Induced lactation in non-pregnant ewes

An experiment in two parts has been conducted to study the artificial induction of lactation in sheep.Part I was an exploratory trial during 1957 involving 15 dry, non-pregnant, three to six year old females and one yearling castrate male.Treatments consisted of various levels of estrone and diethylstilhestrol with and without progesterone.Prolactin was given alone or in combination with one or both steroids in four treatments.Oxytocin treatment was given to one ewe.Secretion was produced on ten treatments but was not collected.Part II was an experiment in artificially inducing lactation conducted during 1958, involving 11 head of dry, six to seven year old ewes.Treatment I was a graded dose of estrone; Treatment II a 1:40 estradiol to progesterone ratio.Treatments III, IV, and V were respectively: 1:40, l:80, and l:200 ratios of diethylstilhestrol to progesterone.Treatments VI, VII, VIII, and IX were O.25 mg, 0.50 mg, 1.00 mg and 5.00 mg of diethylstilhestrol respectively.Treatment X was 3 c.c. peanut oil injected every other day, with Treatment XI being udder manipulation with no injections.All injections were given intramuscularly, every other day, in a peanut oil carrier for 27 days.Measurable secretion (more than 0.30 gm.) was obtained from the ewes on Treatments I, IV, V, VI, VII, VIII, and IX, with peak daily productions being 29.90 gm., 306.81 gm., 29.70 gm., 5.50 gm., 142.43 gm., 610.52 gm., and 406.69 gm.respectively.A small amount of honeylike secretion was obtained from Treatment XI.This as well as the secretion obtained from Ewe Number V was present at the start of the experiment and was not due to treatment.Secretion was collected from four normal ewes that had just lambed for a colostrum sample and from ten normal ewes that had lambed earlier for an advanced lactation sample.Chemical analyses for fat, protein, lactose, ash, and total solids on all samples showed the secretion from the treated ewes to be lower than normal colostrum in all components.As lactation proceeded the secretion rapidly assumed the composition of normal milk; both chemically and physically.Routine histological examinations were conducted on Ewes Number I, IV, IX, X, and XI.Ocular micrometer measurements on alveoli and lumina revealed percent increase over the control average alveoli diameter to be 24.23,112.37, 156.19, and 246.39 percent for Treatments I, IV (right and left half), and IX respectively* Percent increase over the control average lumina diameters were 117.16, 414.18, 502.24, and 728.38 percent for Treatments I, IV (right and left half), and IX respectively.