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Abstract

Conventional methods for determining the reproductive performance of sheep bred either after estrus synchronization during the breeding season or after induction of estrus/ovulation during the non-breeding season take a long time and may give misleading results due to the effect of environmental factors. Laparoscopic observations allow real-time monitoring of ovarian activity around estrus or ovulation. This study was aimed at assessing the superovulatory effects of follicle-stimulating hormone (FSH) and equine chorionic gonadotropin (eCG) treatments by laparoscopy during breeding (September-November, n=12) and non-breeding (April-June, n=12) seasons in Akkaraman sheep. In both seasons, after CIDR withdrawal, the ewes were injected either with 600 IU eCG or 300 μl (20 mg/ml) FSH twice at 12 hour intervals. Plasma P4, E2 and LH concentrations were determined at the time of intra-vaginal CIDR insertion (day 0) and then at its withdrawal (day 12), followed by 3 and 6 days of eCG or FSH injections. After 3 (first observation) and 6 (second observation) days of hormone injections, laparoscopy was performed to record ovarian activity in both seasons. The eCG increased (p<0.05) the numbers of large follicles (first observation) and CL (first and second observations) in the breeding season compared to FSH treatment. CL, small-moderate and large follicle numbers of eCG treated ewes were higher (p<0.05) than those of FSH at both observations in the non-breeding season. In the breeding season, eCG treated ewes had higher (p<0.05) plasma P4 (3 and 6 days after hormones injections) and E2 (3 days after hormones injections) concentrations than those of FSH. In conclusion, the results of the present study indicate that treatment with eCG during the non-breeding season can support ovarian activity, and thus increase ovulation rate and plasma hormone concentrations around induced estrus/ovulation in Akkaraman ewes.

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Authors and Affiliations

U. Şen
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Abstract

In this work studies ofM OVPE growth of InAlGaAs/AlGaAs/GaAs heterostructures are presented. The HRXRD and SIMS measurements indicate the high structural and optical properties as well as high uniformity oft hickness and composition ofI nAlGaAs quantum wells. This work is the .rst step towards elaboration oft he technology oft he strained InAlGaAs/GaAs heterostructures for advanced optoelectronic devices working in the visible part oft he spectrum. The investigations ofSi (n-type), Zn (p-type) .-doped GaAs epilayers and centre Si-.-doped InxGa1-xAs single quantum well (SQW) are presented. The .-doping layer was formed by SiH4 or DEZn introduction during the growth interruption. The electrical and optical properties oft he obtained structures were examined using C-V measurement, EC-V electrochemical pro.ler, Raman spectroscopy (RS), photore.ectance (PR) and photocurrent (PC) spectroscopies. Technology oft hick GaN layers grown on sapphire by HVPE is very promising as a part off reestanding GaN substrates manufacturing. Further works will be focused on the optimisation of growth, separating layers from substrates and surface polishing. The in.uence oft he growth parameters on the properties of( Ga, Al)N/Al2O3 and Mg dopant incorporation was studied.

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Authors and Affiliations

B. Boratyński
R. Korbutowicz
B. Paszkiewicz
R. Paszkiewicz
D. Pucicki
D. Radziewicz
B. Ściana
M. Tłaczała

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