The transition period is one of the most stressful times in the life of a dairy cow. After calving, a metabolic shift occurs as lactation begins and the cow enters a negative energy balance. A dairy cow in transition has 60 to 70 days to successfully repair damage to the reproductive tract caused by calving and be ready to get pregnant again. During this time, a dramatic shift occurs in the epithelial tissue of the reproductive tract. This epithelial tissue covers all exterior and interior surfaces of the body and serves as the first line of defense against immune challenges. Sound epithelial tissue is critical to reproductive success and must be repaired efficiently post-calving.

It is critical for dairy cows to mount an effective immune response to eliminate reproductive tract pathogens that enter during the birthing process and to repair damaged tissues. This helps prepare the animal for subsequent pregnancies.

If this remodeling process happens in a robust manner and the inflammation quickly goes away, this is an acute inflammatory response and is a good thing. And studies show that performance trace minerals are important for a robust immune response. Performance trace minerals are a specific category of organic trace minerals that include a complex trace mineral bonded to an essential amino acid, resulting in a mineral that is soluble, stable, absorbable and metabolizable.

These particular trace minerals keep this response moving along and returning the cow’s reproduction tissue to normal. However, if the process of moving through the inflammation processes is slowed down or prolonged, the cow may experience chronic inflammation, which is energetically expensive and negatively impacts milk production and her ability to get pregnant efficiently.

Inflammation needs to be at the top of every dairy producer’s list of concerns because if not managed properly, it can be costly to your dairy operation. If post-calving inflammation persists and becomes chronic, you will either need to spend money treating it, or your earning potential will drop as a result of reduced production.

Chronic inflammation implications

Preventing chronic inflammation is important as it can consume a large amount of nutrients, and it can also cause an animal to struggle to hold a pregnancy or even get pregnant. This happens because nutrient partitioning of the animal is compromised by the ongoing inflammation.

For example, research by Lance Baumgard at Iowa State University shows that an animal undergoing an inflammatory response can easily lose more than 1 kilogram of energy (glucose) to the immune system in a day. This means nutrients, energy and trace minerals are diverted from nonessential functions like milk production, reproduction and fetus growth in order to fuel the continued inflammatory response.

Trace minerals matter in cow reproduction

A study investigating how to maximize reproductive efficiency throughout the lifecycle of the cow was conducted by James Ferguson at the University of Pennsylvania. The study assigned 156 pregnant Holstein cows into two blocks; one using a daily supplementation of inorganic trace minerals, and the other replacing a portion of the inorganic trace minerals with performance trace minerals (zinc, copper, manganese and cobalt). Diets were fed from 60 days before the projected calving date through 250 days post-calving.

The study showed partial replacement of the standard inorganic diet with performance trace minerals helped improve cow fertility:

• Cows fed the performance trace minerals had fewer open days (138 versus 146 days) than cows fed the inorganic trace mineral diet.
  
  
• Cows on the performance trace mineral diet had fewer days to first ovulation (34 versus 37 days) than cows fed the inorganic diet.
  
  
• More cows (90.2%) fed the performance trace minerals became pregnant during the study than cows fed the inorganic trace mineral diet (83.3%).
  
  
• Cows fed performance trace minerals that also experienced a transition disorder in the study went on to achieve higher pregnancy rates than cows fed the inorganic trace mineral diet. Performance trace minerals provided an “insurance policy” to achieve a higher pregnancy rate in the presence of a transition challenge.

Mitigate negative impacts of inflammation

Optimum, balanced nutrition including performance trace minerals, especially zinc, manganese and copper, is important for the development of a robust immune system and reproduction of dairy cows. Zinc is especially important for reproductive tract maintenance and repair after calving.

However, as in all aspects of livestock production, it’s not just one thing but a combination of practices that will give you the best outcomes for managing inflammation and improving reproduction success.

Here are a few best practices to consider:

• Choose a dairy cow diet that is appropriate for where the animal is in its lactation or lifecycle for improved performance throughout its life.
  
  
• Involve your veterinarian in decisions to manage inflammation in your herd including prevention, as well as treatment of chronic inflammation.
  
  
• Be thoughtful about your pre-calving management process – the transition process as you move animals from pen to pen, the housing you’re using and even the types of bedding or flooring being used. If you are unsure, consult with an expert.
  
  
• Have people accessible who know how to properly manage the stress of animals during the birthing process.

Getting a dairy cow pregnant in a timely manner post-calving is of the utmost importance, and it all starts with the remodeling of the reproductive tract. Managing inflammation is the key to this process. Feeding performance trace minerals as a part of your dairy cow nutrition program can ensure a dairy cow has enough nutrients to fuel her maintenance needs and have enough left over to support her next pregnancy.  

Adam Geiger is a Research nutritionist with Dairy Zinpro Corporation. Email Adam Geiger.