The objective of this study was to test whether the sexual behavior of the ram affects the ram effect. Rams exhibiting either high (HP) or low (LP) levels of sexual performance (on the basis of serving capacity tests) were exposed to 89 anestrous ewes for 28 d. Thirty-two anestrous ewes were not exposed to rams. The objective of this study was to compare the efficacy of estrus induction by HP (...

Ewes were treated with a medroxyprogesterone acetate (MAP) sponge for 8 d followed, at sponge removal, with 500 IU pregnant mare serum gonadotropin (PMSG) at d 30, 40 or 50 (d 0 = lambing) to induce estrus. Dry and lactating ewes were divided into equal numbers at each postpartum day and bred at estrus. Conception rates and number of accessory sperm were determined by flushing the oviducts 3 d ...

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 total number of 136 pregnant ewes with the same age and parity were used in the present study. The experimental ewes reared during Arabic months or lunar months, from the 1 Gomady to Zol-hega, 1432 AH. The available data for each animal were obtained from the records of Sheep Farm, Project of Experimental Farms. Lambing season started at months, Shawal to Zol-hega. After lambing, the ewes wer...

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...