Long-term production effects of clinical cryptosporidiosis in neonatal calves

Abstract

Cryptosporidiosis can have a devastating effect in neonatal calves, resulting in diarrhoea, dehydration and, in severe cases, death of the animal. The disease is caused by Cryptosporidium spp. and is one of the most common causes of calf enteritis in the UK. The parasite is very difficult to remove from the farm, as the oocysts have a tough outer wall which enables the parasite to survive for several months in moist temperate environmental conditions and it is difficult to kill oocysts with common disinfectants used on a farm. If appropriate management practises are applied, the disease is usually self-limiting and most calves will recover. It has been shown, in studies with children and in lambs, that severe clinical cryptosporidiosis can result in long-term growth and cognitive impairment compared with individuals with no obvious signs of the disease. This study measured the long-term growth rate of beef calves on farm by comparing groups of animals that had suffered differing degrees of clinical severity of cryptosporidiosis as neonates. A group of 27 beef calves were enrolled in the study and monitored from birth to 6 months of age. The calves were scored for severity of cryptosporidiosis and weighed at regular intervals. The average difference in weight gain, at 6 months, between a group of calves that had severe cryptosporidiosis as neonates and a group of calves with no clinical signs of infection was 34 kg. Those calves that had experienced severe cryptosporidiosis as neonates showed a significantly reduced live weight gain compared with those calves showing no clinical signs of infection (P = 0.034). Therefore, the impact of severe cryptosporidiosis in neonatal calves has longer term effects on weight gain and production efficiency, resulting in the parasite having a greater impact on cattle production than previously thought.

Cryptosporidium Infections in Africa—How Important Is Zoonotic Transmission? A Review of the Evidence

“…With an infectious dose for neonatal calves as low as 17 oocysts (32), ensuring that young stock are not exposed to an infectious dose on farms where other stock are already infected can be challenging. As with humans (see previous subsection), it has also been shown that severe cryptosporidiosis in calves and lambs may have long-term consequences regarding growth, weight gain, and productivity (33)(34)(35), as well as the more immediate effects from the acute infection.…”

The effect of Cryptosporidium parvum, rotavirus, and coronavirus infection on the health and performance of male dairy calves

“…This study highlighted the reduced growth associated with a C. parvum and BCoV infection, and the increased risk of respiratory disease associated with a C. parvum infection. A recent paper identified the effect of C. parvum on long-term weight reduction (Shaw et al, 2020), but no studies have specifically identified BCoV as having an effect on the growth of dairy calves. This reduction in growth was likely due to damage to enterocytes, leading to villous atrophy and ultimately malabsorption of nutrients (Cho and Yoon, 2014).…”

Cryptosporidium Species and C. parvum Subtypes in Farmed Bamboo Rats

“…They are responsible for significant mortality in both young children [1,3] and neonatal farm animals [4][5][6][7][8]. In addition, cryptosporidiosis has been associated with retarded growth in humans and farm animals [9][10][11][12].…”