Complying Hormonal Protocols

Low fertility in dairy cows is due many factors, and has created an important reduction in the economic benefit in the dairy business. It is clear that high milk production is compromising the duration and intensity in the heat expression (Wiltbank et al., 2006). The implementation of heat synchronization programs and ovulation are necessary to optimize the reproductive efficiency in the herd. (Santos, 2007).  Scientists and researchers developed a reproductive synchronization system that helps to overcome the problems and limitations, increasing the opportunities and herd fertility. This program was developed in the University of Wisconsin – Madison in 1995. (Pursley et al., 1995) and is known with the name of “Ovsynch Program”; there are a variable number of protocols and synchronization programs with different names but all of them are based in the same principle.   

The insemination programs and specially the Time Artificial Insemination (TAI) require an important investment of time, money and hard work in a very short period of time; those should be made fully and consistently every week.  The requirements for a TAI program are compatible with the hormonal protocols used to synchronize the estrous and a high percentage of animals will be fertile at the insemination time; however the synchronization protocols that allows the TAI and minimize or eliminate the heat detection should be implemented in a practical and easy way into the daily operation of the dairy or the program will fail due to a breach and lack of protocol compliance. (Fricke et al., 2003).

Many factors can affect the fertility, like body condition, nutrition and health, management and milk production, environmental temperature and comfort; the surfaces where the cows are walking, standing and eating, socializing and during the milk process. The animal distribution and parity as well as overcrowding are factors that affect the fertility of the herd. 

Figure1. Cause and Effect Chart for Pregnancy Production

 

Figure 1. Illustrates all the elements that interact to reach an effective pregnancy production

The success or failure of any heat synchronization program or TAI depends of many factors, some of them were mentioned before like factors that affect the fertility; there are other ones, like the non-compliance of the synchronization protocols, the mistake in the hormone management or the place or time of the application. The strict compliance in the injections and hormonal management are fundamental factors in the success of the program, as well as how the animals will respond to these injections; these factors will explain the variations in the results of the TAI programs. The estrous cycle, the follicular wave dynamics as well as the non-cycling cows are factors that affect the results and the ability to implement and develop a synchronization program in the herd and are fundamental factors in the success or failure of the program (Adapted Fricke 2005).

There is evidence that demonstrate that the synchronization programs works well in high productions cows. Both scientific research and anecdotal evidence supports the idea that Ovsynch and Pre-synch works well for high production cows in North America managed under confinement systems. Many factors affect reproductive performance, and many consultants have observed a wide range of performance among farms that have adopted the same protocol. Reduced performance of these protocols is rarely due the physiologic responses of individual cow to the hormonal protocol, but almost always can be attributed to compliance issues at the farm level. (Fricke et al., 2006)

Regardless which protocol the farm is using, there are fundamental considerations that can determine the success or failure of any TAI program, and some of these considerations are: 

It is the most important condition that determines the success or failure of a program, if the hormonal injections are not administrated the exact day in the correct place and with the complete doses the protocol will fail. Thus, nothing less than 100% protocol compliance should be considered acceptable. Therefore, farms that cannot achieve near 100% protocol compliance should consider focusing on other methods to improve reproductions including heat detection and heat detections aids. (Fricke et al., 2006).

Cyclicity.

The results depend also of the reproductive status of the cow. To reach a good response to the reproductive programs the cow should have active ovaries, she should be cycling and have a healthy uterine track. The an-ovular cows or non-cycling cows should be identified and might consider the use of other hormonal devices that can help to reactivate the ovary function. 

Figure 2. Cyclicity and Synchronization Efficiency.

Figure 2 shows compiled information from a 6000 cows Dairy. The cyclicity and synchronization efficiency goals are 90%; monitoring cows shows that only 68.75% of the cows enrolled in the program were cycling and 63.64% of them synchronized effectively. This is a good example of a herd were a group of cows are not cycling and the compliance of the hormonal protocols is not complete and/or correct getting at the end a low cyclicity and poor synchronization efficiency rate.(ABS Global Inc) 

It is fundamental that the people involved in the hormonal injection process and management understand and know the economic investment that a synchronization program implies, that understand the fundamental bases of the synchronization process and how they work; to do that they should receive a full and complete training in the following points: 

Due to the wide variety of synchronization programs, the people involved should know and understand which programs the farm is using. Some producers are using more than one program; this could be a confusing factor that can affect the effectiveness and program compliance. 

It is important to clarify that we are working with a “synchronization” program, which means that every step in the process should be synchronized too; the schedules in the hormonal injections, days of the week and time should be synchronized also. The days of the week and times should be established clearly in a calendar were every people involved in the program understand and follow strictly; this is a very important factor than can affect the result. 

Table 1. Example that a schedule of hormonal shots and TAI for the Pre-synch/Ovsynch program.

PGF = Prostaglandin F2α

GnRH = Gonadotripin-releasing Hormone

AM = Morning   PM = Afternoon   TAI= Timed A.I 

 It is very important to read the label instructions on each hormonal product used (GnRH or PGF2α). Some of them require refrigeration, sun light exposure or the extreme hot or cold temperatures can affect the effectiveness of the product; knowing and understanding the management, procedures and precautions is essential. In United States the label instruction come in English language, so the label should be translated into the employee’s languages and posted in a visible place for all the people manipulating those hormones.

The use of the proper equipment for the injection administration is fundamental in the program success. The pharmaceutical companies recommend the use of one dose syringes and 16 or 18 x 1½ gauge needle. In almost all research demonstrated that the application in the semitendinosus muscle below the izquiatic tubercle with 1½ inches long and 20 gauge needle minimize the errors. Be sure that the animal is well restrained at the time of the application (Pursley 2006). 

It is recommended that a veterinarian train the personnel that will be doing the hormonal injections to the cows. The correct hormone management, application and procedure are important factors, deep IM is the most recommended way. 

It is fundamental for the program success that the employees receive a clear and complete list of the cows that will receive the injections as well as a proper and clear identification on the cows. The list should be organized by ID number and by pen to facilitate the process. A common complaint for people doing the job is the time that they have to dedicate to find missing cows that are not in the proper pens. Frequently the pushers and milkers mix cows in different pens causing loss of time and delays in the program; sometimes the managers are not updating the cow movements and inventories in the software. It is very important keep the information accurate and updated. Anyway, this situation can’t be an excuse for the employees to fail in the hormone applications; they should find every cow in the list and be sure that they received the complete dose of the right hormone that day. 

Figure 3. Example of an enrolled list

All the synchronization programs should be monitored regularly to determine if the program is working accordingly and to make the necessary adjustments. For the evaluation usually the farms are using special codes in the dairy software. With these codes the conception rate could be evaluated and is easy to see how the environment, temperatures, nutrition, breeding technique, technicians and other factors are affecting the results.

The blood progesterone test is a valuable tool to evaluate the cyclicity and the synchronization efficiency of any TAI program; it is a tool to evaluate the cows and the people, is expected that with high number of animals cycling we will have high number of animals synchronized if the hormones management and compliance is good and well managed. 

Figure 4 TAI monitoring program using blood progesterone test.

 

Figure 4 shows the results from a blood progesterone test to monitor a 6000 cows dairy. The information shows that 100% of the animals were cycling but only 78.95% of them were synchronized, which means that the people responsible to give the hormones shots were making mistakes in the management or hormones applications. (ABS Global)

In normal conditions of health, nutrition, management and compliance the monitoring results should reach the goal of 90% of the cows’ cycling and synchronized. (Figure 5)

 

Figure 5.  Blood Progesterone test to monitor a TAI program, observe that 100% of the enrolled animals were synchronized. (ABS Global)

Today a high number of dairy farms are using any kind of synchronization program. The owners are investing time and money to increase the reproductive efficiency and the pregnancy productions.  Is the responsibility of all the people involved in this program to understand all the factors and comply strictly with all the requirements and responsibilities that the program require. The compliance of schedules as well as the correct hormone management are fundamental factors in the success or failure of these programs. The people responsible of the hormones shots should be sure that every cow enrolled in the list received the complete dose in the right place at the right time on the right day. 

COMPLIANCE IS ALLWAYS THE MOST IMPORTANT INGREDIENT

No matter what program you chose, the injections have to be applied correctly. The compliance is the most important ingredient to make the program works properly. The experience shows that asking people without proper program understanding and training or with poor interest is always a costly mistake. Finally the injection schedules and lists should be always correct and exact (Adapted from Pursley 2007) 

Fricke, P. M., 2005. Systematic Synchronization and Resynchronization Systems for Reproductive Management of Lactating Dairy Cows.  Proceedings of the 4^th Annual Arizona Dairy Conference pp 33-45.

Fricke, P. M., R. A. Sterry. 2006 Management Strategies to Improve Fertility in Lactating Dairy Cows.  Proceedings of High Plains Dairy Conference.

Pursley, J.R., M.O. Mee, and M.C. Wiltbank. 1995. Synchronization of Ovulation in Dairy Cows Using PGF_2α  and GnRH. Theriogenology 44:915-923.

Pursley, J. R., 2006. Seven Ways to Improve Fertility of Dairy Cows. Proceedings of Kentucky Dairy Conference.

Pursley J.R., 2007. Strategies and Rationale for Resynchronization of Ovulation in Lactating Dairy Cows. Proceedings of Dairy Cattle Reproductive Conference. pp.37-42.

Santos, J.E.P. 2007. Optimization Tips and Alternatives for Timed Insemination at First Service. Proceedings of Dairy Cattle Reproductive Conference, pp 23-34

Wiltbank, M., H Lopez, R Sartory, S. Sangsritavong, and A. Gumen. 2006. Changes in Reproductive Physiology of lactating Dairy Cows due to Elevated Steroid Metabolism. Theriogenology 65:17-29