Characterization of Breast Meat Collected from Spent Lohmann Brown Layers in Comparison to Commercial Ross Broilers

Abstract

The objective of this study was to compare characteristics and properties of breast meat from spent Lohmann Brown layers (SP, 90 weeks old, n = 24) and those of commercial broilers (BR, 6 weeks old, n = 24). The breasts of both SP and BR were collected from a local processing plant, vacuum-packed in a plastic bag, and stored at-18ºC until further analyses. The SP showed a greater water-holding capacity, tougher and chewier texture (p<0.05). Both raw and cooked SP breasts comprised the greater total collagen but lower soluble collagen than those of BR (p<0.05). Muscle fibers of the SP, observed under scanning electron microscope, were small, with average fiber diameter of 37.85±1.40 μm, densely packed and surrounded by complex networks of connective tissue. The lower myofibril fragmentation index and alkaline-soluble protein fractions of the SP (p<0.05) suggested lesser degree of postmortem fragmentation and protein denaturation in SP compared to BR. Based on differential scanning calorimetry, multiple endothermic transitions were observed in both raw BR and SP breast samples. While BR thermograms comprise five transitions at 57.7ºC, 64.2ºC, 67.6ºC, 72.3ºC and 77.6ºC with total ΔH of 15.31 J/g dry meat, the SP samples exhibited four transitions at 55.1ºC, 62.1ºC, 70.5ºC and 77.7ºC and total ΔH of 17.62 J/g dry meat. Overall, the findings indicated that cooked meat toughness of SP was attributed by the high total and heat-stable collagen content, densely packing of small muscle fibers, and the superior myofibril integrity.

Effect of Breed and Diet on Carcass Parameters and Meat Quality of Spent Hens

“…The same happens with the values obtained for the TPA test. Our results were satisfactory compared with those reported in the literature for laying hens, since they were lower than those previously reported (Chueachuaychoo et al, 2011;Khwunsiri et al, 2007;Limpisophon et al, 2019).…”

“…In the present study, CF group samples showed higher textural parameters for hardness which could be attributed to the lower cooking loss percentage (higher water holding capacity) of the meat assessed. However, the tough texture assessed for the CF group (diet effect) could also be attributed to other parameters not assessed in the present study (e. g. muscle fibre size and arrangement; connective tissue amount, spatial distribution, and composition; and post-mortem biochemical events) (Limpisophon et al, 2019). Hence, further investigations should be realized to evaluate the diet effect on the abovementioned parameters to corroborate our results.…”

“…The spent hen meat has been underutilized for human consumption mainly due to its undesirable tough texture caused by the extended slaughter age and breed effect, which could lead to an increase in muscle fibre diameter, more stroma protein content, and heat-stable crosslinked connective tissues. Therefore, the meat of these animals requires more cooking time, which could affect its quality (Chueachuaychoo et al, 2011;Limpisophon et al, 2019;Mir et al, 2017;Semwogerere et al, 2018). In this way, the values obtained were higher than those found in previous studies with Mos young hens (14.83N) (Pateiro et al, 2018), local breeds (14.12 N) (Cassandro et al, 2015), and broilers (7.64N) (Wattanachant et al, 2004).…”

“…respectively) by a previous study (Rizzi et al, 2007) which found significantly higher (P < 0.01) dressing percentages in local breeds comparing to hybrids (Hy-Line White 36 and Hy-Line Brown; 55.89% and 57.65% respectively). Laying hens are relatively small in size to reduce energy requirements since genetic improvements on the hybrid strains have focused exclusively on egg production (Limpisophon et al, 2019;Rizzi et al, 2007). In this sense, despite the lower results for live and carcass weight in industrial lines were expected, Isa Brown obtained similar values for these parameters than those obtained for some dual-purpose breeds.…”

“…tom yum soup) (Semwogerere et al, 2019;USDA, 2019). In addition, spent hens have high amounts of protein and omega-3 fatty acid contents that could provide a new approach for processed food, revaluing their use as a source of protein, lipids, pigments, flavour, and odorous compounds in canned and comminute products (Jin et al, 2007(Jin et al, , 2011Limpisophon et al, 2019;Polizer et al, 2019) or even as a sustainable animal origin resource (e. g. food-grade lipids) (Safder et al, 2019).…”