Scienceline Publication Repository: No conditions. Results ordered -Date Deposited. 2024-03-29T08:41:05ZEPrintshttp://eprints.science-line.com/images/Scienceline.pnghttp://eprints.science-line.com/2022-05-23T19:23:23Z2022-05-25T03:18:59Zhttp://eprints.science-line.com/id/eprint/375This item is in the repository with the URL: http://eprints.science-line.com/id/eprint/3752022-05-23T19:23:23ZEffect of Heat Stress on Developmental Competence of In Vitro Matured Oocytes of Camelus Dromedaries with Different QualitiesThe deleterious effect of heat stress on cumulus-oocytes complexes (COCs) competence is well recognized in different livestock species. Therefore, the present study aimed to investigate the effect of physiologically relevant heat stress on the developmental competence of camel COCs during in vitro maturation (IVM). A total of 1548 COCs were divided into six groups in this study. The groups were named K1 and K2 representing good and low-quality COCs incubated at 38.5oC for 30 hours. While K3 and k4 represent good and low-quality COCs exposed to 41oC for the first 6 hours of IVM. Finally, K5 and k6 represent the groups of good and low-quality COCs exposed to 42oC for the first 6 hours of IVM. After exposure of COCs to heat stress at 41°C and 42°C during the first 6 hours of in vitro maturation, the COCs were incubated at 38.5°C for 24 hours of IVM. The in vitro matured COCs were activated to cleave using ethanol followed by 4 mM 6-DMAP and developed embryos were cultured in vitro for 7 days post parthenogenetic activation. The results of this study indicated that heat stress at 42oC significantly decreased the Pb (polar body) extrusion rate in K4 and K6, compared to other groups. Additionally, the embryo cleavage rate was significantly lower for good and low-quality oocytes exposed to heat stress (K2, K3, K4, K5, and K6), compared to good quality COCs of the control group (K1). The cleavage rate was lower for low quality (K2; 63 ± 1.28) than good quality COCs (K1; 53 ± 1.85). The percentages of oocytes that developed to the blastocyst stage were lower for K2, K3, K4, K5, and K6 than K1. Moreover, the blastocyst rate was lower for K2 (9 ± 0.22) than K1 (15 ± 0.22). The results of this study indicated that exposure of camel oocytes to heat stress for 6 hours during in vitro maturation severely reduced extrusion of polar body, cleavage, and blastocyst rates. The low-quality camel COCs were reduced developmental capacity than good quality oocytes.G. AshourA. El-SayedM. KhalifaN. Ghanemnassergo@agr.cu.edu.eg2022-05-23T19:23:12Z2022-05-25T03:19:14Zhttp://eprints.science-line.com/id/eprint/374This item is in the repository with the URL: http://eprints.science-line.com/id/eprint/3742022-05-23T19:23:12ZApplication of different hormonal protocols for improving reproductive performance of Barki ewesThis investigation was designed to assess reproductive improvement in Barki ewes using different hormonal protocols. Seventy-five non-pregnant and non-lactating Barki ewes were randomly assigned into three equal groups (25 ewes each), namely G1, G2 and G3. (G1) served as control, while (G2) was treated with an intravaginal progestagen impregnated sponge for 12 days then was removed. On the ninth day, all treated ewes received an intramuscular injection of prostaglandin F2α. (G3) was also synchronized as G2, in addition to on the 10th day ewes were received an intramuscular injection of 750 IU PMSG in descending doses for three days so that the last dose was injected at the 12th day concurrently with sponges' removal. Meanwhile, on the 14th day, all ewes in G3 were received an intramuscular injection of hCG hormone (500 IU/ewe). The results showed an increase in plasma progesterone level from the first day of pregnancy and rises up to the last day before parturition. Progesterone was found to be higher in G3 (that had higher twining rate) than in G2 than in G1. Insignificant increase in estrus response was observed in groups (G2, G3) compared to G1 (100, 100 and 92%, respectively). Conception rate was significantly higher in G3 (100%) than G2 (92%) and G1 (88%). While, abortion rate was higher in G1 and surpassing G2 and G3 (9.0, 0.0 and 0.0 %, respectively). Lambing rate was significantly higher in G3 as compared to G2 and G1 groups (100, 92 and 80 %, respectively). While, weaning rate was recorded to be insignificantly higher in G2 than in G1 and G3 (100.0, 95.45 and 94.29%, respectively). It could be concluded that, hormonal manipulation using intravaginal progestagen impregnated sponge and PMSG in the presence of hCG; would be a proper way for enhancing the reproductive efficiency of Barki ewes.G. AshourM. F. El-Bassionymoharramf@yahoo.comS. M. DessoukiM. A. El-Wakeel