Sperm Morphology: Research Update for Cattle Vets

In May this year, QSML’s Director and Senior Advisory Morphologist, Dr Viv Perry, addressed audiences at both the “Theory into Practice” International Bull Fertility Conference in Westport, Ireland and the Australian Veterinary Association Annual Conference in Brisbane.

Dr Perry completed her PhD in bull fertility at the University of Queensland Veterinary School and has conducted extensive research into male and female ruminant fertility over the past 30 years at universities in Australia and the UK. Research into environmental effects upon fertility and sperm quality is an integral part of QSML’s service to the Australian cattle industry.

Dr Perry spoke on the progress of research into sperm morphology analysis within the BBSE in Australia, and the importance of standardising the assessment of abnormalities amongst laboratories within one country.

Key research areas discussed

• The effects of grain feeding, or a single mild acidotic event, on sperm morphology in the following months. A single occurrence of subclinical rumen acidosis can reduce sperm morphology for up to 90 days.
• The effects of protein supplementation of the first-calf heifer during lactation on the development of bull calves. Age at sexual maturity in the bull was reduced when protein pellets were provided to the lactating heifer.
• The effects of protein supplementation during pregnancy on puberty in bull offspring (research undertaken with Katrina Copping). Protein supplementation of the first-calf heifer during conception and early gestation may reduce age at puberty in the bull progeny.
• The effects of breed, season and location upon morphology in the bull. QSML research has shown that some breeds are more likely to fail the BBSE on morphology than others, and that breed influences the type of abnormalities likely to be observed. For example, Santa Gertrudis and Droughtmaster bulls may be more likely to show vacuole abnormalities than an Angus bull.

Why standardisation of morphology assessment matters

Dr Perry highlighted the effect different equipment has on the ability to detect sperm abnormalities:

• Nigrosin eosin slides under bright field microscopy may reduce the ability to observe head abnormalities compared to DIC microscopy.
• Using phase contrast without due diligence in focusing on each sperm head may also reduce the ability to observe small head abnormalities compared to DIC microscopy.

For a more detailed breakdown, download Dr Perry’s AVA proceedings paper:

• A Refresher on Sperm Morphology, Proceedings of the AVA Annual Conference, Brisbane, 2018. V.E.A. Perry.

Two of the research papers mentioned are also available:

• Peri-conception and first-trimester diet modifies reproductive development in bulls. Copping KJ, Ruiz-Diaz MD, Rutland CS, Mongan NP, Callaghan MJ, McMillen IC, Rodgers RJ and Perry VEA (2018) Reproduction, Fertility and Development 30: 703–720.
• Subacute ruminal acidosis reduces sperm quality in beef bulls. Callaghan MJ, McAuliffe P, Rodgers RJ, Hernandez-Medrano J and Perry VEA (2016) Journal of Animal Science 94: 3215–3228.

Dr Perry is readily available to QSML clients for consultation on individual cases.