The information provided in this section is purely for educational purposes and you should check with your veterinarian for advice on dealing with health issues with your animals.

The Ewe
DAYS 0–7 > Greatest risk of embryo loss due to heat and humidity stress

DAYS 30–90 > Critical period for placental and mammary gland development. Reduced fetal growth, birth weights, vigor, and lower milk production result from poor nutrition at this time. Macro- and micro-mineral supplementation is vital. Impairment cannot be made up for later.

DAY 60 > Booster vaccination (following pre-breeding vaccine) protects ewe against chlamydiosis and vibriosis abortions

DAYS 100–BIRTH > Nutritional demands of fetuses place greatest demand upon ewe

DAY 120 > Vaccination against respiratory, clostridial diseases and tetanus stimulates high level of antibodies in colostrum, (forming by about day 136). Periparturient rise of internal parasite egg production: deworm to protect lambs.

DAY 150 or BIRTH > Colostrum production ceases; 24–36 oz available to lambs.

DAYS 21–28 > Maximum milk production attained. Maximum production requires maximum nutrition. Feed best hay, match grain amounts to number of nursing lambs.

DAY 60 > Many ewes producing less than half of the amount of milk they produced at peak production.



The Lambs

DAYS 20–24 > Embryos implanted in uterine wall

DAY 35 > First primary fiber follicles form

DAYS 60–63 > Most primary fiber follicles formed; lateral primary follicles begin to form

DAYS 90–100 > Secondary wool follicles begin forming

DAYS 100–BIRTH > 70% of fetal growth occurs

DAY 120 > Fetal lambs immunocompetent: capable of forming some antibodies

BIRTH > Antibody-rich colostrum (received within 24 hr of birth) provides passive immunity for up to 10 weeks; primary follicle fibers shed

DAYS 7–14 > Lambs begin eating creep feed; some rumen function by day 14; 250% increase (from birth) in growth/maturity of secondary follicles

DAYS 28–42 > Lambs convert from high-milk, low-feed to low-milk, high-feed diet

DAYS 42–56 > Rumen becomes fully functional; lambs vulnerable to coccidiosis (add coccidiostat to feed)

DAY 60 > 75% of secondary follicles growing fiber; lambs vulnerable to high parasite loads (deworm)

DAY 70 > Disease immunity of lambs, gained by colostrum, depleted (vaccination vital)

DAYS 91–98 > In vaccinated lambs, antibody titers peak; booster of vaccine at this period “confirms” to immune system that antibody production is important

A easier to read file can be downloaded here.