May 23, 2022 7:34 am

A roadmap for timed artificial insemination

Cattle breeding has been modernized in various ways and has absorbed new techniques in recent years. One of those that can generate the most productive and economic impact is the fixed-time artificial insemination (FTAI), that allows to improve the reproductive indices of the wombs and the genetic quality of the weaned calves.

Miguel Riso, INTA technician, defines the IATF as “a technique that, through the use of hormones, allows the synchronization of oestrus and ovulation of the wombs, with which a large number of animals can be inseminated in a short period of time”.

With this tool, the work of heat detection, which constitutes an error factor, is eliminated, the insemination time is reduced, the proportion of cows that calve early increases and it is easier to attend calvings, which are concentrated in a specific period. brief.

The control of the cow’s cycle is achieved by applying a treatment based on hormones that the female produces naturally, basically estradiol and progesterone, in such a way that the day and time of ovulation of all the treated bellies is synchronized. This allows all the cows to be inseminated at a fixed time and achieve pregnancy rates similar to those of a natural heat.

Some producers have little knowledge of the IATF and are afraid of moving from the conventional service with bulls, developed over many years, to schemes that allow reaching new productive ceilings.

Ricardo Seguí, a veterinarian from Ayacucho who, with his work group, attends to 30,000 breeding cows in the Salado basin, 9,000 of which are already under this system, dispels those apprehensions. “Artificial insemination at a fixed time can be implemented from one year to the next with good results, if due precautions are taken,” he clarifies.

With the IATF you can access breeding genetics

First, it is necessary to have suitable and motivated personnel, with good management of the farm. Second, facilities in adequate conditions (corrals, chute, traps, locks, etc.)

Regarding the requirements of the farm itself, a satisfactory body condition of the cows at the time of calving must be ensured, because this factor determines the time of the first subsequent heat. “Satisfactory body condition should not be synonymous with a fat cow, but rather in good condition. In the classification that goes from 1 to 5, it is necessary to have 3-3.5. Thus, with good body condition, 45-50 days after calving, FTAI can be implemented”, abounds Follow.

If the cows have a lower body condition –for example 2 or 2.5- insemination can also be implemented, but if a subsequent feeding is ensured that allows weight gain to be achieved. If that process does not occur, the pregnancy rate will be compromised.

In practice, in herds of mature cows with service of three months, the IATF can be organized in thirds, separating the herd in “head” (calves during the first 30 days); “body” (from 31 to 60) and “tail” (calves in the last 30 days). In heifers, this classification is not necessary because they normally arrive at service with good ovarian activity.

In herds in good nutritional status, the possibility of inseminating part or all of the herd on a predetermined date allows high pregnancy rates to be achieved and simplifies calving care.

The IATF also allows access to rodeo-improving genetics quickly, through the use of semen from high-performance bulls, which have a favorable impact on production rates. The technique makes it possible to enter the field with “state-of-the-art” genetic packages and set a course very quickly.

First, it is necessary to have suitable and motivated personnel, with good management of the farm. Second, facilities in adequate conditions (corrals, chute, traps, locks, etc.)

Naturally, the decision of which genetics to choose from a catalog of an insemination center has to do with the forage production of the field, with its production system, with the destination of the production (calves for sale at weaning, rearing or complete cycle) and with the degree of complexity that the breeder admits, among other factors.

However, beyond each particular situation, there are genetic attributes that must be privileged in breeding herds. For example, if a field in the Salado Basin is considered, there are numerical records that should be considered.

Seguí attaches great importance to fertility and a moderate adult weight of cows for fields in the depressed area of ​​the province of Buenos Aires. “In most of the national production conditions, breeding cows are fed all year round on grass, with which they must cover all their requirements, plus some hay or silage supplement in the best of cases. Therefore, in general, moderate-sized cows that are easy to maintain are suitable,” he recommends.

Another parameter to take into account is milk production, a character with which care must be taken because it is linked to a greater demand for energy. If the production system is not prepared to meet the requirements of a very dairy cow, she will lose body condition and her future pregnancy will be compromised.

Beyond these predictable parameters through the Expected Differences Between Progenies (DEP), it highlights the importance of the structural correction of the breeder, from the head to the hooves. “It is convenient to see the bulls live, in addition to the illustrations in the catalogs, because there may be inconspicuous deficiencies in a photo, such as bad hooves, incorrect poise, temperament problems, etc., which will be transmitted to offspring and create a problem. where there wasn’t,” he warns. Among other characters, structural correction requires reviewing the size, poise, genitalia, depth, width, butchery muscles and the breed quality of the breeder to be incorporated in each herd.

For his part, Santiago Debernardi, genetic advisor and commercial manager of Select Sires & Juan Debernardi, says that “fixed-time artificial insemination in commercial rodeos generates many advantages, which is why it has been growing exponentially in recent years.”

The benefits can be classified into two large groups. On the one hand, it can improve reproductive management and herd management. On the other hand, it gives the possibility of making an improving genetic contribution. Both impact the profitability of breeding.

The advantages for herd management are as follows: “With a hormonal shock, cows that do not come into heat due to insufficient nutrition after calving can be activated. Thus, with the placement of intravaginal devices, the next pregnancy is brought forward to have much more “head” for calving. In addition, with insemination you can have calvings in a shorter period of time, concentrated, which facilitates efficient feeding of the cows and prepartum vaccinations”, argues Debernardi.

There is genetics to get calves with more kilos at weaning
There is genetics to get calves with more kilos at weaning

The contribution to the organization of the rodeo is specified in the previous stages. “The implementation of artificial insemination requires several previous steps that are carried out throughout the year in order to arrive in good condition at the time of insemination. These steps are a well-armed forage chain so that the cows are eating well after calving, their location close to the chute, the organization of calving cuts, among other precautions”, lists the businessman.

On the other hand, the IATF gives the possibility of introducing genes from animals tested in the herd and making an improvement genetic contribution. The genetic adviser and commercial manager of the company explains that “since the frozen semen could be kept to be used later, the opportunity to test the breeders before using them was created.”

With this technique “you can know in advance the contribution of a bull in the weight at birth of a calf, in its weight at weaning or in its weight per year. With these measurements, it is possible to find out which is the one that best transmits these characteristics to its offspring, in order to later extract semen and massify it”, adds Debernardi. With this methodology, characters such as maternal ability, speed and ease of fattening, and efficiency of feed conversion into meat, among others, are being measured. All this is the genetic information that the breeders have that can be incorporated into commercial herds.

Particularly for a farm in the Salado basin, which generally sells its calves at weaning, the genetic advisor says that artificial insemination allows the incorporation of maternal genetics. This concept translates into using semen from bulls that produce longer-lived cows, that are easily bred, docile and with a high efficiency of conversion of grass into meat, to be able to survive in good and bad years adapting to periods of food restriction.

“Today there is genetics that meets these characteristics and allows us to produce calves with 30 kilos more at weaning in the same environment and with the same forage resources of the basin, through fixed-time artificial insemination,” Debernardi concludes.

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