A Cost Comparison of AI and Natural Service

Genetic cost of production in commercial swine operations is influenced primarily by the structure of the breeding herd. The following cost comparisons pinpoint some of the facility, equipment and labor differences between “semen delivery systems” which is a component along with replacement female systems in genetic cost of production.


One of the first steps in developing a genetic program is deciding whether replacement breeding animals will be generated by the producer or purchased from outside sources. Although more and more producers have turned to purchasing replacement gilts from commercial seedstock suppliers, many still produce their own. Arguments can successfully be made for either approach, ANS 94-802S, “Should Replacement Gilts be Raised or Purchased?” addresses this question.


As pork producers have realized the value of more precise genetic programs, much of their attention has turned to buying or producing specific maternal lines and gaining access to specific terminal sires that will push them towards greater market premiums. The procedures used to evaluate these genetic costs of production are the same for all sizes of operations, but there are efficiencies of size.


Semen Delivery Systems


The semen delivery system is simply the type of service that is used for mating. Common semen delivery systems are: natural – pen mating, natural – hand mating, or artificial insemination (AI). The number of boars required will be dictated by the structure of the sow herd and the semen delivery system. To compare genetic costs, the information that is needed is the cost of the boars, the salvage value, annual replacement rate, maintenance cost and insemination cost.




In the following cost comparisons of natural service and AI mating programs price quotes on 10/3/95 provided by Minitube of America were used to determine AI equipment costs. The fixed costs for purchase price of the boars were estimated to be $800 for natural service boars with 3 years of use. On-farm AI boars cost $2500 and were used for 2 years, and boars for a small stud cost $5500 and were used for 2 years. Variable costs for boar maintenance were estimated to be $.75 per boar per day. The boar to sow ratio was 16:1 for natural service, 107:1 for on-farm collection and 250:1 for the small stud. It was also assumed that sows were mated an average of 2.1 times/year. The estimates for labor required per mating are from Flowers (1992) and are based on only one breeding barn design. A labor cost of $10 per hour was assumed for both mating and semen collection and processing.


Cost Comparison


Table 1 presents the cost comparisons per mated sow across mating systems and indicates that AI has a considerable cost savings over natural service. If on-farm semen collection and processing is used rather than purchased semen another large savings can be realized per sow. For on-farm collection and processing there is a cost savings relationship with the size of operation.


Table 1. Cost per mated sow using various programs.

Mating Program Natural Service AI w/Purchased Semen AI w/On-Farm Collection; 200 Sows AI w/On-Farm Collection; 1,000 Sows AI w/Small Boar Stud; 50 Boars
Min./Mating 22.6 13.5 15.3 15.3 15.3
Labor Cost ($10/hr) $ 7.53 $ 4.55 $ 5.10 $ 5.10 $ 5.10
Boar Fixed Costs $ 7.94 $ 5.56 $ 5.56 $ 5.56
Boar Variable Costs $ 8.14 $ 1.22 $ 1.22 $ 0.20
Semen Cost $ 14.00
AI Lab Structure Cost $ 0.68 $ 0.68 $ 0.14
AI Lab Equipment Cost $ 2.04 $ 0.41 $ 0.07
AI Disposable Supplies Cost $ 0.65 $ 0.85 $ 0.85 $ 0.85
Total $ 23.61 $ 19.20 $ 15.45 $ 13.82 $ 11.92


Tables 2 and 3 describe the sensitivity of the costs presented in Table 1 to the assumptions applied on the variables of minutes required per mating and boar to sow ratio. Table 2 shows that if the actual time required for insemination of a sow was 25% greater than the assumption of 13.5 minutes, then $1.14 would be added to the total cost of each AI program shown in Table 1, i.e. AI with purchased semen would be $19.20 + $1.14 = $20.34. If the actual time required for insemination of a sow was 10% greater, then total cost of each AI program would increase $0.46.


Similarly, Table 3 describes changes in the assumptions on boar to sow ratio. If a boar to sow ratio of 125:1 (50% increase in boar numbers) is preferred in the small stud AI situation, this would increase the total cost per mated sow to $14.80 ($11.92 + $2.78 + $0.10 = $14.80). Remember that an additional assumption was that boars in the small stud were priced at $5500 and those in the on-farm AI situations were $2500.


Table 2. Effect of change in time required per mating on total cost per mated sow.

Mating Option Percentage Change
10 25 50
Natural Service $ 0.75 $ 1.88 $ 3.77
Boar Collection $ 0. 06 $ 0.14 $ 0.28
Sow Insemination $ 0.46 $ 1.14 $ 2.28


Table 3. Increase in fixed and variable boar costs per mated sow due to decreased number of sows per boar.

Mating Program 10% Change in Sows/Boars 25% Change in Sows/Boars 50% Change in Sows/Boars
Fixed Cost Variable Cost Fixed Cost Variable Cost Fixed Cost Variable Cost
Natural Service $ 0.79 $ 0.81 $ 1.99 $ 2.04 $ 3.97 $ 4.07
On-Farm AI $ 0.56 $ 0.12 $ 1.39 $ 0.30 $ 2.78 $ 0.60
Small Stud AI $ 0.56 $ 0.02 $ 1.39 $ 0.05 $ 2.78 $ 0.10


The application and use of AI on commercial swine farms offers significant opportunities for increasing profits. Cost savings and additional revenue can be generated by AI from two sources: 1) reduction of costs associated with boar maintenance and 2) increased receipts for market animals due to superior genetic merit. However, in the above examples genetic merit was not evaluated in the cost savings of the mating programs. In addition, the successful implementation of AI is dependent on the management skills of the breeding technician. If the proper estrous detection, insemination and processing procedures are not followed reductions in profit could result from the use of AI. The mating programs presented also differ in the risk associated with low boar fertility. Producers with on-farm AI with a limited number of boars can be the most adversely affected if semen production is reduced.




When determining the replacement female system and the semen delivery system it is important to ask: “What do I want to do?” and “What can I do?”. In order to make the best decision the cost and inputs required for each option must be understood and weighed with the value of increased genetic merit associated with each system. It is also important to realize that the cost comparisons presented here may use some assumptions that are not appropriate for your situation. For best results complete this procedure using figures from your operation. To make genetic improvement via AI, use performance evaluated seedstock selected from at least the upper 50% of boars in a herd that is realizing genetic progress through the use of a performance testing and genetic evaluation program. Commercial producers should require seedstock suppliers to follow a sound genetic improvement program and then use genetic information when purchasing breeding animals along with acceptable health, reproductive soundness, and skeletal structure.




Almond, G., J. Britt, J. Carr, B. Flowers, C. Glossop, M. Morrow, and T. See. 1994. The SWINE AI Book: A field and laboratory technicians’ guide to artificial insemination in swine. ISBN: 0-9640737-0-6. Southern Cross Publishing, Raleigh, NC.
Christine, R.R. 1995. Personal Communication and Price Quotes, Minitube of America.
Flowers, W.L. 1995 Reproductive Management: A technical and Economic Analysis of Natural Mating versus Artificial Insemination.
Flowers, W.L. 1992. Artificial Insemination in Swine. Agri-Practice. Vol. 13, No. 2: pp. 36-40.
See, M.T. 1994. Should replacement gilts be raised or produced? ANS 94-802S. NCSU.


Reviewed by:
Darwin G. Braund, Ph.D. and William L. Flowers, Ph.D., Department of Animal Science, and Kelly D. Zering, Ph.D., Department of Agricultural and Resource Economics, North Carolina State University.