Insemination of Cows during Transition and Metabolic Stress
Putting back to day 120 the insemination of cows in metabolic stress: an idea to validate for the health and profitability of the herdsMarc-André Sirard
- One of the recurring problems with dairy cattle diet is the marked increase in energy needs during lactation. High-producing cows are simply unable to ingest all of the energy necessary for production.
- Despite increases in food quality, dietary efficiency must also be examined as a function of physiology to minimize the consequences of this weight loss.
- Cows with a BHB blood level (ketones in the blood) of more than 1.2 mM/L are subject to acetonemia.
- Our cows’ productivity level is still on the rise with an average surpassing 9,000kg for Holstein cows and attaining more than 10,500 kg to reach the 90th percentile.
- These production levels are certainly a feat, but they also represent a risk. The biological barrier begins to makes its presence felt since, in high producers, dairy production is sometimes associated with reduced fertility.
- How can we enhance fertility without affecting productivity or, conversely, how can we maintain or even increase productivity without affecting fertility?
- The solution potentially resides in gaining a better understanding of the impacts of higher levels of production on the reproductive system.
- It is reasonable to believe that delaying insemination from day 60 to day 120 post-partum, depending on the cow’s metabolic rate, will allow for energy balance to return and lead to an increase in fertility, as well as longevity, without economically penalizing the dairy farmer.
- In addition, this delay will allow for the production of a more productive and fertile replacement heifer.
Thanks to economic and epigenomic analysis, the objective is to provide farmers with the tools needed to determine the energy state of lactating cows, as well as the economic and biological benefits and disadvantages of delaying the insemination of cows with a BHB blood level greater than 1.2 mM/L.
Results and potential benefits
- For the epigenetic portion of the project, it is possible that the embryos will be different between days 60 and 120, particularly for cows with a high BHB level. This distinction will allow us to choose markers associated with the metabolic status. Because the markers identified on the embryos will also be measured on post-natal tissues in order to identify the metabolic programming indicators, these markers will be validated on hundreds of individuals in order to obtain the strength necessary to develop a diagnostic tool.
- These indicators could be used for a range of purposes, including herd monitoring to choose the heifers to be retained and in conjunction with a tool for Boviteq to modulate the relative value of embryos and animals produced according to the mother’s production. These tools are essential to the development of factual management practices, based on measurements taken at birth (biomarkers) and in milk (BHB), and quickly adopted by farmers.
- For the economic portion of the project, a modification in the time of reproduction may have negative economic impacts on the current and future lactation of cows. There is a potential to save money if we are successful in identifying cows using the tool. The tool, which will be developed as part of this project, will then be made available to potential users with the goal of guiding farmers.
- The results of the project will therefore provide a new rating system that can be integrated in the service offer available to farmers by their centre of expertise (Valacta). In addition, the analysis completed as part of this project will allow us to obtain conclusive data for the next step of the project, which would involve a large-scale validation in collaboration with Valacta and their database.
In accordance with the program objective of developing scientific and technological skills, this proposal will allow for the training of a doctoral student in genomics and a master’s student specializing in the technico-economic management of dairy farms. Both will be enrolled in the Department of Animal Sciences at Université Laval.
Partnership for innovation in dairy production and dairy processing (EPI 2015-2019):
- Fonds de recherche du Québec – Nature et technologies
- Consortium de recherche et innovation en bioprocédés industriels au Québec