Vol.1,#2 Buy an embryo or ET calf or ?

Farm Update

"Flour" 2016 Heifer sired by "Flashback 704"

"Flour" 2016 Heifer sired by "Flashback 704"

The rain has continued to fall with the total now reaching 50” for the last 4 months. That far exceeds the rainfall total for an entire normal year here. Needless to say mud has been a big problem: the cows and calves are anxious to move to the grass fields. Hopefully that will occur before this issue is published.

We have several excellent homozygous polled heifer calves for sale sired by several different bulls. Look to our website for information on these calves. Delivery of any purchases can usually be worked out for a nominal fee. We are already scheduled to make a trip as far East as Southern Wisconsin this summer.

Quarterly Topic: Should you buy an Embryo, Embryo Transfer Calf or Neither?

Recently there has been an increasing trend by many (promoters) breeders of Shorthorns to sell packages of similarly pedigreed embryos. Production of these embryos, whether by classic methods or the newer in vitro fertilization process, has become an integral part of both their marketing and sale strategy. Comparison of both the potential benefits and disadvantages of purchasing embryos or embryo transfer offspring is extremely important. This is paramount whether trying to build a Shorthorn herd or engaged in showing Shorthorns.

The pervasive marketing of “embryo packages” in Shorthorn sales should be met with a healthy dose of skepticism. Most “embryo packages”consist of 3-5 embryos that may or may not be sexed but are full brother/sister. The marketing implication is they will be “winners” simply based on pedigree and parental show success. The reality is quite different. I like to pose the question “How many 7’ basketball players have 7’ sons let alone that are also successful basketball players?”. Mother nature has a way of throwing a wrinkle into the mix because of random genetic mix. Even more important is the selection process that is utilized to select the the cows that are used to to produce these embryos. Mostly they are selected on show records, pedigree, Estimated Progeny Differences (EPD’s), and the latest genomic profile. Often they are simply declared great cows by their owners and promoted as such. Many are pampered “hot house” cows with no real life experience or track record of living in pastures or producing offspring. Buyers must be willing to put a lot of faith in the selection process and “gamble” that they will get a quality bull or heifer. Beyond the embryo purchase price, one must pay for placement of the embryo in a recipient cow and hope implantation is successful. Implantation success rates are extremely variable with most being below 50 %. Utilization of quality recipient cows is extremely important to avoid passing on communicable disease problems, such as Johne’s Disease or Bovine Leukemia Virus. The recipient cow has to have good maternal instincts with adequate milk production. Needless to say there is a lot of expense and risk in simply buying embryos. Cost of embryos, receipts, implantation, drugs, and Veterinary care with low success rates should make a potential embryo buyer pause before embarking on the “embryo to live calf” journey.

A Mother's Love

A Mother's Love

Purchasing an embryo transfer (ET) calf carries its own set of drawbacks. The aforementioned potential disease risks from the calf’s recipient dam is the first potential problem. Birthweight of the calf will be affected by the strength of placental attachment in the recipient dam versus its real dam. Growth rate of the calf can be distorted either positively or negatively by the milk production of its recipient dam. Obviously there will be no direct correlation with regard to any of these factors because the actual dam is not a part of the growth process. Furthermore multiple replicas of the same parental mating can result in narrowing genetic bases and direct show ring competition between a plethora of siblings. Not a good situation if one’s goal is be successful in the show ring environment or sell offspring from the purchased ET calf. Uniqueness of pedigree is totally lost along with valid data on all the growth parameters typically measured in calves.

Given the above shortcomings why does anyone buy embryos or ET calves? Most people believe it will hasten the development of their herd, make them competitive in the show ring, or give them the opportunity to sell high dollar Shorthorns. Personally I see this as simply hoping that everything “clicks” without necessarily totally understanding the limitations.

With a naturally produced calf “fudging of the calf’s data” can still take place but it will be because of the lack of integrity on the seller’s part rather than the “altered biological circumstances” it grew up in. The list of advantages that are inherent in the purchase of a naturally produced calf is long but the most salient ones include the following: 1) birth and growth data that is derived from growing and developing through the input of its own dam 2) more chance of a unique pedigree 3) wider genetic base for all Shorthorns 4) less disease risk from outside sources and 5) marketing opportunities because the calf is not the Nth copy of the same parental mating.

Undoubtedly the production of ET/IVF calves will continue to be big business. Each individual Shorthorn breeder must evaluate all the pros and cons before choosing to purchase embryos or ET/IVF calves. I have tried to shine a little light on some of the controversies of this whole process. Personally I have elected to abstain from either the purchase or production of ET/IVF embryos or calves. Long term I believe my herd selection process will be more accurate and personally rewarding without ET/IVF calves.

Joseph Schallberger, DVM PhD
Whispering Hills Farm
Member Academy of Veterinary Consultants