Consumer interest in free-range and organic poultry is growing. Two concurrent experiments were conducted to assess 1) the impact of alternative genotype and production system and 2) the impact of genotype and diet on meat quality of chickens for specialty markets. Specifically, a slow-growing genotype (slow) and a fast-growing genotype (fast) were raised for 91 and 63 d (females), respectively, or 84 and 56 d in the case of the second trial (males). In each trial, the slow birds were placed before the fast birds to achieve a similar final BW at processing. Each genotype was assigned to 4 pens of 20 birds each and raised in indoor floor pens in a conventional poultry research facility; each genotype was also assigned to 4 floor pens in a small facility with outdoor access. A low-nutrient diet was used, formulated for a slower rate of production. Birds were commercially processed and deboned at 4 h postmortem. In the second trial, the diets compared were a conventional diet that met NRC requirements or the low-nutrient diet, and all birds were raised indoors. There was an interaction between genotype and production system for the color (b*; P < 0.05). The meat and skin of the slow birds became more yellow when the birds had outdoor access; however, this did not occur when the fast birds had outdoor access. The breast meat of the slow birds had more protein and alpha-tocopherol (P < 0.05) than the fast birds and half the amount of fat (P < 0.05). In addition, the meat of the outdoor birds had more protein than the indoor birds (P < 0.05). The slow birds had poorer water-holding capacity but were more tender than the fast birds (P < 0.05). The type of diet had little impact on meat quality. These data indicate that meat quality differences exist between genotypes with different growth rates and raised in alternative production systems.

Consumer interest in organic and natural poultry products raised with outdoor access is growing. An experiment was conducted to assess the effects of outdoor access and genotype on meat quality. One slow-growing genotype (S), 2 medium-growing genotypes (M1 and M2), and a commercial fast-growing genotype (F) were raised (straight-run) for 81, 67, or 53 d, respectively. The placement date was staggered in order to achieve a similar final body weight. Each genotype was assigned to 3 pens of 24 birds each and raised in indoor floor pens in a naturally ventilated facility; the S and F genotypes were also assigned to 2 floor pens with outdoor access containing 36 birds each. All birds were provided with the same starter, grower, and finisher feeds, and birds were commercially processed. Pectoralis samples were collected at 6 h postmortem for proximate analysis and evaluation of meat quality. The principal effect of outdoor access was to make the meat more yellow in the case of the S genotype (P < 0.05) although not the F genotype (P > 0.05). Drip loss and cook loss (%) were affected (P < 0.05) by genotype, with the highest losses occurring with the S genotype and the lowest losses occurring with the F and M genotypes. Tenderness was affected (P < 0.05) by gender as well as production system but only in the F birds. Pectoralis dry matter (%), fat (%), and ash (%) were largely unaffected (P > 0.05) by genotype or outdoor access. These data indicate that meat quality differences exist among genotypes with very different growth rates and reared with or without outdoor access.

Consumer interest in organic and free-range poultry production is growing. An experiment was conducted to assess the impact of genotype and outdoor access on growth rate and carcass yield. One slow-growing genotype (S), 2 medium-growing genotypes (M1 and M2), and a commercial fast-growing genotype (F) were raised (straight-run) for 81, 67, and 53 d, respectively. The placement date was staggered in order to achieve a similar final body weight and each genotype was processed on the same day. Each genotype was assigned to 3 pens of 24 birds each and raised in indoor floor pens in a curtain-sided house with ventilation fans; the S and F genotypes were also assigned to 2 floor pens with outdoor access (during daylight hours) containing 36 birds each. All birds were provided with the same starter, grower, and finisher feeds, and birds were commercially processed. Weight gain was similar (P > 0.05) among genotypes, but males gained more weight (P < 0.05) than females. The S and F genotypes had the highest and lowest (P < 0.05) feed intakes and, consequently, the lowest and highest (P < 0.05) feed efficiencies, respectively. The F genotype had the greatest (P < 0.05) breast yield (%) and the lowest (P < 0.05) wing yield (%). The S genotype exhibited the lowest (P < 0.05) breast yield (%) and the greatest leg quarter yield (%). Birds given outdoor access had greater (P < 0.05) bone strength in the tibia, and the F genotype had highest (P < 0.05) bone strength. These data indicate that substantial growth performance and yield differences exist among genotypes in alternative poultry systems.

Broiler breast fillets are sometimes characterized grossly by white parallel striations in the direction of the muscle fibers, and the condition is referred to as white striping. Depending on the severity of white striping, fillets can be classified as normal (NORM), moderate (MOD), or severe (SEV). The present study was intended to determine the factors associated with the occurrence of white striping in broiler breast fillets. Broiler birds (59 to 63 d) of 4 different commercial high-yielding strains (both males and females) fed with industrial type or phase-feeding regimens, were processed and ready-to-cook carcass weight was recorded. The carcasses were deboned at either 4 or 6 h postmortem. Fillets were scored for the degree of white striping at 24 h postmortem, and dimensions of fillets (length, width, cranial thickness, and caudal thickness), pH, color (L*, a* and b* values), cook loss, and Meullenet-Owens razor shear energy (MORSE) values were determined. About 55.8% of the birds used in the study showed some degree of white striping with MOD and SEV categories as 47.5 and 8.3%, respectively. Higher degrees of white striping were significantly (P < 0.05) related to higher cranial fillet thickness and ready-to-cook weights. The occurrence of SEV degrees of white striping was accompanied with increased b* values or yellowness of the meat. The growth differences in strains could influence the incidence of this condition, but feeding regimens and chill hour during processing did not. In addition, the degree of white striping did not show any significant (P > 0.05) relationship between various meat quality parameters such as pH, L*, a*, cook loss, and MORSE. In conclusion, the results of this study suggest that there is a greater chance of higher degrees of white striping associated with heavier birds, but the condition is not related to any major changes in cooked meat quality.

A total of 1,040 birds from 5 common commercial genetic broiler strains were raised and processed to analyze the effect of strain and deboning time on meat quality. The birds were processed at either 6 or 7 wk of age in 4 replications each. Carcasses were deboned at either 2 or 4 h postmortem (PM; n = 52 birds per treatment). Carcass and breast weights were measured on each bird to calculate breast yield. Muscle pH was measured at time of deboning. Fillets deboned at 4 h PM were measured for length, width, and height to evaluate footprint analysis. At 24 h PM, fillets were weighed to calculate drip loss, and color (L*) was also measured. The fillets were then cooked to 76 degrees C, and cook loss was calculated. Fillets were then subjected to shear analysis using the Meullenet-Owens razor shear method where shear energy (N x mm) was calculated to evaluate tenderness. The strains in this study were chosen for differences in yield; therefore, as expected, breast yield was significantly different among strains. Variation in meat quality attributes existed among strains deboned at 2 h PM, but there was no consistent relationship between meat quality and breast yield. However, at 4 h PM, fewer differences among strains existed in meat quality characteristics (tenderness, water holding capacity, and pH). As expected, deboning at 2 h PM resulted in higher shear energy, higher muscle pH, and lower L* value compared with deboning at 4 h PM in all but one strain. However, water-holding capacity was not affected by deboning time at either age interval. Footprint analysis showed that most differences among strains were in heights measured at the fillet midpoint and caudal end. These results suggest that early deboning may affect meat quality of broiler strains differently, resulting in greater variation within the industry.