“Having a successful repro program is critical to the economic success of your dairy,” remarked CNY Regional Dairy Specialist Dave Balbian. “We all know that ‘Getting Cows Pregnant Puts Money in Your Pocket.’”
Balbian was speaking to attendees at 2017 CCE Central New York Dairy Day, which took place at the Otesaga Resort Hotel in Cooperstown, and featured speakers Dr. Julio Giordano, known for his expertise in Dairy Reproduction; and PRODAIRY Director Dr. Thomas Overton.
Balbian said generally — considering all factors — lowering average days in milk (DIM) from 200 to 150, equals an increase of about 10 lb., per cow, per day, just from having a fresher herd. “This is real money. It may not seem like a lot, but it’s income you never receive because its milk not going out the door,” Balbian emphasized.
In an animated and interactive presentation, Giordano educated attendees on the basics of dairy reproduction before advancing to new research results.
He stressed the importance of understanding the link between the cow’s reproductive organs and her brain when she is receiving treatments to increase synchronization of her estrous cycle.
“We start with a complicated picture,” Giordano said, pointing out the hypothalamic- pituitary- ovarian axis on a diagram presented in a power point. “I just want you to think about the fact that there are parts of the brain that are very important to control reproduction, and then we have the uterus and the ovaries that are the other very important organs that control reproduction. We have messages going back and forth between the brain of the cow and her uterus and ovaries. That’s what helps to control things and keep them going.”
Giordano explained the hormones are produced by activity in the brain, which impact follicle production and release. “The follicle is the one responsible for estradiol production. Once a follicle ovulates and becomes a CL (corpus luteum), the CL produces progesterone. It’s very simple. No progesterone; no pregnancy.”
The hypothalamus is either stimulated by circulating estrogen to produce a gonadotropin-releasing hormone (GnRH), or is stimulated by progesterone to stop production of GnRH.
GnRH, which is what is found in synchronization products, controls the release of luteinizing hormone (LH). “When you’re giving GnRH to a cow, you’re making that cow ovulate. It goes very fast.”
Giordano said the cow will ovulate within about 28 hours after an injection of GnRH. “The timing of this event is very important.”
The greatest detriment to this function is the level of progesterone in the cow, hence if the cow is producing a high level of progesterone, she will be less likely to ovulate. Therefore she needs to be in a specific stage of the estrous cycle to maximize fertility of the timed A.I. (TAI) breeding.
“Remember, high progesterone; lower ovulation rate.”
The hormone prostaglandin, available in natural or synthetic forms, may be introduced to cause the demise of a stubborn CL, which hold up the cow’s natural cycle. Sometimes, this is all it takes to restore the normal cycle.
The “normal” estrous cycle is usually about 21 days long, but may range from 17 to 24 days. A cycle consists of a luteal phase (day 1-17) under the influence of progesterone, followed by a follicular phase (day 18-21) under the influence of estrogen. The cycle begins with standing heat/estrus. Peak estrogen secretion may last 6 – 24 hours, with ovulation usually 24 – 32 hours after estrus begins.
Giordano emphasizes that timing is critical!
“Always prioritize your timing!”
The timing in which you give the GnRH in relationship to the release of prostaglandin and the timing in which you give the GnRH in relationship to breeding, is critical to the success of the breeding program.
“We’re catching our cows way too late.”
Each cow should be assessed individually, as research has shown that a “blanket approach” does not work in this case.
In his second presentation, Giordano acknowledged there are alternative programs to getting dairy cows pregnant. “You guys are very diverse in your preferences and your resources.”
Research and experiments show that the same results are obtainable through different approaches.
“You’ve got to use the program that better suits your needs.”
Two main routes include the ones that use more heat detection, using timed A.I. (TAI) as a safety net for cows that go undetected, or a more planned, systematic approach using intensive TAI.
Giordano reported that, unfortunately, too many cows simply go undetected. “The methods that we use for heat detection are not perfect!”
This of course, equals more time and money lost to the farm.
“Any successful repro program has three main components,” Giordano explained, “be proactive, systematic, and consistent. Attention to detail is very critical, too. The big difference between the farms that got 25 percent preg rate and 35 percent preg rate is attention to detail! Attention to a lot of small details will take you to the next level.”
Synchronization products and reproduction programs were discussed. The importance of timing was emphasized repeatedly. Delaying days in milk (DIM) can cause the cow’s reproductive system to become nearly dormant. These cows need a jumpstart.
“You have cows going too long! You have a lot of cows that are bred too late. Not good!”
Research is showing for presynchronization of the estrus cycle, most cows should be bred on a 10 d/12d schedule as opposed to the 14d/14d schedule many farms use for convenience.
Delayed breeding and low service rate compounded together equal failure in your reproduction program.
Combined strategies work for many farms. Any program that works for the farm and is proven through cow fertility will provide the farm with higher profitability.
“These things are complex,” Giordano affirmed. “The only things you can do, is speed things up and promote heat expression.”
If you have a superior heat detection method, you may not need to go to the TAI. On the other hand, you may want to go to a synchronization program, using a synchronization product. “Go from no intervention to more intervention.”
Research shows about 20 percent of cows could benefit from synchronization programs.
Giordano encouraged attendees to use technology.
“The use of technology is absolutely critical! I would encourage you to at least think about it and think about the benefits of technology — any technology that can help you to run a repro program that will be successful.”
Farm conditions are also critical to a successful reproduction program.
“High productivity, excellent health, and excellent reproduction are compatible at the farm level,” Dr. Thomas Overton reminded attendees.
The right footing, the right flooring, nutritional management, routine scheduling; all factors concerning the cow being at ease and able to respond to hormones and treatments more receptively; this all contributes to her attitude and reproductivity.
Overton focused on the issue of nutrition and its impact on reproductivity in the dairy cow. Through study results, he showed how energy levels in transition cows, both postpartum and prepartum, critically impact uterine health and subsequent fertility.
“Excellent feeding management of diets during the dry and transition periods is critical for overall success,” he said.
Even particle size of straw and hay in dry cow rations can affect cows, as many will not eat what is too long for their consumption.
Calcium status impacts uterine health during the postpartum period.
“Trace elements, especially chromium, appears to have positive effects on subclinical endometritis and may affect subsequent fertility.”
Overton emphasized the opportunity of profiting by minimizing subclinical disease.
Studies of added chromium in the cow’s diet show an impact of positive milk yield and an uptick in immune systems. “There may be some opportunity there.”
Overton remarked most producers look for one nutritional tweak that will elicit positive changes. However, research shows that many little things combined make the difference.
“Whenever I ask producers if it is worth it to go after the extra milk and better reproductive performance, their answer is yes.”
Go to prodairy.cals.cornell.edu for more information.