RESUMEN
The inclusion of eating quality traits in sheep genetic improvement programmes is desirable. Intramuscular fat (IMF) plays a key role in ensuring consumer satisfaction when eating lamb, but genetic progress for IMF is constrained by a lack of routine data collection. This study investigated the potential for IMF predictor traits to substitute for measured IMF in genetic improvement programmes. Carcass and predicted IMF (near-infrared estimated IMF and marbling score) data were available on 10,113 New Zealand lambs, 1678 of which also had measured chemical IMF on a slice of M. longissimus lumborum on which the predictions of IMF had been made. Genetic antagonisms were observed between carcass lean traits and IMF. The genetic correlation between the predictors and measured IMF approached one, indicating that predictors of IMF can be used in genetic improvement programmes. Through using selection indexes, simultaneous increases in IMF and the existing terminal selection index are possible, provided all traits are measured. This study highlights the importance and potential of predicted IMF to achieve genetic improvement in traits of importance to consumers.
Asunto(s)
Músculo Esquelético , Carne Roja , Ovinos , Animales , Tejido Adiposo , Comportamiento del Consumidor , Carne/análisisRESUMEN
The percentage of intramuscular fat content of lamb meat is a key index of consumer acceptability. Hyperspectral imaging is a potential technique for in-line measurements of intramuscular fat in fresh meat. However, little work has been conducted to investigate the robustness of hyperspectral imaging data and associated multivariate models over time. Fifteen trials consisting of eight independent flocks across five years were used to quantify robustness of partial least squares regression (PLSR) models developed using data collected with the same imaging system. Two models were developed; one using data from the first year of the trials, and a progressive model that cumulatively includes data in chronological order. The two models performed similarly, in terms of the coefficient of determination (R2), standard error of prediction (SEP) and bias, when experimental conditions were consistent. However, under varying imaging conditions, the progressive model was able to account for this variability resulting in higher R2 and lower SEP.
Asunto(s)
Imágenes Hiperespectrales/veterinaria , Carne Roja/análisis , Tejido Adiposo , Animales , Imágenes Hiperespectrales/métodos , Análisis de los Mínimos Cuadrados , Músculo Esquelético/anatomía & histología , OvinosRESUMEN
This study investigates the performance of a partial least squares regression model to predict intramuscular fat (IMF) in lamb M. longissimus lumborum developed using near infrared (NIR) data collected under a range of different conditions. A total of 26 independent NIR datasets were collected across 7 years, including 14 flocks, four devices and several measurement conditions. A model is developed and its performance is tested using a total of n = 3201 NIR spectra and intramuscular fat percentage measurements by wet chemistry. The model had a coefficient of determination by cross-validation of 0.52, which agrees with previous results using smaller numbers of animals. Overall the results show that near infrared models can be robust across many varying conditions. These models could potentially be implemented in an automated meat quality monitoring system.
Asunto(s)
Tejido Adiposo , Carne Roja/análisis , Espectroscopía Infrarroja Corta/veterinaria , Animales , Análisis de los Mínimos Cuadrados , Músculo Esquelético , Nueva Zelanda , Oveja Doméstica , Espectroscopía Infrarroja Corta/métodosRESUMEN
This study evaluated a range of diffuse reflectance spectroscopic (Vis-NIR spectrophotometers) and imaging (Hyperspectral imaging cameras) instruments for predicting pH, IMF and shear force values of beef in a meat processing pilot plant. A total of 364 beef striploin samples were evaluated and prediction models were developed using PLSR. Models for pH and IMF (except Vis snapshot camera) showed good fit with high Rcv2 (0.29-0.92) and low SECV values. Good prediction accuracy with high Rp2 (0.44-0.90), RPD and low SEP values was also observed. While low values of Rp2 for shear force was observed, the expected curvilinear relationship between predicted values of shear force and predicted values of pH was observed suggesting that spectroscopic measurements were able detect biophysical factors associated to these two attributes. Overall, it can be concluded that diffuse reflectance spectroscopy combined with chemometrics has a great potential to be used as an on/in-line quality monitoring system for the meat processing industry.
Asunto(s)
Imágenes Hiperespectrales/veterinaria , Carne Roja/análisis , Espectroscopía Infrarroja Corta/veterinaria , Tejido Adiposo , Animales , Bovinos , Femenino , Manipulación de Alimentos , Calidad de los Alimentos , Concentración de Iones de Hidrógeno , Imágenes Hiperespectrales/métodos , Masculino , Músculo Esquelético , Resistencia al Corte , Espectroscopía Infrarroja Corta/métodosRESUMEN
Electronic cigarette (e-cigarette) advertising regulations differ across countries. This study examines how differences in e-cigarette advertising regulations influence exposure to e-cigarette advertising, and perceptions about what participants had seen and read about e-cigarettes. Data come from the ITC Four Country Survey (Canada [CA], United States [US], Australia [AU] and United Kingdom [UK]) carried out between August 2013 and March 2015 (nâ¯=â¯3460). In 2014, AU and CA had laws prohibiting the retail sale of e-cigarettes containing nicotine while the US and UK had no restrictions, although a voluntary agreement restricting advertising in the UK was introduced during fieldwork. Smokers and ex-smokers were asked whether in the last six months they had noticed e-cigarettes advertisements and received free samples/special offers (promotion), and about their perceptions (positive or otherwise) of what they had seen or read about e-cigarettes. Data were analyzed in 2017. US and UK participants were more likely to report that they had noticed e-cigarette advertisements and received promotions compared to CA or AU participants. For TV and radio advertisements, reported exposure was higher in US compared to UK. For all types of advertisements, reported exposure was higher in CA than AU. Overall, nearly half of AU (44.0%) and UK (47.8%) participants perceived everything they had seen and read about e-cigarettes to be positive, with no significant differences between AU and UK. Participants in countries with permissive e-cigarette advertising restrictions and less restrictive e-cigarette regulations were more likely to notice advertisements than participants in countries with more restrictive e-cigarette regulations.