1995 . Volume 18, Number 2
1995 . Volume 18, Number 2
Genetics do make a difference in commercial pork production. When thinking about genetic programs the goal should be genetic improvement in the economically important traits. Genetic improvement can be slow, because we are dealing with a biological system that requires a minimum of 1 year to turn a generation. However, any genetic improvement that is made in a herd is permanent and if the improvements are made in economically important traits it will be profitable.
The National Swine Improvement Federation has established the economic values in Table 1 to be used as guidelines. These values may not be appropriate for all situations but are good estimates to use when making comparisons.
| Trait | Economic Value | Unit of Change |
|---|---|---|
| Number born alive | 13.50 | pig |
| Litter birth weight | 4.50 | pound |
| Adjusted 21-day litter weight | .50 | pound |
| Number at 21 days | 6.00 | pig |
| Days to 230 pounds | -.17 | day |
| Backfat probe | -15.00 | inch |
| Feed efficiency | -13.00 | pound |
| Average daily gain | 6.00 | pound |
| Percentage carcass lean | 1.10 | percent |
What is the economic return for making genetic improvement? For every .1 in (2.54 mm) reduction in backfat there is a 11.8 lb. reduction in the amount of feed required per pig per day and a $1.50 per head carcass premium. By reducing the number of days to market by 1 day, feed/pig/day is reduced by 3.1 lb. and fixed costs are reduced by $.17.
For example the difference in value between a boar (A) with a -.15 in EPD for backfat and a -3.5 EPD for days to 230 pounds and a boar (B) with a backfat EPD of 0 and a days to 230 EPD of -.5 can be obtained as follows:
| Improved feed efficiency | ((0 - -.15) /.1) x 11.8 x $.08 | = | $1.42 |
| Improved growth rate | ((-.5 - -3.5) / 1) x 3.1 x $.08 | = | $0.74 |
| Less fixed costs | ((-.5 - -3.5) / 1) x $.17 | = | $0.51 |
| Carcass premiums | (( 0 - -.15) / .1) x $1.50 | = | $2.25 |
| Advantage of boar A over boar B | $4.92 per pig |
If in a one year period each boar produced 500 offspring, Boar A would be worth an additional $2,460 over the purchase price for Boar B.
If you compare buying gilts that are .1 in leaner, improve number born alive by .3 pigs per litter, 21 day litter weights by 5 lb., and number weaned by .2 to keeping gilts from the herd with no genetic improvement the difference would be as follows:
| Improved feed efficiency | ((.1 - 0) / .1) x 11.8 x $.08 | = | $0.94 per pig |
| Carcass premiums | ((.1 - 0) / .1) x $1.50 | = | $1.50 per pig |
| Improved number born alive | (.3 - 0) x $13.50 | = | $4.05 per parity |
| Improved 21 day litter weight | ( 5 - 0) x $.50 | = | $2.50 per parity |
| Improved number weaned | (.2 - 0) x $6.00 | = | $1.20 per parity |
| Advantage of purchased gilts | $3.22 per pig |
If the sows averaged four litters and 10 pigs per litter the additional value of the purchased gilts would be $128.80.
M. Todd See,
NCSU Extension Swine Specialist