The objectives of the study were to determine (1) oestrous expression rate and (2) the effect of oestrous expression prior to progesterone-based Ovsynch protocol on pregnancy rate in Holstein cows. All cows (n = 917) were subjected to 7-day progesterone-based Ovsynch protocol. In this protocol, cows that expressed oestrus before (HEAT1) the scheduled second GnRH were inseminated 20 h later after the onset of oestrus without GnRH administration. Cows that expressed oestrus after the second GnRH administration (HEAT2) or did not express oestrus (NOHEAT) received fixed-timed AI. Oestrous expression was determined by using activity-rumination monitoring system and all cows were inseminated with sexed semen. Oestrous expression rate prior to FTAI was 40.5% and the majority (p < .01) of oestrous expression were in HEAT2 compared with HEAT1 in both primiparous (71.8 vs. 28.1%) and multiparous cows (69.5 vs. 30.5%). The mean interval from intravaginal device removal to the onset of oestrus was 47.4 ± 0.9 h and 62.9 ± 0.5 in HEAT1 and HEAT2, respectively. Primiparous cows (47.7%) had a higher (p < .01) expression rate compared with multiparous cows (37.2%). Overall pregnancy rate was 37.4% and there was two-way significant interaction between parity and oestrous expression on pregnancy rate (p < .01). Both primiparous (48.1 vs. 35.8%) and multiparous cows (47.4 vs. 28.4%) that expressed oestrus had greater (p < .01) pregnancy rate compared with cows that did not express oestrus. There was no difference in pregnancy rates of HEAT1 and HEAT2 in both primiparous (44.7 vs. 49.5%) and multiparous cows (47.2 vs. 47.6%). Pregnancy rate was not influenced (p = .21) by milk production (high or low) in both primiparous (47.6 vs. 48.6%) and multiparous (54.9 vs. 42.1%) cows that expressed oestrus, respectively. In conclusion, cows showing oestrus before or after second GnRH of the Ovsynch protocol had greater pregnancy rate than cows not showing oestrus.
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http://dx.doi.org/10.1111/rda.14293 | DOI Listing |
Eur J Neurosci
December 2024
University of Iowa, USA.
17β-Estradiol (E2) is a sex hormone that acts on many brain regions to produce changes in neuronal activity and learning. A key brain region sensitive to E2 is the dorsal striatum (also called caudate-putamen), which controls motor behaviour, goal-directed learning and habit learning. In adult rodents, oestrogen receptors (ERs) in the dorsal striatum are localized to the plasma membrane and include ERα, ERβ and G protein-coupled ER (GPER).
View Article and Find Full Text PDFReprod Domest Anim
November 2024
Mestrado Profissional em Clínicas Veterinárias, UEL, Londrina, Paraná, Brazil.
This study evaluated the effects of pre-synchronisation with injectable progesterone (P4) on the ovarian follicular dynamics of Bos taurus indicus cows in anoestrous treated with a timed artificial insemination (TAI) protocol. Multiparous Nelore females (n = 47) at 30-60 days postpartum were used in this study. 10 days before (D-10) the TAI protocol, antral follicle count (AFC; follicles ≥ 3 mm), ovarian condition and body condition score (BCS; 1-5) were assessed and were randomly allocated into two groups: Pre-sync (n = 25), which underwent pre-synchronisation with 150 mg of injectable P4 intramuscularly (i.
View Article and Find Full Text PDFReprod Domest Anim
October 2024
CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.
Theriogenology
December 2024
Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, 10-719, Olsztyn, Poland. Electronic address:
Reproductive success requires considerable energy investment. Research has shown that some adipokines, i.e.
View Article and Find Full Text PDFReprod Domest Anim
September 2024
Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky, USA.
The establishment of pregnancy involves a fine-tuned balance between protection and tolerance within the maternal immune system, as the female needs to accept a foreign antigen (the semi-allogenic fetus) while still being able to combat pathogens from the uterus. In the horse, the first uterine exposure to paternal antigens is during mating when sperm is introduced to the tissue and draining lymphatics of the uterus. Additionally, it has been suggested that seminal plasma and its proteins within it play an essential role in preparing the female tract for a suitable immunologic environment but this has not been confirmed in the horse.
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