Multiparous Suffolk and Suffolk-cross ewes were randomly allotted to treatments within breed and year to measure effects of ram exposure, during transition from anestrus to breeding activity, on reproductive performance. Treatments were: 1) ewes joined with two mature vasectomized Rambouillet rams for 15 d before breeding (DC), 2) ewes maintained across a net wire fence from two vasectomized ra...

Mature ewes (12 per group) were given prostaglandin F20t (PG; 10 mg intramuscularly) on day 10 of an estrous cycle, to regress corpora lutea, or on day 16, after natural corpus luteum regression. Ewes treated on day 10 or 16 were in estrus on day 12 or 17, respectively. The PG-treated and untreated ewes were mated at estrus and necropsied 2 hr later. Sperm were counted in the oviducts, the uter...

MANALU, W. 1999. The effect of superovulation prior to mating on fetal growth in Iambs from Javanese thin-tail ewes. Jurnal Ilmu Ternak dan Veteriner 4 (4): 243-250. Twenty-nine fetuses (11 fetuses from 9 non-superovulated ewes and 18 fetuses from 8 superovulated ewes) were used to study the effect of superovulation of ewes prior to mating on fetal weight, fetal length, the length of the body a...

The purpose of the study was to optimize postoperative comfort in lambs anaesthetized for the surgical creation of scoliosis while maintaining the ewe-lamb relationship to miminize rejection rates. The first management plan produced six scoliotic lambs but intraoperative hypoventilation and hypovolaemia followed by postoperative dyspnoea, pain, monitoring and nursing difficulties, hypothermia, ...

The ovulation induced in anestrous ewes by the sudden introduction of males is not accompanied by estrous behavior unless ewes are primed with progestagens. Although CIDR devices (which contain 0.3 g of progesterone; Pfizer, Auckland, New Zealand) may be used for more than one treatment, conception rates decrease when CIDRs previously used for long times are used again. In cows, if previously u...

The interval from onset of estrus to preovulatory luteinizing hormone (LH) release, conception and fertilization rates, and number of accessory spermatozoa per ovum at 48 hr postmating in untreated cyclic ewes and fn progestogen-pregnant mare serum gonadotropin (PMSG) treated, anestrous ewes were compared in efforts to identify sources of lowered fertility for matings induced in anestrous ewes ...

The incidence of oestrus (6/46) and ovulation (14/46) in ewes given antisera to androstenedione, oestrone, oestradiol and testosterone either separately or as a mixture of these sera at the time of treatment with progestagen sponges alone or progestagen sponges followed by LH-RH was similar to that of control ewes (2/13 and 6/13 respectively). The number of corpora lutea (CL) recorded for those...

Factors affecting ewe prolificacy (number of lambs born per ewe lambing) were evaluated using records on 9705 Targhee, 12,721 Suffolk, and 7231 Polypay lambings from flocks participating in the US National Sheep Improvement Program. Factors considered were ewe age and season of lambing. Prolificacy was affected by age of the ewe (P<0.001) and was highest for ewes lambing between 4 and either 7 ...

Three experiments were conducted to determine: (1) the direction of uterine contractions in Days 32 and 52 postpartum ewes (Experiment 1); (2) the effect of PGF(2alpha) on direction of uterine contractions (Experiment 2); and (3) the effect of PGF(2alpha) on fertility rates in Day 32 postpartum ewes (Experiment 3). In Experiment 1, non-lambing (>90 days postpartum) and lambing ewes (day of lamb...

In two experiments, 64 crossbred ewes that had lambed in September or January and had their lambs removed within 24 h after birth were assigned to four groups and given the following treatments: group 1 (16 ewes)-1 ml saline, im or iv on d 10 postpartum; group 2 (24 ewes)-150 microgram/gonadotropin releasing hormone (GnRH) in 1 ml saline, im or iv on d 10 postpartum; group 3 (16 ewes)-150 micro...