Influence of Growth Rate of White Striping in Broiler Breast Fillets31 December 2012
Faster growing broilers tended to have an increased occurrence of higher degrees of white striping in the breast fillets, according to new research from Arkansas. The degree of white striping was associated with changes in the chemical composition of the breast fillets.
White striping refers to the occurrence of different degrees of white striations on broiler breast fillets and thighs of larger broilers, yet little is known about its causes, according to V.A. Kuttappan and colleagues at the University of Arkansas.
In a paper published recently in Poultry Science, they explain that the objective of their study was to estimate the occurrence of normal (NORM), moderate (MOD) and severe (SEV) degrees of white striping with respect to the growth rate of broilers and to compare their proximate composition without the confounding effect of diet.
Straight-run day-old chicks (n=280) were randomly assigned to either a low- (LED) or high-energy (HED) diet (five replicates of 28 birds per dietary treatment). Birds were processed at 54 days of age and live weight, deboned fillet weight and occurrence of white striping were recorded.
As expected, the Fayetteville-based group report that birds fed the HED had lower (P<0.05) feed conversion ratios than birds fed LED (2.08 versus 2.28). Also, HED-fed birds had heavier (P<0.05) live and fillet weights than the LED-fed birds.
A greater (P<0.05) percentage of breast fillets from LED-fed birds were scored NORM, whereas HED-fed birds produced a greater (P<0.05) percentage of SEV fillets.
Fillet weight and yield (percent of live weight) increased (P<0.05) as the degree of white striping increased from NORM to SEV.
Additionally, NORM fillets had greater (P<0.05) lipid and lower (P<0.05) protein content than SEV fillets. Also, NORM fillets had greater (P<0.05) percentages of saturated faty acids than SEV fillets; however, proportions of all monounsaturated fatty acids, as well as linoleic and linolenic acids, were greater (P<0.05) in SEV than NORM fillets.
Kuttappan and colleagues conclude their results suggest that an increased growth rate results in increased occurrence of higher degrees of white striping in broiler breast fillets, and the various degrees of white striping are associated with differences in chemical composition of breast fillets.
Kuttappan V.A., V.B. Brewer, J.K. Apple, P.W. Waldroup and C.M. Owens. 2012. Influence of growth rate on the occurrence of white striping in broiler breast fillets. Poult. Sci. 91(10):2677-2685. doi: 10.3382/ps.2012-02259
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