Control of Lambing Through Synchronization of Estrus and Induction of Parturition

The ability to program the time of birth for our livestock species offers several advantages to the producer. By concentrating lambing into a short defined period or periods it allows better utilization of labor and facilities. In addition, it should increase lamb survival since better supervision can be maintained for these specific periods. Furthermore, lambs are grouped more closely by age and can be more uniformly managed in such groups. Two trials (1983-84 and 1984-85) were conducted to study the effectiveness to prostaglandin F2α to synchronize estrus and flumethasone to induce parturition in a planned lambing program

Integrated Management of Reproduction in the Ewe

The ability to group lambing into a short predetermined period offers several desirable benefits to the producer. By concentrating lambing into a shorter period, one should be able to provide closer supervision and thereby increase survival. Also, lambs of similar age can be worked for castration, docking, vaccination, etc. as a group. Part-time producers may find it desirable to program lambing to coincide with available leave time if lambing can be confined to a reasonably short period. A trial was conducted during the 1982-83 breeding-lambing season to evaluate a combined program of synchronization of breeding and induction of lambing to achieve such a program

Relative Effectiveness of Estrous Synchronization Methods in the Ewe

The value of synchronization is in reducing the breeding period. Prostaglandin F2α (PGF) has been demonstrated to effectively synchronize ewes during the normal breeding season. Different methods of synchronizing estrus with PGF have been proposed. The purpose of this trial was to compare the relative effectiveness of singular PGF injection vs. a dual injection of PGF 10 days apart to a control for synchronizing estrus in the ewe during the normal breeding season

Evaluation of Urea, Casein, Soy Protein Isolates or Zein in a Semipurified Diet Fed to Lambs

The objectives of this study were to determine how protein source would influence nitrogen balance and ruminal fermentation when fed in a semipurified diet to lambs

Synchronizing Estrus with 5 or 10 MG Prostaglandin F2α in the Ewe

The length of the breeding period can be decreased through estrous synchronization. This enables the producer to reduce the length of the resulting lambing period allowing for more efficient use of labor and facilities during lambing. Past synchronization trials at this station have found intramuscular injections of 10 or 15 mg PGF to be effective in synchronizing estrus during the normal breeding season. This study evaluates 5 or 10 mg PGF for relative effectiveness for estrous synchronization

Synchronization of Estrus in the Ewe with Various Dosages of Prostaglandin F2α

Prostaglandin F2α (PGF1) was evaluated at various dosages to determine its relative effectiveness to synchronize estrus. The effect of intramuscular injections of 0 (control), 10 and 15 mg PGF during the normal breeding season was studied over a 2-year period using a crossbred ewe flock. Parameters discussed are time to conception after injection during first and second estrous cycles, number of ewes lambing and lambing rate. PGF at 10 and 15 mg was effective in synchronizing estrus between 32 and 80 hours post-injection

The Effect of Exposure to Teaser Rams on Lambing Performance of Hampshire and Columbia Ewes

The common recommendation that use of teaser rams will stimulate earlier estrous activity and increased lambing rates is based on limited data for specific locations. This study was undertaken to measure the responses following exposure to teaser rams in purebred Hampshire and Columbia ewes in South Dakota normally bred during September

Fed and Fasting Nitrogen Metabolism by Lambs Fed a Semi-purified Diet Supplemented with Urea or Zein

Most finishing diets include corn as a primary energy source. If the finishing diet consists mostly of corn, a large proportion of the protein needed by the ruminant is supplied through corn protein. A protein in corn, zein, largely escapes ruminal degradation (60%) and the ungraded fraction is passed into the small intestine for digestion. Since urea and zein act differently in supplying proteins and amino acids to the small intestine of the ruminant, an evaluation of nitrogen retention in lambs was conducted. The objective of this study was to evaluate the effects of diet nitrogen change, time and fasting on nitrogen metabolism by lambs fed urea or zein in a semipurified diet