Predictive Equations of Carcass Characteristics and Primal Cut Weights of Native Mexican Guajolotes Using Body Measurements

ABSTRACT This study was conducted to develop predictive equations for carcass characteristics and primal cut weights of native Mexican guajolotes using body measurements (BM). For this study, a total of 36 male guajolotes (Meleagris gallopavogallopavo), aged 6 to 10 months, and mean slaughter body weight (SBW) of 4543.14 ± 656.60 g, were used. The birds were kept under traditional extensive conditions. ThefollowingBMswererecorded24 h before slaughter: thoracicperimeter (TP), body circumference (BC), body length (BL), wing length (WL), keel length (KL), shank length (SL) and shank diameter (SD). After slaughter, hot carcass weight (HCW), cold carcass weight (CCW), hot dressing percentage (HDP), cold dressing percentage (CDP), organs and viscera weight (VIS) and abdominal fat weight (AFW) were recorded. The carcasses were dissected in to five primal cut (breast, thigh, drumstick, back and wing). The SBW and BMs showed moderate to high positive correlations (p<0.01; 0.34≤r<0.97) with carcass characteristics and primal cut weights. In the equations generated to predict HCW, CCW, HDP, CDP, VIS and AFW, the R2 ranged from 0.40 to 0.96, and the predictor variables were SBW, KL, BC, WL and SL. Regarding the equations developed to predict the primal cut weights, R2 ranged from 0.58 to 0.91. In these models, SBW, BC, SD, WL and KL explained most of the observed variation. The prediction equations obtained in the study had moderate to high accuracy; therefore, they can be used by researchers, technicians and poultry producers to obtain information on the carcass composition of native Mexican guajolotes.

摘要 本研究旨在通过体尺指标（Body Measurements, BM）建立墨西哥本土火鸡（Meleagris gallopavogallopavo）的胴体性状及分割肉块重量预测方程。本试验共选用36只6~10月龄雄性墨西哥本土火鸡，其平均屠宰活体重（Slaughter Body Weight, SBW）为4543.14±656.60 g。试验鸡采用传统粗放式饲养管理。屠宰前24小时，测定以下体尺指标：胸周径（Thoracic Perimeter, TP）、体围（Body Circumference, BC）、体长（Body Length, BL）、翅长（Wing Length, WL）、龙骨长（Keel Length, KL）、胫长（Shank Length, SL）及胫直径（Shank Diameter, SD）。屠宰后，记录热胴体重（Hot Carcass Weight, HCW）、冷胴体重（Cold Carcass Weight, CCW）、热屠宰率（Hot Dressing Percentage, HDP）、冷屠宰率（Cold Dressing Percentage, CDP）、脏器总重（Organs and Viscera Weight, VIS）及腹脂重（Abdominal Fat Weight, AFW）。随后将胴体分割为5个主要部位：胸肉、大腿、小腿、背部及翅部。屠宰活体重与各体尺指标均与胴体性状及分割肉块重量呈中度至高度正相关（p<0.01；0.34≤r<0.97）。在用于预测热胴体重、冷胴体重、热屠宰率、冷屠宰率、脏器总重及腹脂重的预测模型中，决定系数R²取值范围为0.40~0.96，所选预测变量为屠宰活体重、龙骨长、体围、翅长及胫长。针对分割肉块重量建立的预测模型，其决定系数R²取值范围为0.58~0.91；此类模型中，屠宰活体重、体围、胫直径、翅长及龙骨长可解释绝大多数观测变异。本研究所得预测模型精度处于中度至高水平，因此可被科研人员、技术人员及家禽养殖户用于获取墨西哥本土火鸡的胴体组成相关信息。