A comparison of preferences for pork sandwiches produced from animals with and without somatotropin administration.

Experimental auction markets were designed and used to investigate consumer preferences for sandwiches produced with meat from pigs treated with porcine somatotropin. A second-price, sealed-bid auction procedure was used to determine willingness to pay to exchange a pork loin sandwich with leaner meat from pigs treated with somatotropin for a similar sandwich with meat from untreated pigs. The research was conducted using a sample of 114 undergraduate students in Iowa, Arkansas, Massachusetts, and California. At the end of the experiment 33 of 58 subjects would not bid to change their leaner pork for typical pork, whereas 15 of 56 subjects would not bid to change their typical pork for leaner pork. The results suggest a preference for leaner meat from the treated pigs, but also the potential for niche markets for meat and meat products from untreated pigs.

Patterns associated with season and facilities for atrophic rhinitis and pneumonia in slaughter swine.

Three slaughter checks were performed for each of 21 swine producers at 6-month intervals. Two slaughter checks were performed during the winter, and 1 slaughter check was performed during the summer. Lesions of atrophic rhinitis and pneumonia were evaluated during the slaughter checks. Two types of farrowing facilities and 4 types of grower/finisher facilities were used by the swine producers. Lesions of atrophic rhinitis and pneumonia were compared among seasons and among types of facilities. Lesions of both atrophic rhinitis and pneumonia varied with season. Lesions of atrophic rhinitis were more severe among hogs slaughtered in the summer, whereas lesions of pneumonia were more severe among hogs slaughtered in the winter. Lesions of atrophic rhinitis were more severe in hogs farrowed in central, enclosed farrowing houses and finished in enclosed, mechanically ventilated buildings than in hogs farrowed individually in sow huts and finished on dirt lots. Knowledge of disease patterns associated with season and facilities is useful for assessment of herd health status and for implementation of control programs.

Energy use in pig production: an examination of current Iowa systems.

This paper compares energy use for different pig production systems in Iowa, a leader in US swine production. Pig production systems include not only the growth and performance of the pigs, but also the supporting infrastructure of pig production. This supporting infrastructure includes swine housing, facility management, feedstuff provision, swine diets, and manure management. Six different facility type × diet formulation × cropping sequence scenarios were modeled and compared. The baseline system examined produces 15,600 pigs annually using confinement facilities and a corn-soybean cropping sequence. Diet formulations for the baseline system were corn-soybean meal diets that included the synthetic AA l-lysine and exogenous phytase. The baseline system represents the majority of current US pork production in the Upper Midwest, where most US swine are produced. This system was found to require 744.6 MJ per 136-kg market pig. An alternative system that uses bedded hoop barns for grow-finish pigs and gestating sows would require 3% less (720.8 MJ) energy per 136-kg market pig. When swine production systems were assessed, diet type and feed ingredient processing were the major influences on energy use, accounting for 61 and 79% of total energy in conventional and hoop barn-based systems, respectively. Improving feed efficiency and better matching the diet formulation with the thermal environment and genetic potential are thus key aspects of reducing energy use by pig production, particularly in a hoop barn-based system. The most energy-intensive aspect of provisioning pig feed is the production of synthetic N for crop production; thus, effectively recycling manure nutrients to cropland is another important avenue for future research. Almost 25% of energy use by a conventional farrow-to-finish pig production system is attributable to operation of the swine buildings. Developing strategies to minimize energy use for heating and ventilation of swine buildings while maintaining pig comfort and performance is a third critical area for future research. The hoop barn-based alternative uses 64% less energy to operate buildings but requires bedding and 2.4% more feed. Current Iowa pig production systems use energy differently but result in similar total energy use. Compared with 1975, current farrow-to-finish systems in Iowa require 80% less energy to produce live market pigs.

Nonsolar energy use and one-hundred-year global warming potential of Iowa swine feedstuffs and feeding strategies.

Demand for nonsolar energy and concern about the implications of fossil fuel combustion have encouraged examination of energy use associated with agriculture. The United States is a global leader in pig production, and the United States swine industry is centered in Iowa. Feed is the largest individual input in pig production, but the energy consumption of the Iowa swine feed production chain has yet to be critically examined. This analysis examines nonsolar energy use and resulting 100-yr global warming potential (GWP) associated with the swine feed production chain, beginning with cultivation of crops and concluding with diet formulation. The nonsolar energy use and accompanying 100-yr GWP associated with production of 13 common swine feed ingredients are estimated. Two diet formulation strategies are considered for 4 crop sequence x ingredient choice combinations to generate 8 crop sequence x diet formulation scenarios. The first formulation strategy (simple) does not include synthetic AA or phytase. The second strategy (complex) reduces CP content of the diet by using L-lysine to meet standardized ileal digestibility lysine requirements of pigs and includes the exogenous enzyme phytase. Regardless of crop sequence x diet formulation scenario, including the enzyme phytase is energetically favorable and reduces the potential excretion of P by reducing or removing inorganic P from the complete diet. Including L-lysine reduces the CP content of the diet and requires less nonsolar energy to deliver adequate standardized ileal digestible lysine than simply feeding soybean meal. Replacing soybean meal with full-fat soybeans is not energetically beneficial under Iowa conditions. Swine diets including dried distillers grains with solubles and crude glycerol require approximately 50% more nonsolar energy inputs than corn-soybean meal diets or corn-soybean meal diets including oats. This study provides essential information on cultivation, processing, and manufacture of swine feed ingredients in Iowa that can be coupled with other models to estimate the nonsolar energy use and 100-yr GWP of pig production.

Consumer acceptability of milk from cows treated with bovine somatotropin.

Experimental auction markets were used to investigate the acceptability to undergraduate students of milk from cows treated with bST. The auction market was used to elicit willingness of participants to pay to exchange "bST milk" for "normal" milk when given repeated market participation. The results suggest that more than 60% of participants would purchase milk from cows treated with bST at economically feasible discounts.