David R. Stender

Field Performance Evaluation of a Ventilation System: A Swine Case Study

Swine finishing facility ventilation has become relatively complex and is often mismanaged as a system. One of the few ways to truly understand these systems is to spend time systematically going through the many components of the building and how they work as a system. To learn to help producers better, a team of university Extension specialists that included agricultural engineers and animal scientists spent an extended period carefully documenting conditions in a deep-pit swine finishing building with two 1,000-head rooms. Exhaust fans connected to the manure pit and wall fans were operated at various stages as a negative-pressure ventilation system. A computerized controller activated exhaust fans, a ventilation curtain actuator, heaters, stir fans, and a spray cooling system. Gravity-controlled baffled ceiling inlets were evenly spaced in the building to provide good air distribution during cold and mild weather conditions. Following the review of current conditions and operating parameters, performance deficiencies were identified and recommendations were given regarding controller settings, inlet settings, and the transition to natural ventilation. Specific recommendations included changing minimum ventilation speed settings of fans based on animal size, removing inlet stops during warmer weather to avoid premature transition to natural ventilation, a change in how fans were staged, a change in setpoint, and the specific temperature at which the cooling system was engaged.

Comparison of Different Styles of Swine Finishing Facilities within a Uniform Production System

Swine originating from one farrowing and nursery source were grown in five different finishing facility types. Three of the facilities were considered contemporary styles and two facilities were based on older technologies. The total data set included information collected on 46,408 pigs from 25 groups. The three contemporary facility styles included a fully slatted, hybrid ventilated facility; a fully slatted tunnel ventilated facility; and a partially slatted naturally ventilated facility. These newer facilities were compared to an older, less environmentally controlled facility and an outdoor feeding lot. No significant differences were observed in production performance of the three styles of newer buildings (p > 0.05). Significant differences were found in feed efficiency (p < 0.05), days to market (p < 0.10), and yield (p < 0.05) among all (new and old) facility types. Feed efficiency and yield were found to be significantly better in the newer rather than the older facilities (p < 0.05). Average daily gain (ADG) for the new facilities was found to be significantly different (p < 0.05) by season of the year. The variation in death loss, feed efficiency, and ADG appeared to be relatively consistent among the different styles of finishing facilities. A basic cost analysis showed that the production cost differences among the three styles of contemporary finishing facilities is small and therefore decisions on the type of building should be based more on management preferences than cost savings.

Lean and Fat Deposition Measurements for Purebred Berkshire Pigs Housed in Hoop Barns in Iowa

and Implications Previous research on meat quality of pork has demonstrated that purebred Berkshires have advantages over most commodity based pork. Therefore a Certified Berkshire Pork program has developed and is a vital niche market in Iowa and the United States that provides economic opportunity for a growing number of producers. This research has also documented that Berkshires have a significantly poorer feed conversion than other breeds, thus raising their cost of production. Understanding how feed programs and growth rates affect lean and fat deposition rates is a critical aspect to these niche programs in order to maximize profitability and quality of the Berkshire pork products marketed. From these two trials there are differences between the two trials for both barrows and gilts that may not be accounted for by seasonal affects. Overall, barrows averaged an inch of backfat between 200 and 240 lb body weight whereas gilts approached this backfat depth between 260 and 300 lb. Lean deposition rates were different between barrows and gilts and between trials. This difference makes it critical when selecting animals for marketing and achieving consistency in meat quality within a marketing system. The differences between barrows and gilts indicate it may be more critical that each are fed differently than in commercial production systems.

The real world of ventilation troubleshooting: a swine case study.

Swine finishing facility ventilation has become relatively complex and is often mismanaged as a system. One of the few ways to truly understand these systems is to spend time systematically going through the many components of the building. To learn to help producers better, a team of university Extension specialists that included agricultural engineers and animal scientists spent an extended period carefully documenting conditions in a deep-pit swine finishing building with two 1,000-head rooms. Exhaust fans in the pit and walls operated at various stages throughout the year as a negative-pressure ventilation system. A computerized controller activated exhaust fans, a ventilation curtain actuator, and heaters. Gravity baffled ceiling inlets were evenly spaced in the building to provide good air distribution during cold and mild weather conditions. Following the review of current conditions and operating parameters, performance deficiencies were identified and recommendations were given regarding controller settings, inlet settings, and curtain management. The overall operating characteristics of the ventilation system and air quality in the animal space were documented ventilation and related management changes were discussed with the owner/operator.