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The parameters of the Gompertz function used in alternative genotype scenarios

 
Genotype scenario1 Maturing rate φi Adult weight of protein mass αP Adult weight of lipid mass aL Lean meat, % ADG, kg/d
Benchmark 0.0136 35 59.5 60.0 1.003
High lean meat % 0.0134 37.0356 54.38 61.0 1.003
High ADG 0.0141 35.7902 61.3553 60.0 1.060
High adult weight of protein mass 0.0136 40.295 59.5 61.2 1.084
High adult weight of lipid mass 0.0136 35 74.465 58.4 1.052
High maturing rate 0.01565 35 59.5 60.0 1.154
1The genetic potential of pigs in other scenarios differs from the benchmark scenario. The difference is equal to approximately 1 (genetic) standard deviation of the relevant parameter. The change in potential is determined under ad libitum feeding and before applying the optimization program. Lean meat percentage and ADG are measured at 110 kg live weight.



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Price parameters examined in the sensitivity analysis1

 
Parameter values used in the analysis
Variable Baseline scenario Alternative scenario2
Price of pigmeat at the farm gate, €/kg3 1.53 1.6983
Price of a 25-kg piglet, €/kg 57 52.44
Price of NE, €/MJ NE4 0.099 0.0782
Price of lysine, €∙g−1×MJ−1 NE4 0.022 0.0169
Target range3, kg 76 to 92.5 85 to 105
One point of lean meat percentage3 0.02
Discount due to undesired weight, €/kg3 0.02
Daily discount rate, % 99.89
1Sources: Tike (2014), Grisportalen (2014), and authors’ own calculations.
2Each parameter was increased or decreased by a factor of 1 SD (±SD). Price variation was as observed during the period of 2010 to 2012.
3Base price of pigmeat is applied for carcasses that are within the “target range” and contain 60% lean meat. For each additional kilogram deviating from the target range, an additional €0.02 discount is charged. For each percentage point of lean meat below (above) 60%, an additional €0.02 price discount (premium) is applied.
4The price of compound (€/MJ) feed is: price of NE + price of lysine ´ lysine content of feed.



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Average daily gain, lean meat percentage, and nitrogen (N) excretion as a result of the optimization program for different genotypes and simulation results for nonoptimal scenarios where pigs were fed ad libitum

 
Baseline scenario
Ad libitum scenario: simulation results
Genotype1 ADG, kg/d Lean meat, % N excretion2, kg/pig ADG, kg/d Lean meat, % N excretion3, kg/pig
Benchmark 0.89 63.3 3.69 0.98 59.7 3.54
High lean meat % 0.9 64.0 3.79 0.95 60.6 3.52
High ADG 0.93 63.2 3.68 1.00 59.2 3.57
High adult weight of protein mass 0.97 63.7 3.82 0.97 60.0 3.54
High adult weight of lipid mass 0.9 62.0 3.49 1.02 58.4 3.60
High maturing rate 1.02 62.9 3.54 1.00 58.9 3.59
1Other genotypes differ from the benchmark genotype. The difference is approximately equal to 1 SD genetic increase in the relevant trait. Genetic change is determined before the optimization program has been applied.
2Calculated for a grow-finish pig, from 25 kg BW to slaughter.
3Calculated based on optimal decision pattern for ad libitum feeding scenario under the condition of improved market situation for a grow-finish pig, from 25 kg BW to slaughter after 91 d of fattening.



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Economic results (value function converted to euros per pig space per year; impact of genotype scenario on net returns of €/100 kg pigmeat) under the optimal fattening and harvest pattern for different genotypes and sensitivity of economic values on market assumptions.

 
Baseline scenario
Difference in the value function between the benchmark genotype and other genotypes for alternative scenarios measured as €/100-kg pigmeat2
Genotype1 Net return, €∙pig space unit−1∙yr−1 Baseline scenario Increase price of pigmeat Decrease price of piglet Decrease price of MJ NE Decrease price of lysine Elevated target BW
Benchmark 7.2
High lean meat % 10.1 0.92 1.09 0.95 1.34 0.78 1.13
High ADG 11.3 1.27 2.24 1.55 1.91 1.43 1.66
High adult weight of protein mass 14.8 2.31 3.90 2.76 3.76 2.45 3.13
High adult weight of lipid mass 3.1 −1.25 −0.52 −0.99 −1.22 −0.81 −1.00
High maturing rate 19.8 3.70 6.28 4.51 5.30 4.12 4.45
1Other genotypes differ from the benchmark scenario. The difference is equal to approximately 1 SD genetic increase in the trait before the optimization program is applied.
2The impact represents the difference to the baseline scenario and it represents the effect of one SD increase in the price of pigmeat, decrease in the piglet, MJ NE or lysine price and the effect of a change in the target slaughter weight.



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Sensitivity of nitrogen (N) excretion to assumptions regarding the market situation

 
Baseline scenario
Increase in cumulative N excretion, g/kg of carcass gain in alternative scenarios compared to baseline scenario2
Genotype1 Cumulative N excretion3, g/kg of carcass gain Increase price of pigmeat Decrease price of piglet Decrease price of MJ NE Decrease price of lysine Elevated target weight
Benchmark 56.77 −1.59 −0.78 −0.06 −0.07 2.75
High lean meat % 57.76 −2.11 −1.04 −0.05 −0.25 2.86
High ADG 56.27 −1.59 −0.88 −0.01 −0.20 2.86
High adult weight of protein mass 56.97 −1.08 −0.79 −0.15 −0.07 3.35
High adult weight of lipid mass 54.63 −0.13 −0.09 0.31 0.53 2.97
High maturing rate 54.51 −1.05 0.05 0.26 0.07 3.91
1Other genotypes differ from the benchmark scenario. The difference is equal to approximately 1 SD genetic increase in the relevant trait. Genetic change is determined before the optimization program is been applied.
2The impact represents the difference in the baseline scenario, and it represents the effect of a 1 SD increase in the price of pigmeat, piglet, megajoules NE, or lysine or the effect of a change in the target slaughter weight.
3Calculated for a grow-finish pig, from 25 kg BW to slaughter.