NEW REPRO RESEARCH PRESENTED AT DCRC
ore than 250 progressive dairy producers, academia, and industry personnel gathered in Reno, Nevada November 8-10, 2017 for the Dairy Cattle Reproduction Council (DCRC) annual meeting. While there, guests discussed new and advanced practices to achieve outstanding reproductive performance.
During the annual meeting, the DCRC invites speakers from around North America to present cutting-edge research and discuss hot-topics impacting today’s dairy reproductive performance. Topics covered this year included hormone use in dairy cattle, the importance of cow health on fertility, effects of heat stress during late gestation, heifer rearing, use of in vitro embryos and genomics, decision-making with sexed semen, and many more. Here is a quick summary of some of the talks:
Transition cow health and fertility
Dr. Eduardo Ribeiro with the University of Guelph, presented the “Impact of Transition Cow Health on Fertility.” Dr. Ribeiro showed data highlighting early pregnancy loss as a major factor impairing reproductive efficiency of dairy cattle.
In addition to early pregnancy loss, Dr. Ribeiro also demonstrated how diseases such as metritis, mastitis, lameness, and digestive and respiratory problems during the early postpartum period decreased the likelihood of cows to become pregnant after artificial insemination (AI), and increased the risk of pregnancy loss after 45 days of gestation.
Recent research of Dr. Ribeiro’s laboratory in Canada has demonstrated that the timing of disease has a negative effect on fertility of dairy cows. Disease that occurs before the end of the voluntary waiting period (VWP) has a similar, negative effect as disease that happens during the time of breeding and early pregnancy.
These findings confirm that disease has a negative carryover effect on fertility, with consequences still observed three months after the disease had subsided. Dr. Ribeiro concluded that prevention of postpartum disease is the best approach to reduce these negative effects on fertility. However, complete prevention is nearly impossible.
Future research is required to investigate the effects of minimizing inflammation of clinical diseases and how that could potentially mitigate some of the negative effects on reproduction.
Voluntary waiting period and first service repro strategies
Dr. Julio Giordano, from Cornell University, presented another great talk on the “Impact of the VWP, first-service management strategies, and how these decisions can alter profitability.”Research has demonstrated that extending the VWP from 50 or 60 to 88 days in milk (DIM) may increase conception rates at first service.
When extending the VWP, the greatest increase in conception rate is observed in first lactation cows. Dr. Giordano suggested that extending the VWP may lead to greater profitability in those first lactation cows but not in cows in their second and greater lactation.
Several factors influence profitability when changing the VWP, but the two major factors are:
- differences in replacement costs
- income over feed costs
Furthermore, when extending the VWP from 60 to 88 DIM the increase in first-service conception rate must be 10 to 11 percentage points greater for first lactation cows and 7 to 12 percentage points greater for multiparous cows to generate the same number of pregnancies by 90 DIM.
Dr. Giordano concluded that the duration of the VWP and how that affects herd performance and profitability depends upon complex interactions between reproductive performance, culling dynamics, lactation performance, and the economic market.
Recognizing reproductive excellence
Every year DCRC recognizes dairy farms that exude excellence in reproductive efficiency, fertility, and reproductive management. Dr. Glaucio Lopes from Alta Genetics, examined the records of the 2017 DCRC award winners to show similarities and differences among the 24 award recipients in his presentation “Digging Deep into Records of DCRC Award Winners.”
Pregnancy rate is one of the most common metrics to evaluate the success of reproductive programs. So it should be no surprise that the average pregnancy rate of winning herds has steadily increased throughout the years of the award program. In fact, all award winners from 2017’s contest had over 30% pregnancy rate throughout 2016. However, Dr. Lopes was emphatic on highlighting that pregnancy rate is not the only metric used by the awards committee to select the winners.
Though reproductive management strategies differed among award winners, most farms used some form of fixed timed-AI program as part of their management system, in combination with estrus detection and AI. Despite practices that were common in the beginning of this decade, no farms used 100% fixed timed-AI, nor 100% estrus detection to select cows for all services.
Of the 24 winners, 13 dairies use some form of a presynch-ovsynch program, with a combination of synchronization and estrus detection for AI on all services. Eleven of the award-winning dairies use a 100% timed AI program for first service, followed by a combination of re-synchronization and estrus detection for subsequent services.
The range in VWP among the award winners was vast, ranging from 41 to 76 DIM. First service conception rates were outstanding, even for the dairies using sexed-semen on lactating cows, ranging from 37% – 66%.
An interesting observation presented was that disease incidence of the award-winning dairies was extremely low. Though the incidence of disease could be underreported in the computer records, this observation agrees with the presentation and conclusions of Dr. Ribeiro.
In conclusion, maximizing reproductive efficiency and performance is important to a successful and profitable year ahead. The annual meeting hosted by DCRC provided valuable information to dairy professionals that will benefit the dairy industry this year, and the years ahead.
Please visit http://www.dcrcouncil.org/ to learn more about this great organization, and the benefits of becoming a member.
DCRC is a proactive organization with long-term interest in raising awareness of issues critical to reproductive performance. Through information and communication, it strives to deliver the latest in technology and resources.
Article written by Dr. Benjamin Voelz, Premier Account Manager and Dr. Glaucio Lopes, Vice-President of DCRC and Alta University Manager, Alta Genetics.
For more details on the DCRC annual meeting, or with follow-up questions on this article, please contact: Benjamin Voelz (firstname.lastname@example.org) or Glaucio Lopes (email@example.com).