Changes in semen quality in Estonian Holstein AI bulls at 3, 5 and 7 years of age
2006 (English)In: Reproduction in domestic animals (1990), ISSN 0936-6768, E-ISSN 1439-0531, Vol. 41, no 3, 214-218 p.Article in journal (Refereed) Published
The predictability of semen quality of mature sires from measurements at an early age is not well established. The aim of the present study was to determine age-dependent changes in the quality of bull semen from six Estonian Holstein (EHF) bulls, processed when the sires were 3, 5 and 7 years old. Fertility data such as 60-day non-return to oestrus rates (60d-NRRs) were available for 3-year-old bulls. From each batch, semen straws were analysed immediately after thawing [i.e. post-thaw (PT)] (controls) and after a swim-up (SU) procedure. The analyses comprised subjective and computerized measurements of sperm motility using computer-assisted sperm analysis (CASA) as well as estimations of sperm concentration, morphology and membrane integrity. There was a significant (p less than 0.05) increase in the percentage of sperm motility (SU), membrane integrity (PT, SU) and normal tail and acrosome morphology (SU) with an increase in the age of the sires. The percentage of total motile spermatozoa PT measured by CASA correlated between 3- and 7-, and between 5- and 7-year-old bulls (p less than 0.05). In addition, the proportion of head abnormalities tended to correlate between all three age groups both PT and after SU (p less than 0.1). The sperm parameters correlating with fertility were average path velocity (VAP) (p less than 0.001), total motility as measured by CASA (p less than 0.01) linearly motile spermatozoa (p less than 0.05) and CASA-assessed numbers of motile spermatozoa (p less than 0.05), all after SU selection. The results showed that overall semen quality examined at 3 years of age is related to the semen parameters later in bulls life. Moreover, CASA-assessed motility after SU seems to be a reliable marker for semen quality assessment as it shows correlation not only between the ages, but also to field fertility.
Place, publisher, year, edition, pages
Wiley-Blackwell , 2006. Vol. 41, no 3, 214-218 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-101802DOI: 10.1111/j.1439-0531.2006.00682.xISI: 000238482800005OAI: oai:DiVA.org:liu-101802DiVA: diva2:666813