Biocontainment. Within populations. The Sandhills Calving System. Actions to prevent the spread of infectious agents.

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1 Principles of The Sandhills Calving System and how they apply to other production systems Sandhills Calving System reduces scours Successful Farming John Walter and Betsy Freese Jan, 6 David R. Smith, DVM, PhD University of Nebraska Lincoln In about an hour, Clements finishes a chore that has helped cut calf scours on his Loup y, Nebraska, ranch to nonexistent The McLean y System of Swine Sanitation Domino Ranching Management system to control internal parasites of young pigs Based on farrowing hygiene and movement of sow and pigs to clean pastures Tested A A. These large, healthy pigs were protected from the ravages of parasites B. These unthrifty pigs became parasitized soon after they were born Reviewed USDA Yearbook of Agriculture. pp B Biocontainment Actions to prevent the spread of infectious agents Prevent Effective Contacts Within populations physical separation minimize contact time minimize dose-load

2 Increase host resistance Remove / prevent entry of the agent neonatal calf diarrhea Death loss Performance loss Treatment costs Labor, medication Human toll Risk for injury, frustration neonatal calf diarrhea: Public Health Concerns Zoonoses Salmonella Cryptosporidia Antibiotic usage nts bacteria E. coli, Salmonella viruses rotavirus, coronavirus protozoa cryptosporidia fungi mycotic superinfection

3 nts of calf scours Diarrhea-causing organisms are common in cattle populations including herds without scours problems. bovine coronavirus cryptosporidia Time The battle between exposure and immunity begins at birth Antibodies from colostrum Passive Antibodies from colostrum Active immune response Window of vulnerability Passive Acquired Passive Acquired

4 Window of vulnerability Scours Scours in Days specificity of calf scours Population susceptible to scours: calves 1-3 weeks of age Frequency histogram age of calves at death Also when calves become infective Nebraska Field Disease Research Diagnostic investigation Field epidemiology Case-studies of interventions at death (days) 21 More 26 Nebraska Sandhills Beef herd experiencing severe losses to calf scours 42 cattle with live births, managed as a single group intensive grazing No treatment or control interventions 48 deaths due to scours An epidemiologicallypure scours epidemic and RECORDS!

5 Frequency of births and deaths by week /1 /8 /2 / /9 /22 /29 /16 /23 6/ 6/12 6/19 6/26 /3 6/6 6/13 6/ 7/3 More 6/27 7/4 date of birth deaths Factors of the calf explaining death from scours years 3 years?! 4 years of dam Factors of the calf explaining death from scours Calves born on the day of a pasture-move were more likely to die (OR=1.9, p=.9) of the calf at death of deaths or more (days) of death over time 3 Death in the same age-range 3 throughout the calving season /14 6/3 6/23 7/13 8/2 at death (days) of death

6 .6..4 Low Low risk risk Before /2 /2-/8 /9-/ /16-/22 /23-/29 /3-6/ 6/6-6/12 6/13-6/19 6/-6/26 6/27-7/3 After 7/3 Week of birth Proportion of the calves born each week that eventually died from neonatal diarrhea High High risk risk Levels of pathogen exposure increase over TIME within a calving season Increasing ANIMAL DENSITY (more effective contacts and environmental contamination) MULTIPLIER EFFECT Cows - low level shedders Calves multiply pathogens to higher and higher levels resulting in greater Time infectivity Multiplier Effect Biocontainment strategies for neonatal calf diarrhea Eliminate the agent and keep it out Increase host resistance Colostrum! Prevent effective contacts older infective calves and contaminated environment! Center for Food Security and Public Health Iowa State University -3 Sandhills Calf Scours Project Re-create the conditions existing at the start of the calving season Clean calving area Absence of older calves as a source of exposure Percent Frequency of births /1 /8 / /22 /29 6/ 6/12 6/19 6/26 7/3 More /2 /9 /16 /23 /3 6/6 6/13 6/ 6/27 7/4 by week of birth 6% % 4% Low Low risk risk High High risk risk 3% % % % /1 /8 / /22 /29 6/ 6/12 6/19 6/26 7/3 More /2 /9 /16 /23 /3 6/6 6/13 6/ 6/27 7/4 Sandhills Calving System Re-create the conditions at the start of the calving season Move pregnant cows to new calving pastures each week Minimize dose-load Improve maternal bonding Segregate calves by age to prevent the multiplier effect Percent Frequency of births /1 /8 / /22 /29 6/ 6/12 6/19 6/26 7/3 More /2 /9 /16 /23 /3 6/6 6/13 6/ 6/27 7/4 by week of birth 6% % 4% Low Low risk risk 3% % % % /1 /8 / /22 /29 6/ 6/12 6/19 6/26 /2 /9 /16 /23 /3 6/6 6/13 6/ High High risk risk 7/3 More 6/27 7/4

7 Ranch #1 9 cows Deaths attributed to scours Dead calves Year Less death and illness due to neonatal scours (p<.1) Minimal to no treatment or antibiotic use 24-fold reduction in animal health expenses (p<.1) All-Causes Death Rate Ranch #2 3-4 cows All causes for death Year Sandhills Calving System reduces scours Successful Farming John Walter and Betsy Freese Jan, 6 "This is the number one thing I've done over the years that has benefited us economically," Clements says. The Principles of Animal Hygiene and Preventive Veterinary Medicine those more particularly concerned with the food- producing animals must think in terms of hygiene, for their success is in no small measure dependent upon their knowledge of the subject Leunis Van Es Lincoln, NE 1932 David R. Smith, DVM, PhD Dipl. ACVPM (Epidemiology) Extension Dairy / Beef Veterinarian Dept. of Veterinary and Biomedical Sciences 126D VBS P.O. Box 839 Lincoln, NE (42) FAX: (42) dsmith8@unl.edu