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

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BACKGROUND
Escalon, CA
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BACKGROUND

• SAN JOAQUIN
• DELTA COLLEGE
• 2000-2002
• OREGON STATE UNIVERSITY
• B.S. IN ANIMAL SCIENCE 2004
• OREGON STATE UNIVERSITY
• M.Ag. GRADUATE STUDENT

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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

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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

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CLOVER SPECIES

• SUBTERRANEAN CLOVER
• Trifolium subterraneum

Cultivars Formononetin DM
Yarloop 1.5
Dwalganup 1.3
Dinninup 1.2
Geraldton .9
Tallarook .8
Daliak .2
Clare .15
Trikkala .15
Seaton Park .12
Bacchus Marsh .11
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CLOVER SPECIES

• RED CLOVER
• Trifolium pratense

Cultivars Formononetin DM
Broad .99
Tetraploid .90
Morocco .14
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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

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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

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PHYTOESTROGENS

• PHYTOESTROGENS CONTAIN ESTROGENIC COMPOUNDS
• COUMESTANS
• ISOFLAVONES
• LIGNANS

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PHYTOESTROGENS

• COUMESTANS
• COUMESTROL
• MOST COMMON
• COUMESTAN
• MOST ESTROGENIC
• POTENCY OF ALL
• PHYTOESTROGENS

(ADAMS, 1995a)
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PHYTOESTROGENS

• ISOFLAVONES
• FORMONONETIN
• MOST IMPORTANT ISOFLAVONE PERTAINING TO RUMINANTS
• REDUCED AND DEMETHYLATED INTO THE MORE
  ESTRTOGENIC COMPOUND EQUOL

(Lundh, 1990)
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EQUOL

• 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

(Lundh, 1990)
(ADAMS, 1995a)
Equol
Estradiol
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RUMINANTS AND ISOFLAVONES

• 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

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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

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EFFECTS ON SHEEP

• PERMANENT
• REPEATED GRAZING
• DECREASES RESPONSIVENESS TO ESTROGEN
• BARRENNESS
• CERVIX- SERVES AS A RESERVOIR FOR SPERM DURING
  INSEMINATION AND OVULATION

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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

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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

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ADDITIONAL PROBLEMS

• DYSTOCIA
• UTERINE PROLAPSE
• ABORTIONS
• NEONATAL MORTALITY

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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

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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

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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

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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

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QUESTIONS?

• THANK YOU