Does a High Energy Diet Reduce Sperm Quality in Bulls?

The short answer: yes. Here’s the long answer, why it happens, and how to reduce this temporary loss of sperm quality.

What we know

Breeding bulls in Australia are commonly fed high energy diets before sale, generally in the form of grain.

A high energy grain ration can cause the bull to develop a mild form of acidosis, particularly when intake is uneven. This is often accompanied by slight lameness and diarrhoea.

What we learnt

A study by QSML with Ridley Agriproducts showed that a single occurrence of subclinical rumen acidosis can reduce sperm morphology for up to 90 days. Unfortunately, this can lead to a bull being excluded from sale under single sire mating criteria.

What you can do

Targeting moderate rates of gain (under 1.5 kg a day) and increasing roughage in a TMR, or giving access to better quality roughage, can reduce acidotic events. That way, sperm quality can be assured for the bull buyer in the following breeding season.

Read Dr Viv Perry’s paper for a more detailed breakdown.