Browsing by Author "Verastegui Castro, Karla Lucia"

Genetic selection of broilers has produced heavier birds that grow faster, with consequent change in morphology and allometry (relative growth) of their body parts. Wooden Breast (WB) is a defect of the breast muscle that affects meat quality. Its cause is unknown, but heavy weight and/or rapid growth rate seem to be predetermining factors. The aim of this work was to study the differences in morphology and relative growth (allometry) between WB affected and unaffected birds. Random groups of a total of 350 male chickens of 5 hybrids were slaughtered at 7 different ages. Morphometric measurements of heart, liver, intestine, breast muscle, girth, coracoid, clavicle, keel and leg bones were analysed with a statistical software. Affected birds presented higher body weight, heavier, longer and thicker breasts and heavier livers than unaffected birds. On the other hand, unaffected birds presented longer legs, heavier intestines and hearts. Keel length, coracoid length and clavicle length did not present any difference between both groups. The comparison of allometric curves of affected and unaffected birds showed differences in almost all body parts, but the heart and liver. Clavicle was the only body part that presented a slower growth rate in unaffected birds, all the other body parts showed a higher growth rate. The relationship between breast thickness and clavicle, coracoid and keel lengths, had a great effect on the presentation of WB. Affected birds presented changes in morphology and growth, very similar to the ones caused by genetic selection. Genetic selection of broilers is very complex and dynamic and it may be possible that WB has several causes. It seems that one of them is the lack of support of the breast muscle, due to an impaired growth of its bone structure.