Effect of Using Low Doses of PGF2α and GnRH Hormones on Reproduction of Dairy Cows

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, Kafr Elsheikh University, Egypt

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

Abstract

The research aims to improve reproductive performance of repeat breeder or anestrous cows using PGF2 α and GnRH through in intra vulva injection. In this study, 30 Friesian dairy cows were not conceiving for a period ranging from 120 to 250 days after calving. Cows divided into three groups, 10 cows in each group and were subjected to the following protocols. Group1 (G1): was injected with 50 μg GnRH on Day 0 and 5 mg PGF2α on Day 7 then the oestrus cycle was monitored. Group 2 (G2): cows were injected twice 5 mg PGF2α, 11 days apart. Group 3 (G3): was injected with 50 μg GnRH at Day 0, 5 mg PGF2α, at Day 7 and then injected with 50 μg GnRH at day 9 and fixed timed artificial insemination (TAI) was performed 16 to 18 h. The results showed that, exhibited oestrus 100, 90 and 80% in G3, G2 and G1, respectively. Pregnancy rates were significantly highest in G3 and G2 than in G1. The progesterone (P4) concentration on day 24 post-insemination was 10.253, 11.235 and 11.567 ng/ml in pregnant versus were 3.245, 1.985 and 2.036 ng/ml in non- pregnant cows in G1, G2 and G3, respectively. Progesterone concentration at 2nd GnRH or PGF2α injections were significantly lower in pregnant cows than in non-pregnant cows in G1, G2 and G3 groups. The economic evaluation was shown that 2 PGF2α protocols had the cheapest cost (L.E 21/animal) highest pregnant cows.

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Egyptian Journal of Veterinary Sciences
Volume 54, Issue 7 - Serial Number 7
The Scientific Conference of Kafr Elsheikh University (One World.......One Health, 5th– 8th October 2022)
November and December 2023
Pages 237-244

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History

  • Receive Date: 30 August 2023
  • Revise Date: 14 November 2023
  • Accept Date: 15 November 2023

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