REPRODUCTIVE management and its impact on the overall success of a dairy operation are a critical component of dairy production.

Andrew Sandeen with The Pennsylvania State University Extension said the full impact of management successes or failures often won't be seen in the short term, however, as managing for reproductive efficiency requires patience and a long-term mindset.

Sandeen said there are three important considerations for producers to get into this long-term mindset on reproductive management: (1) genetic progress, (2) future production and (3) efficiency.

Also, he said to keep in mind that reproductive management overlaps with many other management areas, adding, "There are close relationships with heifer management, milk production, feed management and herd health."

Genetic progress. Why would a dairy producer NOT want to make genetic progress in the herd? Sandeen said the specific improvements a producer is aiming for may be up for debate, but it only makes sense to aim high.

"Whether through intentional selection of good sires or using more advanced technologies with embryos and/or genomic testing, there is plenty of opportunity to make progress," he said.

Many dairy operations around the country still use natural service, to some extent, for breeding purposes. Though there are a number of risks to having breeding bulls around, Sandeen said a dairy owner has the right to decide whether or not to use them.

However, he noted, "with a long-term mindset, how much might you be selling yourself short? Where is that bull from, and what steps have been taken to make sure he is actually going to benefit the operation? Are the benefits truly outweighing the risks?"

Sandeen said it might be worth examining current versus potential genetic progress in the herd, including factors such as inbreeding.

"There may be reasonable justifications for using a particular natural service bull in the herd, but it's worth making a concerted effort to avoid the 'duds' and any complications they might bring to the operation," he explained.

Future production. Achieving timely conception certainly has an impact on milk production. According to Sandeen, it also affects the rate of calves being born to use as replacements or to merchandise for additional income.

"This doesn't just pertain to lactating cows," he added. "A significant segment of the herd that often receives less attention is the young stock, both pre- and post-breeding. These heifers are the future of the dairy herd," Sandeen emphasized.

He said Penn State recommends breeding Holstein heifers when they are 13-15 months of age, weigh 750-800 lb. (or 55% of mature bodyweight) and measure 48-50 in. at the withers. Accomplishing that, they should be nearing 1,300 lb. (or 85% of mature bodyweight) by 23-24 months of age and have already delivered a calf.

If heifers are calving later than 23 months of age, Sandeen said there is no benefit to milk production — just the added costs of caring for the animals longer. In today's economy, it is not often profitable to have an average age at first calving of 25-plus months, Sandeen explained.

Efficiency. Many different strategies can be used to achieve timely first insemination postpartum, according to Sandeen. A strategy can be chosen that works well within the operation's unique conditions, taking into account factors such as labor, equipment and drug costs.

However, he pointed out, "what about those cows that fail to conceive after the first service? There needs to be a strategy for pregnancy diagnosis and subsequent insemination that minimizes the length of time cows are open."

Even in herds that are achieving really good conception rates, having a good rebreeding strategy is important, Sandeen said, adding that it might be the difference between having an average of 125 days open (good) or 160 days (not so good).

Several options are available for diagnosing pregnancy around 28 days. "Having this early information helps manage for rebreeding, but there is a frustrating factor to realize," he said.

On average, 10-15% of pregnancies in dairy cows are lost between days 17 and 42. This means that a small but significant percentage of cows diagnosed as pregnant on day 28 will later turn up open, Sandeen said.

"Diagnosing pregnancy at a later stage of pregnancy will avoid the frustration of noticing lost pregnancies after early diagnosis but might hinder the goal of reducing the time window between inseminations," he explained.

Regardless of the approach to rebreeding, heat detection can be helpful. Sandeen said there is no need to wait until a synchronization protocol has been completed before rebreeding a cow: If she is exhibiting standing behavior and seems to be cycling normally, she can be bred.

"If workers on a dairy, regardless of their official role, are on the watch for cows in estrus, these small efforts can go a long way," he said.

There are many benefits to implementing proven strategies for reproductive management.

"Just remember to be patient and think about the long-term picture," Sandeen said. "You're in a position today to make decisions that can benefit you well into the future, even though you might not see all of the benefits immediately."

'Brown gold'

In the heart of Wisconsin, a project is underway to produce energy from a resource that's in little danger of running low: cow manure, also known as "brown gold."

Although some manure can be used as fertilizer, nutrient imbalances and pollution caused by manure runoff can create environmental problems. Large dairies produce up to 25 tons of manure each day that require millions of gallons of water to manage.

Thanks to a $7 million grant from the U.S. Department of Agriculture's Biomass Research & Development Initiative, researchers from the University of Wisconsin-Madison have partnered with several Wisconsin companies to form a consortium that is piloting new methods for turning dairy farm manure into useful products.

The consortium's first major undertaking, the Accelerated Renewable Energy (ARE) Project, has already been implemented at Maple Leaf Dairy in Manitowoc County, Wis. Home to 5,000 cows, the dairy is helping the Madison researchers study manure processing techniques and technologies that could also benefit other Wisconsin dairies.

ARE co-investigator and biological systems engineering assistant professor Troy Runge said the project presents an opportunity to support a renewable energy economy while developing value-added products from biomass.

Runge's lab, housed within the university's Wisconsin Energy Institute, analyzes separation techniques to improve efficiency and economic performance. As part of the project, researchers have assessed a variety of manure separation systems, and they've found that even simple, low-cost systems can recycle the water involved in processing manure and help manage nutrients.

"This is a great example of a multidisciplinary, public/private partnership happening right here at the Wisconsin Energy Institute," Runge said. "It's also an example of a project that is important to Wisconsin."

After small plant fibers in the manure are separated out and anaerobically digested to create biogas, liquids from the digestion process are used to fertilize crops, while leftover solids are converted into useful chemicals and bioplastics. The larger plant fibers can be used for animal bedding and mulch or as a starting material for ethanol fermentation.

Runge works closely with Aicardo Roa-Espinosa, president of SoilNet LLC and a biological systems engineering adjunct faculty member. Roa-Espinosa developed the technology behind the manure separation system that drives the ARE project. Together, Runge and Roa-Espinosa monitor the quality, quantity and composition of biogas produced from fermented manure from Maple Leaf.

These separation systems have the potential to help farmers better manage manure and to use it in ways that benefit soils, the environment and human health.

For example, the project's new approach to manure separation also yields fertilizer that is more concentrated and homogenized, allowing farmers to apply it with much greater precision and control over nutrient content. This method not only improves crop fertilization and limits pollution, but it also recycles water.

The cellulosic (non-food) plant biomass derived from the dairy manure additionally means that dairies could eventually become cellulosic biorefineries.

"This is a triple-win situation," said project collaborator Tom Cox, a professor of agricultural economics in the College of Agriculture & Life Sciences. "We would like to make money by doing the right thing by the environment and society."

Volume:87 Issue:10