In the 1950's and 1960's pig inventories in the U.S. were influenced mainly by the availability of feed stuffs. The Midwestern states provided the most economical source of grain to be used as livestock feed. Variation in the pig inventory was due to seasonal farrowing practices because the harsh Midwestern winter weather and the use of outside facilities limited the farrowing of pigs to 7 months of the year. These two facts along with increased slaughtering capacity soon made the Midwest the center of swine production and the packing industry.

The 1970's brought increased pig prices and profitability to the full time farmer part time swine producer. This change in profitability resulted in new technologies and more specialization. Confinement facilities started to emerge which included indoor breeding/gestation buildings, farrowing crates on specialized flooring and slatted nursery and finishing buildings. The use of indoor facilities took some of the seasonal variability out of the pig inventories.

Rapid expansion in states out of the corn belt, contract hog facilities, investment capital from non-agricultural sources, multiple site production systems and "mega farms" highlighted the 1980's and the first 5 years of the 1990's. We saw the rise of many large pig companies. Most of which have been responsible for North Carolina's sow herd growth, now second only to Iowa's.

Possibly the two most dramatic occurrences in the past 50 years have been in the last two year. In 1995 we saw the lowest hog prices in the U.S. since the 1960's. Also for the past 5-7 months we have been paying more than two times the 10 year average for corn. These experiences have changed some growth plans for producers and have finalized the retirement plans from the swine business for others.

This brings us to the topic of farm management practices which for discussion purposes, I will break down into four categories. They will be addressed in the following order: 1) Production systems, 2) Facility design, 3) Management procedures, and 4) Feeding management.

PRODUCTION SYSTEMS

In the U.S. today the trend has been away from single site production commonly found on smaller sow farms to multiple site systems. Most multiple site systems will consist of separate sites for the sow unit, the nurseries, and the finishers. A few multiple site systems may locate the nursery and finisher on the same site. The main reason for the development of the multiple site system was to wean piglets off-site away from the sow herd and its infectious diseases. The practice of weaning pigs off site has taken on many names through the years. Medicated early weaning (MEW) was used first and consisted of weaning 5-7 day old pigs with an intensive medication program. This evolved into a modified medicated early weaning (MMEW) which increased the wean age to 16-21 days and decrease the medication protocol. Segregated early weaning (SEW) soon became the standard for commercial production systems and the main difference from MMEW is the almost complete elimination of medication.

The result of this progression to multiple site systems has been beneficial to the production performance in most cases. It is important to remember if switching to off-site weaning that there are additional production costs that must be off-set by improved performance (i.e. transportation, labor utilization, etc.). The principle behind off-site weaning is that while the piglets are nursing on the sow and less than 21 days old there are specific diseases not transmitted to them by the sow. Therefore the weaned pigs are removed from the sow herd free of many disease organisms. The success is related to the stability of the disease level in the sow herd. Porcine reproductive and respiratory syndrome (PRRS) has created problems in stabilization of not only PRRS on these farms but also other disease organisms also.

Pig movements change dramatically as it is now necessary to transport newly weaned 16-21 day old pigs. If the distance is not too far (< 60 miles) it is not necessary to use a specially designed trailer. Movement of nursery pigs to finishers is done in large trailers so that only one or two trips are needed to empty a nursery. Large farms have the ability to locate only 2 or 4 weeks of pigs on a site or in a building, therefore allowing depopulation if needed. Smaller farms (< 600 sows) are likely to have all 8 weeks of weaned pigs in one building with 8 rooms. The economy of constructing separate rooms or buildings clearly lies with larger sow units.

FACILITY DESIGN

Facility design in the U.S. has changed in the past few years with the most common being that sow units have gotten larger. The most important issue to consider when looking at facilities is that climatic differences will affect the performance of each facility type. Before designing a sow facility it is important to match gestation spaces and farrowing stalls to projected pig flows. This is done by dividing total pigs produced per year by projected pigs/sow/year (p/s/y). This gives you the number of active sows to which you add 12% to get total spaces including sows, boars and open gilts. This is then divided by 7.3 to get the number of farrowing crates. For example, if you want to wean 400 pigs per week or 20,800 pigs per year and you expect to get 21 p/s/y therefore 20,800 divided by 21 would be 990 active sows. This plus 12% is 1,110 total gestation and farrowing spaces needed to generate 400 pigs per week. When 1,110 total spaces is divided by 7.3 spaces/farrowing crate you get approximately 160 farrowing crates for this farm. Therefore, the breeding/gestation building would have 950 spaces and there would be 160 farrowing crates.

Sows are most commonly housed in individual gestation crates and fed either once or twice per day. In most cases flooring is partially slatted concrete. Replacement gilts are kept in pens until bred and then moved to crates. Tunnel ventilation systems are common and evaporative coolers may or may not be installed. The farrowing rooms are designed allowing 2-3 rooms to be weaned per week on large farms. This helps maximize lactation length while still allowing all in/all out. Flooring is typically woven wire but plastic and coated wire is also used. Water is provided by either bowls or nipples. Feed bowls have gotten larger to minimize physical restriction to lactation feed intake. Heat lamps and sleeping mats help create warm, dry environments for the piglets.

Much more variation in facility design occurs in nurseries. Number of weeks on the site is one major difference which is normally related to sow herd size. Tunnel ventilation buildings again are common with building lengths getting up to 110 feet. Standard power ventilated units still are commonly used in systems with less than 400 pigs per week. Curtain sided nurseries that were only before seen in the southern U.S. are showing up in the Midwest. The key to any ventilation system is to provide a warm draft free environment to the pig the first 2 weeks post-weaning. Flooring is normally metal which is durable and easy to clean. Some production systems which are weaning very young pigs (10-14 days) are using plastic or rubber coated floors to increase comfort. Pen size is best if kept < 30 pigs per pen. Pigs are given 3 sq. ft. if out weights will approach 65 lbs.

Finishers are of two basic ventilation types. Power tunnel ventilation is common in the southern U.S. where wind velocities are inconsistent. In the Midwest due to better wind velocities double curtain buildings work very well. Most buildings are totally slatted (concrete) but partially slatted buildings are seen. Finishing stocking density is usually 7.25-8 sq. ft. per pig.

MANAGEMENT PRACTICES

The discussion concerning management practices will focus on the sow unit, the nursery and the finisher.

Sow Units. The breeding areas in most sow units will have the weaned sows and boars held close together until sows are bred. Weaned sows should be fed heavily for the first 2-3 days post weaning to decrease their sense of catabolism prior to mating. It is not uncommon for these sows to eat 6-8 lbs. during this period. Most weaned sows will be in heat 4-7 days post-weaning. This is referred to as wean-to-estrus interval and it plays a role in the reproductive efficiency of a herd. Breeding may be done naturally, artificially (AI) or a combination of both. Sows are bred two times with the first service being when the female is first observed in heat. Sows should be moved to the gestation area within 7 days post-mating to avoid increase stress during implantation of embryos. Sows will stay in this crate until 40 days or for the entire gestation period depending on the system. After 40 days some systems move sows to a different area of gestation for the remaining 75 days.

After mating the next management steps involve monitoring each female for failure of conception or pregnancy loss. Heat detection starts at day 18 post-mating and is continued until females are about 40-45 days pregnant. Heat detection can slow down after the female has been mechanically pregnancy checked positive at day 30-35 and has not shown heat by day 45. If the pregnancy is lost after day 45 fetal tissue should be found behind the females. She will likely show estrus 4-6 days after the abortion. A second mechanical pregnancy check is done at 50-60 days. Visual checks are done after that period up to farrowing.

Sow body condition scoring is done on a weekly basis and under condition sows are identified to ensure they receive extra feed until condition is restored. Correct condition of sows entering the farrowing crate is important to subsequent reproductive performance and longevity. Each day sows are observed for structural fitness and health status. If needed, appropriate treatments are administered to these sows and the information including date, product, amount, and withdrawal time is recorded.

The farrowing house management as it pertains to the sow focuses on lactation feed intake. Maximizing lactation feed intake is essential to obtaining high wean weights and minimizing sow weight loss. The later of these is important to keeping wean-to-estrus intervals short which will be beneficial to the next reproductive cycle. The piglet is the other focus at this time and attention must be given to details. I prefer the following program for piglet care. On day one, cross-fostering is done on newly farrowed sows to even out litters for both number of piglets and size. When making the "runt" litter this female receives 2-3 pigs more than the other sows to anticipate higher pre-weaning losses. Processing of piglets occurs on day two and consists of clipping needle teeth, docking tails and administering injectable iron. Antibiotic therapy may occur at this time depending on the specific needs of each farm. Castration is done at 5-7 days of age and piglets falling behind are moved to nurse sows to help them catch up. Weaning is done at 16-21 days. Every day pigs and sows are observed for illnesses that need to be treated. Some production systems include much more routine antibiotic therapy and an intensive vaccination program.

Replacement gilts normally are introduced to the sow herd 30-45 days prior to mating. This acclimation time has been extended to as much as 100 days due to PRRS. Gilts are exposed to cull sows in a building separate from the rest of the herd to avoid overwhelming the stable sow farm. In some systems nursery or growing pigs are used to acclimate new gilts but the availability of these pigs in multiple site systems is limited. Breed age for gilts is targeted at 190-210 days of age.

Nurseries. The keys to successful nursery management are to provide the weaned piglet a warm dry draft-free environment, a fresh adequately balanced diet, and plenty of clean water. Temperatures in the nursery will start high and ramp down with time. The first week will be 85° F; the second, 81° F; the third, 77° F; and the 4th-8th week will be 72° F. This lower temperature at the end helps to stimulate higher feed intake. Also during the first and second week, sleeping boards will be found in the pens to give the pigs a warm surface to lie on. Smaller pigs may also require a supplemental source of heat such as a heat lamp.

Feed is provided 2-3 times a day in small amounts on a feeding board which can be the same as the sleeping board. This continues for the first 7 days after which pigs are then fed in the feeders. The starter diet is typically pelleted and the 2nd and 3rd stages will be in a meal form. It is important to keep feed fresh to encourage intake.

Water systems can be bowls or nipples. If nipples are used it is helpful to use at least one per pen that can be set to drip when the pigs first arrive. This helps the pigs locate the source of water. Don't underestimate the importance of water intake because these pigs can dehydrate very quickly.

Pigs are sorted by size and placed at 25-30 pigs per pen with 2.8-3 sq. ft. per pig. Sick pens are left empty at the beginning to allow for pulling of pigs that need special attention. When these pigs are identified they are placed in the sick pens. At this time treatments are administered and a mixture of water and feed may be provided to stimulate consumption.

Nursery rooms should be run all in/all out each and every time without exception. These rooms are then power washed and disinfected prior to pigs re-entering the facility. This allows minimization of disease organism carryover from the previous group. If specific disease organisms are a problem clean boots and coveralls may be used between buildings or rooms. In the case of chronic disease spread in the nursery involving organisms not found in the newly weaned pigs (i.e. TGE, PRV, PRRS, etc.) nursery depopulations may provide a break in the cycle. It is important that all pigs be removed from the building. If the site contains more than one building it may be possible to depopulate only the buildings and not the whole site. Proper cleaning and down time of at least two weeks is essential.

Finishing. Temperature in finishing facilities is set at 68-72° F and if it gets above 80-85° F sprinkler systems will provide cool water for the pigs. Hot summer weather creates the most problems related to feed consumption and growth. Feed is delivered either pelleted or in meal depending on the diet cost and the cost of pelleting. Dry feeders are by far the most common but some wet/dry feeders are being used. Split sex feeding is done wherever possible and as with many things is more easily accomplished in larger systems.

Placement of pigs occur at about 65 lbs. and if possible pen to pen placement from the nursery is preferred. The decrease fighting and stress on the pigs allows for better adjustment to their new surroundings. Again pens are left empty to provide space for pulling out poor doers, allowing for more consistent and proper treatment of these pigs.

Marketing consists of topping the barn off when a group of pigs weighs approximately 275 lbs. live weight. We have found that in the U.S. this is the most profitable weight to start the selling. The rate at which the remainder of the pigs are marketed depends on the variation of growth weights and the need for the spaces they now occupy. Due to other variations in the entire system this timing can change dramatically. The goal in the U.S. would be to market most of the buildings at an average of 265-275 lbs. As with the nursery when the barn is empty it is essential to wash and disinfect it.

FEEDING PRACTICES

Feeding practices in the U.S. vary due to geographical location and source feed stuffs. By far, soybean meal is the most commonly used source of protein except in nursery starter diets. Corn is the principle energy source with barley, milo, wheat midds and fat showing up in some diets.

Sows in gestation are fed 4.5 to 6.0 lbs. depending on genetics and condition desired. Lactating sows are fed ad libitum to maximize milk output and minimize weight loss. In the nursery 3-4 stages are typically seen with the last one making up about 60% of the total feed consumed. Finishing programs may have as many as 12 or as few as 2 diets but most will be 4-5 diets. Protein supplementation in all these diets have continued to increase as leaner genetics and healthier pigs generate lean tissue at faster and faster rates. The key point to remember here is that the addition of protein to diets will not make pigs leaner unless they have the capability to utilize the amino acids for muscle growth.

DISEASE PREVENTION PROGRAMS

My philosophy on vaccination programs has always been to keep them as simple as I can but yet effectively prevent the diseases I thought needed to be dealt with. In the past few years with the move toward multiple site production and the introduction of PRRS to our list of diseases the number of products being used has increased rather than decreased. I will show the diseases in the U.S. most commonly vaccinated for and which vaccines I use on our farms. The following list is of diseases that may be encountered in the U.S. for which vaccines are available. By no means is this list intended to be fully complete.

The vaccination programs on our farms is kept to a minimum whenever possible. Therefore each farm does not have the exact same program but rather a program specific to that farm. Our sow units will routinely vaccinate sows, gilts and boars for Lepto spira sp., Erysipelothrix rhusiopathiae, Porcine parvo virus, Aujesky's disease, PRRS, and Haemophilus parasuis. A few farms will use a pre-farrow Escherichia colibacillosis and Clostridium perfringens program. The piglets receive PRRS vaccine at weaning on some farms but on others they receive it coming out of the nursery. As pigs enter the finisher they receive Erysipelothrix rhusiopathiae and Salmonella choleraesuis.

Vaccination programs are very important to disease prevention but you must also be aware of biosecurity. High pig density areas will tend to have more problems with a larger number of diseases. It is important to follow basic biosecurity rules that should include a change of boots and coveralls between farms and at least washing hands. Shower in sow units are common in the U.S. but nursery/finishers are usually only shower in if they are within multiplication systems. Common sense is the important thing to remember here. Pig free areas around facilities are nice but often hard to come by. Starting with high health herds and maintaining that health status will do more for improving grower performance than anything else the swine industry has seen yet.

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