Newsletter – 2021 – April

Effects of metritis treatment strategies on health, behavior, reproductive, and productive responses of Holstein cows
V.R. Merenda, D. Lezier, A. Odetti, C.C. Figueiredo, C.A. Risco, R.S. Bisinotto, and R.C. Chebel

Metritis is a uterine disease that affects 20 to 40% of cows in the United States and is characterized by a fetid, watery, reddish-brownish vaginal discharge. In some cases, these symptoms are accompanied by fever, dullness, anorexia, and dehydration, which characterizes a case of puerperal metritis. Cows that present metritis are more likely to have impaired reproductive performance and are at greater risk for culling. It is not clear, however, what are the effects of specific treatments for metritis on health, reproduction, and milk production. The authors’ objectives in this study were to compare the effects of treatments with ceftiofur and ampicillin on uterine health, behavior, reproduction, and milk production.

Materials and methods

• The study was conducted in 2 Florida commercial dairy herds.
• Herds averaged approximately 2,400 lactating cows and had a rolling herd average of 11,191 kg (24,672 pounds)/cow.
• The study included 718 cows.
• Cows were evaluated for presence of metritis/puerperal metritis at 4, 6, 8, 10, and 12 days in milk (DIM).
• Cows diagnosed with metritis or puerperal metritis received 1 of 2 treatments:
  • Ampicillin – ampicillin trihydrate (11 mg/kg) once a day for 5 consecutive days. Cows in this treatment were moved to a hospital pen, where they remained until 72 hours after the last treatment. Cows were then moved back to their original pen.
  • Ceftiofur – ceftiofur crystalline free acid (6.6 mg/kg) twice, 72 hours apart. Cows that received this treatment remained in their original pen during treatment.
• Automated activity monitoring devices were fitted in a subset of cows to monitor behavior.
• Rectal temperature was measured daily from 0 to 6, and at 11 days after metritis diagnosis.
• Blood samples were collected at 0, 1, 2, 6, 7, 8, and 14 days after metritis diagnosis.
• Cows were examined at 28 ±3 DIM for purulent vaginal discharge and uterine samples were collected to evaluate cytological endometritis.
• Ovaries of a subset of cows were evaluated with an ultrasound to determine resumption of cyclicity.
• Pregnancy was evaluated at 40 ±3 and 60 ±3 days after insemination.
• Individual milk yield was recorded monthly.

Results

• Cure of metritis did not differ 11 days after the beginning of the treatments (Ampicillin = 64.6 ±1, Ceftiofur = 63.5 ±3.1%).
• Compared with cows treated with Ceftiofur, cows treated with Ampicillin had:
  • greater rectal temperature in the first 6 days after treatments
  • greater incidence of purulent vaginal discharge at 28 ±3 DIM (Ampicillin = 82.6 ±3, Ceftiofur = 74.4 ±2.7%)
  • tended to have greater prevalence of cytological endometritis (Ampicillin = 77.8 ±2, Ceftiofur = 61.7 ±7.5%)
• Among primiparous cows, treatment with Ceftiofur resulted in reduction in hazard of pregnancy and increased the median days to pregnancy (Ampicillin = 145, Ceftiofur = 169 days).
• Milk yield up to 14 weeks of lactation did not differ between cows treated with Ampicillin (38.0 ±4 kg) or Ceftiofur (37.5 ±0.5 kg).

The authors concluded that Ceftiofur was more efficient in reducing rectal temperature and improving uterine health of cows with metritis. The improved reproductive performance observed in primiparous treated with Ampicillin, however, was an important finding, which warrants further investigation. In addition, behavioral responses improved sharply after metritis diagnosis and treatment, regardless of the antimicrobial used.

Access the paper at: https://doi.org/10.3168/jds.2020-19076

Associations between genomic merit for daughter pregnancy rate of Holstein cows and metabolites postpartum and estrus characteristics
R.C. Chebel and A. Veronese

The inclusion of daughter pregnancy rate (DPR) traits in dairy cattle breeding programs has contributed to halting the negative trend of reproductive efficiency. Recently, the genomic merit for DPR (GDPR) was reported to be associated with estrous behavior and hormonal profile associated with the establishment and maintenance of pregnancy. The authors’ objectives in this study were to determine the association between GDPR and occurrence and characteristics of estrous postpartum, and the concentration of IGF-1 postpartum.

Materials and methods

• 821 genotyped (Clarifide, Zoetis) Holstein primiparous cows were enrolled in this study between December 2016 and December 2017.
• Animals were fitted with automated estrous-detection devices (SCR Inc.) 30 days prior to expected calving date.
  • Heat index, activity peak, and rumination nadir were recorded for all estrous events. Daily rumination was collected between -14 and 28 days in milk (DIM).
• Cows received first artificial insemination (AI) based on heat detection or following Ovsynch (started at 75 DIM).
• Pregnancy was confirmed by palpation 38 ±3 days after AI and confirmed at 87 ±3 days.
• Blood samples for the measurement of IFG-1, non-esterified fatty acids (NEFA), and beta-hydroxybutyrate (BHB) were collected at 7, 14, 21, and 28 DIM.
• GDPR was divided into quartiles for analysis.

Results

• GDPR was positively associated (P < 0.01) with the hazard of estrus within 62 DIM (HR = 1.16; 95% CI: 1.06, 1.28). The interval from calving to first estrus was smaller for Q4 when compared with Q1 (mean: 48 vs. 53 d).
• GDPR was positively associated with estrous duration (P = 0.02).
• GDPR was negatively associated with rumination nadir at estrus (P < 0.01).
• A positive association was observed between GDPR, IGF-1, and glucose concentrations. On the contrary, a negative association was observed between GDPR, NEFA, and BHB.
• GDPR was not associated with pregnancy and pregnancy loss at first AI service.
• GDPR was positively associated with the hazard of pregnancy (P < 0.01).

In conclusion, selection for GDPR might select for animals with better hormonal and metabolic recovery postpartum. Consequently, these cows will return to cyclicity earlier. In addition, selection for GDPR might improve estrous detection because of estrous characteristics in cows with high GDPR scores (i.e., longer estrous duration and more intense estrous signs).

Access the paper at: https://doi.org/10.3168/jds.2020-18207

Prevalence and risk factors related to anovular phenotypes in dairy cows
P.L.J. Monteiro, B. Gonzales, J.N. Drum, J.E.P. Santos, M.C. Wiltbank, and R. Sartori

Postpartum anovulation can be detrimental to reproductive performance of dairy cows. Multiple risk factors have been associated with delayed returned to cyclicity postpartum. In addition, different anovular phenotypes, based on the maximal diameter of the anovular follicle, have different etiologies. Thus, the authors’ objectives were to investigate the association between risk factors associated with anovulation and the prevalence of anovulation and anovular phenotypes.

Materials and methods

• The study included 942 cows (primiparous = 357 and multiparous = 585).
• Cows were classified as anovular if no corpus luteum (CL) was observed during ultrasonographic examination of the ovaries at 35 ±3 and 49 ±3 days in milk (DIM).
• Anovular cows were divided into 3 groups based on largest follicle observed.
  • Follicle size 8-13mm (lower luteinizing hormone [LH] pulsatility)
  • Follicle size 14-17mm (intermediate LH pulsatility)
  • Follicle size >18mm (lack of a LH surge)
• Risk factors included body condition score (BCS) at 35 DIM, milk production, diseases (e.g., retained placenta, metritis, lameness, digestive disorders, and respiratory diseases), and dry period length.

Results

• 5% of cows were classified as anovular.
• Anovular cows had a longer dry period (94 vs. 41 days; P = < 0.01) and lower BCS at 35 DIM (2.8 vs. 3.0; P < 0.01), when compared with their counterparts.
• The odds of being anovular increased twofold or threefold for cows that had 1 or 2 disease events, respectively.
• Anovular cows with smaller follicles had a lower BCS (P < 0.01), longer dry periods (P < 0.01), and greater number of disease events, when compared with the other phenotypes.
• Cows with more follicles had greater milk yield (P < 0.01) when compared with other phenotypes.

In conclusion, anovular cows had a greater incidence of diseases during the postpartum period and a reduced BCS at 35 DIM. Lower BCS and reduced disease occurrence were associated with anovular conditions with follicle diameters 8-13mm and 14-17mm. Extended dry period increased the risk of anovular conditions with follicle diameter of 8-13mm.

Access the paper at: https://doi.org/10.3168/jds.2020-18828

DCRC webinar features use of digital technologies

Join Dairy Cattle Reproduction Council (DCRC) for its next webinar on May 13, starting at 2 p.m. Central time. Ricardo Chebel, University of Florida College of Veterinary Medicine associate professor, will address “Using digital technology to optimize health and reproductive management.” The one-hour webinar is free.

The May 13 webinar will address:

• Review of available health sensor technologies
• How to use data to help enhance dairy cattle repro programs
• Recommendations on what to look for in a sensor technology system

To register for this webinar, go to: http://bit.ly/DCRCmay13webinar and follow the prompts. If you are a DCRC member and cannot attend the live program, you may access the webinar at: www.dcrcouncil.org after May 27.

One Registry of Approved Continuing Education (RACE) credit for this DCRC webinar was granted by the American Association of Veterinary State Boards.

Chebel earned his Doctor of Veterinary Medicine degree from the Universidade Paulista in Brazil. He completed his dairy production medicine residency at the University of California-Davis in 2004. He held teaching positions at Washington State University, University of Idaho, University of California-Davis and University of Minnesota before moving to Florida. Chebel served on the committee that organized and created DCRC, and is a past DCRC vice president and president. Chebel’s research encompasses dairy cattle health, management and welfare, with an emphasis on periparturient cow health and behavior, automated devices for monitoring periparturient cows and pre-weaned calves, reproductive physiology and management, automated devices for estrous detection and improvement of fertility.

For more information about DCRC’s webinars, e-mail Luciano Caixeta, DCRC Education Committee chair, at: lcaixeta@umn.edu or e-mail DCRC at: jodee@dcrcouncil.org.

Metritis: Treatment options, predictive tools

To treat or not to treat, is a question dairy producers often ask. Similarly, they often consider to treat with antibiotics or to not treat with antibiotics. These questions can pertain to a variety of dairy cattle health disorders, including metritis, which is defined as inflammation of the uterus caused by bacterial infection.

Metritis is one of the diseases with greatest incidence during dairy cows’ early postpartum period. Metritis negatively influences milk yield, resumption of ovarian cyclicity, pregnancy per artificial insemination and calving interval. These “strikes” against a cow may lead to early culling.

During the 2020 Dairy Cattle Reproduction Council Annual Meeting, Klibs Galvão, University of Florida, addressed “Can Uterine Infections be Treated or Managed Without Antibiotics?” When contemplating metritis treatment scenarios, dairy producers and veterinarians typically consider cow welfare, antimicrobial resistance, economics and cure rate.

If a producer/veterinarian decides to treat a cow’s metritis, ceftiofur tends to be the antibiotic of choice, Galvão explained. It’s effective and does not require milk withdrawal. Also, ceftiofur was shown to improve the hazard of pregnancy and milk yield by 60 days in milk (DIM). However, milk yield for a 300- or 305-day lactation did not increase. Admittedly, other antibiotics have shown efficacy for treating metritis. That said, only ceftiofur hydrochloride (Excenel*), ceftiofur crystalline-free acid (Excede*) and oxytetracycline (Liquamycin LA-200*) are labeled for treatment of metritis in the United States.

Galvão noted that treating metritis with antibiotics increases the cure rate by 15 to 19 percentage points. Yet, there’s a considerably high self-cure rate – 55 to 62 percent – in cows left untreated at the time of diagnosis. If the condition does not improve or worsens, affected cows receive supportive treatment.

Substantial economic impact

Looking at the economics of treating cows, decreased milk yield and reproductive performance, and herd survival, researchers put the average cost of metritis in 2020 at $511 – ranging from $156 to $948. Lower milk production contributed the largest profit loss in the calculations.

An economic analysis of treating/not treating cows with ceftiofur resulted in a greater proportion of pregnant cows (71 vs. 61 percent), decreased culling by 300 DIM (29 vs. 39 percent) and decreased profit loss ($204 vs. $407, in U.S.$) than untreated cows. Furthermore, analysis showed the mean difference in profit between the ceftiofur-treated and untreated controls was $202 (range of $132 to $271, in U.S.$), and replacement cost (49 percent) and saleable milk (28 percent) accounted for most of the variation in the profit loss difference.

Options beyond antibiotics

Researchers have conducted trials that involved treating cows for metritis without using antibiotics, including Optimum UterFlush. This product improved cure rate, fertility and survival, compared with cows receiving diluted povidone iodine. This study did not include an untreated control or antibiotic-treated group. Thus, researchers could not conclude if the compound was as effective as an antibiotic to treat metritis.

Another study compared the anti-inflammatory ketoprofen with ceftiofur hydrochloride for treating metritis. Researchers observed that cows treated with ketoprofen were more likely to not complete the initial course of treatment (12 vs. 5 percent) and to need extended treatment that included antibiotic treatment (61 vs. 31 percent), compared with ceftiofur-treated cows. Hence, a substantial proportion of cows eventually received antibiotic treatment, although dose numbers dropped in the ketoprofen group compared with the ceftiofur treatment (1.8 vs. 3.6 doses). Health, fertility and survival did not differ between the two treatment groups. Thus, antibiotic use could decrease when the initial treatment is with ketoprofen.

In another study, scientists used flunixin meglumine and ceftiofur hydrochloride to treat metritis. No additive effect was observed.

A University of Florida group tested chitosan microparticles (CM) to treat metritis. CM did not improve the cure of metritis and was detrimental to milk yield, survival and fertility, compared with untreated cows.

Animal welfare perspective

Galvão and his research team observed that ceftiofur treatment increased cure rates when evaluated 12 days after treatment, but it did not affect culling or death in the first 60 DIM. “If we consider increased cure rate by 12 days after treatment as an indicator of welfare, treating the cow at the time of diagnosis may be preferred,” he said. However, Galvão feels more specific measures of welfare, such as assessment of visceral pain and measurement of biomarkers of pain such as substance P, should be performed to make more objective conclusions.

Antimicrobial resistance perspective

On the other hand, if the goal is to reduce antimicrobial resistance, then not treating the cow at time of diagnosis might be preferred. This approach is more likely to negatively impact animal welfare and herd economics.

“We observed that only 16 percent of the untreated cows received escape antibiotic treatment for metritis (2020 study), which could have marked consequences for acquiring antimicrobial resistance if implemented on a large scale,” said Galvão. A recent survey of 16 herds across the United States pegged metritis incidence at 25 percent. With approximately 9 million non-organic dairy cows in the United States, approximately 2.25 million cows are being treated with antimicrobials for metritis (annual basis). This number could fall to nearly 0.36 million if only 16 percent of the cows received antimicrobials for treating metritis.

While this approach may seem appealing, this could lead to a loss of $450 million to the U.S. dairy industry (assume loss of $200 per untreated cow). “Therefore, given the large incidence of metritis in dairy herds and the potential for welfare and economic benefits of treating cows with metritis with antimicrobials, it is difficult to expect that producers would forgo treatment in exchange for a potential, though uncertain, reduction in antimicrobial resistance.”

Predicting self-cure

With metritis having a self-cure rate of 55 to 62 percent, researchers seek a way to predict which cows will cure without antibiotic treatment. “This could significantly reduce the use of antibiotics as a treatment for metritis,” said Galvão.

One study evaluated haptoglobin concentration and DIM at diagnosis as possible variables that could predict metritis cure. The cutoff for these variables was restrictive; only 31 percent (for haptoglobin) to 35 percent (for DIM) of the cows would be flagged for self-cure. However, positive predictive value was large – 80 percent (for haptoglobin) to 82 percent (for DIM) – meaning that 80 to 82 percent of the cows predicted to self-cure would self-cure. The remainder would require antibiotic treatment. Therefore, if these predictors were implemented, antibiotic use could be reduced by 25 to 29 percent.

Future related studies should focus on other variables that can be assessed on the farm, such as milk yield up to metritis diagnosis and rectal temperature. Rumination and activity monitors could potentially be used to predict metritis cure. Furthermore, the advent of machine learning may make it possible to analyze the vast amount of information that can be used to predict metritis cure.

Galvão concluded that developing models that can predict metritis self-cure may decrease the need for antibiotics. Plus, dairy managers should place a greater focus on preventive strategies to reduce the prevalence of metritis.

To read Galvão’s DCRC Annual Meeting proceedings paper, log into the DCRC Member Center and click on the “Proceedings” icon.

References available upon request.

*The Dairy Cattle Reproduction Council does not support one product over another. Any mention herein is meant as an example, not an endorsement.

(Editor’s Note: For each issue, DCRC interviews a member to learn more about his/her career, involvement with DCRC and thoughts about dairy cattle and reproduction. We encourage you to recommend someone for this feature by contacting JoDee Sattler at: JoDee@dcrcouncil.org)

Katelyn Allen
Hoard’s Dairyman magazine
Fort Atkinson, Wisconsin, USA
DCRC member since 2020

A 2019 graduate of Virginia Tech in dairy science, Katelyn Allen joined the Hoard’s Dairyman magazine’s editorial team after graduation. Her responsibilities include creating and editing content for the magazine, e-newsletter and blogs. Allen also helps produce Hoard’s Dairyman’s DairyLivestream webcasts and coordinates the resources available in the Hoard’s Dairyman Bookstore.

Hoard’s Dairyman serves dairy farmers and people in the dairy industry across the country and around the world by providing news, research, trends and practices to help with their dairy farms and businesses. This happens through the magazine, e-mail newsletters, webinars and live webcasts. The company also shares information with farmers in Hay & Forage Grower and Journal of Nutrient Management magazines.

From an editorial perspective, Allen focuses on genetics/reproduction and youth activities. Her strong farm roots and agricultural youth activities make these subject areas a natural fit. Allen’s family owns and operates a Registered Holstein dairy, Glen-Toctin Farm, in Jefferson, Md. Her youth activities included dairy bowl, dairy judging and showing cattle through 4-H, FFA and state and national junior Holstein association events. In college, Allen participated in dairy judging, Dairy Challenge, dairy club and Alpha Zeta. Her dairy judging team placed second at World Dairy Expo.

Allen’s interest in dairy cattle reproduction stems from her lifelong interest in developing cow families and making each generation better than the last. “The promise of a new calf is one of the most exciting things on a dairy farm,” she stated.

Relatively new to the Dairy Cattle Reproduction Council (DCRC) “family,” Allen became the new DCRC Awards Committee chair in November. Also, in 2020, she worked with DCRC members to update “Dairy Cattle Fertility,” a “joint book,” created and published by Hoard’s Dairyman and DCRC.

When asked about DCRC’s influence on dairy cattle reproduction education and improvement, Allen responded, “I saw firsthand how DCRC members contributed to the Dairy Cattle Fertility book, iterations of which began in 1964 and have always been one of our top-selling items to teach schools, dairy farmers and industry people about the basics, as well as nuances of dairy cattle reproduction. I think the annual Excellence in Dairy Reproduction Awards program is also an excellent platform to recognize and promote farmers who are doing a great job with dairy herd reproduction. That encourages other farms when they see what is possible.”

Despite her limited DCRC experience, Allen noted that she has learned valuable information from the organization. “I learned more about just how expansive and innovative dairy cattle reproduction and genetics research is in today’s global world. Specifically, I have learned about blood and milk pregnancy tests. Before joining DCRC, I was not too familiar with these technologies.” She believes that future research must keep in mind maintaining animal fertility as well as the longevity of dairy farms. “As with all aspects of the industry, farm profitability has to be part of the discussion because farmers must have the ability to invest in improving genetics and technologies,” she stated.

Allen predicts that DCRC will continue to provide information for farms to improve their reproductive efficiency. “However, the tools farmers have will grow. They will become more technological and, hopefully, more integrable with one another,” she remarked.

• Council on Dairy Cattle Breeding Triannual Evaluation, April 6
• Dairy Calf and Heifer Association Annual Conference, April 6-8, Appleton, Wisconsin, and Virtual
• National Mastitis Council webinar, April 15, 2 p.m. Central time
• 2021 DCRC Excellence in Dairy Reproduction Awards nominations due April 30
• 2021 DCRC Scholar applications due April 30
• Animal Agriculture Alliance Stakeholders Summit, May 5-6, Virtual
• Dairy Cattle Reproduction Council webinar, May 13, 2 p.m. Central time
• American Dairy Science Association Annual Meeting, July 11-14, Louisville, Kentucky
• American Society of Animal Science-Canadian Society of Animal Society Annual Meeting and Trade Show, July 14-18, Louisville, Kentucky
• Council on Dairy Cattle Breeding Triannual Evaluation, August 10
• National Cattlemen’s Beef Association, August 10-12, Nashville, Tennessee
• World Dairy Expo, September 28-October 2, Madison, Wisconsin (tentative)
• American Association of Bovine Practitioners Conference, October 7-9, Salt Lake City, Utah
• National Association of Animal Breeders, October 27-29, Lake Geneva, Wisconsin
• Council on Dairy Cattle Breeding Triannual Evaluation, December 7
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