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

Abstract

Two spent hen breeds (Mos and Isa Brown) fed with three different diets [commercial feeding (CF); corn, pea, and triticale (CPT); and corn and wheat (CW)] were studied to assess their laying performance, carcass characteristics, and meat quality parameters (breast and drumstick). A total of 48 hens reared in a traditional free-range system were used. Birds were slaughtered at 72 weeks of age after the moulting in an accredited abattoir, and measurements (for each bird) of carcass and meat started at 24h post-mortem. The results demonstrated a breed and diet effect (P < 0.05) on laying performance, carcass, and meat quality. The Mos breed showed lower laying performance, higher live weight (P < 0.001), carcass weight (P < 0.001), dressing percentage (P < 0.001), and carcass fat (P < 0.001) than Isa Brown. The breed also affected physicochemical parameters of drumstick and breast (P < 0.05). Concerning the diet effect, spent hens fed with commercial feeding shown heavier live weight (P <0.01) and carcass weight (P <0.01). Diet significantly affected most of meat quality parameters, being CPT the formulation that most affected (P < 0.05) drumstick composition, while in the breast was CF (P <0.001). Significant (P ≤ 0.005) effect in breast colour, cooking loss and hardness were observed in animals fed with alternative diets to CF. Regarding nutritional quality, no breed or diet effect (P < 0.05) was observed in MUFAs, PUFAs and n-6 contents of meat. Overall, both breeds showed a high protein and low-fat content in the breast, showing these hens as an opportunity for the development of meat products as well as an economic purpose for spent hens that reach the end of their productive lives.

Influence of Genotype on Meat Quality in Laying Hens after the Egg Production Season

“…LB and LW leg muscles after laying were characterized by significantly (p < 0.05) lower lightness (L*) and higher levels of yellowness (b*) and redness (a*) compared to pectoral muscles. Our results were confirmed in previous studies [11,22,26]. In our study, the genotype of birds did not significantly affect the pH 24 value of pectoral and leg muscles.…”

“…Myoglobin content in the muscles of young birds is lower compared to older birds and increases with physical activity. This was confirmed in another study by Vargas-Ramella et al [11] in which high levels of leg muscle yellowness (b*) were also obtained in Isa Brown (b*-13.03) at 72 weeks of age. High levels of muscle yellowness (b*) are influenced not only by the age of the birds but also by nutrition or the maintenance system [23,24].…”

“…A large proportion of consumers, more than 74%, are guided by its appearance when choosing meat [21]. Meat color and fattiness, which from the consumer's point of view determine demand, are influenced by factors such as age, sex, genotype, nutrition and housing system [11,21]. In our study, the genotype of the birds did not significantly affect the color of the pectoral and leg muscles.…”

“…Meat that comes from laying hens after the production period is not readily consumed due to poor organoleptic and sensory properties, while there are countries where old chickens are a delicacy and traditional dishes are prepared from them, e.g., Thailand's tom yum soup or broths with a strong aroma in Africa [10,11]. Choe and Kim [12], on the other hand, have shown that meat from old chickens is characterized by high levels of myofibrillar protein and omega-3 fatty acids.…”

Muscle oxidative stability, fatty acid and amino acid profiles, and carcass traits of broiler chickens in comparison to spent laying hens

“…In this study, the dressing percentage in broilers chickens (72.1%) was quite near to that reported in other studies ( 24 , 25 ). At the same age, the dressing percentage in spent hens (69.3 %) was close to that reported in Mos spent hens (69.8 %), but higher than that of ISA Brown spent hens (63.0 %) ( 26 ). Genetic differences and feed regiment could be to responsible for this discrepancy.…”