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 Knowledge for the CommonWealth

Swine Industry News And Notes

Livestock Update, June 1998

C. M. Wood, Animal & Poultry Sciences, Virginia Tech


The question has come up about calculating the Fat Free Lean Index from information on the kill sheets. The following equations can be used to calculate the index. Choose the one that matches the information (Fat-O-Meater or ruler) on the kill sheet. You'll also need the hot carcass weight.

Fat-O-Meater measurement between 3rd and 4th from last rib (10th rib), 7 cm off midline:

FFLI = 51.367 + (0.035*Hot Carc. Wt.) - (12.26*Fat-O-Meater Backfat Depth)

Ruler measurement, last rib at the carcass split:

FFLI = 50.767 + (0.035*Hot Carc. Wt.) - (8.979*Ruler Backfat Depth)


NPPC is pushing for all major packers to begin requiring Level III PQA of all producers in order to sell hogs. Over the years, the certification process has become more and more streamlined, and can be accomplished in a workshop setting. If you are interested in setting up such a workshop for producers in your area, and would like me or Allen Harper to help certify producers, please get in touch. Both of us have served as verifiers in the past, and have found the management information contained in the PQA booklet to be very helpful to producers.


Should I buy all my genetics, or raise my own?
This decision has become much like deciding whether to mix your own feed, or buy it from someone else. Several factors need to be considered when deciding whether to raise your own replacement animals (boars or gilts): how much time you want to devote to this aspect of the enterprise, how comfortable you are with genetic principles, and how much money you want to invest in labor and equipment. At a minimum, in today's market, you'll need a scale, a backfat probe, and a spreadsheet program, as well as a good source of outside boars, at the least. An accurate set of records from birth to culling is also a must.

Advantages to buying your genetics include less work on the farm and the opportunity to make faster genetic changes. Disadvantages include the risk of disease, and more money invested in breeding stock: good genetics cost more, and you're paying someone else for their time and expertise.

I've been raising my own gilts, and think it's safer disease-wise. How can I keep track of their genetics?
You will need an identification system that can track pedigree information. If you don't know anything about the genetics of the sires and dams, then you can't track genetics. You will also need to decide which traits are most important for you, and come up with a reasonable method for measuring the performance of your animals for those traits. For example, if litter size and backfat are the most important, then you will need to record number of pigs born alive in each litter, then record weight and backfat on market hogs. The NSIF Guidelines, available from NPPC, contains detailed recommendations for on-farm genetic programs. Also, we keep track of genetics at the Virginia Tech Swine Center with a fairly simple system. Please get in touch if you would like more information.

If I'm going to buy my gilts to take advantage of better genetics, how do I make sure I don't have a disease outbreak?
Biosecurity remains very important in the swine industry. The first step is to check out the disease profile of the herd from which your new gilts are coming and make sure it is not too different from yours. Lower than yours, and you run the risk of introducing a new disease to your herd. Too much higher than yours, and the new gilts may have difficulty adjusting. Second, make sure you have an isolation facility AT LEAST 300 yards away from your pigs. The farther away, the better. Always check the new animals last, and never backtrack. If you wear the same footgear, consider disposable boots, and disinfect the footwear before going back to the farm. Blood test the new animals, twice preferably, and keep them in isolation at least 30 days. Expose them to your bugs by turning in cull animals, or by mixing some manure into their feed. A further adjustment period once the new animals have been into the herd can be helpful as well. All of this means planning well ahead in deciding to purchase animals.

If I decide to raise my own gilts, what kind should I raise?
Ideally, you want gilts that will breed early, farrow a large litter without difficulty, wean a high percentage of those pigs, breed back promptly, then repeat at least twice a year for several years. The pigs should grow fast and efficiently, with a high lean gain. They should go to market at 260 lb with less than an inch of backfat. Of course, this kind of package is hard to come by, and will require a long-term commitment.

To raise replacements, you will need a source of genetics (boars, and maybe gilts) with excellent maternal characteristics. You should always buy the best you can afford. To get the most from your market hogs, you need to match the maternal genetics with an excellent terminal breed or line. Decide on a crossbreeding program that will allow you to take advantage of heterosis in your gilts, and their offspring. For many producers, a static rotation or rotaterminal system works well. Then plan on keeping meticulous records on replacement gilts and market hogs. The Pork Industry Handbook has some good information on crossbreeding systems, and performance testing of pigs.

How do I compare genetics? I'm trying to decide between several sources.
Unfortunately, there is no easy answer to this one. Results from NPPC's terminal line project (available on the Internet) can help, but there are many other sources of good seedstock as well. With today's genetic evaluation programs, animals within a breed or line can be compared objectively, but not animals in different genetic populations. The best answer I have is to ask plenty of questions about genetics, keep in mind management differences when evaluating performance, and don't forget factors like disease profile and service after the sale. You should look for an environment that is as similar to yours as possible. Once you have decided on your source, buy the best you can afford.

I bought a super lean boar, but he isn't very interested in breeding gilts. Any suggestions?
Several possibilities come to mind. First, make sure the boar is physically capable of breeding. An attached frenulum can cause problems, for example. Second, make sure the boar has not become intimidated. Turn him in with just one gilt that is in heat and observe what happens. Third, try penning the boar next to a gilt that is in heat, and allow another boar to breed her. Then turn him back in with her. If you still can't get a boar to breed, contact your supplier and ask for a refund. Reputable breeders offer guarantees on their breeding stock.

This boar may also be a good illustration of the fact that some traits are antagonistic to each other. In general, maternal traits and carcass traits fall in that category, which can result in this kind of situation.

I have a fairly small herd. I've heard you can use AI to improve genetics. How do I go about that?
The first step is to learn how to AI pigs. This is a simple technique compared to that needed in cattle. There are some excellent videos and booklets available from NPPC if you are willing to teach yourself. Otherwise, someone in Extension should be able to help. If you've been hand mating, you're more than halfway there. If you plan to jump from pen mating to AI, you probably should try some hand mating first. The most important factor in successful AI is accurate heat detection. Especially if you plan to purchase semen, which would be true in this case, timing becomes critical. It will probably take some trial and error to get it right, so start with some inexpensive semen. Once you feel comfortable with AI, then you can invest in semen from elite boars to improve your herd genetics. To get maximum benefit, you should also be evaluating your sows’ performance to decide which to breed with the purchased semen.

A lot of these high-lean hogs seem to have problems walking, and real lean sows go down in the farrowing barn more often. Are we getting pigs too lean?
From the consumer and packer perspective, no. From the farm perspective, maybe. In many cases, problems like these are due as much to management of the high-lean pigs as to the genetics of the high-lean pigs. Listen to any recommendations your seedstock supplier makes about the care and feeding of these animals. In many cases, they do need a bit more TLC along the way, and the sows may need coaxing to eat enough feed while in the farrowing barn. Pay close attention to the nutrition of the pigs: they may need a higher percent of calcium and phosphorus in the diet, along with more protein.

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