A recent study conducted by M.M, Buhr, L. Bosch and E.F. Curtis of the University of Guelph compared the effectiveness of BTS extender and Androhep. Both products are very popular in the swine industry and the debate regarding product superiority has raged for many years. Results from the study were published in the 1998 Ontario Swine Research Review as well as the Ontario Farmer (May 26, 1998). The following comments are a summary of the report printed in the 1998 Ontario Swine Research Review.

"Little difference was found in a trial examining how well two popular semen extenders work. Sperm from five boars were processed as if for artificial insemination (AI) using commercial extenders Androhep and BTS."

Results indicated that there were "highly significant differences among boars and between ejaculates from the same boar." "Androhep was marginally better than BTS in preserving viability, and BTS was considerably better than Androhep at maintaining motility." They also found that "many sperm cells were apparently alive and swimming even after ten days, when we know that fertility is almost impossible." It was their opinion that "the different effects of BTS and Androhep on motility and viability make it difficult to select one "better" extender."

The researchers suggested that producers should not be concerned about whether their supplier uses Androhep or BTS extender, but could ask their supplier to identify boars whose semen lasts longer. They further noted that their trial did not attempt to measure field fertility, but added that "other work has found little difference between these extenders."

Following is a summary of two other papers discussing trials that evaluated boar semen extenders.

1. Jean-Paul Laforest at Laval University in Montreal conducted a trial which compared B.T.S., Modena, MR-A and Androhep. Effectiveness of the extenders was evaluated based on a field trial that measured farrowing rate and litter size. The 3 to 4 day Androhep farrowing rate was 88.6% while litter size was 11.7. Semen diluted with BTS produced a farrowing rate of 83.3% and litter size of 11.5 when the semen was 3 to 4 days old. Statistically speaking the difference between these results was not significant. Laforest expressed the opinion that "a miraculous long extender is not available for the moment and might never be. ... In practical terms, on farm, reproductive management, especially heat detection and follow up of gilts and sows after insemination are probably the most important factors affecting the results of AI."

2. In a trial conducted by Drs. L.A. Johnson, J.G. Aalbers and H.J.C. Grooten 2896 gilts and sows on 1463 farms were inseminated with one, three and four day old semen. The semen had been processed at six different AI units. The extenders compared in the study were BTS, Modified Modena (MM) and MR-A. Semen used on days one and three contained 3 billion cells, while day 4 semen contained 6 billion cells.

"Sows inseminated with BTS and MR-A extended semen had higher farrowing rates than MM (79.3, 77.6 vs 50.4, P<.0001), higher total pigs per litter (11.4, 11.1 vs 10.0, P<.0001) and higher total pigs born alive (10.7, 10.5 vs 9.4, P<.0001)." Although this trial did not compare Androhep it does show that BTS is a very effective semen extender.

With deep regrets we were informed of the passing of Mr. Warren Stein. Warren has been an acquaintance since 1965 and I can still remember the time when the Stein family had the foresight to purchase the high health SPF herd owned by Fred W. Stock.

Warren always had a distinct vision for Ontario's hog industry and its many members. His passing leaves a great vacancy which will be felt by many.

The original BTS extender was developed by a team of researchers working under the auspices of the Research Institute for Animal Science and the Federation of Swine Artificial Insemination Societies. Drs. L.A. Johnson, J.G. Aalbers and H.J.C. Grooten were looking for a product with which semen could be frozen more effectively. During this process they found that a particular combination of selected ingredients was very effective for fresh semen preservation. The product was named "Beltsville Thawing Solution" or BTS for short.

The formula for BTS was never patented as funding for the research project was provided by the Dutch and American government. Consequently other parties have been able to copy the formula for the extender and a variety of BTS products is now available on the market.

The Federation of Swine Artificial Insemination Societies continues to sponsor research in the area of semen extenders. Funding for this work is derived from royalties paid by those who use the Federation's extender formula.

ITSI has and continues to carry the extender used by the Federation of Swine Artificial Association Societies as this in our opinion is a product of the highest quality and most economical to use. The best advice that we can give is to design your own trial and evaluate both lab and field results. If you would like assistance with the design of such a trial, please contact our office.

ITSI is pleased to offer Dymax ultrasound technology to its customers. Dymax has been developing ultrasound technology for 18 years. They are known as an innovator in this rapidly changing field.

Dymax TM18, a pregnancy tester designed specifically for the swine industry, has been available in Europe for 5 years. The unit is new to North America due to marketing agreements with other companies.

The TM18 offers a light, compact alternative to competitors. It includes 2 batteries and a charger. For more information, or a demonstration please contact your local ITSI representative.

Insemination Technics and Supplies International, Inc.
1-800-692-4874

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Alberta: 403-944-2575
Manitoba: 204-736-4112
Quebec: 418-692-1932
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E-mail: information@itsi-ai.com

The following article, written by Michelle Follensbee, has been reprinted with permission from the Western Hog Journal winter 1998 edition.

Pregnancy detection is a key component of breeding management. Detection of open animals can reduce non-productive sow days, maximize facility utilization and be useful in predicting future production.

Although boar exposure provides the most cost-effective means of detecting open sows or gilts, it is not foolproof. Pregnancy detection is most commonly done with A-mode or Doppler ultrasound. A-mode ultrasound machines emit a beep in response to fluid in the reproductive tract. Dopplers allow the user to hear movement associated with fetal heartbeat and blood flowing through the uterine artery. These instruments are accurate beginning around day 28 to 35 of gestation. They are easy to use and inexpensive, however, they are prone to false positives.

The results of Real-time Ultrasound (RTU) are displayed as a two-dimensional image allowing the user to see the reproductive tract stated, "the chance of a diagnostic error is reduced compared to other methods of pregnancy detection."

TABLE 1: Accuracy of Real-time Ultrasound

Day of Gestation: 17-20 21-23 24-30 38-44 52-58 Sensitivity 79 100 100 100 100 Specificity 50 58.3 70 44 37 Accuracy 75 97 98 98 99

Glen presented the results of a field trial with 305 sows and gilts that were pregnancy tested using RTU from day 17 to 58 of gestation (Table 1). Sensitivity is the ability to correctly diagnose pregnant animals as pregnant. Specificity is the ability to correctly diagnose open animals as open and accuracy is a combination of the two.

Glen pointed out that although the specificity does not appear that reliable with RTU it is able to detect open animals much earlier than other pregnancy detection devices.

TABLE 2: Cost of Real-time Ultrasound

Sows/Week Total Sows $/Sow Tested $/Year 25 500 2.21 2878 100 2000 0.50 2605 500 10000 0.04 1149 Based on an initial instrument cost of $9000 (US) with a life of three years and maintenance costs of $400 (US)/year

Dr. Almond described RTU as a new technology that is becoming affordable. The ultrasound instruments used at the seminar were roughly $8,000 (US). Although the RTU probes are expensive, they may be cost-effective on large operations, especially where farrowing rate is a problem. Dr. Julia Keenliside, Alberta Provincial Swine Veterianarian, felt that RTU could be a very useful tool for diagnosing breeding problems and for evaluating pregnancy detection methods and techniques currently being used on farms.

The North Carolina State University Extension Service has developed an interactive web site (http://mark.asci.ncsu.edu/reproduction/rtu/rtu.htm) with several spreadsheets for determining the economics of owning and using Real-time Ultrasound for pregnancy determination. One of the spreadsheets details the cost of Real-time Ultrasound relative to the number of sows tested per week (Table 2).