Journal of Animal Research: v.5 n.2, p. 289-292. June 2015

DOI Number: 10.5958/2277-940X.2015.00049.2

Polymorphic Sperm Phenotype Suggesting Genetic Sperm Defects in a Jersey

( Bos taurus ) X Zebu ( Bos indicus ) Crossbred Bull

Madurantakam N. Sundararaman * , Alagappan Gopinathan, Arunachalam Subramanian

Frozen Semen Bank, Department of Animal Genetics and Breeding, Madras Veterinary College, Tamil Nadu Veterinary and Animal

Sciences University, Chennai, INDIA.

*Corresponding Author: MN Sundararaman; Email: sundararaman@tanuvas.org.in

Received: 18 March, 2015

Accepted: 15 May, 2015

ABSTRACT

Data on semen collections from a Jersey X Zebu crossbred bull, consistently producing semen with high proportion of sperm

abnormalities was collected and the semen characteristics were analyzed. Observation of the records of 58 ejaculations from

the bull has revealed that 96.6% of the ejaculates were rejected for poor semen quality especially in sperm morphology. A

representative semen sample from the bull also showed sperm abnormalities up to 72.9%, of which 14.9% and 14.5% of the

spermatozoa exhibited loose heads and microcephalic heads respectively. Coiled tail (16.7%) and short tail (14.9%) were the

main tail defects observed. Since sperm defects were consistently appearing in high proportions in almost all the ejaculates the

genetic cause of the sperm defect was suspected.

Keywords: Bull spermatozoa, Polymorphic sperm phenotype, Genetic sperm defects

Abnormal morphology of sperm is a noncompensable

adversely (Chenoweth, 2005; Chemes, 2012). The present

trait and the merit of the sperm morphology assessment

study is on a Jersey X Zebu crossbred bull, repeatedly

as an in-vitro fertility test of bulls has been well

producing ejaculates containing high proportion of

established. Further, the relationship of proportion of

different types of sperm defects.

morphologically normal and abnormal spermatozoa with

A Jersey X Zebu crossbred bull, aged 30 months,

conception has also been proven (Padrik and Jaakma,

maintained at a frozen semen production centre in Tamil

2001). The most common causes of sperm abnormalities

Nadu State, India was reported to have consistently

are environmental, andrological or endogenous especially

producing ejaculates with high proportion of sperm

for nonspecific head and flageller defects (Chemes and

abnormalities. The ejaculates from the bull were evaluated

Rawe, 2003; Chenoweth, 2005). However, certain types

for semen volume, sperm concentration, sperm motility

of head shape and tail defects are genetic in origin. The

and sperm morphology by conventional methods using

causative factors lead to impaired spermiogenesis and

phase contrast microscope and photometer. Morphological

sperm maturation (Chenoweth, 2005) which more often

evaluation was done using 3% Rose Bengal stained sperm

results in specific sperm defects. Since the sperm head,

slides. A total of 200 spermatozoa were counted for

which carries the genetic material from the sire to the

assessment of sperm abnormalities. Semen characteristics

offspring, plays a vital role in the fertilization process,

recorded for the 58 ejaculates collected from the bull

even a small proportion of sperm head defects significantly

at the frozen semen production centre were studied. A

affects fertility (Al-Makhzoomi et al., 2008). Decapitated

representative ejaculate from the bull was taken using

sperm, microcephalic sperm heads and short tail are some

artificial vagina and the semen sample was evaluated for

of the genetic sperm defects which influence the fertility