EXAGENWhy Start from Day 1?

Decrease the Risk of Crypto with the 3 day Preventative Plan – In Advance of Treatment – just like Vaccination Protection

8 August 2017

Introduction
By referring to the review of work published in Australia (Gunn et al 2016),  we get an insight into just how many areas exist where management has an impact on how crypto infects a calf shed. Faubert & Litvinsky (2000) reported results without the sensitivity of the advanced techniques used by Gunn et al (2016) to identify pathogens. Faubert & Litvinsky only examined cryptosporidial risk and not all pathogens.

Reference Gunn et al (2016):
Note: One farm may not represent all farms. It does represent the infective agents identified day-by-day during the first 3 weeks of calves in a calf shed.
This work showed that on this farm, rotavirus expressed itself earlier in the calfpen environment. It has a shorter prepatent period. It may also show that it is more difficult for farmers to manage once it is established. Other data published as graphs identify the features of the shed which show the increase in cryptosporidium with time.

How does this preventative role for Exagen compare with a vaccination Program?
The role vaccination plays is clear – decrease the severity of signs, improve the rate of recovery, and decrease the virus presence before the shed is loaded with (rota) virus – one of prevention before it gets established. These are exactly the same goals for EXAGEN against Cryptosporidium parvum.
EXAGEN from Day 1 – a different type of a preventative plan – Needs to start before 3 days of age if it is to be compared with a vaccination plan, similarly preventing the take off/ sudden escalation of infection.
There has been much speculation of the possibility of a vaccine for control of cryptosporidiosis. So far it has not been successful, and to the best of my knowledge no recent progress has shown either antibody and cellular immunity can be developed and be available for when the protection is required. The closest farmers can go for crypto scours is to use Exagen on the farm with a history of cryptoscours – not much different from rotavirus vaccination really, relying on a different way to mitigate the risks of the respective diseases. Get in early before crypto is expressed and before it is spread between calves.
By examining the graphs in that review and concentrating on crypto scour specifically, the calves are excreting oocysts well in advance of apparent significant contamination of pen walls, and calf pen floors. It would be reasonable to say we do not know exactly how the infection appeared in 3 -5 day old calves. We do know that there is a risk of crypto infection from the calf’s mother either in the calving down process or early in the calving down area. However Gunn work shows that the tractor tray is a real risk factor. It suggests that it requires rigorously cleaning, repeatedly, probably every day or second within the same season (Gunn et al 2016). It is known that an incubation period of 3 days would be required before these infections appear in a calf (Thomson 2016).

Is Halocur® an alternative?
It is important that calves which do start to excrete around day 3 are prevented from developing clinical scours, and that this is not just a delaying of the excretion of oocysts (as for Halocur treated calves) but that oocysts are destroyed so that any multiplication intra-intestinally is halted. This is Exagen’ target – death to oocysts while multiplying in the gut, not just putting up a stop sign and then letting them go – 7 days later to infect the shed and contaminate the handlers and the general environment.

Castro-Hermida et al (2003) research shows that by giving beta-cyclodextrin 3 times daily to mice it is possible to prevent 99.4% of infections becoming established. This compares with 70% with twice daily treatment with betacyclodextrin. The total dose per day is the same 25 g in either 2x (12.5 g) or 3x (8 g) split doses. Three days of treatment are required to knock out infections in mice and stop the re-infection cycle from recommencing. This activity would be included as part of the mitigation action plan described by Moore and colleagues from the Washington State University (2012). Other parts of the plan include hygiene protocols for daily cleaning, and biosecurity protocols to reduce potential spread within the unit.
Without Exagen it is difficult to plan, when the calves remain in an environment slowly becoming overwhelmed by excretion from calves with clinical signs.
Calf to calf spread can only be prevented if calves stop excretion – a task that Exagen is ideally suited (Castro-Hermida et al, 2001). There is no surge from the re-expression of inhibited stages as happens with Halocur (Silverlas et al. 2009)

Knock it down once and stop cryptosporidial scours in its path. Go to the source from day 1 or as soon as the calf is isolated from its mother and in the calfpen. If this is longer than 3 days then consider a longer period of Exagen use than just 3 days.

Additional Factors in the Ultimate Calf Gut Protection Plan:
1. Protect and Stimulate the Natural Gut Flora/The Role of Probiotics:
Optimise the gut development, its natural gut flora, decrease stress which upsets the establishment and potential loss of the Lactobacillus spp. and the influence they have as natural beneficial strains.
The difficulty in recommending a specific probiotic is that the commercial availability of these very specific strains is lagging behind the science. In the species that are desirable there are limited strains within it that have the required characteristics. Hence Lactobacillus reuteri (some strains) and Lactobaciullus plantarum (some strains) may be listed on a product but even then not have the profile required.
In general though
• Found naturally from birth.
• Are inhibitory of other like Lactobacillus species . L reuteri (Christiansen et al), and L plantarum (Rodriguez-Palacios et al, 2017) may have the required profile.
• Some strains of these species are inhibitory of bacterial species such as E coli, and salmonella amongst others. (Rodriguez et al, 2009; Ratsep et al, 2017)
• They are of bovine origin. Bovine strains are essential if they are to be retained to become established.
• Are acid resistant to pass through the stomach.
• Are temperature robust for storage and transport.
• Deliver the correct number of bacteria – generally more than 1 x 109
• Define if there are prebiotics that promote the probiotics strains targetted.

In general the Lactobacilli strains identified are slower to establish themselves as important species in the developing gut, and they are sensitive to stresses (Fuller 1989) such as transport, especially moving up and down ramps, rough handling or surgical interventions – castration or dehorning or changes to feed patterns. The beneficial Lactobacilli spp take time to overcome ‘weedy’ species such as E coli that readily invade from soon after birth.

2. Colostrum’s Role in Gut Development:
Colostrum is important for maturing the different parts of the intestinal tract (Buhler et al, 1997). It works in tandem with the gut microbiome by supplying hormonal and growth factors acting throughout the gut. This maturation helps prevent the adhesion of pathogens, and advances nutritional digestion and absorption of food at the same time (Hammon & Blum 1997).

Summary
a) Hygiene – recognise risk factors and keep to good housekeeping (biosecurity). Refer to Disinfection Part I, Part II
b) Exagen from Day 1 to mitigate the output and cross-contamination of the new calves. Use it for three days for a clean shed, or 7 – 10 days for a shed showing calf scours.
c) Manage stress. Gentle management, develop and maintain routines in the shed.
d) Continue colostrum for its growth factors and not just its antibody content. These growth factors are present in early lactation phases of the cow.
e) Probiotics but you may need some assistance to decide which species and strains within species are more effective.

References:
Buhler C, H Hammon, GL Rossi, JW Blum (1997), Small intestinal Morphology in Eight-Day-Old Calves fed Colostrum for different Jurations or Only Milk replacer and Treated with Long-R3-Insulin-Like-Growth factor I and Growth Hormone Amer Soc of Anim Sci 76: 758-765
Castro-Hermida J A, Y Gonzalez-Losada, F Freire-Santos, A M Oteiza-Lopez, A Ares-Mazas Unexpected activity of b-cyclodextrin against experimental infection by Cryptosporidium parvum. J Parasit (2000), 86 1118-1120
Castro-Hermida J A, G L Yolanda, F Freire-Santos, M Mezo-Mendendez, E Ares-Mazas. Evaluation of b-cyclodextrin against natural infections of cryptosporidiosis in calves. Veterinary Parasitology 101 (2001) 85-89
Faubert GM, Y Litvinsky, 2000. Natural Transmission of Cryptosporidium parvum between daks and calves oin a dairy farm. Parasitology 86 495-500
Fuller R. (1989). A Review: Probiotics in man and animals.Journal of Applied Bacteriology. 66, 365-378
Gunn A, J House (2005). Calf Scours in Southern Australia. Beef Enterprises Phase 2. Project code: AHW.057 Published by Meat & Livestock and University of Sydney. Australia Gunn A, J House, P Sheehy, A Thompson, D Finlaison, P Kirkland (2016), B.AHE.0025 Molecular methods for detection of calf scour pathogens. Pub.: Meat and Livestock Australia Limited The University of Sydney and NSW Department of Industry and Investment. Hammon H,JW Blum (1997) Prolonged Colostrum feeding Enhances Xylose Adbsorption in Neo-natal calves. J Anim Sci 75 2915-2919
Lee Y-K, KY Puong, AC Ouwehand (2003). Displacement of bacterial pathogen from mucus and Caco-2 cell surface by lactobacilli. Jl Medical Microbiology 52, 925-930
Moore AD, K Heaton, S Poisson, WM Sischo (2012) Dairy Calf Housing and Environment: The science Behind Housing and On-Farm Assessments. Pub Washington State University Extension: EMO 045E
Ratsep M,S Koljaig, E Sepp, J Scmidt et al (2017) A combination of probiotic and prebiotic product can prevent the germination of Clostridium difficile spores and infection. Anaerobe 47 94-103
Rodriguez-Palacios A, HR Staempfli, JS Weese (2017) High doses of Halotolerant Gut-Indigenous Lactobacillus plantarum reduce Cultivable Lactobacilli in Newborn Calves without Increasing Its Species Abundance. International Jl of Microbiology, 2017, Article ID 2439025, 11 pages
Rodriguez-Palacios A, HR Staempfli, T Duffield, JS Weese (2009). Isolation of bovine intestinal Lactobacillus plantarum and Pediococcus acidilactici with inhibitory activity against Escherichia coli 0157, and F5. Jl of Appl Microbiol 106 393-401
Silverlas C, C Bjorkman, A Egenvall: (2009). Systematic review and meta-analyses of the effects of halofuginone against calf cryptosporidiosis. Preventive Veterinary Medicine Jl. Prevent med.2009.05.003
Thomson, Sarah (2016) Cryptosporidiosis in farm livestock.PhD thesis. Submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy, Institute of Biodiversity Animal Health and Comparative Medicine University of Glasgow 2016.

Halocur® is the registered trademark of MSD Animal Health.
Copyright: Bruce Pauling B.V.Sc.
8 August 2017

EXAGEN – Why Start from Day 1?