Dairy Resources - Breeding/Reproduction

MARCH 2023

Highlights

• A meta-analysis was conducted on 19,723 pregnancy diagnosis records in dairy cows.
• Four periods were defined due to the embryonic development up to 90 days of gestation.
• Transrectal ultrasound is the dominant method of pregnancy diagnosis.
• Pregnancy losses ranged from 27% in early embryonic to 2% in later fetal stages.

Abstract

Pregnancy losses are a biological challenge and economically important in dairy herds. A meta-analysis was conducted to quantify losses in 4 periods from 19 to 90 d of pregnancy corresponding to the physiological development of gestation in dairy cows. A total of 19,723 diagnostic records from 46 studies were included. Pregnancy losses averaged 27%, 13%, 7%, and 2% in the early embryonic (19 to 32 d), late embryonic (30 to 45 d), early fetal (45 to 60 d), and later fetal (60 to 90 d) stages. These results provide a formal synthesis of the incidence of pregnancy losses in dairy cows.

A. Albaaj, J. Durocher, S.J. LeBlanc, S. Dufour
DOI:https://doi.org/10.3168/jdsc.2022-0278

March 2023

Herd gestation and health management are key aspects of effective dairy farm operations and animal welfare improvement. Unfortunately, very little is known about the developmental divergences induced by assisted reproduction technologies (ART) and their consequences once the animal is mature. Indeed, the gestational and health outcomes of this subset of the Holstein population is yet to be characterized. In this study, the intergenerational impacts of ART conception were assessed by looking at the gestation and health outcomes of a large cohort of cows (n = 284,813) for which the conception methods were known. Our results showed that cows conceived by multiple ovulation embryo transfer (MOET) and in vitro fertilisation (IVF) displayed longer gestations: +0.37 ± 0.079 and +0.65 ± 0.21 day compared to cows conceived by artificial insemination (AI). Surprisingly, animals conceived by all methods experienced a similar 1-day decline in average gestation length from 2012 to 2019. Cows conceived by IVF were not more likely to experience stillbirths but were affected by common diseases such as ovarian cysts, mastitis, and uterine diseases in different proportions compared to cows conceived by other methods. This study provides new and unique information on ART animals regarding perinatal mortality and general health outcomes.

S. Lafontaine*, R. Cue, M. Sirard
Theriogenology
Vol. 198, pp 282-291

* Centre de recherche en reproduction, développement et santéintergénérationnelle (CRDSI), Département des Sciences Animales, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec, G1K 7P4, Canada

September 2017

Could too many ovarian follicles, at too young of an age, mean a shortened herd life for dairy females? (Farm Journal)

If heifers “use up” their ovarian reserves early in life, they may have shorter productive herd lives, compared to same-age herdmates with lower follicle counts. That’s the hypothesis evaluated by a team of researchers led by James Ireland, Professor of Animal Science and Physiology at Michigan State University.

July 2021

Many dairy herds are implementing a beef-dairy crossbreeding program for all or a portion of their lactating cows in order to add value to newborn calves. In beef cattle, there is a moderate to high correlation between heritability of growth traits and their genetic correlations with birth weight (e.g., yearling body weight has a heritability of 58% and a correlation with birth weight of 0.61). Although there are several considerations such as market for beef-dairy cross calves, replacement heifers needed, and calf death losses due to dystocia and the subsequent survival and performance of lactating cows, the potential for added value by implementing a beef-dairy crossbreeding program must not neglect the potential to increase calving difficulty due to increased birth weights.

July 2019

Over the past two decades, a reproduction revolution has occurred in the dairy industry. The development of fertility programs and their adoption by the dairy industry over the past decade has largely driven this reproduction revolution.

December 2019

“She’s open.”

Say those two words to any producer and you’re almost guaranteed to see them scowl. Unfortunately, it’s a phrase dairy farmers hear all too often.

June 2016

It is increasingly common for dairy managers to use tools that allow for pregnancy diagnosis earlier than the traditional 35 to 45 days after insemination. Diagnosing pregnancy early is beneficial for identifying open cows and allowing for reinsemination strategies that will help minimize days open and increase profitability, but losing confirmed pregnancies can be very frustrating.

September 2019

Every producer knows that dreaded feeling when you find a cow who once was pregnant suddenly show up as “open.” Not only is this a discouraging feeling, but the loss of pregnancy can snowball into long-term financial impacts as well.

March 2019

Abstract:

This study was designed to evaluate whether commonly used gonadorelin products that are commercially available in the United States results in comparable ovulation and pregnancy per AI (P/AI) in synchronized lactating dairy cows. A total of 1411 Holstein cows receiving a Double-Ovsynch protocol (DOV) for conducting the first postpartum AI were randomized to receive one of the following GnRH products throughout the Double-Ovsynch: 1) Cystorelin® (CYS, gonadorelin diacetate tetrahydrate, n = 484); 2) Factrel® (FAC, gonadorelin hydrochloride, n = 482) or; 3) Fertagyl® (FER, gonadorelin diacetate tetrahydrate, n = 515). A subgroup of cows (n = 487) received ovarian ultrasound exams and collection of blood samples for progesterone (P4) analysis. Proportion of cows ovulating following the 3^rd GnRH of DOV tended (P = 0.07) to differ between GnRH salts (hydrochloride = 61.5% vs. diacetate = 72.7%) but was similar for GnRH products (FER = 74.1% vs. FAC = 61.5% vs. CYS = 72.2%). Interestingly, a logistic regression analyses that considered the circulating P4 at the time of GnRH treatment indicated lower ovulation responses to FAC compared to FER and CYS; although greater circulating P4 decreased ovulation response to all GnRH products. Results for P/AI at 60 d post-insemination differed between GnRH salts (P =  0.02) as well as GnRH products (FER = 47.8% vs. FAC = 42.0% vs. CYS = 49.8%; P = 0.04). In conclusion, fertility following use of the Double-Ovsynch was less following a hydrochloride-based GnRH product likely due to lesser ovulatory responses throughout the synchronization protocol.

M. Luchterhand, C. A. Gamarra, R. S. Gennari, P. D. Carvalho, R. V. Barletta, A. H. Souza
https://doi.org/10.1016/j.anireprosci.2019.01.006

March 2020

Abstract:

The objective of the present study was to assess the effectiveness of an intravaginal thermometer in the field prediction of the second stage of labor and to determine its impact on the health of dams and newborn calves. Holstein cows (n = 241) were randomly selected about 5 (mean ± SD: 4.7 ± 2.0) days before the expected date of calving and the thermometer was inserted into the vagina. Another 113 cattle served as controls. There was no false alarm during the experiment. The risk of dystocia (Score >1) was 1.9 times higher, the prevalence of stillbirth was 19.8 times higher, the risk of retained fetal membranes (RFM) was 2.8 times higher and the risk of clinical metritis was 10.5 times higher in the control group than in the experimental group. The prevalence of stillbirth was 7 times higher in cows with dystocia compared to cows with eutocia. The presence of dystocia and stillbirth increased the risk of RFM 4 and 5 times, respectively. The occurrence of RFM increased the risk of development of clinical metritis with a 22 times higher odds. The results indicate that the use of calving alert systems not only facilitates controlling the time of parturition and providing prompt and appropriate calving assistance but also decreases the number of dystocia cases and improves reproductive efficiency, postpartum health of the dam and newborn calf survival.

Ali Ismael Choukeir, Levente Kovács, Zoltán Szelényi, Luca Fruzsina Kézér, Ervin, Albert, Mohamed Kamel Abdelmegeid, Andela Baukje, Mária Aubin-Wodala, Dávid Buják, Krisztina Nagy, Ottó Szenci
https://doi.org/10.1016/j.theriogenology.2019.10.004