Year: 2020
Title: Modification of the Standard 7-Day Ovsynch Protocol to Increase the Luteolytic and Synchronization Risks in Dairy Cows
Author: Atanasov, Branko
Author: Adamov, Nikola
Author: Celeska, Irena
Author: Ilievska, Ksenija
Author: Angjelovski, Branko
Author: Trbogazov, Zvonko
Author: Davkov, Filip
Author: Dovenski, Toni
Author: Opsomer, Geert
Author: Stevenson, Jeffrey
Abstract: Abstract We hypothesized that a single dose of PGF2α belatedly injected on day 8 after GnRH-1 in cows receiving a 7-day Ovsynch-56 protocol (GnRH – 7 days – PGF2α – 56h – GnRH – 16h – timed AI) will increase the proportion of cows with complete luteolysis. At day 35±3 postpartum, 70 lactating Holstein cows from one herd were scored for body condition and pre-synchronized with PGF2α and GnRH (3 days apart) and 7 days later submitted to an Ovsynch-56 protocol for first AI after random assignment to two treatments: (1) OV-7 (n=35) with an injection of PGF2α either on day 7; or (2) OV-8 (n=35) on day 8 after G1, respectively. Blood was collected before the first PGF2α, at day 7 and day 8 in OV-7 and OV-8, respectively, at AI and at 7 days after AI to assess progesterone concentration. Ten cows were classified as acyclic and were excluded from the analysis resulting in 60 cows (OV-8, n=27; OV-7, n=33). In total, more (P=0.01) OV-8 cows and more (P=0.04) primiparous OV-8 cows had complete luteolysis compared with their OV-7 herd mates. In addition, more (P=0.008) OV-8 cows with BCS<2.75 had complete luteolysis compared with their OV-7 herd mates, whereas no difference was observed between treatments among cows with BCS ≥2.75. In conclusion, delaying the application of PGF2α by 1 day reduced the percentage of primiparous cows and cows with poorer BCS having incomplete luteal regression at the time of AI.
Publisher: Walter de Gruyter GmbH
Relation: Macedonian Veterinary Review
Identifier: oai:repository.ukim.mk:20.500.12188/21413
Identifier: http://hdl.handle.net/20.500.12188/21413Identifier: 10.2478/macvetrev-2020-0028
Identifier: https://content.sciendo.com/view/journals/macvetrev/43/2/article-p161.xmlIdentifier: https://www.sciendo.com/pdf/10.2478/macvetrev-2020-0028Identifier: 43
Identifier: 2
