Technical Service Hybrid Turkeys
Ontario, Canada
Introduction
Maximizing fertility begins in the dark-out building with attention to environmental management, nutrition, lighting and biosecurity in order to capture the genetic ability of your breeder candidates. If the dark-out period is not optimal and the flock is not uniform or physiologically prepared to come into production, you will not experience the best overall fertility or maintain good fertility throughout production.
An insemination program that maximizes fertility must focus on each of the following areas:
- Conditioning of toms and hens
- Farm labour and facilities
- The insemination process: collection, handling and insemination
- Quality control
Conditioning of toms and hens
To maximize fertility you require quality semen. This means a healthy fit tom and hen with good leg strength and footpad quality. Toms need to be selected appropriately. Dispose of males that come into semen production late, produce weak, watery or off-colored semen or semen volumes less than 0.2 cc.
Having good quality semen available for the first insemination is crucial. Toms should be pre¬milked 3 times prior to the first insemination. To maximize use of semen, some companies use the semen from the third pre-milking of younger toms, to spike hens that are later in production.
Lighting hens at 29 to 30 weeks of age and then inseminating 14 days later is standard practice. You must get semen into the hen before she lays an egg to get the highest fertility. Through proper conditioning of the hen, you should be able to artificially inseminate (AI) at least 99% percent of the hens during first insemination.
The insemination program
Hybrid Technical Service staff have had the opportunity to observe and evaluate many different insemination programs. Table 1 illustrates the AI programs used by five major turkey companies in North America on their Hybrid breeding stock. Graph 1 shows the resulting fertilities.
Note: The programs used by these companies on other breeds could be different. It is recommended that you consult the technical service person for the primary breeder whose stock you are using to determine how to maximize fertility for their particular breed or strain.
It is recommended to inseminate hens three times in the first 10 days. First AI usually occurs 14 days after lighting. Although most companies inseminate once per week thereafter, some have successfully lengthened this interval to 10 days with no decrease in fertility and have been able to save insemination dollars per flock.
Farm labour and facilities
Artificial insemination in the turkey industry began as a means to control disease but also to increase the number of fertile eggs (and consequently poults) for sale. To accomplish this, it became necessary to properly train individuals to ensure that the insemination process was done correctly. Having competent AI technicians is critical to the process of good fertility. It is also important to have a manager or service technician that is dedicated to the AI program for each company.
Careful handling of the hen during the AI process is central to maintaining good fertility. Crews must pace the hens while herding them to the AI chute to avoid piling and scratching. It is always a good practice to have the same crews inseminate the same barns on each farm. Barns need to be in good condition for both hens and crew members. Gates and fences should be maintained and built properly. If gates are not working correctly there is a good chance that some hens are escaping into the "inseminated end" of the barn. Are the nests in good condition? It is possible to have hens escaping into aisles and not put back into the proper pen to be inseminated. As part of a good AI program, the AI crew should be regularly checking hens located in the tight or cull pen. If hens have been identified as tight, they should be removed from flock. Hens marked "suspicious" or "broody" should be checked by the AI crew during every insemination.
Artificial insemination process
Good quality semen has a thick consistency and a pearly white color. Semen with a reduced concentration of spermatozoa is grayish in color and watery in appearance. Deep yellow buff colored semen usually has a high content of defective and/or under developed spermatozoa, which if used will result in lower fertility. It is critical when pooling semen to use only good quality semen from each tom. Depending upon the reason, semen from one poor tom could affect the holding ability and fertilizing potential of the whole sample. If semen looks visually normal in color and consistency, you can be relatively sure that spermatozoa concentration and motility of semen are satisfactory enough to assure high fertility. However, when in doubt, discard it (refer to Hybrid Turkeys Info Sheet "Semen Quality" for more information).
To obtain the maximum amount of good quality semen, all males should be collected a minimum of twice per week. Two days rest between milking is recommended. Lapses for extended periods can lead to a lowering of semen production and quality of spermatozoa. Toms which are kept for "back up" or "insurance" purposes only should also be regularly milked. If this semen is not absolutely required, it should be discarded.
To minimize the chances of faecal contamination of the semen it is recommended that male turkeys not be fed 4-6 hours prior to semen collection. If they are to be collected first thing in the morning, delay feeding until afterwards. Semen should be milked into a clean vial or syringe which contains a pre-determined amount of extender added before milking commences. Disinfectant or soap should never come in contact with semen vials - the residue it leaves will kill semen cells. Begin with 3cc of extender added to the empty vial, with maximum semen-plus-extender per vial being 12cc.
Whether your semen comes from "on farm" toms or a stud facility, placing vials of extended semen into an agitator at 100 RPM at 37ºF (3ºC) will increase the lifespan of the semen. Ice packs or crushed ice are recommended. Vials should have a large surface area to allow maximum access to oxygen during the agitation process. Semen can be transported from the stud facility to the laying farm in temperature-controlled coolers if transport time is less than 30 minutes, but it should be placed into an agitator once it arrives at the lay farm.
Quality control
Written programs must be in place to ensure consistency between farms and to ensure that mistakes do not happen due to lack of knowledge or understanding by farm staff. Collection and analysis of data can prevent errors from happening, and allow early detection - and correction - of potential problems. Very small errors can result in large drops in fertility.
Recording the following information has been found to be useful in maximizing fertilities:
- Precise data from each milker/milking including date, number of toms milked per pen, quantity and quality.
- In a stud facility, analysis of each prepared vial with the data recorded.
- All equipment used in semen analysis is regularly checked and calibrated.
- Occasionally use a spectrophotometer to sample semen directly from the AI straws from the last vial of the day.
- Time of preparation for each vial and time it is used.
- Semen filtering may have a positive effect on quality. Filters from each milker should be monitored for the amount of faecal material. This can be done by wiping the filter with a tissue or paper towel and comparing the amount of faecal material between filters and milkers.
- Weekly fertility checks on all flocks.
Summary
Artificial insemination of turkey hens is a very labour-intensive activity ... and is not the career of choice for most people! However, to have an effective AI program, it is essential to have dedicated workers with a high level of expertise. Successful insemination, and high fertility results, depends on those persons milking the toms and those doing the actual inseminating. If a company can realize this by ensuring good working conditions and treating this job as a specialized position, the payback will definitely be there in maximum fertility.
From Proceedings of the "Midwest Poultry Federation Convention", St. Paul, Minnesota, U.S.A. and by courtesy of Hybrid Turkeys.
