Prediction of cull cow carcass characteristics from live weight and body condition score measured pre slaughter

Abstract

A study was conducted to provide information on the degree of carcass finish of Irish\ncull cows and to investigate the usefulness of live animal measurements for the prediction beef breeds (albeit with a moderate R2 value compared to the carcass weight prediction)\nusing objective, non-intrusive and easily measured live animal measurements, should\nbe of benefit to farmers finishing cull cows in Ireland.\nof cull cow carcass characteristics. Live weight (LW) and body condition score\n(BCS) were recorded on cows entering an Irish commercial slaughter facility between\nSeptember and November, 2005. Data pertaining to sire breed, age and carcass characteristics\nwere collected and subsequently collated for each cow. For analysis, cows\n(n = 2163) were subdivided into three breed categories: dairy breed sired by Holstein/\nFriesian (FR), sired by early-maturing beef breeds (EM) and sired by late-maturing\nbeef breeds (LM). The proportion of cows slaughtered at the desired (TARGET)\ncarcass standard (cold carcass weight ≥ 272 kg, carcass conformation class ≥ P+ and\ncarcass fat class ≥ 3) was low (on average 0.30), but did differ (P < 0.001) between the\ndairy and beef breed categories (0.22, 0.47 and 0.53 for FR, EM and LM categories,\nrespectively). Regression procedures were used to develop equations to predict cold\ncarcass weight, carcass conformation score, carcass fat score and proportion in the\nTARGET category from LW and BCS. Equations predicting cold carcass weight had\nhigh R2 values for all breed categories (0.81, 0.85 and 0.79 for the FR, EM and LM,\nrespectively). Equations predicting carcass fatness had moderate R2 values for the beef\nbreed categories (0.65 and 0.59 for the EM and LM, respectively). Equations predicting\ncarcass conformation and the TARGET category yielded lower R2 values. The successful\nprediction of carcass weight for all breed categories and of carcass fatness for the