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EFFECTS OF SEX, AGE, PRESLAUGHTER FACTORS AND HOLDING CONDITIONS ON THE QUALITY CHARACTERISTICS AND CHEMICAL COMPOSITION OF TURKEY BREAST MUSCLES
Abstract
One hundred sixty 16- and 20-week old hen and tom turkeys were randomly selected, further randomized into five groups and treated to certain preslaughter factors and holding conditions, namely, excitation followed by a resting or non-resting period and ad lib feeding or 15 hrs feed withdrawal, prior to anesthetization with sodium pentobarbital and slaughter. The purpose of the study was to partition the effects of excitation, feed withdrawal and anesthetization with sodium pentobarbital (prior to slaughter), sex and age on certain quality characteristics and chemical composition of turkey breast muscles. Anesthesia completely eliminated struggle at slaughter and caused significant differences in initial pH, tissue glycogen (g/100 of sample), water holding capacity (WH), shear force (kg), yield (%) and color (a(,L)) values when compared with the free struggle (control) group. However, anesthesia had no effect on the chemical composition, final pH, cooking loss (%), thaw loss (%) and live weight (kg). Feed withdrawal had significant effect on final pH, WHC, live weight, and moisture content when compared with the fed group. Excitation prior to anesthetization showed significant differences in WHC, shear, yield, live weight and color (L, a(,L)) as compared to non-excited group. The dark color observed in the free-struggle group appears to have been contributed principally by cytochrome c as shown by isoelectric focusing, isoelectric gel fractionation, and the reflectance spectra. Age had a significant effect (P < 0.01) on tissue glycogen, shear, yield, thaw loss, live weight, color (L) and fat content. Significant differences (P < 0.01) were observed on live weight and ash content values due to sex. There was a significant age/sex interaction on thaw loss, live weight and protein values with age contributing more to the interaction on thaw loss and both variables contributing prominently to the interaction on live weight and protein values. Also, a significant interaction (P < 0.05) was observed between feeding and excitation on WHC with both variables having fairly equal effect in causing the interaction. A significant interaction was noted between treatment and age on glycogen content, final pH, WHC and live weight. It appears that age contributed more to glycogen, treatment to final pH and WHC, and both variables were equally responsible for the interaction on live weight. Significant treatment/sex interactions were observed on shear and live weight with treatment and sex contributing largely to the interactions respectively. Finally, the significant three way interaction (treatment x age x sex) observed on yield, live weight and color (a(,L)) appears to have been contributed by the three variables with regard to yield and live weight values while treatment seemed to be the overwhelming contributor to the interaction on color (a(,L)).
Subject Area
Agriculture
Recommended Citation
NGOKA, DABIRICHUKWU ANOZIE, "EFFECTS OF SEX, AGE, PRESLAUGHTER FACTORS AND HOLDING CONDITIONS ON THE QUALITY CHARACTERISTICS AND CHEMICAL COMPOSITION OF TURKEY BREAST MUSCLES" (1981). ETD collection for University of Nebraska-Lincoln. AAI8118176.
https://digitalcommons.unl.edu/dissertations/AAI8118176