Newsletter – 2017 – February
From the DCRC President’s Desk:
By Dr. Todd Bilby
Don’t forget that the 2017 Reproduction Awards program gets underway next month. DCRC is again seeking nominations of dairy herds with exceptional reproductive performance.
Last year, a record 128 herds were nominated for the contest! We’re thrilled with how dairy producers and their advisors have embraced the program and look forward to another robust response to our call for entries. The achievements of participating dairies are nothing short of incredible—and offer tremendous practical lessons for everyone involved in the dairy industry.
Nominations will be accepted starting March 1. Nomination forms are due by April 30 and may be completed online. As a reminder, dairy farms must be nominated by professionals who serve the dairy industry, such as veterinarians, extension agents, A.I. and pharmaceutical company representatives, plant and co-op field staff, consultants and others.
Award recipients will be honored at the 2017 DCRC annual meeting in Reno, Nevada, Nov. 8 – 9, 2017. Please note the annual meeting will take place Wednesday – Thursday this year, a shift from our usual Thursday – Friday meeting schedule.
Speaking of the annual meeting, the program committee has put together another fantastic agenda. Here’s a sneak peek at the topics you’ll learn more about in Reno.
Dynamic speakers will share their insights around the general themes of consumer relations, new technologies and data management, reproductive management strategies, as well as herd health and employee management. Breakout sessions will address topics including:
- Antibiotic and hormone use on dairies
- When and how to use IVF and genomics
- Big data—how to manage and use it
- Analyzing semen choices—conventional, sexed or beef sires
- Advice from DCRC Reproduction Award winners
- Impact of transition cow health on fertility
- Ties between calf health and cow longevity
- Improving employee skills to benefit cow health
More details about the program and topics will appear in the next issue of the DCRC newsletter, so stay tuned.
Sign up for DCRC Webinars
The schedule for our top-notch webinar series is set and once again, we are pleased to offer a full slate of top-rated topics from previous DCRC annual meetings, as well as other areas of reproductive importance.
And, since our Spanish webinar was so successful last year, DCRC will offer another webinar in Spanish this year—slated for Dec. 15. For the first time, DCRC will offer a webinar in Portuguese, too—which is scheduled for Oct. 27.
Sign up now to save your spot. The webinars offer a fantastic employee meeting opportunity, bringing topical expertise to your dairy without having to leave the farm.
Also, be sure to check out DCRC on social media—follow us on Twitter (@DCRCouncil) and Facebook.
Rumination Time an Indicator of Dystocia
Researchers recently evaluated whether rumination time and reticuloruminal pH and temperature of dairy cows and heifers could indicate calving difficulties. The results were published in the February 2017 issue of the Journal of Dairy Science.
Data show that rumination time decreased from baseline 28 hours before calving for both normal and cows that experienced dystocia.
- Between eight and four hours before calving, it decreased to 32.4 ± 2.3 minutes/4 hours and 13.2 ± 2.0 minutes/4 hours in normal and cows that experienced dystocia, respectively. Then it decreased below 10 and five minutes during the last four hours before calving.
- Time to return to baseline suggested lower rumination activity in cows that experienced dystocia than in normal dams for the 168-hour postpartum observational period.
- Reticuloruminal pH decreased from baseline 56 hours before calving for both groups of cows, but did not differ between groups before delivery.
The researchers note that based on their results, continuous monitoring of changes in rumination time and reticuloruminal temperature seems to be promising in the early detection of cows with a higher risk of dystocia. Depressed rumination activity of dystocia-experiencing cows after calving highlights the importance of the postpartum monitoring of cows experiencing difficulties at calving.
Safely Obtain DNA and Sex Embryos
Researchers recently evaluated the effect on the gestation rate of conducting a biopsy of in vivo (VV) and in vitro-produced (IVP) bovine embryos. The research was conducted to determine how assisted reproductive techniques can be combined with genomics to maximize the benefits of both technologies. Results were published in the March 1, 2017, issue of the Journal of Theriogenology.
The embryos were divided into groups:
- VV-B (380 biopsied embryos) and VV-C (229 intact embryos—controls)
- IVP-B (91 biopsied embryos) and IVP-C (227 intact embryos—controls)
No effect (P>0.05) of the biopsy was observed for any of the treatments, the pregnancy rate at day 60 post-transfer being similar among groups. Also, no effect (P>0.05) of the embryo’s stage of development was detected on pregnant recipients when in vitro embryos were transferred.
The results indicated that biopsy does not affect the viability of IVV and IVP bovine embryos and can be used in commercial programs to associate assisted reproductive technologies with genomic selection.
Feed Heifers to Maximize Reproductive Development
Cattle uterine gland development occurs after birth. The timeline of gland development has been described in various species, but little is known about how dairy calf diets influence uterine development. To better understand this, researchers at Virginia Tech recently set out to determine the effects of early postnatal plane of nutrition and estrogen supplementation on uterine development in calves. Their results were published online by the Journal of Dairy Science Feb. 1, 2017.
Calves in the study received two different planes of nutrition. In addition, calves in the trial received supplemental estradiol or a placebo (control), per study design.
The researchers conclude that heifer calves on a restricted diet exhibited a uterine structure and profile that suggests possible delayed uterine development. These changes appear to be corrected by week 10 of life. Also, this work provides evidence supporting the contention that early estradiol exposure has detrimental effects on uterine gene expression.
Practical Perspectives about Dairy Sire Fertility
By Mel DeJarnette, Select Sires
Since artificial insemination was first introduced, it’s been recognized that individual sires vary in reproductive capacity and pregnancy success rates.
As a result, data-gathering techniques have been implemented to track, monitor and document these differences. Over time, improvements in semen extenders and processing procedures have yielded more efficient systems for production of a consistent, highly fertile frozen semen product.
Nonetheless, many of the apparent differences in sire fertility are not easily explained by semen quality attributes and are often not repeatable.
Although many technological advances in dairy herd reproductive management have been implemented, fertility remains a “yes” or “no” answer and therefore is subject to all the nuances characteristic of binomial data.
Furthermore, sire fertility data gathered on-farm may often contain biases pertaining to semen usage as a function of price, genetics, calving ease or results from a previous sire fertility estimate.
Definitions to Remember
Delving further into sire fertility, it’s important to keep these terms in mind:
- Estimate: An evaluation based on opinion or approximated from imperfect or incomplete data; a calculation that is not exact.
- Accuracy: The degree to which the result of a measurement or calculation conforms to the correct value.
- Precision: Sharply or clearly determined; the degree to which a measurement procedure gives the same results each time it is repeated under identical conditions.
What do the Numbers Mean?
Conception is a binomial variable because only two possible outcomes exist from a given insemination (pregnant or not pregnant). The most common example of this is the outcome of a coin toss, with each toss having a 50:50 probability of showing heads or tails and the answer is totally independent of all prior outcomes.
Although the expected answer from a series of 10 coin tosses would be 5 head and 5 tails, this is only expected to occur once in every 4 attempts and 75 percent of attempts will not yield a 50:50 ratio. If you tossed a coin 1,000 times, it would be a rare occurrence to get exactly 500 heads and 500 tails (about 2.5 percent of attempts) and about 10 percent of the time the outcome is expected to favor one outcome or the other by a spread of 50 (i.e. 25 tosses).
It is this characteristic of binomial data that makes fertility data inherently imprecise requiring large numbers of services (hundreds to thousands) for any meaningful degree of accuracy.
In addition, the probability for pregnant or not-pregnant outcomes after a given service is seldom equal (50:50). Most lactating dairy cows have success rates in the range of 30 to 40 percent, whereas well-managed heifers may achieve conception rates of 60 percent or greater.
Figure 1 illustrates the effect of herd (female fertility) on the expected pregnancy outcomes from 10 doses of semen from a 100 percent fertility sire (assuming one exists). When the female conception rate is near 50 percent, five pregnant females are predicted—but this is only expected to occur in 25 percent of any given series of 10 services: 75 percent of the time the answer will not be 50:50.
In reality, no 100 percent conception-rate sires exist. And within any population of females, some females are more at risk to become pregnant to a given service than are others due to a number of environmental factors influencing herd fertility and individual animals.
It is unrealistic to expect every sire within a herd to be equally assigned to females of similar fertility.
In practice, numerous factors interact to result in preferential bias in semen use both within and among herds. Bulls of extreme genetic value and price are often preferentially used in females predisposed to greater conception (primiparous, first service, high genetic value for fertility traits and A.I. after standing estrus).
Sire Fertility Estimates
Estimated sire fertility is a single value for each individual, based on population data, and typically expressed as deviation from an overall average conception rate for the sampled population.
These values are calculated using complex statistical models that typically include corrections for herd, month (season), year, parity, service number, days postpartum and milk production. Other factors such as technician, interval between services and breeding code may also be included.
Most calculations are based on large data sets from dairy records processing centers. Units of a deviation typically approximate a 1.0 percentage unit difference in the proportion of females expected to become pregnant after A.I. relative to the proportion for the average bull in the population evaluated, which is typically centered at 0.0.
To maximize the accuracy of sire fertility estimates, the following factors should be considered:
- A common unit of measure for how females are diagnosed pregnant at a stipulated and consistent interval after A.I.
- A common basis for decision to inseminate (standing heat, rubbed tail paint, fixed-timeA.I.)
- No errors in recorded data (e.g., wrong A.I. date, incorrect cow or bull identity)
- No errors in outcome measurement, whether detection of females returning to estrus, palpation of uterine contents, or ultrasound evaluation
- No biases from preferential treatment in pairing sires and females or culling animals
- Sufficient number of complete records to discern between chance and reality
However, differences or errors in these areas permeate all data sets and contribute to measurement error surrounding an estimate—regardless of the number of observations.
Many factors that impact the fertility potential of both males and females are not included in statistical models because there are inadequate data to calculate correction factors or the factors are simply not accounted for in the dataset.
If semen from all sires was distributed equitably, there would be little concern about these “missing” correction factors. Producer bias in sire use, based on perceived value or fertility, creates artifacts within the data that are often difficult (if not impossible) to identify and account for.
Other factors not accounted for in published estimates of sire conception rate (CR) include:
- Health of the animal receiving A.I.
- A.I. to timed or detected estrus
- Estrous detection accuracy
- Timing of insemination
- Protocol compliance
- Semen cost
- On-farm semen storage
- Semen handling
- Technician competence
- Intentional management bias
It is tempting for producers, semen sales personnel and industry consultants to split hairs in search of that high-conception ideal sire that will solve the reproductive woes of a particular herd. The nature of fertility data and sire fertility estimates, however, simply do not lend themselves to the precision necessary to achieve such goals.
The important questions for a producer and an A.I. center to ask regarding estimated differences are:
- Is the difference real or does it reflect random chance?
- Will the detected difference have a meaningful impact in a producer’s herd?
In most cases, the bull is not the major cause of observed poor on-farm conception rate and attempting to fix the problem by changing bulls will have a minimal impact.
In general, sire fertility should always be used as secondary selection criteria to genetics. When used as a primary selection tool, the inherent imprecision of fertility data will result in the unnecessary exclusion of many sires that may be much more genetically valuable options.
A.I. centers go to great effort and expense to identify and eliminate collections and/or sires possessing semen quality attributes indicative of substandard fertility potential.
The fact that all major sire fertility evaluation systems indicate only 5 to 7 percent of all sires evaluated have deviations more than 3.0 points below the mean is a testament to the efficacy of these quality control programs and the ability of the industry to provide producers with a consistent quality product. You cannot toss a coin much more repeatable and precisely than that.
This does not imply that no differences exist in male fertility. However very few sires are sufficiently different from average that producers should even acknowledge that there may be “repeatable” economic implications from the use of their semen.
As future research efforts focus on this small sub-fertile population of sires, additional novel semen quality traits will be identified and added to the list of reasons semen collections (or sires) are culled and will further improve an already admirable track record.
DCRC member can access the full paper at dcrcouncil.org.
Nilo F. Francisco
DCRC Member since 2006
I am the breeding/reproduction supervisor for Alliance Dairies in Trenton, Florida. The dairy was established in 1990 with more than 2,000 milking cows.
Today, it is the largest free-stall dairy on one site in the state, employing more than 140 people. Our Holstein herd now consists of more than 6,200 total cows. Our two grazing dairies have 5,500 mature cows and we have more than 8,000 young stock raised on-farm for replacements on our dairies. We are a 100 percent artificially inseminated herd and use the Double Ovsynch® protocol on all sites.
In my role, I oversee the implementation of synchronization programs across the three dairies in our group. I also am responsible for recordkeeping and bull selection.
As the dairy grows, we believe that having the best employees on our team is one of the keys to our success.
I obtained my veterinary degree in the Philippines and have more than 30 years of experience.
I practiced veterinary medicine in the Philippines for 15 years, focusing on reproduction for buffaloes and beef cows for the Bureau of Animal Industry, Department of Agriculture, Republic of the Philippines.
I joined Alliance Dairies more than 16 years ago.
Maintaining—and improving—reproductive performance on our three dairies is my focus. Every day. That means keeping our breeding program updated is a must. DCRC helps with this goal.
Updated knowledge on reproduction and synchronization programs, as well as on farm trials done on-site in collaboration with the University of Florida faculty and students, keeps us in the loop.
DCRC events and communications have helped with:
- Reproduction and general management strategies for our dairies.
- The importance of strict implementation of protocols and programs is one of the keys for any reproduction program.
What’s ahead? I think the continuous improvement of reproduction and milk production on most of the dairy herds across the United States shows positive signs ahead and how to overcome negative challenges.
For DCRC, I have a positive outlook for the organization. It’s getting bigger and better each year.
Mark your calendars for the Dairy Cattle Reproduction Council’s 2017 webinar series. These highly regarded sessions offer attendees from across the United States and around the world access to high-quality information and interaction with industry experts from the comfort of their farm or office.
The 2017 series will feature six presentations, giving you numerous opportunities to learn more about important dairy reproduction topics. The informational series begins with its first webinar Friday, Feb. 24, and continues every other month throughout 2017.
The webinars feature top-rated topics from previous DCRC Annual Meetings, as well as other areas of reproductive importance. Again this year, DCRC will offer a webinar in Spanish—slated for Dec. 15. And for the first time, DCRC will offer a webinar in Portuguese, which is scheduled for Oct. 27.
Each webinar begins at1 p.m. Central time. We look forward to you joining us!
Save these dates:
- Management of Transition Cows: A Nutritionist’s Perspective with Dr. Tom Overton
- February 24, 2017
- Register here
- Ovulation Synchronization Programs: An Update with Dr. Richard Pursley
- April 28, 2017
- Register here
- Heifer Rearing Programs: Making Decisions About Replacements with Dr. John Lee
- June 23, 2017
- Register here
- 10 Years of DCRC: Where We’ve Been and Challenges for the Next 10 Years with Dr. Jeff Stevenson
- August 25, 2017
- Register here
- Identificação e tratamento de doenças uterinas em vacas leiteiras (Identification and Treatment of Uterine Diseases in Dairy Cows) with Dr.Klibs Galvao in Portuguese
- October 27, 2017
- Register here
- Aplicación de tecnologías genómicas para la selección en rebaños lecheros comerciales (Application of Genomic Technologies for Selection in Commercial Dairy Farms) with Dr. Francisco Peñagaricano in Spanish
- December 15, 2017
- Register here
To register for a webinar, please visit Webinars and follow all prompts. As the webinar approaches, you will receive an email with information on how to log in for attendance. Can’t make it live? DCRC members may access all past webinars at dcrcouncil.org.
Special thanks to our sponsors who make these webinars possible.
- DCRC Webinar – Management of Transition Cows from a Nutritionist’s Perspective, February 24, 1 p.m. Central Time.
- Western Dairy Management Conference, February 28 – March 2, Reno, Nevada.
- Southern Dairy Conference, March 6 – 8, Atlanta, Georgia.
- Western Canadian Dairy Seminar, March 7 – 10, Red Deer, Alberta, Canada.
- 2017 Professional Dairy Producers of Wisconsin Business Conference, March 15 – 16, Madison, Wisconsin.
- 2017 Central Plains Dairy Expo, March 29 – 30, Sioux Falls, South Dakota.
- Tri-State Dairy Nutrition Conference, April 17 – 19, Fort Wayne, Indiana.
- Florida Dairy Production Conference, April 20, Gainesville, Florida.
- DCRC Webinar – Ovulation Synchronization Programs Update, April 28, 1 p.m. Central Time
- 2017 DCRC Reproduction Award entries due, April 30
- Discover Conference: Dairy Replacement Heifers: Transitioning from Weaning through First Lactation, May 31 – June 1, Itasca, Illinois.
- DCRC Webinar – Heifer Rearing Programs: Making Decisions About Replacements, June 23, 1 p.m. Central Time.
- 2017 ADSA Annual Meeting, June 25 – 28, Pittsburgh, Pennsylvania.
- 2017 ASAS-CSAS Annual Meeting & Trade Show, July 8 – 12, Baltimore, Maryland.