Large offspring syndrome (LOS) may be initiated in ovine embryos after exposure to in vitro conditions. The objective of this study was to compare various parameters of the gravid uterus on day 140 after fertilization: (i) in ewes (n=4) bred naturally, and in ewes (n=18) after transfer of embryos produced in vitro, and (ii) in single, twin and triplet pregnancies after transfer of in vitro prod...

The objectives of the present study were to determine the time of uterine involution and ovarian activity using ultrasound examination and progesterone assay. Weekly progesterone levels were measured starting one week postpartum until two weeks after the 1(st) postpartum estrus in Barbary ewes lambed during winter in AL-Bayda city, north of Libya. A total of 15 Barbary ewes were used in the pre...

Lamb-specific odor is used by ewes to discriminate between their own and alien offspring. Recent studies have demonstrated that fostering can be facilitated by transferring own-lamb odor to alien lambs via cloth stockinettes. The objective of the present study was to investigate the effectiveness of the odor-transfer technique in enticing ewes with a single lamb to adopt an additional lamb ("ad...

Data from 644 exposures and 552 lambings were used to analyze reproductive traits of 1/2-Finnish Landrace, 1/2-Dorset ewes (1/2 Finn); 1/4-Finnish Landrace, 3/4-Dorset ewes, (1/4 Finn) and Dorset ewes. Ewes were exposed to Hampshire or Suffolk rams for spring lambing from 1973 to 1978. The analytical model included fixed effects of ewe birth year (EBY), ewe breed (BR), lambing year within EBY a...

To determine whether a link exists between reproductive seasonality and the structure of the gene for melatonin receptor Mel(1a), the latter was studied in two groups of Mérinos d'Arles (MA) ewes previously chosen for their genetic value, which took into account their own out-of-season ovulatory activity adjusted by environmental parameters and that of their relatives. The genomic DNA of 36 ewe...

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...