Impact of GnRH and PGF2α Synchronization Protocol in Friesian Cows under Egyptian Environmental Conditions on Oestrus, Progesterone Concentration and Pregnancy Rate

Abu El-Hamd, Mohamed ِAwad; Gabr, Sherif A.; Soliman, Soliman H.; Fouad, Wael Fekry; El-Hamady, Wael A.; Omar, Mohammed E.A.; Abu El-Hamd, Emad H.

doi:10.21608/ejvs.2025.352895.2606

Impact of GnRH and PGF2α Synchronization Protocol in Friesian Cows under Egyptian Environmental Conditions on Oestrus, Progesterone Concentration and Pregnancy Rate

Articles in Press

Document Type : Original Article

Authors

¹ Animal Production Research Institute, Agricultural Research Center, Ministry of Agriculture, Egypt

² Department of Animal Production, Faculty of Agriculture, TanTa University, Egypt

³ Animal Production Research Institute, Agricultural Research Center, Giza, Egypt

⁴ Animal Production Research Institute (APRI), Agricultural Research Center (ARC), Ministry of Agriculture, Egypt

⁵ Animal Production Research Institute, Agricultural Research Center, Ministry of Agriculture, Egypt.

10.21608/ejvs.2025.352895.2606

Abstract

The objective of this study was to evaluate some hormonal treatment protocols to improve fertility on Friesian cows during summer and winter seasons. A total of 48 Friesian cows were used. Average age ranged between 46–96 months, weighing 440 – 560 kg and 2-6 parities are used. Cows were divided into two treatment groups in summer and two groups in winter season (12 animals in each). Cows in all groups were exposed to heat stress severe heat stress (THI = 74 to <76) during the summer season compared with absence of heat stress (THI less than 72) during the winter season. Rectal temperatures (RT) and respiration rate (RR) over the summer heat stress period (June, July, and August) as compared to the winter season. In all protocols cows were exhibited oestrus lower significantly in summer than winter season. All cows treated with 5-d Cosynch-72 on summer and winter seasons oestrus lower significantly (P<0.01) than cows treated with 5-d Cosynch-88protocols about by 62.50 vs 87.50% in protocol 1 and 2, respectively. Progesterone (P₄) concentration in cows treated with protocol 1 (5-d Cosynch-72) on the day of artificial insemination was significantly (P<0.01) lower in pregnant cows than in non-pregnant cows during artificial insemination (oestrus), but it was higher in pregnant cows five, ten, and twenty-four days after artificial insemination than in non-pregnant cows. P4 concentration was not significant differ during pre-treatment in all animals. P4 concentration pre- and treatments tended to be similar in both pregnant and non-pregnant cows.

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