Iowa pork producers are witnessing an increasing market demand for naturally raised pork— pigs raised outdoors or in a deep-bedded system without the use of antibiotics, growth promotants, or animal by-products. To address the growing demand for information about systems meeting natural pork protocol, the National Pork Board, Iowa State University, and private individuals formed a committee to design a farrow to finish system utilizing one hoop barn per group of pigs. Pigs were farrowed in a removable pen equipped with heated creep area. At the time of weaning, sows and pens were removed. The young pigs then stayed in the hoop barn and were fed to market weight. During the winter, an interior hoop was constructed over the rows of pens and this secondary structure was heated using a radiant tube heater.

At the ISU Allee Demonstration Farm in 2004, two groups of sows were farrowed using this design. The first group of 22 gilts farrowed 216 pigs in February or 9.8 pigs/sow. A total of 162 pigs were weaned at 5 weeks of age for an average of 7.4 pigs/sow. Energy costs for producing those animals were $8.06/pig weaned. A total of 150 animals reached market weight and were sold at 6 to 6.5 months of age. Another group of 14 second parity sows farrowed in the same facility in July. Those 14 sows produced 130 live pigs or 9.3 pigs/sow. A total of 89 pigs were weaned at 5 weeks of age for an average of 6.4 pigs/sow. At the time of this report the pigs born in July were 3.5 months old and had not yet reached market weight.