PSII-21 Evaluation of the impact of the magnitude of errors in the sorting of pigs and market price for market on the optimal market weight

摘要

The objective was to estimate the impact the accuracy in which pigs are sorted for marketing has on the optimal market carcass weight (CW) using a stochastic model. Three levels of bodyweight estimation error (BWEE) with SD’s of 0, 4, and 8% of BW were simulated. Initially, pigs were marketed in 3 marketing cuts (MCUT), 25% at 169, 25% at 179, and 50% at 193 d of age. The timing of marketing was shifted in 7d intervals with mean marketing ages of 155.5 to 211.5 d. Sort loss was calculated using the Tyson Foods marketing system. Sort loss ($/pig) values were fitted to a polynomial function of mean CW for each level of BWEE. Pork production costs were estimated using an industry spreadsheet. A base price of $1.433/kg of CW was used to produce a small profit per pig. Market prices of $1.653 and $1.322/kg of CW were used to reflect times of large profit or losses per pig. Barrow and gilt lean premiums were included. The optimal CW’s to maximize profit/pig and daily returns above daily costs were estimated for each combination of BWEE and market price. With accurate sorting (BWEE = 0), the optimal mean age was 183.5d at a mean CW of 96.4 kg and a profit of $3.49/pig. With less accurate sorting (BWEE = 8%), the optimal mean age decreased to 181.5 d with mean CW of 95.2 kg, and profit of $2.89/pig. With this marketing system, the optimal market ages decreased by 1 to 2d and CW’s decreased by 0.6 to 1.3kg as the accuracy of sorting decreased. The lower market price reduced the optimal CW by 1.2kg (2d) and increased 2.4kg (4d) with the higher market price.