Reproduction efficiencies represent one area of dairy farm management that continues to challenge dairy farmers. Much time is spent evaluating reproduction performance in a herd. There are many reasons cited for why cows don’t get pregnant and many solutions are recommended to improve herd fertility. Yet the dismal fact still remains that overall, reproduction efficiencies on many dairies are poor and cost the operation a lot of money every year. Poorly performing reproduction programs on a dairy result in fewer fresh cows per year, more cull cows and fewer replacement heifers.

The single largest influence that a repro program has on the gross income of a dairy operation is the number of cows freshening into the milking herd at any given time. The more often a cow can re-enter a milking herd as a fresh cow and the total percentage of fresh cows in the herd will have a significant impact on milk produced by the herd. I would argue that reproductive efficiency in a dairy herd has the greatest long-term effect on gross revenue over any other management area of a dairy operation.

Metrics for monitoring efficiencies

Realizing that more fresh cows in a given time period will result in more revenue produced during the productive life of a cow, dairy management must focus its attention on getting cows bred. Pregnancy rates and calving intervals are two metrics for monitoring and evaluating reproductive efficiency in dairy herds. We should strive to keep pregnancy rates high and calving intervals low. At the center of attaining both of those goals is heat detection.

Without a doubt, my observations have convinced me that heat (estrous) detection is the number one factor in reducing overall reproductive efficiency in dairy herds. Too often, suitable heat detection programs are not implemented or, if they are, they are not adhered to. According to one study, as much as 60 percent of the variation in reproductive efficiency can be attributed to poor or inaccurate heat detection (Senger, ARPAS Professional Animal Scientist 17:129-138).

Heat detection (just as milking and feeding your cows) is totally under the control of dairy management. Missing a heat and a potential breeding means that the cow will not have an opportunity to be bred again for three weeks. What needs to be understood is the primary reason cows don’t get pregnant on dairies today are human management factors and not necessarily the fault of the cow or the weather. Though there will be incidents of dystocia, retained placentas and cystic ovaries that may have an effect on pregnancy rates, an aggressive herd health program both prepartum and postpartum will lower the incidence of metabolic problems that result in extended days-in-milk and calving intervals.

Photos: travenian & urbancow/istock

Don’t ignore nutrition

Naturally, a discussion on reproduction efficiencies will be tied to proper nutrition before and after calving. Adequate energy levels along with proper protein fractions, amino acid and mineral/vitamin balances will have an effect on a cow’s ability to conceive by the third month of lactation. Many dairy operations expect a cow to produce 120 or more pounds of milk per day at the peak of her lactation and at the same time conceive a pregnancy. Yes, indeed, in the pursuit of profitability we are pushing our cows to the upper limit of their genetic potential. A properly balanced feed ration goes hand-in-hand with reproductive efficiencies on our dairy farms today.

With feed costs being the single biggest expense on a dairy, it’s very tempting for a dairy farmer to trim a few dollars off of a feeding program with the hopes that it won’t adversely affect the milk production or the reproduction. At the risk of sounding too cliché, “You get what you pay for,” when it comes to ration costs. If you want the big milk and, at the same time, run a 13.5-month calving interval with an annual culling rate of less than 40 percent, you’re going to have to spend the money on proper nutrition.

Avoiding a prolonged period of negative energy balance for the fresh cow during the first two months of lactation should be a top priority for the transition cow diet. A healthy cow’s dry matter intake will usually catch up to her productive and metabolic requirements in four to five weeks into the lactation. It isn’t unusual for a cow to pull down a full body condition score or more – as much as 200 pounds of body weight – during the first weeks of lactation and it’s the dairy management’s responsibility to see that the cow is receiving adequate dietary energy levels that will in turn allow her to express a strong estrus even during the voluntary waiting period prior to breeding. An extended period of negative energy balance will first reduce milk production as the cow compensates for the lack of energy but will also delay estrus and strong heats. A cow in a negative energy balance will not conceive.

The prepartum diet will also have a large impact on follicular health. The ovarian follicle that will result in a pregnancy is formed weeks before the cow freshens. A pre-partum diet needs to focus on energy levels as well a proper cation-anion balance to avoid milk fever, retained placentas or ketosis. Any one of these metabolic problems during the transition period will have an impact on reproductive efficiency during the lactation.

Tips to improve efficiencies

Though feed costs are the number one expense on a dairy, and proper nutrition will heavily influence the milk production on the farm, if a heifer doesn’t become pregnant she will never produce milk and if a milk cow doesn’t continue to freshen once every year or so, the best nutrition program in the world will fall far short of its potential. In a dairy economy that delivers low milk prices while production expenses continue to climb, improving your reproduction management will recover a lot of potentially lost revenue. Here are some tips to improving reproductive efficiencies on your dairy:

Daily monitoring of estrus activities and a dedicated heat detection program are still the cornerstone to a successful AI program.

Keep complete and detailed records of freshening dates, heat dates and any metabolic disorders that will enable you to track a cow’s history and get her bred on time.

If dairy facilities and manpower make it difficult or impossible to monitor heats on a daily basis, work with your veterinarian to establish an Ovsynch program that will allow you to time-breed your cows.

Proper nutrition both before and after calving has a large impact on the reproductive efficiency of your herd. Work with your nutritionist or feed sales professional in implementing close-up rations and fresh cow rations that will keep metabolic problems to a minimum.

Set goals. Pregnancy rates (PR) more than 25 percent. Annual culling rates less than 40 percent. Calving intervals (CI) under 14 months. Average days open (DOPN) around 100.

Recognize that every cow and heifer on the dairy represents an investment and they need to provide you with a return on that investment.

Cover Photo: Vaida_P/istock