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Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan

Citation:   No Citation available.
Authors:   B. F. Wolter , M. Ellis, S. E. Curtis, G. D. Schnitkey, E. N. Parr, and D. M. Webel
Keywords:   Pig Housing, Economic Analysis, Space Allocation, Group Size

The study objective was to compare the economic performance of nursery systems based on large (100 pigs) or small (20 pigs) group sizes and two floor-space allowances (adequate or reduced). A total of 1920 pigs were used. Pig performance data were from two trials carried out over a 4-wk period immediately post-weaning. The trials compared four treatment combinations (2 x 2 factorial) of group size and floor-space allowance: 1) small group (20 pigs/pen) at a floor-space allowance for maximum growth (.17 m 2 /pig) (SREQ); 2) small group (20 pigs/pen) at a reduced floor space (.15 m 2 /pig) (SRED); 3) large group (100 pigs/pen) at a floor space for maximum growth (.17 m 2 /pig) (LREQ); and 4) large group (100 pigs/pen) at a reduced floor space (.13 m 2 /pig) (LRED). The economic analysis was based on a nursery building with 409 m 2 floor space and used economic data collected on U.S. farms from 1988 to 1998. Treatment results are presented in the following order: SREQ; SRED; LREQ; and LRED. Reduced floor-space designs had greater annual animal throughput (23,040; 26,880; 24,000; and 28,800 pigs/yr) and, therefore, lower fixed costs per pig sold ($0.21; $0.19; $0.20; and $0.17). However, pigs housed at reduced floor space were 2.7% lighter at the end of the nursery period than those given adequate floor space, and pigs in large pens were 4.3% lighter than pigs in small pens. Overall, total costs per pig sold (i.e. variable, fixed, and management costs) were marginally reduced by moving to reduced-floor-space or large-group designs ($34.91; $34.74; $34.70; and $34.56). However, because of the increased pig weights out of the nursery, the small group size treatments resulted in greater total returns per pig sold ($32.41; $31.44; $30.89; and $30.16). Consequently, returns over total costs per pig, which were negative, were greater for pigs reared in small groups at an adequate floor space (-$2.50; -$3.30; -$3.81; and -$4.40). A selling price of $2.07 per kg live weight was assumed in the current model, however, sensitivity analysis suggested that the break-even pig selling prices per kg live weight for each system were $2.23; $2.29; $2.33; and $2.38, respectively. Increases in pig growth rates of 2.4%, 4.8% and 6.5% above those observed in the current study would be required for nursery systems with the small group size at a reduced floor space, large group size at an adequate floor space, and large group size at an adequate floor space, respectively, to have the same returns as from small groups at an adequate floor space. Results of this study suggest that penning pigs in the large groups or at the reduced floor-space allowance negatively influenced pig performance such that economic returns were decreased. (Download PDF)    (Export to EndNotes)