Fixed-time AI: the benefits of AI without heat detection

News
Mar 15, 2013
art8515

Tail paint and stick-on detectors; these and others are the trappings of heat detection, a necessary evil if one wants to reap the benefits of artificial insemination (AI). But the effort of watching for the tell-tale signs of a cow in heat is often beyond the constraints of most commercial cattlemen.

But there is another option, fixed-time AI (FTAI). FTAI, while labor-intensive in its own way, sidesteps this issue by allowing for AI without heat detection.

Generally speaking, FTAI dispenses with heat detection by synchronizing a group of heifers or cows via a combination of hormones and then breeding them all at once by AI. Depending on which protocol is being used, cattle go through the chute three times over the course of a few days to a few weeks and are handled all at once at any given time. Because the cattle are treated as a group and are synchronized based on a schedule, heat detection and the necessity to check on cattle multiple times a day is removed.

FTAI protocols were first developed by the University of Missouri (MU) Extension’s beef reproduction specialist, David Patterson, in the early 2000s. Extensive research has been conducted at MU and later by other universities.

Benefits

B.J. Macfarlane, manager of the Shasta College Farm in Redding, CA, runs 50 of his own commercial cows and has a cattle-breeding business where he breeds other people’s cattle in northern California and Oregon. When asked what drew him to using FTAI rather than usual AI systems requiring heat detection, he answered:

“Time management on large groups of cows and heifers. And time management is the biggest advantage. You don’t have to heat check them and you’ll get more AI-sired calves.”

This latter point is another frequently-cited motivating factor for FTAI or AI in general: better calves faster. At a 2011 presentation by the Beef Reproduction Task Force—a multistate initiative combining the efforts of eight different state Extension programs—Mike Kasten of Millersville, MO, presented the results of his operation’s experiments with AI.

“None have worked remotely as well as the fixedtime AI breeding protocols we are using today,” he told the audience.

Kasten’s commercial cow/ calf operation is focused on producing “white table cloth” beef and replacement heifers for the “Show-Me-Select” program. Kasten has been working with AI for 38 years and has found it to be essential in genetic improvements of his herd. He called the genetic benefit of AI without the necessity of watching cows for heat detection afforded by FTAI exceptionally beneficial to commercial cattlemen.

“The access to high quality proven genetics is certainly the biggest positive of all,” Kasten’s presentation concluded. It also went on to point out, “The ability to use one bull over large groups of females is a great benefit. [It g]ives you the ability to target genetics for a specific end product.”

The convenience of FTAI over standard heat-detection AI is also an important detail. Kasten reported his operation doesn’t heat-detect at all and the ability to breed all animals at one time is a tremendous time-saver.

“Timed AI it makes life easy and especially when I’m breeding someone else’s, they like that it gets done in a day,” said Macfarlane.

He uses the Select-Synch with 7-day CIDR (controlled intra-vaginal drug releasing) insert FTAI protocol and he generally only runs it on hiefers. He said he also uses the same protocol with good results on his embryo recipient cows. Kasten uses the “Show- Me Synch” protocol for heifers, which requires four trips through the chute and a 14day CIDR. According to Iowa State University Extention’s Iowa Beef Center (IBC), this protocol is the easiest in terms of labor and cost relative to other recommended FTAI protocols.

Various studies from academic sources on FTAI have found more cattle conceive earlier and that the short time some of the protocols last allows for multiple chances to conceive in a 60- to 65-day breeding season. And getting the entire herd—or an entire class within the herd, such as heifers vs. cows—AI serviced on one day means a greater likelihood of getting calves born in a tight window. Macfarlane said this, too, was another great benefit.

“You’ll have all your calves born in one month. Some will be two weeks early, some will be two weeks late, but you get them all at once rather than strung out over 60 days or more.”

Kasten’s presentation cited some economic benefits associated with the calves born of FTAI protocols. In the firstyear results of their FTAI breeding trials, they noted increased age of calves at weaning (average 11 days) due to more calves born early in the target calving window; time and animals saved during calving since there was a better ability to predict when calving would happen and resources could be allocated accordingly; and increased weaning weights do to age and genetic improvements afforded by AI sires.

Challenges

FTIA is not without its challenges, however. As with any AI system, it is more labor- and cost-intensive than natural service. IBC has a list of recommended FTAI protocols and all of them rank either medium or high in both cost and labor on a low-medium-high scale.

The cattle must be run through the chute at least three times in most FTAI protocols, which means they must be gathered and placed somewhere for a while for easy access—which necessitates facilities and feed stored up at the location—or gathered each time, and must be

handled each time. But the removal of the heat detection step makes the handling far easier since the same thing is being done with each animal at each step.

Kasten estimated from his operation’s FTAI breeding trials that the time it takes for an animal to be handled with him and a helper is roughly five minutes per cow and slightly longer per heifer. He additionally tracked the cost per head at about $36 head for the necessary hormones, supplies, labor and semen (at $20/straw) for the whole protocol.

For Macfarlane, however, one of the biggest issues is conception rate.

“In the past, the conception rates [with FTAI] were not as good as with heat detection,” he said. He did emphasize, however, that ever-increasing work and research on FTAI has largely fixed this issue. He also mentioned that more AI-sired calves get produced in FTAI simply because “semen gets in more animals” rather than with heat-detection AI programs.

Conception rates with FTAI can vary because of a number of factors. Age, body condition, nutrition, management, and chosen protocol all play a relevant role in conception rates. That said, a consensus seems to exist across academic studies that FTAI conception rates float around the 55-65 percent range for heifers and 60-70 percent for cows when done properly and with well-chosen protocols for the situation.

Kasten reported the first three years of heifers bred in his FTAI trials (born in 2001, 2002, and 2003) had, by breeding season 8, 7 and 6, respectively, good retention and overall AI conception rates. The number of animals still in the herd ranged from 63-71 percent and the percentage of AI services resulting in a live calf over the lives of those animals ranged from 74-77 percent.

While both Kasten and Macfarlane are commercial cattlemen and have found FTAI to work well for them, Kevin Borror, manager of the Tehama Angus Ranch, has not found it useful to his seedstock operation. They have been doing heat synchronization and heat detection on their females. Having that ability has made FTAI not overly attractive to them.

“The biggest problem was we didn’t get as many bred. I think some of the heifers may—and I stress ‘may’— have even skipped a cycle because we had more heifers calve in the third cycle than ever.”

Borror did point out, however, that they had only tried FTAI once on heifers and a little on their spring cows, which he described as hard to get bred regardless the method. Despite his experience, he was aware of and frequently cited the data supporting FTAI. He agreed that, if lacking the facilities or time necessary to heat detect, FTAI might work for a producer wanting to take advantage of AI.

Macfarlane had a suggestion to anyone considering adding FTAI to their breeding program.

“Don’t get discouraged because chances are your first and second year might not be as good as you’d like on conception rate,” he said. He pointed out, however, that diligence and being willing to try out different protocols to find what works best is essential. For him, the benefits outweigh the difficulties.

“There’s too much to be gained on genetics with an AI bull.”

Kasten, too, has found the benefits of FTAI outweigh the challenges. He has created the Kasten Beef Alliance—a cooperative with other commercial cattlemen who buy his replacement heifers—because of his dedication to genetic excellence in commercial cattle and was awarded the 2004 Commercial Commitment to Excellence Award by Certified Angus Beef LLC.

Kasten advised the audience of his presentation that discipline in sticking to a protocol and trust in the technology is key for someone considering FTAI.

More information

There are a number of available protocols for FTAI. Protocols vary greatly based on a number of factors such as whether it’s being used on cows or heifers. And—as one agricultural blogger said— there seem to be new tweaks each year as new data is collected and different tactics are discovered.

Generally speaking, FTAI involves the application of Gonadotropin Hormone Releasing Hormone (GnRH), progestin, prostaglandin F 2 (PGF), and AI in some combination. Protocols differ on when to apply the various elements, how often, and on what days in the cycle.

For example, one of IBC’s recommended FTAI protocols for heifers calls for the application of a GnRH and an intravaginal progesteronereleasing insert on the first day, removal of the progesterone insert and application of a PGH on day 7, followed by another application of a GnRH with the AI service on roughly day 9. See the infographics on page 21.

There is a wide range of commercially available hormones suitable for a FTAI.

Check with your veterinarian and/or Extension program representative for advice on what might work for your operation.

There are more suggested protocols listed on iowabeef center.org/estrus_synch.ht ml. Some of the original research and researchers on FTAI can be found at the MU Extension at extension.mis souri.edu/. — Kerry Hallday, WLJ Editor

{rating_box}