Economics of Finishing Pigs in Hoop Structures and Confinement: A Summer Group under Different Space Restrictions
The study was conducted at the ISU Rhodes Research and Demonstration farm. The two types of pork grow-finish production facilities compared in this study are hoop and total confinement. This is the eighth group of finishing pigs that has been evaluated in these facilities and the forth summer group. This study was conducted from April 2001 to September 2001. 
Past reports examined the differences between the two facility types to evaluate facility performance under summer and winter seasons. This report similarly examines the difference between the two facility types. An additional focus of this group is pig stocking density rates. Stocking rates of 9, 10.5, and 12 square feet per pig are evaluated for the hoop system. Net revenue per pig for the hoop systems were $19.79 (12 square feet), $22.41 (10.5 square feet), and $17.74 (9 square feet), respectively. The net revenue per pig for the confinement system was $16.25 per pig. 
The hoop facilities showed a dramatic drop in production efficiency when the facilities were stocked at a rate of 9 square feet per pig. The feed conversion increased nearly a tenth of a pound of feed per pound of gain and the average daily gain decreased by .6 pounds per day compared with the other stocking densities. However, feed efficiency and average daily gain only improved slightly when the space allowed per pig was 12 square feet compared with 10.5 square feet. Moreover, the reduction in space per pig from 12 to 10.5 square feet allowed a more efficient use of both facilities and bedding per pig. This allowed the group stocked at 10.5 square feet per pig to increase net revenue by $2.62 per pig over the hoop stocked at 12 square feet per pig. This difference is impacted somewhat by a difference in the weight of the pigs that were marketed (Table 1). They were on feed for a slightly longer time period. Despite this difference in sale weight the study suggests that a decrease in space utilized from 12 to 10.5 square feet per pig would increase the profit level for hoop facilities during the summer. 
Net revenue for the hogs from the hoop facility with 12 square feet of space was $3.54 per pig over the confinement system. This difference was greater than the average of the three previous summer groups, which favored the hoops by $1.43 and saw a difference in hoop net revenue vs. confinement net revenue that ranged from $.20 to $3.05 per pig. The range of differences can be explained by a number of reasons. Some can be attributed to on farm research variables such as weather and disease exposure. Another key issue is the distribution of marketing. This changes the performance of the remaining hogs as well as the average sale weight
Livestock Enterprise Budgets for Iowa
Fixed Costs. Costs that will occur regardless of the level of production each year. They generally include such things as depreciation, interest, taxes, and insurance on facilities, breeding livestock, and livestock equipment and facilities. Depreciation is assumed to be 8% of the original value of facilities and equipment annually. Interest averages one-half of the original value of facilities over its lifetime, or 5% annually. Taxes and insurance add 1% for a total of 14% of the original investment annually for fixed costs.
Evaluation of antioxidants by a rapid polarographic method
A simple, rapid, precise, and reproducible method and an adaptable apparatus for polarographic measurement of lipid peroxidation and antioxidant activity is described. This method measures antioxidant activity within a few min time as compared to the hours or days needed for several widely used methods. Peroxidation rates were measured for different lipids as a function of amount of lipid, and amount of biocatalyst. The method is applicable to the detection and measurement of the antioxidant effects exhibited by weak antioxidants and has been satisfactorily used for the measurement of the antioxidant activity of different concentrations of powerful antioxidants.