The effects of dietary clover species on reproduction in the ewe
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THE EFFECTS OF DIETARY CLOVER SPECIES ON REPRODUCTION IN THE EWE. LACEY BEAM DEPARTMENT OF ANIMAL SCIENCES OREGON STATE UNIVERSITY. BACKGROUND. Escalon, CA. BACKGROUND. SAN JOAQUIN DELTA COLLEGE 2000-2002 OREGON STATE UNIVERSITY B.S. IN ANIMAL SCIENCE 2004 OREGON STATE UNIVERSITY

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THE EFFECTS OF DIETARY CLOVER SPECIES ON REPRODUCTION IN THE EWE

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THE EFFECTS OF DIETARY CLOVER SPECIES ON REPRODUCTION IN THE EWE

LACEY BEAM

DEPARTMENT OF ANIMAL SCIENCES

OREGON STATE UNIVERSITY


BACKGROUND

Escalon, CA


BACKGROUND

  • SAN JOAQUIN

    DELTA COLLEGE

    2000-2002

  • OREGON STATE UNIVERSITY

    • B.S. IN ANIMAL SCIENCE 2004

  • OREGON STATE UNIVERSITY

    • M.Ag. GRADUATE STUDENT


REPRODUCTION

  • REPRODUCTIVE DIFFICULTIES IN SHEEP GRAZING CLOVER SPECIES WERE FIRST RECOGNIZED IN 1946 (Bennetts et al.)

  • “CLOVER DISEASE”

    • SYNDROME OF ABNORMAL REPRODUCTIVE FUNCTIONS OF EWES GRAZING CLOVER PASTURES


GRAZING

  • LEGUMES ARE A WIDELY AVAILABLE FEEDSTUFF FOR MAINTAINING RUMINANT ANIMALS

  • SHEEP ARE A USEFUL TOOL IN A GRAZING SYSTEM

    • SEED TO SOIL CONTACT

    • CREATES MORE TILLARS

    • CONTROLS PLANT SIZE

    • INEXPENSIVE FERTILIZER

    • LEGUMES ARE HIGH IN CP,

      DIGESTIBILITY, INTAKE


CLOVER SPECIES

  • SUBTERRANEAN CLOVER

    Trifolium subterraneum


CLOVER SPECIES

  • RED CLOVER

    Trifolium pratense


PHYTOESTROGENS

  • DEFINITION: COMPOUND THAT EXERTS ESTROGENIC EFFECTS ON THE CNS, INDUCE ESTRUS, AND STIMULATE GROWTH OF THE GENITAL TRACT OF FEMALE ANIMALS

  • CONTAINED IN MANY LEGUMES

  • ESTROGENIC ACTIVITY DEPENDS ON POSITION OF 2 HYDROXYL GROUPS


PHYTOESTROGENS

  • PHYTOESTROGEN CONTENT VARIES BETWEEN PLANT SPECIES, AND GROWING AND HARVESTING CONDITIONS

    • EARLY SPRING:

      • PLANT STRESS DUE TO CHANGES IN AVAILABLE NITROGEN OR PHOSPHORUS

      • TEMPERATURE

    • DISEASE

    • DROUGHT

    • INCREASES PHYTOESTROGEN ACCUMULATION IN LEAVES


PHYTOESTROGENS

  • PHYTOESTROGENS CONTAIN ESTROGENIC COMPOUNDS:

    COUMESTANS

    ISOFLAVONES

    LIGNANS


PHYTOESTROGENS

COUMESTANS

  • COUMESTROL

    • MOST COMMON

      COUMESTAN

    • MOST ESTROGENIC

      POTENCY OF ALL

      PHYTOESTROGENS

(ADAMS, 1995a)


PHYTOESTROGENS

ISOFLAVONES

  • FORMONONETIN

    • MOST IMPORTANT ISOFLAVONE PERTAINING TO RUMINANTS

    • REDUCED AND DEMETHYLATED INTO THE MORE ESTRTOGENIC COMPOUND EQUOL

(Lundh, 1990)


MORE ESTROGENIC THAN FORMONONETIN

RAPIDLY ABSORBED THROUGH RUMINAL WALL

MAJOR ESTROGENIC METABOLITE THAT INITIATES ESTROGENIC EFFECTS IN SHEEP

CHEMICAL STRUCTURE RESEMBLES ESTRADIOL - ALLOWS BINDING TO THE ESTROGEN RECEPTOR

EQUOL

(Lundh, 1990)

(ADAMS, 1995a)

Equol

Estradiol


DEGREDATION AND DETOXIFICATION OF ISOFLAVONES TAKES PLACE IN THE RUMEN

RESULTING IN ESTROGENIC RUMEN CONTENTS

RUMEN MICROBES BREAKDOWN ALL OTHER ISOFLAVONES INTO THEIR NONESTROGENIC METABOLITES

FORMONONETIN EQUOL

RUMINANTS AND ISOFLAVONES


EFFECTS ON SHEEP

  • EWE INFERTILITY

    TEMPORARY:

    • DECREASED FIRST SERVICE CONCEPTION

    • IRREGULAR ESTRUS

      • DECREASED OVARIAN WEIGHTS

      • EXCESSIVE SMALL AND MEDIUM FOLLICLES DEFICIENT OF ANTRUM FORMATION, EARLY ATRESIA

    • REDUCED OVULATION AND CONCEPTION RATES

      • REDUCED LAMBING RATES AND MULTIPLE BIRTHS


EFFECTS ON SHEEP

PERMANENT:

  • REPEATED GRAZING:

    • DECREASES RESPONSIVENESS TO ESTROGEN

    • BARRENNESS

  • CERVIX- SERVES AS A RESERVOIR FOR SPERM DURING INSEMINATION AND OVULATION


EFFECTS ON SHEEP

  • PROLONGED EXPOSURE TO ESTROGEN LEADS TO DEFEMINIZATION OF CERVIX

    • BECOMES SHORTER

      AND BROADER

    • INAPPROPRIATE MUCUS

      VISCOSITY UNABLE SPERM

      TO MIGRATE THROUGH CERVIX

    • LOSS OF ABILITY TO STORE

      SPERMATOZOA


MEASUREMENTS OF ESTROGENIC FEEDS

  • UDDER DEVELOPMENT AND MILK SECRETION IN UNBRED EWES

  • WETHERS MAY ALSO SECRETE MILK

  • INCREASED TEAT LENGTH

    • DIRECTLY CORRELATED TO CONCENTRATIONS OF FORMONONETIN IN PASTURE


ADDITIONAL PROBLEMS

  • DYSTOCIA

  • UTERINE PROLAPSE

  • ABORTIONS

  • NEONATAL MORTALITY


RESEARCH

  • RESEARCH PAPER

  • AREAS OF INTEREST

    • SUBTERRANEAN CLOVER CAN ACCUMULATE UP TO 5% WEIGHT OF ISOFLAVONES

    • ISOFLAVONES ARE ONLY PRESENT IN GREEN CLOVER (ADAMS, 1995a)

    • RAPIDLY DRIED HAY MAY RETAIN ISOFLAVONE CONCENTRATIONS


RESEARCH

  • OBJECTIVES

    • TO DEFINE RAPIDLY DRIED HAY VS. SLOWLY DRIED HAY

    • TO DETERMINE THE DIFFERENCES IN ISOFLAVONE LEVELS BETWEEN RAPIDLY AND SLOWLY DRIED CLOVER HAY

    • TO DETERMINE IF CUTTING AND HARVESTING CLOVER FOR EWE FEED HAS A NEGATIVE IMPACT ON REPRODUCTION


RESEARCH

  • HYPOTHESIS

    • FEEDING SLOWLY DRIED CLOVER HAY TO EWES WILL HAVE LOWER CONCENTRATIONS OF ISOFLAVONES AND LESS NEGATIVE REPRODUCTIVE EFFECTS THAN THE SAME GRAZED CULTIVAR


EXPECTED OUTCOMES

  • SLOWLY DRIED CLOVER HAY WILL CONTAIN LOWER LEVELS OF ISOFLAVONES THAN RAPIDLY DRIED CLOVER HAY

  • NEGATIVE REPRODUCTIVE EFFECTS ON THE EWE SHOULD BE REDUCED COMPARED TO GRAZED GREEN CLOVER

  • SPECIFIC EVENTS DURING THE DRYING PROCESS THAT REDUCES/ELIMINATE ISOFLAVONE CONCENTRATIONS


QUESTIONS?

THANK YOU


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