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Evaluating Facilities
for Transition to
Modern Technologies

ISU Extension Publication #: AEN-195
Author: Dr. Jay Harmon, Dept. of Agricultural & Biosystems Engineering
Content Review: March 1998 by Dr. Jay Harmon

Introduction

Many swine facilities were set up to operate efficiently using farrow to finish technology. Many of these units combined buildings to reduce construction cost and facilitate easy animal movement. Buildings had farrowing and gestation, nursery and finishing, farrowing and nursery, or all functions under one roof. Other operations used separate buildings for each function but they were in close proximity. Generally buildings were not sized to be emptied and cleaned between groups. In fact, in many cases it was necessary to move pigs from the nursery to the finishing building by pen. Rather than precise scheduling of rooms, this was more of a domino scheduling. As pigs were sold from the finisher, room became available for the largest pigs in the nursery which meant that a farrowing crate could be emptied and the pigs moved to the nursery. Another approach was to sell the heaviest pigs from the finisher, move the heaviest nursery pigs to the finisher, wean the oldest litter because space was needed for a sow about to farrow. While these management systems seem outdated, many people have used this system on occasion in the past or still do. Managers may not have a choice because facilities were not set up to allow all in/all out or age segregation production. Approaching this problem is the focus of this paper.

Age segregation rearing (ASR) and all in all out (AIAO) have several advantages, some of which will be discussed here. Advantages include:

Health improvements,

More precise diet feeding,

Better suited environment for different aged pigs,

A more precise schedule making labor scheduling easier,

Easier analysis of the performance of specific groups,

Equipment repair and maintenance can be done between groups.

Like most technologies, there are disadvantages to adopting ASR or AIAO. Disadvantages include:

Carefully planning and management are needed for the system to work properly,

Construction may be more expensive due to small rooms or separate sites,

Facilities are sometimes far apart and transportation of people and animals may be a problem.

Siting Requirements for ASR

The whole point of ASR is to separate pigs before they are infected by disease that the sow herd may care. This means that nursery and finishing facilities should be physically separated from the breeding, gestation or farrowing areas. Exactly how far apart these should be is not a matter of a prescribed number of feet. Of course, distance is one factor to be considered, but so is the direction of the predominate winds. In Iowa the predominate summer wind is from the south and the winter winds are from the northwest. When siting facilities the sow housing should be located downwind from nurseries and finishing facilities. In general terms, this means that the nursery or finishing facility should be located on the western edge of the farm. This will reduce the risk of transmission of aerial spread diseases.

Minimum safe distance between facilities is not an easy decision. In most cases the people traffic will be a more important factor than the actual distance. Generally, the shorter the distance between two buildings, the more likely the chance that people will walk from one to the other without proper biosecurity measures. In general, 200 to 300 feet would probably be the minimum separation of sows from nurseries or finishing units. Wooded wind breaks help if the wind direct is wrong.

Distance from roads may also be a factor. This, again, is a trade off because for a new facility, the further away from a road that it is located, the higher the expense for developing the driveway. With existing facilities the most important point to remember is that the closer the building is to the road the more likely it is to be visited by a well-intentioned neighbor or salesperson. Again, people traffic is the most important. Limit access to the facility.

Building Requirements

When evaluating a facility for its suitability the exact function makes a great deal of difference in the feasibility of updating buildings. The following are appropriate questions.

Is this an appropriate site?

Is the building separated from other buildings that pose a biosecurity risk?

Will it be easy for workers to track disease from building to building?

Is the building a security risk?

Is it located near similar functioning buildings?

Is the building large enough?

Is there adequate room for the group size required for all in all out? (Table 1)

Will remodeling the building allow enough room for comfortable alleys?

Can the building be adequately ventilated? ( Table 2)

Can a separate air space be created from other rooms?

Is there a chance for air to flow from one room to another through a common area?

Is there a system available to handle the manure?

Can manure handling be separated so that manure from one room does not flow through another?

Does the system get the manure away from the animals without requiring a great deal of manual labor?

Are there separate entrances into each room?

Do pigs have to be driven through one room into another?

Are loading chutes available and accessible for each room?

Can the room be sanitized adequately?

Can feed be delivered in a way that accommodates split sex and phase feeding?

Is remodeling this facility for a new use worth the effort?

Will remodeling the facility result in costs that are more than 50% of new construction?

How many inconveniences are built into the system that make more labor?

What is the proper function for this building?

Table 1 Space Requirements for Various Swine (MWPS-8)

Animal	Maximum Size (lbs)	Floor Area (sq. ft)	Crate Size (ft)
Early Nursery	40	2.5	---
Late Nursery	60	3	---
Finishing	250	8	---
Gestating Sows	450	16	24" by 7'
Boars	500	40	28" by 8'

Table 2 Ventilation Rates for Various Sized Swine. (MWPS-8)

Animal   Sow and Litter Early Nursery Late Nursery Early Finishing Late Finishing Gestation Breeding Weight lbs. 400 12-30 30-75 75-150 150-250 325 400 Ventilation (cfm/hd) Cold Weather 20 2 3 7 10 12 14 Hot Weather 500 25 35 75 120 150 300 Heater Size Btu/hr/hd 4000 350 350 600 600 1000 1000

Examples of Transitions

There are several transitions that are common when producers adopt ASR or AIAO. The most common are changing a farrow to finish operation to a breed to wean operation, or changing a farrow to finish operation to a nursery/finishing operation. In most operations finishing buildings are changed to gestation and breeding (or visa versa) or nurseries are changed to farrowing rooms (or visa versa). These options will be discussed more fully in the following sections.

Changing Nursery Space to Farrowing

Farrowing crates are usually 5' by 7'. Rear alleys should be 24" wide but may be as narrow as 18". Front alleys should be 4' wide but may be as narrow as 3.5'. The front alley space required depends on how much the feed bins on head gates stick out into the alley and the width of the feed cart. This means that a single row of crates requires a room width of 13' to 12'. A double row of crates will require 22' to 20.5'. Room length should allow for 2.5' to 3' alleys on either end. Some producers opt to remove one of these to save space. This means for rows of 6 crates a length of 32.5' to 36' will be required.

The ventilation system may need to be adjusted slightly. Generally a 22' by 36' nursery would hold about 216 head at 3 square feet and the minimum ventilation would be designed to move about 432 cfm (2 cfm/head). This same room converted to a farrowing house would only hold 12 crates and would require 240 cfm (20 cfm/crate) in winter. This means that the minimum ventilation fan normally used in a nursery would be too large for the same size farrowing house. Do not reduce the speed of the minimum ventilation fan to less than 50 percent. Replace the fan if needed to avoid this situation. Summer ventilation fans, likewise, should be ample for a farrowing house converted from the nursery but should have at least 500 cfm/crate capacity.

Another concern in converting this facility would be the lack of utilities. A farrowing house will need an additional water line for drip cooling and extra electrical outlets for heat lamps or mats.

The flooring in most nurseries would be adequate for farrowing except that many times it may not have been designed to accommodate the weight of the sow. Make sure the flooring is adequately supported. Beware of using certain flooring types that could be slick for a sow.

Changing Farrowing to Nursery Space

The conversion of farrowing rooms to nursery space are generally somewhat easy. The simplest conversion is to leave the 5' by 7' flooring and install nursery pen dividers. This wastes some space because the rear alley of the farrowing house remains but is not needed. Conversion is easy because a standard farrowing crate is 35 square feet and would therefore hold 12 pigs to 60 pounds. Each pen would require 24 cfm (2 cfm/crate) in comparison to the 20 cfm/crate that should have been originally installed. During summer weather there should be ample ventilation if it was properly sized before. The disadvantage to this is that it may require additional heat to keep pigs warm because of a low animal density.

If the converted room needs to hold more than the number of pigs housed in the space previously occupied by farrowing crates, then the rear alleyway can be used also. This is a good option if the alley can be removed and replaced with nursery flooring. If the floor of the alley is solid and must be used as part of the nursery pen flooring it will most likely have a problem with dunging patterns. Raising the pens so that the floor of the alley is below the pen flooring is an option but manure will accumulate on the solid surface, resulting in poor air quality from ammonia.

Nearly any shape room may be converted to nursery space. The most important aspects are the reduction of air drafts due to improper ventilation design, the removal of air contamination from adjacent rooms, and avoid cold surfaces like solid concrete.

Adding a feeding system is probably advisable for reduced labor.

Conversion of a Finisher to Gestation and Breeding

The conversion of a finisher to gestation and breeding facilities works well because of the similar environmental requirements for the two types of animals. Both types of animals are well suited for concrete flooring. The biggest obstacle is partially slatted flooring. If a finisher is partially slatted then conversion to a pen gestation is the best conversion. While finishing pigs are generally allowed 8 square feet, gestating sows require 16 square feet and should be housed in groups of 6 to 8 per pen. Solid flooring can then be used for floor feeding if desired.

If the building to be converted is fully slatted, crated or penned gestation could be used. Crated gestation would be more costly due to the removal of penning and purchase of crates. Fully slatted finishing could be converted to pen gestation quite easily except feeding becomes a problem. This can be improved by installing concrete feed and water troughs along the alleys on top of the slats. Crated gestation would also require feed troughs.

Arranging crates in an efficient manner is the biggest difficulty. Gestation crates should be 2' by 7' for sows. Rear alleys should be 2' wide and the front alleys should be 3' wide. This means that two rows of crates require a building at least 21' wide, three rows require 31', four rows require 40', five rows 50' and six rows 59'.

Adding boar crates and breeding pens are a little more inconvenient. Boar crates should be 28" by 8' and have at least the rear 56 inches slatted. Breeding pens should be 10' by 10' and have non-slip flooring.

Ventilation that was designed for finishers should be similar for breeding and gestating animals except breeding animals, especially boars, are more susceptible to heat stress. If crate gestation is selected, use drip cooling over each crate. Interval spray coolers may be used with pen gestation.

Manure storage should be more than adequate because sows are limit fed and therefore produce less manure than finishing animals.

Conversion of Breeding/Gestation to Finishing

This conversion is also relatively simple. Remove crates and breeding pens and replace with penning and feeders. Add nipple waterers. Remove troughs.

Other Possible Conversions

It is less common to convert finishing, gestation or breeding facilities to farrowing or nursery facilities (or visa versa). This can be done but it generally requires additional remodeling costs due to changes in the flooring, and the fact that room sizes are not similar. In many cases this can be accomplished but the remodeling cost begins to approach that of new construction.

Summary

Adopting the technology of age segregated rearing and all in all out takes scheduling of pigs, proper management and the proper building. Conversion of buildings to segregate pigs is sometimes an easy alternative. Important factors are the location of the building in relation to other buildings, the size required for proper pig flow, and the cost in comparison to a new facility. Carefully plan out your changes and it will pay dividends.

1 Prepared by Jay D. Harmon, Ph.D., P.E., Extension Agricutlural Engineer, Iowa State University for "Competitive Technology for the 21st Century" sponsored by the Iowa Pork Industry Center, Iowa State University, Ames, IA held September 16, 1997.

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