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Description:
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Fertility Associated Antigen (FAA ) produced by the accessory sex glands and
contained within the seminal fluid binds heparin and facilitates capacitation in ejaculated
sperm , resulting in improved fertility in bulls capable of producing the protein . In this
study , a total of 206 bulls derived from three populations were evaluated for the presence
or absence of FAA through utilization of the Repro Test at three semen collections over
a 60 -d period . Across all collections , the percentage of FAA Negative bulls ranged from
13 .64 to 36 .11 % . Within the three populations , 32 , 33 , and 67 bulls were observed at
three different collections , of which 3 .03 , 9 .09 and 4 .48 % were FAA Negative at all
three collections , respectively . Furthermore , 27 .27 , 33 .33 , and 20 .90 % of bulls were
observed to have variations within their FAA status after providing an initial FAA
Positive result , respectively . Bull age , sperm concentration , progressive forward
motility , percent normal sperm , ejaculate volume , and scrotal circumference were
determined to be significantly different between FAA Negative and FAA Positive bulls
in at least one collection . However , no consistent trend was observed across populations ,
or collections within a population , with regard to a relationship between these variables
and FAA . Furthermore , of fourteen bulls that produced an ejaculate in which no sperm was detected , 78 .57 % (n=11 ) were FAA Positive despite the lack of sperm within the
ejaculate . No single variable commonly measured to determine bull fertility was
consistent in predicting the FAA status of bulls . The ability to produce FAA precedes
puberty and the Repro Test can be used to identify FAA in prepuberal bulls . However , a
large percentage of bulls , both prepuberal and peripuberal , are capable of displaying
variation in their FAA status (as determined by the Repro Test ) over time . |