PARTNER FEATURE ▶▶▶
Passive immunisation to control calf diarrhoea
Calf diarrhoea is a commonly reported disease in young animals and still a major cause of productivity and economic loss to cattle producers worldwide in both beef and dairy cattle herds. Moreover, neonatal calf diarrhoea (NCD) creates a problem in terms of animal welfare and farmer distress.
BY BRIGITTE DUQUESNE, DVM, GLOBAL TECHNICAL MANAGER RUMINANTS, HUVEPHARMA
D
iarrhoea in calves has a multifactorial aetiology, in which viruses, bacteria, protozoa and management factors (housing, feeding, hygienic conditions) play a role.
Prevention and control strategies for calf diarrhoea involve multiple factors such as peripartum calving management, calf immunity and environmental stress and contamination. Bovine rotavirus, bovine coronavirus, Escherichia coli and Cryptosporidium parvum are the four major enteric patho- gens causing NCD. Due to the structure of the bovine placenta, the calf is born agammaglobulinaemic and therefore depends on the success- ful passive transfer of maternal antibodies (Ig) from colostrum. The absorption of maternal Ig across the small intestine dur- ing the first 24 hours after birth, termed passive transfer, helps to protect the calf against common disease organisms until its own immature immune system becomes functional. Multiple studies have shown that failure of passive transfer, as reflected by low serum Ig concentrations (IgG<10mg/ml), markedly increase morbidity and mortality in dairy and in beef calves.
Oral administration The results of some studies demonstrate that even with optimal dam vaccination and a proper colostrum intake, the natural challenge with infectious agents associated with neonatal diarrhoea may overcome the passive immunity con- ferred by maternal antibodies as well as the neonatal primary immune response. Oral administration of specific antibodies is an attractive approach to establish protective immunity against gastrointestinal pathogens in humans and animals.
Passive immunisation strategy with chicken egg yolk immu- noglobulin, referred to as immunoglobulin Y (IgY) provides an efficacious alternative to prevent and control NCD. It has a large number of advantages compared with treatment with mammalian IgG, including cost-effectiveness, convenience and high yield. Laying hens are very good producers of specific antibodies. After immunisation, the specific antibodies are transported to the egg yolk which can then be purified. A laying hen pro- duces more than 100mg of yolk antibodies (IgY) per egg. IgY also have biochemical properties that make them attractive for oral immunotherapy: they neither activate mammalian complement nor interact with mammalian Fc receptors that could mediate inflammatory response in the gastrointestinal tract. Oral administration of specific IgY antibody has been shown to be effective against a variety of intestinal pathogens such as bovine rotaviruses, enterotoxigenic Escherichia coli, bovine coronavirus and Salmonella spp. Treatment based on IgY modulates the mucosal immune response in the gut towards higher numbers of antibody- secreting cells present in the duodenum and ileum of treat- ed animals. This may represent higher immune surveillance in the gut mucosa, which is one of the main sites of infection of pathogens during the first weeks of life in calves. The results of a recent study indicate that feeding immu- nised egg proteins to calves in the first 14 days of life im- proves growth performance and concentrate intake. Passive immunisation by oral administration of IgY has been shown to be effective to complement current preventive strategies against NCD.
References available on request. ▶ DAIRY GLOBAL | Volume 8, No. 2, 2021 15
PHOTO: HUVEPHARMA
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44
