Advanced Beef Cattle Repro Technology Key

maio 30, 2022 Postar um comentário

Beef cattle, too equally other types of livestock, are extremely important for feeding an ever-growing world population. A bulk of the world is untillable land lending itself to livestock production.

In order to continue step with the increasing number of people, livestock producers must proceed to improve functioning efficiency through early on adoption of new production methods.

An astonishing corporeality of new fauna science technology is being developed by universities, industry and research organizations on a daily basis, and beef cattle reproduction is no exception.

The reproduction technology discussed in this commodity has been available for years just is currently uneconomical for cow-calf producers. Exceptions are heat synchronization, A.I. and perhaps embryo transfers (ET) that offer producers opportunities to rapidly improve genetics at reasonable costs.

Heat synchronization and A.I.

Injecting hormones

"The get-go stride in taking advantage of the opportunity to improve breeding economics is to adopt estrus synchronization as a way to shorten the calving flavor," says Glenn Rogers, DVM, possessor and operator of Holt River Ranch and Grassy Ridge Consulting.

"An reward of estrus synchronization is more calves born earlier in the calving season, resulting in heavier weaning weights. It also allows for more efficient use of labor during calving season. Estrus synchronization is necessary for efficient use of A.I.

"Cow-calf operators might desire to consider A.I. because of the ability to enhance herd genetics more economically than buying the same-quality bulls," Rogers continues.

"A.I. provides a high accuracy of sire expected progeny differences (EPDs) such as calving ease and allows the use and maintenance of fewer bulls."

Embryo Transfer

Embryo Transfer, or ET, is the process of removing one or more embryos (fertilized eggs) from the reproductive tract of a donor female and transferring them to i or more recipient female person. The entire procedure involves convenance a donor moo-cow (usually by A.I.), flushing embryos from the donor and injecting embryos into recipient cows.

The advantage of this practice is that it allows transfer of maternal traits from a super-cow to several recipients, resulting in more calves with the improved genetics.

"To maximize embryo survival in the recipient female following transfer, conditions in the recipient reproductive tract should closely resemble those in the donor," says Tom Troxel, Ph.D., University of Arkansas Partitioning of Agriculture Inquiry and Extension.

"This requires synchronization of the estrous cycles between the donor and the recipients, optimally within one day of each other."

"Superovulation is the release of multiple eggs at a single rut," explains Troxel. "Cows properly treated tin can release as many as ten or more than viable eggs at ane estrus. Approximately 85 percent of all normal fertile donors volition respond to superovulation treatment with an average of five transferable embryos."

Sexed semen

"A.I. and estrus synchronization are the foundation for other breeding concepts," said George Seidel, Ph.D., Colorado State Academy, at the 2015 Cattle Manufacture Convention and NCBA Trade Evidence. "This is especially truthful for sexed semen considering information technology cannot be used without A.I. Sexed semen is now being produced commercially in a number of countries, including the U.S.

equipment for sexing sperm

Positive aspects of this engineering science are accuracy of sexing sperm shut to 90 pct with large sample sizes, and the calves produced appear to exist normal.

The main negatives are sexed semen is expensive, fertility of sexed sperm is somewhat lower than unsexed sperm, and this product currently is only available from relatively few sires, especially beef breeds. It is possible to become semen sexed and frozen on a custom basis.

"The largest cost of sexed semen is lower fertility. At that place are ii primary reasons for lower fertility: Fewer sperm are used per straw, typically 2 meg compared to 20 million or more than sperm for about bulls with unsexed semen, and sperm are slightly damaged by current sexing procedures, so they do not swim quite normally.

"The extent of lowered fertility is about 10 percent under ideal conditions such as good nutrition, well-trained inseminators, excellent heat detection and very conscientious handling of semen.

Under average weather condition, fertility of sexed sperm is about 70 percent of the fertility of unsexed sperm. For example, if unsexed semen from a particular bull in a particular herd results in sixty pct significant cows, the pregnancy rate for sexed sperm can be lxx percent ten 60 percent = 42 percent.

Note these are the results for A.I. 12 to 24 hours after articulate standing estrus; they will exist fifty-fifty lower for timed-A.I. protocols. Sexed semen usually leads to disastrously depression pregnancy rates under less-than-average conditions.

"In my opinion, the logical identify to utilize sexed semen is breeding replacement heifers to produce more replacement heifers," Seidel continued.

"These heifers often will exist bred A.I. anyway, and in that location are several added bonuses: less calving difficulty if they have heifer calves rather than larger bull calves, the replacement heifers should accept the all-time genetics in the herd, and this allows breeding cows to deliver final-cross calves; since few replacements need to come from the cow herd, most tin come up from A.I.'d first-calf heifers."

In-vitro fertilization (IVF)

"ET provides the foundation for in-vitro fertilization," said Seidel. "There are two methods of IVF – conventional and intracytoplasmic sperm injection (ICSI)."

"Conventional IVF procedure involves creating embryos from unfertilized egg cells (oocytes) by fertilizing them with semen in a Petri dish," explains Marking Allan, Trans Ova Genetics managing director of marketing and genomics.

"A trained technician or veterinarian collects oocytes from a donor cow using an ultrasound-guided aspiration known as the Ovum Choice Up (OPU) technique. The oocytes are placed in the Petri dish and fertilized the following twenty-four hours with semen. The fertilized eggs mature in an incubator for seven days, and the resulting viable embryos are transferred into recipient cows.

"IVF has some advantages over ET, although it is slightly more expensive," Allan continues. "A unmarried straw of semen may be used to fertilize one to five donors' oocytes through IVF."

"With ET and superovulation techniques, the technician generally uses iii to four straws of semen per donor cow. Donor cows in an active ET program must be open, while IVF technology allows the donor cow to provide embryos from day twoscore to solar day 100 of gestation."

"ICSI is a process of injecting the sperm direct into the oocyte," said Seidel. "This process provides the capability for rescuing semen that has lost motility, but its genetic cloth is non damaged."

"ICSI is at present used routinely for human infertility cases in which the hubby'south sperm are fairly normal except for move characteristics. At Colorado State University, we besides utilize the procedure routinely for stallions with the same problem. I call ICSI 'fertilization by brute force'."

Split embryos

splitting a vobine embryo

"For splitting, embryos are recovered from a donor cow past flushing," Seidel explained. "The embryo is then sliced in two with equipment consisting of an inverted microscope and an electronically controlled micromanipulator, which holds an ultra-precipitous splitting bract. Embryo halves tin can be transferred either singly or equally twins to recipient females.

The advantage of this technique is that you get two calves instead of one, and the number of live offspring obtained from an ET plan can be significantly increased.

Use of embryo sexing allows producers to concentrate their genetic improvement on either their superior male or female person lines and to dramatically reduce the overall cost of embryo transfer past eliminating 50 percent of recipients."

Some other advantage of embryo splitting is that it allows separation of cells to determine if they are normal. The aberrant cells tin can exist destroyed, and the remaining embryo with normal cells can be transferred to a recipient.

"Most embryo splitting has been done with cattle, resulting in delivery of thousands of calves," Seidel continued. "The practise is not widely used today considering of the extra work required for splitting. A very pocket-size corporeality of embryo splitting has been performed in horses, and information technology is extremely rare in humans."

Cloning

"There are many definitions of cloning and many methods of cloning," said Seidel. "Cloning of potential practical value occurs when copying a genetically outstanding animal."

This commonly is washed by taking a very modest biopsy of skin from the beast to be cloned, growing some of the skin cells in plastic dishes in an incubator and using nuclei of those cells as the genetic material for the clones.

Other body cells besides can exist used, such every bit hair roots or somatic cells in milk or semen. Normally, the donor cells are frozen in liquid nitrogen and thawed when the cloning step is done.

This method of cloning is often termed somatic cell nuclear transfer (SCNT) because somatic (body) cells are used instead of germline cells such every bit sperm, eggs and early on embryos.

"SCNT is not a very practical procedure for many reasons," Seidel continued. "Beginning, success rates are very low, making information technology very expensive. In addition to the expensive equipment needed, plus the services of skilled personnel, many embryos must exist transferred, using many recipients to produce few pregnancies."

"Oocytes must be obtained from abattoir ovaries or via transvaginal aspiration from ovaries of follicle-stimulating hormone-treated donor cows. These expenses add up to over $x,000 per calf produced and much more than for other species such every bit horses considering success rates are even lower than with cattle."

For the cow-dogie producer, the challenge is to stay informed on advanced breeding technology and adopt techniques that will economically increase product efficiency on his or her operation.