Decades of research and production have proven reproduction and nutrition in the dairy cow are absolutely connected. There is no silver bullet and no management program that will offset the effects of compromised nutrition on dairy cow reproductive performance.

There have been countless dollars spent and reports written on this relationship, so this discussion is not new. This article is designed to act as a checklist of nutritional components to keep in place to promote the best breeding performance possible.

Remember: Good nutrition = Good health = Good reproduction. Granted, a great nutrition or health program will not overcome marginal management and vice versa. Everything is tied together. As the old saying goes, a chain is only as strong as its weakest link.

Do sweat the small stuff. Every nutrient counts, and keeping everything in balance is critical. While there are many nutritional concepts we are still working to understand (amino acid, fatty acid balances), make sure all the basics are covered. Reproduction is particularly susceptible to the concept of first limiting nutrient.

Reproductive performance starts well before freshening and even before the transition period. Often, late-lactation cows may be taken for granted, particularly if milk prices are low and the focus is on saving money. Ensuring proper body condition by dry-off can simplify achieving correct body condition scores in early lactation leading up to rebreeding.

Take practical steps to reduce stress in the animal prior and up to the breeding period. Stress caused by heat, cold, overcrowding, bedding/comfort, nutritional, handling and health challenges all act to depress nutrient availability that can be used for reproduction.

In addition to a strong nutrition program (well-formulated diets), a good feeding management program is just as important. For dairies feeding a TMR, use of quality ingredients that are well mixed, delivered in a consistent, timely fashion and evenly distributed is critical for optimal dry matter intake. For dairies not using a TMR, feeding hay, feeding in the barn, outside or some combination for consistent feed and forage availability should receive proper attention.

A proper blend of fats and fatty acids have been shown to enhance reproductive performance in lactating dairy cows (as well as production and component performance). As mentioned, this is still an area requiring considerable study; numerous trials have shown a response to the correct balance of essential fatty acids. Protected forms of omega-3 and omega-6 fats may be beneficial.

Amino acid balance is increasingly shown to be beneficial to overall reproductive success. One recent University of Wisconsin study showed cows supplemented with a protected methionine source saw reduced incidences of early embryonic loss in lactating dairy cows. Maintenance of pregnancy is obviously as important as conception rates.

Energy balance during early lactation is critical to good reproductive performance. Cows that lose significant amounts of weight post-freshening will exhibit delays in first ovulations. It is important adequate energy intake be established as soon after calving as possible. This is a factor of a good transition program and diet as well as a good post-fresh program and diet. The highest-quality (and palatable) forage should be used at this point to promote optimal dry matter intake and build intake in the days and weeks post-calving and leading up to breeding.

Protein balance and components are important to reproduction as well as milk production. Over-feeding protein (some studies have shown excesses of 17 to 20 percent in ration dry matter) can depress conceptions and concurrently increase services per conception and time to rebreeding.

When high levels of degradable protein, coupled with a deficiency of energy, are fed, the excessive ammonia not taken up into microbial protein is absorbed into the bloodstream. This excess ammonia and urea in the bloodstream may reduce fertility at the same time energy is diverted away from milk production or reproduction. Some studies have indicated blood urea nitrogen above 20 milligrams per 100 milliliters (or even somewhat lower values) may decrease the chances of pregnancy.

Minerals (macro- and trace minerals) and vitamins (A, D, E) are all critical to the metabolic functions related to reproduction. While these nutrients are always important for production, health and reproductive performance, during the period from freshening up to rebreeding, mineral and vitamin availability is particularly critical.

Use of highly available sources (maximizing absorption) is helpful to ensure status in the animal as well as preventing over-formulation that can create other problems, including antagonisms of one mineral due to high levels of another.

Strategic use of yeasts, mannan-oligosaccharides/beta glucans, bacteria, fungi or enzyme sources individually or in a well-planned combination are useful to improve rumen and digestive tract performance during these early high-stress periods.

Some products are useful in modulating rumen performance; others protect the gut from pathogen activity; some can enhance nutrient digestibility. There are many of these products available, and each will contribute a cost, so careful screening is very important. Some products will provide more than one benefit, so look for those that will provide the greatest economic advantage.

Each dairy is different, but a common denominator is the importance of use of the best nutritional program possible, promoting good reproductive performance as well as cow health. Reproduction is a core component to efficient production and overall dairy operation. Keeping the previously mentioned steps in mind can help promote an effective breeding and reproduction program.  

Dr. Steve Blezinger is a management and nutritional consultant with an office in Sulphur Springs, Texas. You can email Dr. Steve Blezinger or call (903) 352-3475.

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