Ambassador: Kris Gios, Belgium

Publication date: June 2019 | Theme: Health management

Challenges: Reducing zinc oxide

Kris Gios’ farrow-to-finish unit has trialled feeding herbs in piglet diets instead of including zinc oxide and has reduced production costs by 2.4%. Average daily gain and feed conversion rate have improved and weaner mortality rate has been reduced.

He is trialling three different types of feed, as alternatives to the previous feed which contained zinc oxide. They are:

  • Feed containing herbs
  • Feed with inert fibres added
  • Normal feed

The farm has been antibiotic free since 2012 and has remained so since trying the new diets.



  • A better average daily gain (416g), feed conversion rate (1.58) and reduced weaner mortality rate (2%) were observed when feeding herbs
  • The mortality rate of weaners fed inert fibres declined in line with the herb diet
  • The overall effect of these technical improvements resulted in a reduction in production costs of 2.4% 


  • The price of including herbs in feed was 2.3% higher than the standard diet

Innovation in practice

Kris asked his feed company to come up with an alternative diet excluding zinc oxide. 
The suggestion was to include a combination of herbs, including oregano, at the following rates:

  • Seven days prior to weaning to seven days post weaning  -  3mg herbs/kg feed
  • Seven days post weaning to day 28 post weaning  -  1.5mg herbs/kg feed

Kris also trialled the inclusion of inert fibres in standard feed in an attempt to calm the intestine. 

Three groups of piglets were kept within the same barn. Each group was fed a different diet (either standard, herb-based or inert fibre) and weighed daily. Feed intake was monitored and growth and feed conversion were calculated, along with the % saving (€/pig) across production.

More about this best practice

To access more information, contact RPIG (Belgium): Laurens Vandelannoote