June, 1996 ^. Volume 19, Number 5

It is once again time to make plans for the annual N.C. Performance Market Hog Show. This annual event combines fun and fellowship at the N.C. State Fair with an excellent educational opportunity. Pigs that are nominated, ear-tagged and weighed on-test by July 25th can be exhibited in the performance market hog classes at the fair, where they will be evaluated both live and on the rail. For the live competition, the judge is provided with the average daily gain of each animal, which he uses along with visual appraisal, to determine a ranking. On the rail, the pork carcasses are evaluated for fat depth, loin muscle area, carcass length, loin muscle color, loin muscle marbling, loin firmness and carcass weight. These measures are combined to predict the pounds of lean gain per day on-test, which is used for the final ranking. In today's competitive pork industry, the amount and quality of carcass information collected on the pigs in this program can be quite valuable. Anyone interested in nominating pigs for the 1996 event should contact their County Extension Livestock Agent on or before July 11, 1996.

The official rules for the 1996 show are as follows:

The show is a part of the swine shows at the N.C. State Fair and is open to North Carolina exhibitors with barrows or gilts duly nominated, eartagged and started on test as of July 25, 1996 and weighing a minimum of 220 lbs or a maximum of 260 lbs on October 17, 1996.

ENTRY

1. Entries will be coordinated through County Extension Livestock Agents.

2. Pigs will be entered by July 11, 1996 and there will be no entry fee.

3. Ten pigs may be entered, eartagged, and weighed per farm, firm or family.

4. Pigs will be weighed between July 16 and July 25 and weights will be adjusted upward by 1 lb/day to July 25, 1996.

5. There are no minimum or maximum on-test weights as of July 25, 1996.

6. Barrows or gilts are eligible, but pigs must be castrated prior to being weighed on test.

7. Pigs must have feed and water available in pen before being weighed.

8. Pigs will be eartagged in left ear.

9. An NCSU, NCDA, or other officially designated person will weigh the pigs on test.

10. Pigs will remain on home farm to be fed out.

SHOW

11. Pigs will be entered and shown at the N.C. State Fair according to weight group, wherever possible, while limiting classes to 15 entries per drive.

12. Each farm, firm or family is limited to showing five pigs.

13. Pigs must be entered with the N.C. State Fair by September 15 and must be in place at fair by 5:00 p.m. on October 17, 1996.

14. Pigs must weigh a minimum of 220 lbs or a maximum of 260 to be eligible to show on October 18, 1996 at 2:00 p.m.

15. Average daily gain will be paint-branded on rump of each animal on show day.

16. Premiums will be same as those for State Fair Market Barrow Show with premiums on-foot and on-rail.

17. All pigs will be slaughtered following the show and the champion will be determined by lean gain per day on test.

18. Example starting weights on July 26 and resulting daily gains to make pigs eligible for the show just 84 days later:

19. An official health certificate is required for all hogs and a negative PRV test within 30 days is required for pigs from non-qualified herds.

20. Check the 1996 N.C. State Fair Catalogue for complete rules and show dates.

Todd See

Nothing beats the company of a boar when it comes to stimulating early puberty in young female pigs. But scientists say a sow that's just been weaned from her pigs can "turn on" gilts, too -- without all the time-consuming, labor-intensive effort involved with the boar.

According to research conducted at the University of Missouri, 28% of gilts reached puberty when exposed to estrual sows compared with 48% exposed to boars.

"With boars, we saw a rise in the number of gilts coming into heat right away, and the boars kept stimulating onset of heat among gilts throughout the 50 days of our experiment," says animal researcher Jodi Sterle.

"With estrual sows, the numbers expressing heat were about the same as those with the boars early in the experiment, but tapered off quickly. The best strategy is to expose gilts to sows for 5-7 days after sows have been weaned from the pigs, then move in other sows that have just been weaned from their pigs."

Sterle says getting gilts to puberty early reduces the number of non-productive days and is worth about $1.50/day to pork producers.

Research shows that gilts respond best when exposed to boars 15 minutes daily. But Sterle says that takes a lot of work and there are always some safety concerns when you're handling big boars.

"From a management point of view, exposure to cycling sows by penning the sow with the gilts can improve expression of puberty to almost the same degree as the boar exposure -- without the hassle," Sterle adds.

HogHealth
Vol. 6, No. 1

The proper level of amino acids in the diets of lactating sows may be a key to the timely production of another litter, research at Iowa State University indicates. "There is a problem in the swine industry with reproductive performance after intensive lactation," notes Dan Jones, a graduate student in swine nutrition.

Jones says that following lactation, pigs often experience a delay in resuming the normal reproductive cycle. "We've found that the problem may be associated with amino acid nutrition," he says.

In several trials, one group of lactating sows was fed adequate amounts of amino acids in their diets while a similar group was fed a diet deficient in amino acids. Jones and his advisor, swine nutritionist Tim Stahly, then measured the production of luteinizing hormone, which is closely linked to the onset of estrus and the release of eggs from the ovaries. They found that production of the hormone resumed much sooner after giving birth in the sows receiving adequate amounts of amino acids.

The researchers also found that production of the hormone resumed in less than 10 days after giving birth in sows receiving adequate amounts of amino acids. The pigs with diets deficient in amino acids didn't begin producing the hormone until at least 15 days after giving birth.

"This research indicates that the first 10 days of lactation are very important in terms of nutrition to the long-term productive performance of sows," Jones says.

The research suggests the importance of nutrition for lactating sows, but Jones also points out that nutrition isn't the only source of this problem. He adds that litter size and environment play an important role as well.

HogHealth
Vol. 6, No. 1

The increase of clinical Haemophilus parasuis is seen primarily in high-health status herds, where it can occur as a primary disease, according to John L. Vahle, DVM, a veterinary pathologist at Iowa State University, Ames.

In these animals, he explains, modern production trends such as medicated early weaning have been employed to protect animals from a variety of diseases. "In the case of H. parasuis, these practices may have eliminated natural immunity to the organism," he adds.

H. parasuis also can occur in association with other diseases. "If you have porcine reproductive and respiratory syndrome (PRRS) or swine influenza and a long list of other diseases, it may act as an opportunistic infection and the chance of fatal H. parasuis increases," Dr. Vahle reports.

Clinical H. parasuis causes gross lesions including pleuritis, peritonitis, pericarditis, meningitis and arthritis. This syndrome of polyserositis-arthritis is commonly known as Glasser's disease. In high-health herds, the clinical picture may differ. H. parasuis can strike fast and pigs may die quickly, without warning or clinical signs.

Dr. Patrick G. Halbur, assistant professor of pathology, Iowa State University Veterinary Diagnostic Laboratory, says treatment with antibiotics does not always prevent mortality. Pigs that do survive H. parasuis may have severe internal adhesions. Vaccination is recommended.

HogHealth Vol. 5, No. 6

Producers who see white powdery crystalline deposits around vulvas of sows and gilts should check on the amount of drinking water made available to the animals, advises a research report in the United Kingdom.

Dr. John Walton, a researcher at the University of Liverpool, explains that a long-term shortage of water for housed sows and gilts reduces their output of urine. Therefore, several chemicals are unable to remain as a liquid in the body and instead form crystals in the kidneys and bladder.

The crystals appear externally as a white powder around the vulva, down the tail and sometimes on the backs of the legs.

"Farms with sows in this condition usually have a high sow mortality, more frequent returns to service and more numerous antibiotic treatments for inflammation of the bladder," Dr. Walton says.

Dr. Walton believes the best solution is to provide clean drinking water at all times. If this is not possible, then plenty of water must be given at least 2-3 times daily.

HogHealth
Vol. 5, No. 6

Before deciding on how much, or how little, you can spend on a health program consider the costs of a disease outbreak. Unfortunately, because of the complex effects of a disease and the difficulty in measuring its effects it is not easy to establish the exact costs for any disease. Certainly, disease costs the American hog producer millions of dollars each year. Estimates of the cost of some hog diseases, reported as the cost per sow per year that the disease exists in the herd, are as follows:

The objective of any biosecurity program is to minimize these costs and increase the profitability of the hog enterprise.

There are many opportunities for preventing disease from affecting a herd. As most diseases enter a herd when stock are introduced, it is extremely important to ensure that the appropriate precautions are taken. The most basic steps include ensuring that the pigs come from a healthy herd and they are first isolated from the rest of the herd. However, even when these risks are minimized, disease can still enter a herd. Disease can enter a farm indirectly when it is carried in on contaminated boots, clothing, supplies, or equipment. Therefore:

a. Producers should always have a set of boots and clothing to wear exclusively in the hog unit. Work clothes should never be worn off the unit or where they may come in contact with other hogs, material or objects that have been in contact with other hogs.

b. If producers take their own hogs to market, the truck must be thoroughly washed and disinfected before it returns to the farm. Likewise, boots and clothing must be cleaned and disinfected. If somebody else collects the hogs for market, producers must insist their truck be cleaned and disinfected before it arrives on the farm. Naturally, the truck should not be carrying slaughter hogs from any other farm. Producers should insist on being the first stop for the contract hauler truck. If the producer can't get the contract hauler to adhere to these hygiene standards, a shuttle truck should be used. The shuttle truck or trailer is used to shuttle pigs to the contract hauler. The shuttle vehicle should be washed and disinfected away from the farm after hauling is complete.

c. Producers should adopt a similar attitude to feed, breeding stock, and other service vehicles as they do to slaughter hog trucks. They should insist on being the first delivery for the day and that the truck be washed and disinfected before it arrives. Truck drivers must never enter the hog unit.

d. Farm visitors must be discouraged. When essential people visit, disposable boots and coveralls should be provided. Many farm managers insist that everyone change and shower before putting on boots and clothing provided by the farm.

e. Equipment that has been in contact with other hogs must be thoroughly cleaned and disinfected before it is brought onto the farm.

If producers follow the rules outlined above for preventing the indirect spread of disease and are careful to not introduce disease with purchased pigs then the chances of introducing a disease is markedly reduced. However, pigs will still become sick and as soon as a disease has been diagnosed appropriate treatment must be instituted. There are two points to consider:

1. Confirm the diagnosis. It is senseless and wasteful to attempt treatment of a disease if you are unsure of the cause or are using an inappropriate treatment. Many disease agents have the same clinical signs; a piglet may scour because it is infected with either E. coli, Coccidiosis, or Rota virus. Each of these diseases has a very different treatment. The local veterinarian, diagnostic laboratory, and county agent know how to help obtain an accurate diagnosis. Submitting suitable specimens to a diagnostic laboratory not only assists with the diagnosis but also the antibiotic sensitivity and hence appropriate treatment can be determined.

2. Observe all label directions and drug withdrawal times. The National Pork Producers Council has a Pork Quality Assurance Program to enhance the quality of pork sold to the consumer. This voluntary drug management program is designed to help all producers avoid illegal drug residues, improve management skills, and reduce production costs. It is in everybody's best interest to enroll in that program, complete the program, and meticulously follow their recommendations. Briefly, the recommendations are:

• Read all labels
• Follow label instructions
• Keep accurate records of all drugs used
• Clean equipment and pens carefully
• Follow withdrawal time

Morgan Morrow

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Last modified August 7, 2000