Date of Graduation


Document Type


Degree Name

Master of Science in Poultry Science (MS)

Degree Level



Poultry Science


Casey M. Owens

Committee Member

Samuel J. Rochell

Second Committee Member

Kelly R. Vierck


Broiler, Meat Quality, Muscle Myopathies, Processing, Strain, Tenderness


As the demand for poultry meat continues to grow, the industry is challenged with how to meet these needs of consumers. The growth rate of broilers is continuously improving in order to increase production efficiently resulting in greater yields and an increase in product to satisfy consumer needs. However, the industry has seen an increase in quality issues of the meat as growth rates and growth periods continue to increase. The objective of this study was to evaluate the effect of various strains (standard and high-yielding) and target weights on meat quality attributes such as pH, water holding capacity (WHC), and tenderness values, along with meat quality defects such as myopathies. In this study, 1,800 broilers from four commercial strains (two high breast yielding (HY) and two standard yielding (SY)) were raised sex separately in order to evaluate meat quality trends over time at six different market weights. Birds were processed at market weights ranging from 2043g to 4313g in 454g increments. High breast yielding strains (HY) had higher breast and tender yields than those of the standard breast yielding (SY) strains (P<0.05). There was an increase in breast and tender yields as target weights increased (P<0.05) for both HY and SY strains. Some differences were observed depending on strain for fillet dimensions including length, width, and thickness; however as expected, these measurements increased as target weight increased (P<0.05). Woody breast (WB) had a higher severity in the HY strains for both males and females (P<0.05) when compared to SY strains. However, there were only differences (P<0.05) in white striping (WS) for females, and not males, between HY and SY strains. There were differences for WB and WS (P<0.05), showing that as target weight increased over time, severity of these myopathies increased. Shear values were primarily affected by target weight, but there with inconsistent differences between the high and standard yielding strains. Meullenet-Owens Razor Shear (MORS) energy values were different for both sexes among target weights and generally increased in the cranial region of the fillet (P<0.05) as the target weight increased for males. The MORS peak counts generally increased as target weight increased with both sexes. There was also an increase in the incidence and severity of muscle myopathies as target weight increased. While strain had some effects on meat quality attributes, processing weight had a greater influence on quality, specifically muscle myopathies, water holding capacity, and shear values.