Effect of two prostaglandin injections on days 5 and 6 in a timed AI protocol after estrus expression on pregnancy outcomes in dairy cows during cold or hot seasons of the year
| Autor: | Mufeed A. Alnimer, Mohamed A Abedal-Majed, Ahmad I. Shamoun |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Cultural Studies
medicine.medical_treatment Prostaglandin lcsh:Agriculture 03 medical and health sciences chemistry.chemical_compound Animal science lcsh:Zoology medicine Original Study lcsh:QL1-991 Pregnancy outcomes lcsh:Science 030304 developmental biology lcsh:SF1-1100 Estrous cycle 0303 health sciences Pregnancy business.industry Artificial insemination 0402 animal and dairy science Religious studies lcsh:S 04 agricultural and veterinary sciences medicine.disease 040201 dairy & animal science Pregnancy rate chemistry Estrus Detection Herd lcsh:Q lcsh:Animal culture business |
| Zdroj: | Archives Animal Breeding, Vol 62, Pp 161-170 (2019) Archives Animal Breeding |
| ISSN: | 2363-9822 0003-9438 |
| Popis: | The objective of this study was to test whether prostaglandin (PG) injection on day 30 postpartum (pp) and detection of estrus can affect the efficacy of injecting PG on days 5 and 6 in the timed artificial insemination (TAI) protocol on pregnancy rate in a large dairy herd in hot or cold seasons. Out of 2235 cows, 1998 received an injection of PG at 30±3 d pp and estrus was observed. Cows that displayed estrus during the estrous observation period after PG injection were classified as estrus (E), while those that did not show estrus were classified as nonestrus (NE). Cows in each group were assigned to two treatments: CO-72 (control treatment) (ECO-72 and NECO-72) (day 44 GnRH, day 51 PGF2α, day 54 GnRH+TAI) or PG–PG (EPG–PG and NEPG–PG) (day 44 GnRH, day 49 PGF2α, day 50 PGF2α, day 52 GnRH+TAI). Pregnancy was diagnosed on days 33 and 47 after artificial insemination (AI). The proportion of cows in estrus on the day of TAI was higher (P≤0.05) for cows that received two PG than for cows that received one PG. Pregnancies per AI (P/AI) on days 33 and 47 for cows inseminated during and after a voluntary waiting period in the NEPG–PG treatment had higher rates than for cows in the EPG–PG, ECO-72 and NECO-72 treatments. Moreover, P/AI were significantly (P≤0.05) affected by parity. Primiparous had higher P/AI (37.0 %) than multiparous cows (31.6 %). Cows inseminated in cold months had higher P/AI and reduced PL (35.6 % and 20.8 %) than cows inseminated in hot months (29.1 % and 30.6 %, respectively). In conclusion, treatments with PG on days 5 and 6 after the first GnRH injection increased P/AI. Estrus detection before the beginning of TAI protocol did not affect fertility. To maximize P/AI cows exhibiting heat at any time during the synchronization protocol should be inseminated. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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