Effects of high nutritional density on breast growth and development of leg problems in broilers

• Grant number: 07/05111-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2007
• End date: August 31, 2009
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Ariel Antonio Mendes
• Grantee: Barbara Cristina da Silva Fernandes
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

An experiment will be carried through aiming at to elucidate relative questions to the development of cut chickens, being evaluated the effect of the fast growth, mainly of breast, proportionate for diets with high nutritional density, and the appearance of metabolic illnesses as the femoral degeneration and dyschondroplasia tibial. The experiment will be lead in the experimental installations of the College of Medicine Veterinária and Zootecnia of the UNESP, campus of Botucatu. 305 young chickens of one day will be used, males, of the Cobb ancestry, distributed in six boxes of 5m² each, with population density of 10 birds for square meter, being that 5 of them will be abated before the lodging, for the accomplishment of the collections at moment zero. The birds will be submitted the two treatments, consisting of rations with commercial levels of energy and protein and rations with high levels of these nutrients. The adopted experimental delineation will entirely be casualizado, with two treatments of three repetitions each, being that the birds will receive the rations with normal or raised nutritional density from the first day from age. This experiment will have objective to follow the development of the chest, viscera eatable (heart, liver and moela), intestines and pancreas. As well as the evaluation of the incidence and development of femoral degeneration and dyschondroplasia tibial. The evaluations will be carried through weekly to the 0, 7, 14, 21, 28, 35 and 42 days of age. In the occasion samples of chest will be collected, viscera eatable, intestine, pancreas, femurs and tibias of five birds for treatment. The collected chests will be dissected and its meat will be weighed in half-analytical scales, viscera eatable and pancreas will after be weighed to be removed to the fat of covering and eventual ingests contained in its interior. The intestines, after clean, will be separate in thin, thick and cecos intestines and will be weighed, with aid of half-analytical and measured scale with metric ribbon aid. The quality of the breast meat also will be evaluated, being that the used analyses will be the width and length of the chest, loss of weight for baking and force of shear. Such evaluations will be carried through only to the 28, 35 and 42 days of age. The evaluations of incidence and development of femoral degeneration and dyschondroplasia tibial will be carried through by means of macroscopic examinations and analyses of histologic cuts, which will be evaluated to the 0, 7, 14, 21, 28, 35 and 42 days of age. For femoral degeneration, to the 42 days of age 60 birds (30 of each treatment) will be abated and of them removed the legs for macroscopic evaluation of this region (femoral joint). Thus, five legs for treatment will be chosen, inside of each prop up of injury for femoral degeneration, so that they are examined in a computerized tomographic, for evaluation of the bone structure in the region of head of femur. After this analysis the bone parts will be submitted to the histologic analysis. Of this form it will be possible to evaluate the development of the injuries, by means of different techniques, associating the results and getting information that do not meet available in literature