One Shot Closer to Better Conception Rates
by Carrie Bargren, DVM
The University of Wisconsin-Madison recently published the results of a study that found adding a second shot of PGF(Lutalyse, Estrumate, EstroPlan) to the Ovsynch protocol could increase the rate of pregnancies per artificial insemination (AI) by almost 10%. Following the regular Ovsynch 56 protocol, this second shot of PGF should be given 24 hours after the first, and unpublished data even suggests it could be given anywhere between 8 to 24 hours after. The rest of the protocol remains the same, with the GnRH following the first PGF by 56 hours and breeding her 16 hours later. The diagrams below depict the current Ovsynch 56 protocol and the modified version.
When given the second shot, cows across all lactations had a significantly better response from the corpus luteum (CL) on their ovaries. However, only cows in their second lactation or greater actually had an increase in their rate of pregnancies per AI. It might be worthwhile adding this second PGF if you’d like to improve your overall conception rate or are having a hard time getting the greater lactation cows pregnant.
The one caveat of adding this extra shot, is that it’s an extra shot to remember and get right. Studies have found that with each injection given in a synch protocol, the average compliance is usually around 95%, meaning that on average, 95% of the cows receive the correct injection. With each injection required, compliance goes down, making it even more critical for each one to be done right. For the 4 shots required of the Ovsynch 56 protocol, average compliance is around 81%: out of all breeding eligible cows, 81% receive all injections correctly. Adding the second PGF shot decreases average compliance to 77%. However, with great diligence and care, it is possible to have 100% compliance with any synch protocol. So be warned, modifying the protocol can definitely improve your rate of pregnancies per inseminations, but only if great care is taken to do it correctly.
With the hint of warmer weather on the horizon, it’s time to think about deworming protocols before turning your cattle out on pasture. For years, a variety of pour-ons have been the only option, but not too long ago a new, long-acting product hit the market: LongRange. Now this isn’t a shameless plug for the product, but it is new, currently the only one of its kind and seems to work well, so it’s time to learn more.
LongRange is an eprinomectin based anti-parasitic that has shown to be effective in controlling adult parasites and late larval stages of nine species of the most common intestinal roundworms, lungworms, grubs and mites. The selling point is that it provides 100-150 days of parasite control with only one injectable dose. In the formulation is a polymer that forms a biodegradable gel after injection under the skin. The cow’s body slowly breaks down the gel and with it releases the active drug. This long-term breakdown results in two peaks in effective plasma concentrations in the blood, one right after injection and the second about 70 days later. Both peaks ensure that the plasma concentration remains effective therapeutic levels for a long time.
Efficacy studies have been done on individual species of parasites and LongRange is labeled for the control of each from between 100 days up to 150 days, with the idea being that a single dose given when turning cattle out to pasture for the summer will last all season. To maintain control with a traditional pour-on, cattle would need to be treated a few times throughout the summer. LongRange also reduces parasite burden in pastures due to the long term control in cattle which reduces the opportunity for reintroduction of the parasite larva onto the pasture through manure.
LongRange is dosed at 1 mL/110 lbs (1 mL/50 kg) under the skin in the neck. As with any large volume of an injection, any dose over 10 mL should be given in two sites. There is a 48 day meat withhold and it is not for use in female dairy cattle over 20 months of age (including dry cows), nor can it be used in calves less than three months old. There has been no reproductive safety testing done at this time, so it cannot be used in bulls. To learn more, talk with your veterinarian at your next herd health or stop by the clinic to take a look.
The Sauk County Dairy Promoters Need You!
The Sauk County Dairy Promoters (SCDP) is a board of dairy producers and business people in the dairy industry with the combined goal of promoting the benefits and importance of dairy, both nutritionally and economically. Each year, the SCDP sells milk at the Sauk County Fair and Sauk Prairie Cow Chip, sponsors cheese trays for Super Bowl parties, donates to local food pantries for dairy product, gives presentations at Elementary schools, and much, much more. At each event they are committed to improving the consumer’s dairy knowledge and increase dairy consumption, to the benefit of all!
If you know of events that would provide excellent opportunities to promote dairy knowledge, groups in need of dairy education materials or sponsorship for dairy related events, please contact the board. Or get in contact if you would like to help with promotional events.
Most importantly, without members on the promotion board these events and the ability to reach and educate consumers becomes difficult. Four new members (three dairy farmers, spouses, or passionate, active farm help and one person in a dairy related profession) will be elected on March 22 at the annual meeting held at 7:45pm at Coach House in Rock Springs. As fellow dairy farmers and dairy business people, they know that your time is precious: meetings are only every 1-2 months at a time and location that is convenient for everyone. Here is a list of current members to contact with any questions about the Sauk County Dairy Promoters:
Angel Acker – 393-6037
Dustin Lochner – 279-6215
Angela Marinaro – 963-6185
Kailey Turner – 434-4237
Ann Zielinski – 370-3715
WMMB District 20 Director: Sharon Laubscher – 464-3316
Sauk County Dairy Ambassador: Sarah Zajicek – 370-1001