Genomic Prediction for Whole Weight, Body Shape, Meat Yield, and Color Traits in the Portuguese Oyster Crassostrea angulata

Genetic improvement for quality traits, especially color and meat yield, has been limited in aquaculture because the assessment of these traits requires that the animals be slaughtered first. Genotyping technologies do, however, provide an opportunity to improve the selection efficiency for these traits. The main purpose of this study is to assess the potential for using genomic information to improve meat yield (soft tissue weight and condition index), body shape (cup and fan ratios), color (shell and mantle), and whole weight traits at harvest in the Portuguese oyster, Crassostrea angulata. The study consisted of 647 oysters: 188 oysters from 57 full-sib families from the first generation and 459 oysters from 33 full-sib families from the second generation. The number per family ranged from two to eight oysters for the first and 12–15 oysters for the second generation. After quality control, a set of 13,048 markers were analyzed to estimate the genetic parameters (heritability and genetic correlation) and predictive accuracy of the genomic selection for these traits. The multi-locus mixed model analysis indicated high estimates of heritability for meat yield traits: 0.43 for soft tissue weight and 0.77 for condition index. The estimated genomic heritabilities were 0.45 for whole weight, 0.24 for cup ratio, and 0.33 for fan ratio and ranged from 0.14 to 0.54 for color traits. The genetic correlations among whole weight, meat yield, and body shape traits were favorably positive, suggesting that the selection for whole weight would have beneficial effects on meat yield and body shape traits. Of paramount importance is the fact that the genomic prediction showed moderate to high accuracy for the traits studied (0.38–0.92). Therefore, there are good prospects to improve whole weight, meat yield, body shape, and color traits using genomic information. A multi-trait selection program using the genomic information can boost the genetic gain and minimize inbreeding in the long-term for this population.

Impact of Retail Case Type and Lighting Intensity on Instrumental Color Traits of Ground Beef Patties

The objective of this study was to determine the influence of retail case type and lighting intensity on color stability of ground beef patties. Ground 80:20 beef was procured from a local retail establishment between 7 and 10 d from the box date and ground through a 9.5 mm grinder plate, then formed into 150.25 g patties. Patties were then individually packaged in PVC-overwrap packages and randomly assigned into one of four treatments: open, multideck cases with 3000 K lighting (OPEN3000), open, 3500 K lighting (OPEN3500), enclosed, multideck cases with doors with 3000 K lighting (DOOR3000), and enclosed multideck at 3500 K lighting (DOOR3500). Patties were displayed for 7 d and instrumental color values (CIE L*, a*, and b*) were taken every 24 h. Data were analyzed as a 2 × 2 factorial arrangement with repeated measures, with case type, lighting intensity, and their interaction serving as fixed effects. Patties in DOOR cases possessed greater L* values (P < 0.05) than OPEN cases on d 3 of display. A similar trend existed for a*, where DOOR patties were redder (P < 0.05) than OPEN patties from d 2 to the end of display, and b* values were higher (P < 0.05) in DOOR cases from d 1 to d 4 of display. Patties from the DOOR cases also possessed increased chroma values (P < 0.05) from d 1 to 6 of display, and decreased (indicating more red) hue angle values from d 3 to the end of display. No differences were observed between lighting intensity for any trait evaluated (P ≥ 0.293). These results indicate patties placed in enclosed retail cases with doors are lighter, redder, and more intense in color during display compared to traditional open-front cases, which indicates greater color stability.

Prediction of meat quality traits in the abattoir using portable near-infrared spectrometers: heritability of predicted traits and genetic correlations with laboratory-measured traits

Background The possibility of assessing meat quality traits over the meat chain is strongly limited, especially in the context of selective breeding which requires a large number of phenotypes. The main objective of this study was to investigate the suitability of portable infrared spectrometers for phenotyping beef cattle aiming to genetically improving the quality of their meat. Meat quality traits (pH, color, water holding capacity, tenderness) were appraised on rib eye muscle samples of 1,327 Piemontese young bulls using traditional (i.e., reference/gold standard) laboratory analyses; the same traits were also predicted from spectra acquired at the abattoir on the intact muscle surface of the same animals 1 d after slaughtering. Genetic parameters were estimated for both laboratory measures of meat quality traits and their spectra-based predictions. Results The prediction performances of the calibration equations, assessed through external validation, were satisfactory for color traits (R2 from 0.52 to 0.80), low for pH and purge losses (R2 around 0.30), and very poor for cooking losses and tenderness (R2 below 0.20). Except for lightness and purge losses, the heritability estimates of most of the predicted traits were lower than those of the measured traits while the genetic correlations between measured and predicted traits were high (average value 0.81). Conclusions Results showed that NIRS predictions of color traits, pH, and purge losses could be used as indicator traits for the indirect genetic selection of the reference quality phenotypes. Results for cooking losses were less effective, while the NIR predictions of tenderness were affected by a relatively high uncertainty of estimate. Overall, genetic selection of some meat quality traits, whose direct phenotyping is difficult, can benefit of the application of infrared spectrometers technology.

Relationships of a Detailed Mineral Profile of Meat with Animal Performance and Beef Quality

The mineral profile of beef is a subject of human health interest, but also animal performance and meat quality. This study analyzes the relationships of 20 minerals in beef inductively coupled plasma-optical emission spectrometry (ICP-OES) with three animal performance and 13 beef quality traits analyzed on 182 samples of Longissimus thoracis. Animals’ breed and sex showed limited effects. The major sources of variation (farm/date of slaughter, individual animal within group and side/sample within animal) differed greatly from trait to trait. Mineral contents were correlated to animal performance and beef quality being significant 52 out of the 320 correlations at the farm/date level, and 101 out of the 320 at the individual animal level. Five latent factors explained 69% of mineral co-variation. The most important, “Mineral quantity” factor correlated with age at slaughter and with the beef color traits. Two latent factors (“Na + Fe + Cu” and “Fe + Mn”) correlated with performance and beef color traits. Two other (“K-B-Pb” and “Zn”) correlated with beef chemical composition and the latter also with carcass weight and daily gain, and beef color traits. Beef cooking losses correlated with “K-B-Pb”. Latent factor analysis appears be a useful means of disentangling the very complex relationships that the minerals in beef have with animal performance and beef quality traits.