RELATIONSHIPS AMONG FROZEN-THAWED SPERM CHARACTERISTICS ASSESSED VIA THE ROUTINE SEMEN ANALYSIS, SPERM FUNCTIONAL TESTS AND FERTILITY OF BULLS IN AN ARTIFICIAL-INSEMINATION PROGRAM
Jr. Correa et al., RELATIONSHIPS AMONG FROZEN-THAWED SPERM CHARACTERISTICS ASSESSED VIA THE ROUTINE SEMEN ANALYSIS, SPERM FUNCTIONAL TESTS AND FERTILITY OF BULLS IN AN ARTIFICIAL-INSEMINATION PROGRAM, Theriogenology, 48(5), 1997, pp. 721-731
Frozen semen specimens from 22 Holstein bulls representing a wide rang
e of field fertility levels or nonreturn rates (NRR) were used in this
study. Semen specimens were thawed at 37 degrees C for a minimum of 3
0 sec, followed by assessment via a routine semen analysis (RSA) and o
ther sperm functional tests. The RSA was performed by assessing sperm
count, motility and morphological characteristics. Other sperm functio
nal tests were performed by assessing the acrosomal membrane integrity
, sperm penetration into the cervical mucus and the sperm membrane fun
ctional integrity. Following assessment of sperm characteristics, the
fertility data of the various bulls were compared to the RSA and the f
unctional tests results. Bulls of high and low fertility were similar
in terms of sperm count and progressive motility (P>0.05). Other chara
cteristics measured by the RSA and functional tests were significantly
higher in high fertility bulls (P<0.05). Correlation coefficients amo
ng the various sperm characteristics and fertility of bulls were highl
y significant (P<0.01). The highest correlation coefficients between s
perm characteristics and fertility were obtained for motility (r=0.53;
P<0.01), normal morphology (r=0.59; P<0.01) and swollen spermatozoa (
r=0.57; P<0.01). Analysis of specific sperm swelling patterns showed t
hat those patterns considered to reflect maximal sperm swelling were i
ndicative of high fertility. (C) 1997 by Elsevier Science Inc.