Lactating St. Croix White and Dorper × St. Croix White ewes were used to evaluate the effect of breed and feeding a split ration on body temperature during the cool (March–April) and warm (July–August) seasons in the U.S. Virgin Islands. Within each season ewes were assigned to treatments (n = 8/treatment) based on breed, age, and number of lambs. Treatments consisted of individually feeding ew...

Hair sheep ewes were used to evaluate the influence of various levels of mating stimuli on the duration and timing of estrus and LH concentrations around estrus. Ewes were treated with PGF2alpha (15 mg, im) 10 d apart. At the time of the second PGF2alpha treatment (Day 0) ewes were placed in groups and exposed to different types of mating stimuli. One group of ewes (n = 16) was exposed to an ep...

A sustained-release multi-trace element/vitamin bolus has been devised for administration to ewes in advance of mating. Each bolus contained 5.3g Cu, 50mg Se, 90mg Co, 100mg I, 3.2g Mn and 4.7g Zn with 268x10(3) IU Vitamin A, 54x10(3) IU Vitamin D and 800 IU Vitamin E. About 50% of each nutrient is released during the first 6 weeks. Thereafter the release rate slows and over the remaining life ...

In the absence of livestock contact, recurring lamb mortality in bighorn sheep (Ovis canadensis) populations previously exposed to pneumonia indicates the likely presence of carriers of pneumonia-causing pathogens, and possibly inadequate maternally derived immunity. To investigate this problem we commingled naïve, pregnant ewes (n=3) with previously exposed rams (n=2). Post-commingling, all ew...

The adrenal and renal responses to similar increases in plasma angiotensin II (AII) were studied in chronically catheterized fetal lambs (112-131 days gestation: term 145 days) and adult nonpregnant sheep. The rate of AII infusion was adjusted to compare the effect of similar rises in plasma AII concentration between fetuses and adult ewes. Increases in plasma AII were associated with a decreas...

This experiment studied congenital transmission in sheep experimentally infected with oocysts of Toxoplasma gondii and reinfected at one of three stages of pregnancy. Twenty ewes were experimentally infected with T. gondii strain ME49 (day 0). After the T. gondii infection became chronic (IFAT≤512), the ewes were allocated with rams for coverage. After the diagnosis of pregnancy, these ewes wer...

The litter size of homozygous Booroola Merino ewes results in high perinatal mortality. One subcutaneous implant of crystaline oestradiol in silastic tubing in heterozygous Booroola Merino ewes decreased ovulation rate from 3.18 -r0.15 (n = 39) to 2.03 & 0.14 (n = 35), and decreased litter size (5 8 weeks pregnant) from 2.49 + 0.13 (n = 39) to 1.47 + 0.12 (n = 32), providing a useful management...

The first ovulation and first oestrus after parturition were recorded in four groups of Merino ewes which: (a) reared their lambs normally, (b) were allowed to suckle their lambs only during three 1-hr periods each day, (c) had their lambs removed on the day after birth, or (d) had their lambs removed on the day after birth and were injected intramuscularly with 5 i.u. oxytocin ten times each d...

This study investigated whether the transmission of naturally occurring scrapie in sheep can be prevented using embryo transfer. Embryos were collected from 38 donor ewes in a Suffolk sheep flock with a high incidence of naturally occurring scrapie, treated with a sanitary procedure (embryo washing) recommended by the International Embryo Transfer Society and then transferred to 58 scrapie-free...