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Archive for the ‘Research’ Category

Craig Roerick, University of Minnesota Dairy Extension

Reproduction on a dairy farm can be a challenge for producers even with the best of practices. There are numerous factors that affect reproductive efficiency including heat detection rate, semen quality, AI technique, nutrition, low fertility, cow health, labor, and other dairy management practices. Many producers have found that synchronization programs have greatly improved their reproduction success. With constant evolving research, synchronization programs are constantly becoming more successful with the fine tuning of protocols for using them. But with this evolution of synchronization programs, how do producers know which one is right for their own operation?

Each dairy farm is different in regards to how and why they want to implement synchronization programs. Factors can include labor management, facilities, and the goals for a specific synchronization program. Some of the deciding factors that can play a role are how the program lays out on a calendar week and the cost.

There are number of different synchronization programs that producers can use to get more cows pregnant, but with any of the programs, they count on the standard Ovsynch as the final series of injections followed with a timed breeding. As with any management practice or technology, the different variations of synchronization programs can work for the better or worse for different producers. The table that accompanies this article shows the differences of some of the major synchronization programs and may help you make an informed decision about what program is right for your farm.

Another challenge with any synchronization program for the dairy producer is that they are designed to get more pregnancies at first service. But, making sure that the open cows are found as soon as possible and either put onto a resynch program or bred on standing heat will only help you reach your reproduction goals. There have been several programs that have worked well when trying to minimize the amount of labor as well as compliment the synch program used for first service animals. Here are three options for a resynch program:

  • All cows are given a GnRH injection 7 days before pregnancy check, approximately 32 days post breeding.
  • Pregnancy exam approximately 39 to 40 days post breeding, with non-pregnant cows given a PGF2α.
  • 48 hours GnRH injection administered. Timed artificial insemination up to 24 hours after 2nd GnRH

Looking at all of the synchronization programs that are available for dairy producers to use can be overwhelming. However, if one looks at several basic principles with shot programs, it can help make the programs easier to comprehend so the best decision can be made for the dairy operation. There are a couple of items to remember when deciding to implement or change to a different synchronization program. By following the predetermined protocol, it is going to greatly improve the chances of success. Make sure the correct animal is identified, the correct hormone, dosage and gauge of needle is used, and the timing is accurate. Paying attention to these details will allow the synchronization programs to work the way they were designed. Also, understand and recognize that a synchronization program does not replace the need to identify standing heat.

The reproductive status of the dairy herd has a large impact on the operation’s productivity and profitability. If your farm is looking to obtain a high pregnancy rate, a synchronization program that fits your dairy operation, accompanied with good heat detection, can greatly improve reproductive success.

Caution: Use of the reproductive products in a synchronization program must be done under the direction of a veterinarian since they are prescription products and used in an “extra-label fashion”.

Comparison of Most Common Synchronization Programs.
Synchronization program Injections required No. times must catch the animal Average conception
Fits a 5-day work week calendar? Notes
Ovsynch 3
(2 GnRH,
1 PGF2α)
4 30 – 35 yes
Presynch 5
(3 PGF2α,
2 GnRH)
6 40 yes Uses 2 of the PGF2α as therapeutic treatment along with presynchronizing the cows. Used on 1st service cows.
Cosynch 3
(2 GnRH,
1 PGF2α)
3 slightly less than Ovsynch yes
(4 GnRH,
2 PGF2α)
7 45 – 49 yes,
with some planning
Uses 2 GnRH and 1 PGF2α as therapeutic treatment along with presynchronizing the cows. Used on 1st service cows.
CIDR Synchronization none none, but extra steps needed approx. 40% yes,
with the Ovsynch and Cosynch protocol
Delivers higher level of progesterone to blood stream, which most often causes stronger signs of estrus when CIDR is removed. Can be used with Ovsynch and Cosynch programs. Added cost with the CIDR insert. Most often used in dairy heifers with timed A.I. but also being used extensively in dairy cows.

by Hugh Chester-Jones and Neil Broadwater, University of Minnesota

Recently, a team of producers, contract growers, consultants and industry representatives across the United States, who are members of the National Dairy Calf and Heifer Association** (DCHA), developed guidelines termed as “Gold Standards” for Holstein calves and heifers outlining categories of production and performance expectations. Further standards for other dairy breeds and crossbreds will be developed in the near future. The following are selected examples of health, growth and key housing standards:

Birth to six months

Mortality rates

The age of 24 hours shall be used to distinguish between “dead-on-arrival” (stillbirth) and “calf mortality.” Targets:

  • 24 hours to 60 days: 4% 
  • 61 to 120 days: 2%
  • 121 to 180 days: <1%


Defining scours as a case of diarrhea, which requires any intervention for more than 24 hours. Targets:

  • 24 hours to 60 days of age: <10%
  • 61 to 120 days: <5%
  • 121 to 180 days: 0%

Defining pneumonia as a case of respiratory disease, which requires individual animal treatment with an antibiotic (not use of feed-grade medication). Targets:

  • 24 hours to 60 days: <5%
  • 61 to 120 days: <10%
  • 121 to 180 days: <1%

Growth rate


  • 24 hours to 60 days: double birth weight
  • 61 to 180 days: 2 lb. ADG

Colostrum management

First feeding: 4 quarts within first hour of life.

  • Quality: colostrum free of blood, debris and mastitis. Test for quality with a colostrum tester or IgG meter.
  • Target bacteria count: < 100,000 CFU/mL
  • Target immunity level: 90% of animals at 2 to 5 days of age with blood serum total protein of ≥5.2 g/dL for maternal-source-colostrum-fed calves; ≥4.7 g/dL for purchased-colostrum-replacer-fed calves or serum IgG of ≥10.0 g/L.

Housing standard targets

All calves must have clean and dry pens, draft-free, good air quality.

  • Calves 24 hours to 60 days of age: sized so calf can turn around
  • Calves 61 to 120 days of age: minimum of 34 sq. ft./animal of resting space. Adequate feeding space for all animals to eat at the same time.
  • Calves 121 to 180 days of age include the above and a minimum of 40 sq. ft./animal of resting space.

Six months to freshening


Total death loss from all conditions, but primarily pneumonia.

  • 6 to 12 months: <1%
  • 12 months to freshening: <0.5%


  • 6 to 12 months: <4%
  • 12 months to freshening: <2%

Growth rate

Target growth rate: 1.7 to 2.0 lb. ADG. Perform weigh checks routinely, ideally at least every three months.

By 13 to 15 months of age (breeding) achieve:

  • Weight of 825 to 900 lb.
  • Hip height of >50″
  • Wither height of >48″

Target weight immediately pre-calving: 1350 lb. (or 85% of the weight of full-term, pregnant, mature cows in herd).

Target body condition score at freshening: 3.5 (on a 5-point scale).


Target feeding space:

  • 6 to 12 months: 18″/hd
  • 12 to 18 months: 20″/hd
  • 18 months to freshening: 24″/hd
  • 3 weeks prior to freshening: 30″/hd

Target resting space:

  • 6 to 12 months: 45 sq. ft./hd or 1 freestall/animal
  • 12 to 18 months: 50 sq. ft./hd or 1 freestall/animal
  • 18 months to 2 to 4 weeks pre-freshening: 60 sq. ft./hd or 1 freestall per animal
  • 2 to 4 weeks pre-freshening: 100 sq. ft. or 1 freestall/animal

Target freestall space:

  • 6 to 9 months: 30″ x 54″
  • 9 to 12 months: 34″ x 60″
  • 12 to 18 months: 36″ x 69″
  • 18 months to 2 to 4 weeks pre-freshening: 40″ x 84″
  • 2 to 4 weeks pre-freshening: 43″ x 96″

Vaccination and parasite control

Work with a veterinarian, and, in custom-rearing facilities, dairy owners, to develop a vaccination protocol appropriate to the disease challenges of your operation.

At the Southern Research and Outreach Center in Waseca, we have been contract raising commercial calves from 2 to 4 days to 6 months of age for over 7 years. The above target guidelines are attainable for growth rates. There are still challenges to achieve the expectations in initial immunity level and morbidity (scours only) prior to 60 days of age but we are working with the dairies to continually improve in this area.

More details on these standards can be found on the DCHA web site. Click on ‘DCHA Learning Center’. Take these standards, make copies or post in your calf raising facility as an everyday reminder of management goals you can obtain to benefit you and your future dairy herd.

**Rewritten with permission of DCHA, and Pfizer Animal Health is acknowledged as the project sponsor.

By Jim Paulson, Extension Dairy Educator

I recently attended an American Dairy Science Association Discovery conference titled: “Sustainability in the Dairy Industry”. It was one of the most interesting conferences I have ever attended. It generated a lot of discussion on many aspects of the dairy industry and on the definition of sustainability over all. Truly, sustainability is a “wicked problem”. Sustainability itself is not wicked nor is it a problem. Defining it is. Wicked in this case is not evil but more of a difficult, contradictory and complex problem. The definition of sustainability and the solutions to the problems we are facing are not black and white. The problem and solutions also change over time, whether decades or centuries.

Sustainability has to address three key areas: people, the planet, and profitability. Without a doubt, profitability continues to be the main focus in the dairy industry today. A milk price below cost of production cannot be sustained indefinitely. Clearly, we have seen increasing price volatility (Figure 1) over the last decade and an unprecedented length of the downturn over the past two years. Many are not able to withstand this over long periods. While this downturn affects many producers, it may not affect the supply or price of milk to the consumer. It may, however, have a profound effect on the structure of the industry. Therein lays the problem: who decides what the dairy industry should look like?


Animal abuse issues have been in the news in recent weeks, giving the dairy industry more to deal with. Those who saw the videos would agree that there is no excuse for those involved in the mistreatment of the dairy animals. The farm responded with the firing of the employee, and the employee was arrested and facing animal cruelty charges. But animal abuse is not animal welfare. Animal abuse is black and white, while animal welfare and the sustainability of our systems is becoming a consumer perception issue. It is a people issue as well as potentially affecting profitability. Dairy cattle welfare is moving beyond just science and profit to how dairy cows should be treated and raised. We as an industry need to justify why we do the things we do. It is no longer enough to say, “because it makes us more money.” What does the consumer in the grocery store consider an acceptable quality of life for a dairy cow?

Does size equate with efficiency? Economy of size has been stated as the reason that dairy farms have grown in size and moved west. It depends on cost of production per cwt of milk. What were the driving factors and will they be true in the future? Does it now become a planet issue? We have Concentrated Animal Feeding Operations (CAFOs) and issues of nutrient concentration in small areas with manure storage and handling. This can lead to air quality problems such as dust, smell, and more greenhouse gases. The counter argument asks if it is more per gallon of milk produced. Who determines priority of water use, land use, and feed supply? Again, who will decide what the dairy industry should look like? A comparison can be made to the oil catastrophe in the Gulf of Mexico. While we need the oil, no one considers the pollution acceptable and the petroleum company involved is responsible for the problem, the solution, and the cost.

Let’s take this to the farm level. A current industry hot topic is the coming somatic cell count (SCC) regulations. This is clearly a profit issue. An overall plan that reduces SCC will increase profits. First, research clearly shows that cows with elevated SCC produce less milk— up to 4 pounds per cow per day. Also, with lower SCC milk the producer receives a price incentive. Depending on the level of SCC, this could mean receiving up to $.50 per cwt or more for every pound in the bulk tank. In a herd of 100 cows averaging 20,000 pounds per cow per year, this would equate to an additional $10,000. No matter what the current SCC level is, one starting goal would be to cut it in half. If a dairy does not lower the SCC level below 400,000, they may not be able to find processors to buy their milk; thus, the business would not be sustainable.

Sustainability has to consider many things. A business has to make a profit most of the time in order to be viable. This requires an equitable pricing system and efficiency of production at a competitive cost of production. It requires caring for the animals in a way that is scientifically validated while doing it in a way that is also socially acceptable. We also have to be stewards of our land, water, and air around us. Legislation and regulations will continue to be added until society accepts what we do.