• Cryptosporidia is the major cause of calf scour (57% of cases) in early life with significant cost to the dairy industry (£32-£154/calf (Gunn, 1997)).
  • Orego-Stim® Liquid, when included in milk at 10ml per calf per day for 10 days, significantly reduced Cryptosporidia shedding in dairy calves.


  • Cryptosporidia is a major cause of calf diarrhoea (scour) causing long term damage to the gut lining, depressed nutrient absorption, poor growth performance and can ultimately prove fatal, (Thomson, 2017).
  • Peak shedding of oocysts is in the first 2-3 weeks of life, so early intervention to prevent this significant protozoan from multiplying is essential.
  • Orego-Stim® is a high quality phytogenic eubiotic containing 100% natural oregano oil.

A pilot study was carried out at the University of Reading in the UK. 10 male Holstein dairy calves were assigned to one of two treatments at 2 days of age; Control with no supplements in the milk, Orego-Stim with 10ml/calf/day of Orego-Stim® Liquid added to the milk. The milk used was unsaleable, waste milk from the University dairy herd.  Orego-Stim® was included in both the morning and evening feeding (5ml in 2.5 litres milk) for the first 10 days only.  All calves then received the same milk and concentrates until weaning at day 60.  Calves were individually housed until 21 days of age then housed together in a straw pen until the end of the trial at day 78.  Faecal samples were taken on days 0, 3, 7, 10, 14, 21, 56 and 70 for analysis of Cryptosporidia shedding.

(a,b superscripts denote differences (p<0.02).
Fig 1. Effect of Orego-Stim® on Cryptosporidia shedding in dairy calves. (Adapted from Ray et al., 2019, unpublished),

  • Cryptosporidia was only detected in faeces between days 3 – 21.
  • Calves offered 10ml Orego-Stim® Liquid had lower counts of Cryptosporidia in faeces (p=0.02).
  • Calves offered 10ml Orego-Stim® Liquid numerically gained more weight in the first 10 days (597g/d vs 411g/d; p=0.11).
  • Orego-Stim® Liquid was shown to have a significant benefit in reducing Cryptosporidia shedding in dairy calves offered waste milk.