RESUMEN
A portable ultra-wideband microwave system (MiS) coupled with an antipodal slot Vivaldi patch antenna (VPA) was used as an objective measurement technology to predict sheep meat carcase GR tissue depth, tested against AUS-MEAT national accreditation standards. Experiment one developed the MiS GR tissue depth prediction equation using lamb carcasses (n = 832) from two slaughter groups. To create the prediction equations, a two layered machine learning stacking ensemble technique was used. The performance of this equation was tested within the dataset using a k-fold cross validation (k = 5), which demonstrated excellent precision and accuracy with an average R2 of 0.91, RMSEP 2.11, bias 0.39 and slope 0.03. Experiment two tested the prediction equation against the AUS-MEAT GR tissue depth accreditation framework which stipulates predictions from a device must assign the correct fat score, with a tolerance of ±2 mm of the score boundary, and 90% accuracy. For a device to be accredited three measurements captured within the same device, as well as measurements across three different devices, must meet the AUS-MEAT error thresholds. Three MiS devices scanned lamb carcases (n = 312) across three slaughter days. All three MiS devices met the AUS-MEAT accreditation thresholds, accurately predicting GR tissue depth 96.1-98.4% of the time. Between the different devices, the measurement accuracy was 99.4-100%, and within the same device, the measurement accuracy was 99.7-100%. Based on these results MiS achieved AUS-MEAT device accreditation as an objective technology to predict GR tissue depth.
Asunto(s)
Microondas , Carne Roja , Oveja Doméstica , Animales , Carne Roja/análisis , Mataderos , Composición Corporal , Tejido Adiposo , Ovinos , Aprendizaje AutomáticoRESUMEN
This study evaluated the ability of portable ultra-wide band microwave system (MiS) to predict lamb carcase computed tomography (CT) determined composition % of fat, lean muscle and bone. Lamb carcases (n = 343) from 6 slaughter groups were MiS scanned at the C-site (45 mm from spine midline at the 12th /13th rib) prior to CT scanning to determine the proportion of fat, muscle and bone. A machine learning ensemble stacking technique was used to construct the MiS prediction equations. Predictions were pooled and divided in 5 groups stratified for each CT composition trait (fat, lean or bone%) and a k-fold cross validation (k = 5) technique was used to test the predictions. MiS predicted CT fat% with an average RMSEP of 2.385, R2 0.78, bias 0.156 and slope 0.095. The prediction of CT lean% had an average RMSEP of 2.146, R2 0.64, bias 0.172 and slope 0.117. CT bone% prediction had an average RMSEP of 0.990, R2 0.75, bias 0.051 and slope 0.090. Predictions for CT bone% met AUS-MEAT device accreditation error tolerances on the whole range of the dataset. Predictions for CT lean% and fat% met AUS-MEAT error tolerances on a constrained dataset.
Asunto(s)
Composición Corporal , Microondas , Músculo Esquelético , Carne Roja , Oveja Doméstica , Animales , Carne Roja/análisis , Tomografía Computarizada por Rayos X/métodos , Tejido Adiposo , Huesos/química , Aprendizaje AutomáticoRESUMEN
This study assessed the capacity of magnesium supplementation to reduce muscle glycogen loss, ultimate pH and increase plasma magnesium in pasture fed slaughter cattle. Beef cattle (n = 1075) from 14 farms were supplemented with or without magnesium pellets for 7-14 days prior to slaughter. Magnesium was allocated at 9.83 g of elemental magnesium per head per day, while the control diet was balanced to be isoenergetic and isonitrogenous, but contained no added magnesium. Groups of cattle (n = 44) were slaughtered at the same processing plant over two consecutive seasons, from August - September 2016 to May - July 2017. Magnesium supplementation increased muscle glycogen (P < 0.01) in cattle supplied from 2 of 14 farms, and increased plasma magnesium in 4 of 14 farms (P < 0.01). Magnesium supplementation had no effect on overall incidence of ultimate pH between the magnesium and control supplementation groups. The benefits of short term magnesium supplementation prior to slaughter was inconsistent for protecting muscle glycogen.
Asunto(s)
Magnesio/administración & dosificación , Músculo Esquelético/química , Carne Roja/análisis , Alimentación Animal/análisis , Animales , Bovinos , Dieta/veterinaria , Suplementos Dietéticos , Femenino , Glucógeno/análisis , Concentración de Iones de Hidrógeno , Magnesio/sangre , Masculino , TasmaniaRESUMEN
A portable ultra-wide band microwave system (MiS) coupled with an open-ended coaxial probe (OCP) or Antipodal Vivaldi Antenna (VPA) was tested as a non-invasive objective measurement to predict beef carcase single site fat depth at commercial abattoirs. Experiment one tested the effectiveness of MiS coupled with a VPA. The VPA was used to predict hot carcase P8 (fat depth on the rump) across 4 slaughter groups (n = 241). The VPA was also used to predict cold carcase rib fat (at the quartering site, 75% along the rib eye muscle) across 5 slaughter groups (n = 598). Experiment two tested the ability of MiS coupled with OCP to measure hot carcase P8 across two slaughter groups (n = 435). A machine learning stacking ensemble method was used to create the prediction equations. Datasets were grouped by prediction trait (P8 or ribfat) and probe/antenna then randomly divided into 5 groups based on tissue depth. Precision was greatest using OCP to predict P8 fat depth with a RMSEP of 2.47 mm and R2 of 0.70. The VPA precision was similar for the two tissue depths assessed, hot carcase P8 had an average RMSEP of 2.86 mm and R2 of 0.58 compared to cold carcase rib fat RMSEP of 2.60 mm and R2 of 0.55.
Asunto(s)
Microondas , Carne Roja/análisis , Grasa Subcutánea/anatomía & histología , Mataderos , Animales , Composición Corporal , Bovinos , Femenino , Aprendizaje Automático , Masculino , RadarRESUMEN
The experiment evaluated the ability of portable ultra-wide band microwave coupled with a Vivaldi patch antenna to predict carcase C-site fat and GR tissue depth. For C-site, 1070 lambs, across 8 slaughter groups were scanned and for GR, 286 lambs across 2 slaughter groups. Prediction equations for reflected microwave signals were constructed with a partial least squares regression two-components model and a machine learning Ensemble Stacking technique. Models were trained and validated using cross validation methods in actual datasets and then in datasets balanced for tissue depth. The precision and accuracy indicators of microwave predicted C-site fat depth across pooled and balanced datasets were RMSEP 1.53 mm, R2 0.54, and bias of 0.03 mm. The precision and accuracy for GR tissue depth across pooled and balanced datasets were RMSEP 2.57 mm, R2 0.79 and bias of 0.33 mm. Using the AUS-MEAT fat score accreditation framework this device was able to accurately predict GR 92.7% of the time.
Asunto(s)
Tejido Adiposo/anatomía & histología , Composición Corporal , Carne Roja/análisis , Animales , Aprendizaje Automático , Microondas , Oveja DomésticaRESUMEN
The on-farm factors increasing the incidence of dark cutting were studied in 3145 pasture raised cattle consigned in 66 lots. Animal, environmental and farm management factors were recorded and pasture quantity, quality and mycotoxin concentrations were measured. The relative risk of dark cutting decreased by 26% in cattle grazing pastures with magnesium concentrations exceeding 0.24%. There was a 50% increase in relative dark cutting risk of cattle drinking from dams compared to drinking from troughs. Feeding supplements (hay/silage) in the last 7â¯days prior to slaughter reduced the relative risk of dark cutting by 25%. A high prevalence of mycotoxins was detected in pastures across all farms. In this case pasture ergot alkaloid concentrations above 600PPB increased the relative risk of dark cutting by 45%, while the presence of FumonisinB1 increased risk by 58%. In contrast the presence of 3acetyldeoxynivalenol reduced the relative dark cutting risk by 37%. Sex also affected the incidence of dark cutting, with heifers less likely to cut dark than steers by 47%.