Soladoye, P. O., Shand, P. J., Aalhus, J. L., Garie´py, C. and Jua´rez, M. 2015. Review: Pork belly quality, bacon properties and recent consumer trends. Can. J. Anim. Sci. 95: 325Á340. Several factors can affect pork belly quality and, subsequently, bacon quality. Going by the recent trends in the bacon market and bearing in mind the more choosy nature of the consuming populace, it is imperative to consider the factors that can affect or improve bacon quality, thereby sustaining the current market surge. In as much as both genetic and environmental factors have been identified as largely affecting muscle food quality, nutritional interventions also seem to be a very viable tool to improve the quality of meat and its products. Processing and storage methods can also affect bacon quality, including microbial quality, physicochemical attributes and palatability. Both objective and subjective measures have been explored in assessing belly quality, most of which use belly softness and fatty acid profile as yardsticks, whereas bacon quality has been widely assessed only subjectively in terms of fat quality and slice integrity. Although consumers' and producers' quality perceptions seem to be in conflict, it is the responsibility of all stakeholders in the bacon industries to come together in ensuring a balanced approach to satisfy both parties along the production chain.Key words: Belly softness, environmental factors, genetic factors, nutritional factors, bacon quality Soladoye, P. O., Shand, P. J., Aalhus, J. L., Garie´py, C. et Jua´rez, M. 2015. Article de synthe`se: La qualite´de poitrine de porc, les caracte´ristiques du bacon et les tendances re´centes des consommateurs. Can. J. Anim. Sci. 95: 325Á340. Plusieurs facteurs peuvent influencer la qualite´de poitrine de porc et donc, par conse´quent, la qualite´du bacon. Selon les tendances re´centes dans le marche´du bacon, gardant a`l'esprit la nature plus se´lective des consommateurs, il est impe´ratif de prendre en conside´ration les facteurs qui peuvent influencer ou ame´liorer la qualite´du bacon, et ainsi soutenir l'e´lan courant du marche´. Dans la mesure que les facteurs ge´ne´tiques et environnementaux ayant un effet sur la qualite´de viande ont e´teí dentifie´s, les interventions nutritionnelles semblent un outil viable pour ame´liorer la qualite´de la viande et de ses produits. Les me´thodes de traitement et d'entreposage peuvent aussi avoir un effet sur la qualite´du bacon, incluant la qualiteḿ icrobienne, les caracte´ristiques physico-chimiques et la palatabilite´. Des mesures objectives et subjectives ont e´teé xplore´es pour e´valuer la qualite´de poitrine, dont la plupart utilisent la douceur de la poitrine et le profil d'acides gras comme jalon, tandis que la qualite´du bacon est largement e´value´e seulement en termes subjectifs comme la qualite´du gras et l'inte´grite´de la coupe. Bien que la perception de qualite´des consommateurs et des producteurs semblent contradictoires, il est la responsabilite´de tous les intervenants des industries du bac...

Hernández-Calva, L. M., He, M., Juárez, M., Aalhus, J. L., Dugan, M. E. R. and McAllister, T. A. 2011. Effect of flaxseed and forage type on carcass and meat quality of finishing cull cows. Can. J. Anim. Sci. 91: 613–622. Sixty-two cull cows were fed one of four diets in a 2×2 factorial arrangement, consisting of barley silage or grass hay with or without flaxseed to influence fatty acid composition. After slaughter, carcass grade, meat quality and sensory data were collected. Silage increased live (P=0.002) and carcass (P=0.001) weights of the cows as compared with hay. Muscle width (P=0.013) and score (P=0.010) and rib-eye area (P=0.002) were enhanced when silage was included in the diet, whereas supplementation with flaxseed increased (P=0.003) grade fat depth by 29%. Most subjective and objective retail evaluation traits in steaks from the left longissimus thoracis and ground meat were negatively affected (P<0.05) by the length of the retail display time. Moreover, dietary hay increased (P=0.015) the lean colour values in steaks and ground beef, which was corroborated by lower L* (P=0.009) and higher hue (P=0.010) in steaks and lower L* (P=0.049), chroma (P=0.005) in ground beef as compared with cows fed silage. A significant interaction between forage type and flax inclusion for thiobarbituric acid reactive substances (TBARS) (P=0.050) was observed. After sensory evaluation, steaks from cows fed silage had an increase (P=0.030) in beef flavour intensity when compared with cows fed hay, whereas inclusion of flaxseed in the diet decreased (P<0.001) beef flavour intensity in steaks from cows fed both forage sources. Sensory evaluation of ground beef found that hay-fed cows with flaxseed supplementation had decreased (P=0.03) beef flavour intensity, while the same effect was not observed in ground beef from cows fed silage with flaxseed. Results from this study show that inclusion of flaxseed in the diet reduced off-flavours in steak, but for ground beef this response depended on the source of forage in the diet.

Rodas-González, A., Juárez, M., Robertson, W. M., Larsen, I. L. and Aalhus, J. L. 2013. Characterization of Canadian grade standards and lean yield prediction for cows. Can. J. Anim. Sci. 93: 99–107. Commercial carcasses (n=120) were selected to benchmark the current Canadian grading system for cows (D1, D2, D3, D4;>50% ossification) in comparison to A/AA grades youthful carcasses [over (OTM) and under (UTM) 30 mo of age based on dentition but <50% ossification]. With the exception of the D3 and D4 grades, D1 and D2 carcass grades had similar carcass yield attributes compared with OTM and UTM carcasses; however, rib-eye area from UTM carcasses was the largest (P<0.05), followed by D1, D2 and OTM. As expected, both OTM and UTM grades had lower ossification scores (P<0.05); however, D4 grade showed the highest marbling score (P<0.05). For carcass composition, compared with all other grades, the D3 grade had the highest proportion of lean (P<0.05) due to a lower proportion of dissectible fat (P<0.05); however, it had the lightest carcass weight (P<0.05). Using simple measures of carcass characteristics (grade fat, rib-eye area, marbling and ossification) a prediction equation to estimate lean yield (R 2=0.825; Cp=4.31) could be used to more accurately assess carcass value in cows; however, validation of the equation on a separate population would be required before its application.

Avilés, C., Juárez, M., Larsen, I. L., Rodas-González, A. and Aalhus, J. L. 2014. Effect of multiple vacuum packs on colour development and stability in beef steaks. Can. J. Anim. Sci. 94: 63–69. The aim of this study was to compare the colour stability of steaks from longissimus dorsi muscle previously submitted to four treatments of vacuum packaging and aged for 15 d. Muscle portions were either vacuum packed and aged for 15 d (NRP), or repacked after 2 h (RP2h), 8 d (RP8d) and after 2 h and 8 d (RP2h+8d). Purge loss values from RP8d and RP2h+8d treatments were higher (P=0.019) than those from NRP and drip loss was higher (P=0.001) for RP2h and RP8d. Colour changes during a 30-min period of exposure to atmospheric oxygen immediately after opening the packages were similar for repackaged-aged steaks and NRP steaks (P>0.05). Nevertheless, colour stability during subsequent retail display under atmospheric air conditions was affected by the packaging treatment. The decrease in chroma values (P=0.043) and the increase in hue (P=0.011) between day 3 and day 6 was minimum for RP2h+8d, compared with NRP, RP2h and RP8d. Also, the proportion of pigment in the myoglobin form in these three treatments dramatically increased from day 3 to day 6, while no effect was observed for RP2h+8d (P=0.005). Similarly, the decrease over time in the proportion of pigment in the oxymyoglobin form in meat from the RP2h+8d treatment was much lower (P=0.002) than for the other three packaging treatments. Changes in colour stability associated with multiple vacuum packagings may confound results in experimental designs. Thus, if beef colour is to be evaluated, repeated vacuum packaging should be limited.

The relation of carcass physiological maturity to meat quality in the Canadian Bison Grading System. Can. J. Anim. Sci. 94: 55Á62. A total of 119 bull (n 062) and heifer (n 057) bison carcasses were selected to determine the effectiveness of youthful to intermediate physiological maturity [ossification at the 9th/10th/11th thoracic spinous processes (550%; 51Á65%; 66Á80%)] range to accurately classify bison carcasses with respect to quality. Carcasses were classified into three maturity groups according to ossification at the 9th/10th/11th thoracic spinous processes (550%; 51Á65%; 66Á80%). Carcass, meat quality and sensory evaluation data were then collected. Bull carcasses were significantly (PB0.0001) heavier than heifers (308.0 vs. 228.6 kg), while heifers had higher (PB0.0001) marbling scores than bulls (368 vs. 289). For both genders, ossification group had little or no impact (P!0.05) on any of the meat quality traits. Gender had an impact on the shear force values for both fresh (PB0.0001) and frozen/thawed (P00.0002) samples, with bulls having higher values than heifers. Panellists detected differences between heifers and bulls in initial tenderness (PB0.0001; 7.11 vs. 6.27), flavour intensity (P 00.005; 5.40 vs. 5.14), amount of connective tissue (P00.0002; 7.64 vs. 7.18), and overall tenderness (P00.003; 7.13 vs. 6.50). Only initial juiciness was significantly affected (P00.02) by the ossification group (5.38, 5.64 and 5.76). A gender )ossification group interaction was also detected for flavour intensity (P00.004) and off-flavour intensity (P00.03), but the magnitudes of the differences were in the order of one-half panel unit or less, generally below the detection of most consumers. The range of physiological maturity studied had limited effects on meat quality and support the elimination of an intermediate physiological maturity grade (51Á80% ossification) from the Canadian Bison Grading System. Lo´pez-Campos, Ó ., Aalhus, J. L., Galbraith, J., Larsen, I. L., Jua´rez, M., Uttaro, B. et Robertson, W. M. 2014. La relation entre la maturite´physiologique de la carcasse et la qualite´de la viande dans le syste`me de classement canadien du bison.Can. J. Anim. Sci. 94: 55Á62. Un total de 119 carcasses de bison, taureaux (n 062) et ge´nisses (n 057), ont e´te´se´lectionne´es pour de´terminer l'efficacite´de la gamme de maturite´(jeune a`interme´diaire) [ossification aux 9/10/11 ie`me apophyses e´pineuses thoraciques ( 550 %; 51Á65 %; 66Á80 %)] a`classer pre´cise´ment les carcasses de bison selon la qualite´. Les carcasses e´taient classe´es dans un de trois groupes de maturite´selon l'ossification aux 9/10/11 ie`me apophyses e´pineuses thoraciques (550 %; 51Á65 %; 66Á80 %). Il y a eu alors une collecte de donne´es sur la carcasse, la qualite´de la viande et les e´valuations sensorielles. Les carcasses de taureaux e´taient significativement (PB0,0001) plus lourdes que les carcasses de ge´nisses (308,0 c. 228,6 kg), tandis que les ge´nisses avaient des cotes de persillage plus e´leve´es (P B0,0001) que les ta...

López-Campos, Ó., Aalhus, J. L., Larsen, I. L., Juárez, M. and Basarab, J. A. 2014. Effects of production system and growth promotants on the physiological maturity scores in steers. Can. J. Anim. Sci. 94: 607–617. Over a 2-yr period, 224 crossbred steers were allotted to a 2×2×2 factorial arrangement of treatments to determine the effect of the production system (calf-fed vs. yearling-fed), growth implant strategy (non-implanted vs. implanted) and β-agonist supplementation (no ractopamine vs. ractopamine) on physiological indicators of maturity. Dentition and ossification scores along the vertebral column were collected post-mortem during head inspection and grading. Dentition score was significantly affected (P<0.001) by production system, but not by implant (P=0.68) or β-agonist (P=0.31). There were significant interactions (P<0.001) between production system and implant strategy on the frequencies of carcasses showing ossification in the thoracic, lumbar and sacral vertebral processes. There was a significant interaction (P<0.0001) between the production system and implant strategy on the frequencies of the carcasses considered as <21 or >21 mo of age based on a segregation model using only physiological maturity assessments. These data emphasize the inability of physiological scores to accurately reflect chronological age, with overall classification accuracies of 0.68 and 0.53 for dentition and ossification scores. The highest overall classification accuracies were obtained using the thoracic (0.74) or lumbar (0.69) ossification scores. Implants accelerate the ossification process, particularly in younger animals, thus having a dramatic effect on numbers of animals eligible to be categorized as <21 mo of age based on physiological maturity evaluation.