Management Programs to Optimize Reproduction - PowerPoint PPT Presentation

Loading...

PPT – Management Programs to Optimize Reproduction PowerPoint presentation | free to download - id: 1c8936-ZDc1Z



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Management Programs to Optimize Reproduction

Description:

Management Programs to Optimize Reproduction – PowerPoint PPT presentation

Number of Views:31
Avg rating:3.0/5.0
Slides: 49
Provided by: valued7
Learn more at: http://www.4cattlemen.com
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Management Programs to Optimize Reproduction


1
Management Programs to Optimize Reproduction
GL Stokka DVM,MS Pfizer Animal Health
2
Quality
3
Cow Production Costs
Medium Low High Calves weaned 87 83 90
Calf death loss 3.4 2.9 2.4 wean wt/cow
exposed 455 413 455 Costs Cost/cow/cwt
82 145 61 Health costs/cwt 4(5) 6(4) 3.
50(6) Calf breakeven/lb 0.69 1.36 0.41 ROA
2.88 -15.55 18.16
  • SPA Northern herds
  • Barry Dunn SDSU

4
Health Costs
  • Health Costs as of total maintenance cost of a
    beef cow.
  • 15.00 to 25.00 (3.5 to 5)

5
Cost of Production Targets
  • 0.60/lb cost of producing a weaned calf.
  • Health program costs 5 - 0.03/lb.
  • One dollar difference/head assuming health costs
    at 20/hd. 5 of 0.03 .0015.

6
Management Decisions that Influence Profitability
Health
7
Profitability Health
8
Profitability Health
9
Failure of passive transfer (FPT)
  • Calves with inadequate immunoglobulin
    concentrations at 24 hours of age were 3.2-9.5
    times more likely to become sick and 5.4 times
    more likely to die prior to weaning.
  • Levels lt800mg of IgG/dl are considered inadequate.
  • Wittum TE, Perino LJ AJVR Sep. 1995

10
Health and performance effects of inadequate
colostral transfer in beef calves
  • Lower perinatal IgG1 levels were significantly
    associated with higher morbidity, higher
    mortality and lower gain in the preweaning
    period. (plt0.5)
  • Calves with serum IgG1 levels up to 2500 mg/dl
    were 1.5X more likely to get sick before weaning
    and 2.4X more likely to die before weaning than
    calves with higher IgG1 levels.
  • Calves with IgG1 levels of at least 2700 mg/dl
    weighed 7.38 pounds more at 205 days of age than
    calves with lower IgG1 levels.
  • Dewell, RD., Hungerford, LL., Keen, JE.,
    Grotelueschen, DM., Rupp, GP., Griffin, DD., 2002
    Proceedings AABP

11
Risk of Disease
12
Risk of Disease
13
Vaccinology
14
What is a Vaccine??
  • Contains material originating from the disease
    causing bug that can induce resistance
    (immunity) to disease.
  • Vaccines work by stimulating the body to produce
  • Antibodies
  • Killer Cells
  • Memory Cells

15
IMMUNOLOGY PRINCIPLES
  • INJECTION VACCINATION
  • VACCINATION ? IMMUNIZATION
  • IMMUNIZATION REQUIRES.
  • a. Effective vaccine
  • b. Immunocompetent animal

16
IMMUNOLOGY PRINCIPLES
  • for VACCINATION IMMUNIZATION, requires an
    IMMUNE RESPONSE
  • IMMUNE REPONSE
  • cognition
  • activation
  • effect

17
(No Transcript)
18
IMMUNOLOGY PRINCIPLES
  • mounting an immune response is complicated
    TAKES TIME
  • Immune response takes 3 to 10 days or longer to
    kick in. Longer with naive animals.
  • Peaks in 2 to 4 weeks.

19
Incubation and Protection
  • IBR 3 days, protection 40 to 96 hours.
  • BVD 5 days, protection 21 days .
  • M. hemolytica 7 to 10 days, protection 14 days.
  • Mycoplasma 12 days, protection 14 days
    (doses?).
  • BRSV 5 days, protection 11 days.
  • RBCV - ??
  • Multiple references

20
IMMUNOLOGY PRINCIPLES
Because of IMMUNOLOGIC MEMORY multiple doses
of vaccine SHORTEN THE TIME RAISE THE
IMMUNITY LEVEL AND INCREASE THE NUMBER OF
IMMUNE ANIMALS
21
Challenge Level
High challenge
No or low challenge
Before Vaccination
After Vaccination
Susceptible
Non-Susceptible
With PI
22
Individual Vaccination
  • Induces protection against disease, i.e. clinical
    signs.
  • Reduce susceptibility of an individual against
    infection, infectious dose needed to establish
    infection is higher after vaccination.
  • Reduces infectivity after the occurrence of an
    infection.

23
Herd Immunity
  • Reduced probability of an individual becoming
    infected when it is part of a vaccinated
    population.
  • Chance of becoming infected in a population
    decreases with increasing density of individuals
    being vaccinated.
  • Prevent transmission of pathogen within the
    population to such an extent that the infection
    will eventually be controlled or become extinct.
  • Potgieter L., Immunology of Bovine Virus Diarrhea
    Virus. November 1995 VCNA Vol 11 No 3 pp 501-520.

24
Reproductive Rate(R)
  • The spread of disease depends on the reproductive
    rate (R, how many new cases arise on average from
    one infectious animal) of an infectious disease
    agent.
  • In general at the herd level, the basic
    reproductive rate of the disease in vaccinated
    populations should be below 1 to prevent the
    spread of infection.

25
Reproductive Rate
  • The higher the R the greater the number of
    animals that must be immune in order to prevent
    spread of the infectious agent. If R in a
    vaccinated population is larger than one, then
    the vaccine cannot totally prevent the spread of
    infection and other biosecurity principles must
    be employed.
  • Noordhuizen, JPTM, Frankena, K, C.M. van der
    Hoofd, E.A.M. Graat, in Application of
    Quantitative Methods in Veterinary Epidemiology
    Wageningen Pers, Wageningen, Netherlands 1997
    pp249-269.
  • Hage, et al Vet Micro 53 (1996) 169-180.

26
Herd Immunity
  • Immunization for herd immunity against BVDV need
    be 57 in herds without PIs.
  • 97 with PIs based on mathematical models.
  • For IBR at least 86 of population must be immune
    to reduce Ro to less than 1.
  • For PRV Ro 10. After vaccination 0.5.
  • For Mannheimia? 12 marker calves spread to 10
    others.
  • Cherry BR et al Prev Vet Med 1998
  • Hage, et al Vet Micro 53 (1996) 169-180.
  • De Jong, Kimman Vaccine 1994 761-766.
  • Briggs, et al Am J Vet Res 1998 59401-405.

27
IMMUNOLOGY PRINCIPLES
  • PREEXPOSURE IMMUNIZATION
  • REALISTIC EXPECTATIONS
  • 1. Will rarely make disease rate zero
  • 2. If disease rate is low, hard to see effect

28
IMMUNOLOGY PRINCIPLES
  • Challenge Dose
  • Even a normally protective level of immunity can
    be overwhelmed

29
IMMUNOLOGY PRINCIPLES
  • IMMUNIZATION REQUIRES.
  • a. Effective vaccine
  • b. Immunocompetent animal

30
VACCINE MANAGEMENT FACTORS
  • Vaccine Handling
  • Temperature abuse
  • Ultraviolet light (sunlight)
  • Disinfectants

31
Fetal Protection
32
Fetal Protection
  • IBR
  • BVD
  • Lepto
  • Vibrio
  • Trichomoniasis
  • Neopsora

33
Vaccinations for Fetal Protection
  • Overview
  • The anatomy of the bovine cow-fetal connection
    (multilayered placenta) precludes antibodies and
    other immune cells from crossing the placenta and
    providing protection for the developing fetus
  • Thus the developing bovine fetus is susceptible
    to small amounts of infectious agents (less than
    1000 viral particles)

34
Routes of Persistent Infection
Non-immune pregnant cow exposed to NCP BVDV
Persistently Infected calf
Persistently infected cow giving birth
35
(No Transcript)
36
BVD Transmission
  • PI animals shed large amounts of virus.
  • Excreted in smaller amounts from acutely infected
    animals for only a few days.
  • Direct contact with PI most efficient mode.
  • One hour of direct contact allowing nose-to-nose
    contact was sufficient for transmission.
  • Direct contact with acutely infected can transmit
    though less efficiently.

Houe, Vet Microbiology 1999
37
Risk of transmission
  • Between Herds
  • Most commonly by PI animals introduced to herds.
  • If prevalence is 2, risk of purchasing PI animal
    in a group of 20 is 33.
  • P 1- probability of buying non PI animal. P
    1 0.98n n number of animals purchased.

Houe, Vet Microbiology 1999
38
Fetal protection claims for BVDV Vaccines
39
Failure of foetal protection after vaccination
against an experimental infection with bovine
virus diarrhea virus
  • Two inactivated BVDV vaccines were applied twice
    within a 3 week interval. Challenge virus was
    applied 5 months after completion of the
    vaccination protocol.
  • All calves born from unvaccinates were born PI.
    Six out of 9 calves were born PI with 1 calf
    having pre-colostral antibodies from vaccine A.
    Eight out of 15 calves were born PI with 2 calves
    having pre-colostral antibodies from vaccine B.
  • Zimmer, GM., Wentink GH., Bruschke, FJ.,
    Westenbrink, J., Brinkhof, J., de Goey, I. Vet
    Micro 2002 Vol 89(4)255-265

40
Failure of foetal protection after vaccination
against an experimental infection with bovine
virus diarrhea virus
  • No relation between virus isolation from blood
    and birth of PI calves.
  • No relation between titers after vaccination, on
    day of challenge and birth of PI calves.
  • Challenge model must allow enough time for fetal
    infection to occur, in this study several calves
    born with active immunity indicating fetal
    infection occurred at least 1 month after
    challenge. Infection may have been delayed by
    immune response of the vaccination.
  • Zimmer, GM., Wentink GH., Bruschke, FJ.,
    Westenbrink, J., Brinkhof, J., de Goey, I. Vet
    Micro 2002 Vol 89(4)255-265

41
Foetal cross-protection experiments between type
I and type II bovine diarrhoea virus in pregnant
ewes
  • Fetuses from ewes immunized with BVDV-1 were
    protected when challenged with BVDV-2.
  • All fetuses were infected from ewes immunized
    with BVDV-2 and challenged with BVDV-1.
  • Pre-challenge level of neutralizing antibody is
    not a reliable indicator of fetal protection.
  • Paton, DJ., Sharp, G., Ibata, G., Vet Micro 1999
    64 185-196.

42
Modified live type bovine viral diarrhea virus
(BVDV) provides fetal protection against
challenge with a type 1 2 BVDV
  • Type 1 Challenge
  • One And two doses of NADL vaccine
  • (PregGuard and Bovi-Shield)
  • Challenge with 104.8 TCID 50 doses of
    noncytopathic Type 1 BVD strain 816317,
    administered IN, New York isolate calves taken to
    term
  • 1/38 vaccinates had a PI calf
  • 7/10 control calves born PI
  • No difference between single or two doses

43
Modified live type bovine viral diarrhea virus
(BVDV) provides fetal protection against
challenge with a type 1 2 BVDV
  • Type 2 Challenge
  • One And two doses of NADL vaccine
  • (PregGuard and Bovi-Shield)
  • Challenged with 1 X 103.9 TCID 50 doses of
    noncytopathic BVD Type 2 virus strain 94B-5359a,
    administered IN, Wyoming isolate calves taken to
    term
  • 13/37 vaccinates had a PI calf
  • 9/10 control calves born PI
  • No difference between one and two doses

44
Safety for Administering MLV to Calves Nursing
Previously Vaccinated Pregnant Cows
45
Safety for Administering MLV to Calves Nursing
Previously Vaccinated Pregnant Cows
  • Field Safety Studies in
  • 1rst, 2nd, and 3rd Trimester Pregnant Animals
  • Study Animals and Sites
  • 1rst trimester pregnant beef cows in Leith,
    North Dakota
  • 2nd trimester pregnant holstein heifers in
    Hanford, California
  • 3rd trimester pregnant beef cows in
    Medicine Lodge, Kansas

46
Safety for Administering MLV to Calves Nursing
Previously Vaccinated Pregnant Cows
  • Field Safety Studies in
  • 1rst, 2nd, and 3rd Trimester Pregnant Animals
  • Normal Calving Rates
  • Study Controls (T1) Vaccinates (T2 T4)
  • 1rst Trimester 99.2 (261 / 263) 99.6 (263 /
    264)
  • 2nd Trimester 95.3 (225 / 236) 93.6
    (220 / 235)
  • 3rd Trimester 99.3 (148 / 149) 99.5
    (195 / 196)
  • Total 97.8 (634 / 648) 97.7 (679 /
    695)

47
Vaccines Fetal Protection
  • Complete reproductive protection(BVDV) can not be
    obtained from vaccination. IBR protection seems
    strong
  • Do not over promise what vaccination can do.
  • Incorporate vaccination with the other control
    measures.
  • Biosecurity testing.

48
Summary
About PowerShow.com