was confirmed on rectal palpation at 90 to 120 days after insemination. The average values of total head abnormalities, free loose head, mid-piece, tail abnormalities, proximal and distal cytoplasmic droplets, total tail abnormalities and total sperm abnormalities were 5.45%, 2.44%, 1.19%, 6.19%, 0.74%, 0.57%, 11.16% and 16.38%, respectively. Genetic groups of bull had significant (p < 0.05) effect on all the morphological characteristics of spermatozoa. The lower incidence of total sperm abnormalities (13.45%) was found in the genetic groups of 100% SL and higher (19.28%) in 75% F x 25% L bulls. The genetic groups of bulls had significant effect on first service conception rate of cows. The conception rate was higher in cows inseminated with 100% Local than those inseminated with genetic groups of 75% F x 25% L (53.13% vs 45.88%; p < 0.05). Significantly strong positive correlations were found between total head abnormalities and total sperm abnormalities (r = 0.828; p < 0.01) as well as between total tail abnormalities and total sperm abnormalities (r = 0.892; p < 0.01). It appears from the results that minimum total sperm abnormalities are found for pure breed bulls than cross-bred bulls, and 100% Local, 100% Friesian and 50% SL x 50% F bulls had better conception rates on cows.

Key words: Spermatozoa; abnormalities; bull; genetic group; AI; conception rate

doi: 10.3329/bjvm.v2i2.2555

Bangl. J. Vet. Med. (2004). 2 (2): 129-135