With pork production margins being squeezed, new technology must be economically feasible — and intrauterine insemination has yet to pass that test.

That's the view of reproductive specialist Don Levis, new director of Ohio State University's Pork Industry Center. The intrauterine approach has not proven to be cost-effective when using 2 or 3 billion sperm, nor has it achieved positive results as a low-dose option with 1 billion sperm per artificial insemination (AI).

Three Research Projects

Three recent research projects compared traditional cervical insemination with intrauterine insemination.

Intrauterine insemination is the process of placing sperm directly into the uterine body instead of the cervix, explains Levis (See Figure 1). Fiberoptic deposition is another method being investigated. Contractions carry sperm through the uterine horns to the oviduct where fertilization takes place.

In a research project in the United Kingdom (U.K.), a new intrauterine catheter was compared to a standard, intra-cervical catheter. The trial compared insemination with an 80 ml. dose containing either 1, 2 or 3 billion sperm. There were five farms on which 3,240 sows were artificially inseminated, representing Camborough and standard PIC grandparents.

Levis says the U.K. study shows no big differences in farrowing rate or litter size between the two types of catheters when sows were inseminated with 2 or 3 billion sperm per dose. When sows were inseminated with 1 billion sperm per dose, the standard catheter recorded a lower farrowing rate (65.8%) and litter size born alive (9.0 piglets). The intrauterine catheter achieved an 86.9% farrowing rate and 10.9 piglets born alive.

Overall, results achieved in the U.K. with both catheters were similar, says Levis. But he says the fecundity index (FI) of sows inseminated with the intrauterine catheter (1 billion sperm cells) shows there were 46 to 53 less piglets per 100 sows bred than sows inseminated with the cervical catheter and 2 or 3 billion sperm. The FI is calculated by multiplying the farrowing rate by the litter size born alive.

The reproductive efficiency of three commercial herds in Argentina was also studied, involving 254 sows from different synthetic and PIC breeding lines, says Levis. Half the females in each herd were inseminated traditionally with 100-ml. doses (3 billion sperm). The other half of the sows in each herd were divided into two groups of intrauterine inseminates. Sixty-two of those sows received 50-ml. doses (1.5 billion sperm) and 65 sows received 30-ml. doses (1 billion sperm).

In this study, the farrowing rate was higher for sows in Herd B that were intrauterine-inseminated with the 50-ml. dose (1.5 billion sperm) than for sows receiving 30 ml. (1 billion) intrauterine dosages or 100 ml. (3 billion) cervical dosages.

For Herds A and C, sows cervically inseminated with 100 ml. of semen posted a higher farrowing rate than sows bred by intrauterine insemination, says Levis.

“Sows cervically inseminated with 100-ml. doses of semen had the highest values for total piglets born (except for sows in the first herd inseminated with the 50-ml. intrauterine dose) and the number of piglets born alive,” he observes. Fertility, farrowing rates and piglets born alive were similar for the three herds.

The results for those three Argentinean herds (Table 1) reveal that a single reproductive trait can't be used to demonstrate the value of a product or procedure on total reproductive performance, stresses Levis.

A better picture of catheter performance is provided through a fecundity index of the three Argentinean herds. The index shows that sows in Herd A, cervically inseminated with the 100-ml. (3 billion sperm) dose, had 98 more pigs than sows intrauterine-inseminated with the 50 ml. dose, and 38 more pigs than sows intrauterine-inseminated with the 30 ml. dose.

In Herd C, sows cervically inseminated with 100 ml. of semen had 106 more pigs than the 50-ml. intrauterine group, and 201 additional pigs compared to the 30-ml. group of intrauterine inseminates.

In a Midwestern project, there was no difference in fecundity index for sows inseminated with a cervical catheter (80 ml., 3 billion sperm cells) or intrauterine catheter (80 ml., 1.5 billion sperm cells). Regardless of the method used for insemination, farrowing rate was low for sows cycling seven to eight days after weaning and for repeat breeders.

Table 1. Reproductive performance for fertility rate at Day 30 (%), farrowing rate (%), total piglets born and piglets born alive, with traditional A.I. (100 ml in the cervix) and the intrauterine technique (50 or 30 ml) in three different swine herds (Argentina data).
Fertility rate (Day 30) Farrowing rate
Treatment Herd A Herd B Herd C Herd A Herd B Herd C
30 ml dose (1.0 billion) 87.50 70.83 94.12 87.50 62.50 94.12
50 ml dose (1.5 billion) 83.30 66.67 92.85 75.00 66.67 92.85
100 ml dose (3.0 billion) 81.25 82.42 96.77 79.20 64.58 96.77
Overall Mean 83.30 77.08 95.16 80.20 64.58 95.16
Total piglets born Piglets born alive
Treatment Herd A Herd B Herd C Herd A Herd B Herd C
30 ml dose (1.0 billion) 10.05 10.85 11.56 9.58 8.92 10.44
50 ml dose (1.5 billion) 12.77 10.65 12.69 10.76 9.91 11.61
100 ml dose (3.0 billion) 12.45 11.28 13.33 11.42 10.03 12.23

Moreover, Levis points out that an economic analysis of intrauterine vs. cervical insemination must account for many variables. He concludes that intrauterine insemination technology generally reduces the production cost of a dose of semen as costs are either reduced or spread across more doses.

But when genetic costs are added back into the cost of pregnancy, intrauterine technology does not appear to be cost-effective. “It forces a reallocation, not an elimination, of genetic costs,” he states.

An economic model, created in Microsoft Excel, is available by contacting the Ohio Pork Industry Center (e-mail: levis.7@osu.edu; phone: (614) 292-1351; fax: (614) 292-3513).

Also to be considered with intrauterine insemination is the increased cost of employee training, as well as a lower biosecurity risk with fewer boar studs required.