Proximal Cytoplasmic Droplets Research Articles

Changes in the morphology of spermatozoa during their passage through the genital tract in dairy bulls with normal and impaired spermat ogenesis

An investigation was conducted on changes in sperm morphology along the excurrent duct of bulls. The study comprised 20 bulls with proven fertility and normal semen picture, and 10 bulls with pathologic semen. The morphology of spermatozoa was evaluated on ejaculates and on postslaughter collected contents from the excurrent duct. The incidence of pathologic sperm heads decreased along the duct in both groups of bulls. The main decrease generally occurred in caput epididymidis. In bulls with pathologic semen, the decrease continued in lower regions of epididymis and was deferens. The rate and pattern of sperm removal seem to primarily depend on the quality of spermatozoa entering the excurrent duct. The removal was clearly selective and is assumed to be associated with phagocytosis of spermatozoa mainly in the efferent ductules and proximal part of caput epididymis. Proximal cytoplasmic droplets were present on almost all sperm in the efferent ductules. The incidence decreased during passage along the genital tract. Migration of cytoplasmic droplets from a proximal to a distal position took place between regions C and D of the caput epididymidis. The incidence of middle-piece abnormalities decreased during passage along the genital tract, while the incidence of sperm tail abnormalities increased in the corpus and cauda epididymidis in all bulls.

Effects of age, body weight, body condition and scrotal circumference on sperm abnormalities of bulls used for artificial insemination (AI) programme in Bangladesh

Impacts of age, body weight, body conditions, and scrotal circumference on sperm abnormalities of bulls used for artificial insemination (AI) in Bangladesh have been studied. During 1997-2002, 1390 ejaculates of semen from 71 bulls from Central Cattle Breeding Station and Dairy Farm, Savar, Dhaka, Rajshahi Dairy and Cattle Improvement Farm, Rajabarihat, and District Artificial Insemination Centre, Rajshahi, were collected and examined. Total head abnormalities, free loose head, mid-piece, tail abnormalities, proximal and distal cytoplamic droplets, total tail abnormalities and total sperm abnormalities were recorded. Age of the bulls had significant effect on sperm abnormalities (P < 0.01) except for proximal cytoplasmic droplet. Similarly, body weight had significant effect (P < 0.05) except for the total head abnormalities, while body conditions had no significant effect on mid-piece, total tail abnormalities and total sperm abnormalities except for the total head abnormalities. Scrotal circumference had significant effect (P < 0.05) on all the sperm abnormalities. The present results demonstrate that the middle (8 to < 10 yrs) and older (>10 yrs) bulls having body weight of < 450 kg, very good body condition and 36 to < 38 cm scrotal circumference had the lowest sperm abnormalities. The need for semen examination for morphological abnormalities of spermatozoa in bulls to be used for AI programme is strongly implicated by this study. Key words: Bull sperm abnormalities, age, body weight, body conditions, scrotal circumference, artificial insemination (AI) doi:10.3329/ujzru.v27i0.1959 Univ. j. zool. Rajshahi Univ. Vol. 27, 2008 pp. 73-78Â Â