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Title:Relationships between primal cut weights and economic value and live animal, carcass, and meat quality measurements in crossbred pigs
Author(s):Grohmann, Caleb Jerome
Advisor(s):Ellis, Michael
Contributor(s):Shull, Caleb M; Dilger, Anna C
Department / Program:Animal Sciences
Discipline:Animal Sciences
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:M.S.
Genre:Thesis
Subject(s):pigs
growth
primal cuts
regression
value
Abstract:The objective of this research was to evaluate relationships between growth performance, ultrasonic, carcass, and meat quality measurements and individual and total primal cut weights, and estimated carcass and primal value of crossbred pigs. The study used a population of crossbred barrows and gilts (n = 6,720) owned by The Maschhoff’s, LLC (Carlyle, IL). The pigs were the progeny of 28 Duroc sires and 1038 Landrace × Large White crossbred sows. The growth performance evaluation was carried out from weaning (18.6 ± 1.09 d of age; 5.4 ± 0.32 kg live weight) to slaughter (196.6 ± 8.0 d of age; 137.2 ± 14.0 kg live weight). Pigs were reared in standard wean-to-finish facilities in single-sire, single-sex pens of 20 at a floor space of 0.68 m2/pig. Pigs had ad libitum access to feed and water throughout the study. Individual pig and pen weights were collected at weaning, week 10 of the study, and at the end of the trial. Pen means for average daily gain (ADG), average daily feed intake (ADFI), and gain: feed (G:F) were calculated for each interim and overall growth period. Ultrasonic backfat depth and Longissimus muscle depth and area were measured at the 10th rib on all pigs prior to slaughter. Carcass weight, dressing percentage, and Fat-O-Meater backfat depth and loin muscle depth at the 10th rib was collected on each carcass on the slaughter line. Carcass fat-free lean percentage was calculated from carcass weight, backfat depth, and loin depth for each carcass. The weight of the Boston butt, picnic, loin, spareribs, belly, ham, carcass length, and meat quality measurements were collected on a sample of 4 pigs from each pen that were representative of the range of live weights in each pen at slaughter. Carcass and primal value of each carcass were estimated using average prices reported by USDA AMS (2020) from 2017 to 2019. Correlations were weak between overall ADG, ADFI, and G:F and carcass value (r = -0.12, -0.22, and 0.15 respectively) and primal cut value (r = 0.19, 0.29, and -0.18 respectively). Slaughter and carcass weights were strongly positively correlated with primal cut weights (r = 0.74 to 0.98). Correlations between backfat depth and Longissimus muscle measurements (taken either ultrasonically or on the slaughter line) and primal cut weights were positive and ranged from 0.04 to 0.64. Carcass backfat depth was negatively correlated with carcass value (r = -0.45) but positively correlated with primal cut value (r = 0.56). Predicted carcass fat-free lean percentage was positively correlated with carcass value (r = 0.44) but negatively correlated with primal cut value (r = -0.53). Meat quality measurements were weakly correlated with either primal cut weights or carcass and primal cut value (r ≤ 0.21). Regression analyses were conducted to develop equations to predict primal cut weights (individual and total) and estimated value (carcass and primal) using either live animal or carcass measurements. Curvilinear regression equations provided only small improvements in adjusted R2 and Akaike’s Information Criterion (AIC) compared to linear regression equations for all dependent variables (excluding carcass value). In one-variable equations, slaughter weight (for equations using live animal measurements) or carcass weight (for equations using carcass measurements) explained the most variation in the weight of all individual and total primal cuts and carcass value. In general, the best two-variable equations to predict primal cut weights using live animal measurements included slaughter weight and backfat depth, and using carcass measurements included carcass weight and backfat depth. For most dependent variables, only limited improvements to the predictive accuracy were obtained in equations containing three or more variables when compared to two-variable equations. Results of this study suggest that the relationships of growth and carcass characteristics with primal cut value are the opposite of those with carcass value.
Issue Date:2020-12-10
Type:Thesis
URI:http://hdl.handle.net/2142/109450
Rights Information:Copyright 2020 Caleb Grohmann
Date Available in IDEALS:2021-03-05
Date Deposited:2020-12


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