Infertility in sheep and goats Flashcards
measure of reproductive performance
fertility - % barren + % pregnant
fecundity - no. of lambs/kids born per preg
survival rate - no of lambs/kids that survive to weaning
lambing percentage - no of lambs reared/weaned/sold per 100 ewes put to the ram
poor lambing percentage
poor ovulation + conception rate
high embryonic/foetal loss
high abortion/stillbirth/death
poor conception rate
season repro tract abnormalities fertilisation failure phyto-oestrogens stress male infertility
repro tract abnormalities
relatively uncommon
freemartins, intersexes
ovaries - ovarian hypoplasia + cysts
fertilisation failure
chromosonal abnormalities - 6-12% age - controversial high environment temp nutritional - clover-rich pastures infertility in male
phyto-oestrgens
oestrogen-like compounds made by plants like lucerne, red clover
decr conception due to changes in cervical mucus + sperm transport
poor ovulation rate
BCS
season
age
genotype/breed
effect of v.high or low BCS on lambing %
decr ovulation, lamb birthweight, colostrum production
incr embryonic loss
early embryonic death
asynchrony between embryonic development + timing of P4 rise
dietary intake - overfeeding inversely related to P4 conc
age - uterine environment, ovum
mineral deficiencies
infectious toxoplasma, border disease virus
late foetal death
overfeeding in early pregnancy
underfeeding in late pregnancy
poor BCS
late foetal death-ovine/caprine abortion
chlamydophila abortus - sheep & goats
toxoplasmosis - sheep + goats
campylobacter - sheep
perinatal mortality
still birth disease - water mouth, viral diarrhoea, toxo, chlamydophilia trauma mineral deficiency starvation/exposure
clinical exam
BCS + nutrition
male fertility
exam aborted foetuses/placenta/ewes
plan for next year
pre-mating exam - male, ewe BCS + health
mating harnesses
pregnancy scanning
submission of aborted foetuses
