Assessment of the development of parental broiler Cobb 500 by non-invasive imaging techniques

International audienceIn order to follow the composition of parental broilers (Cobb500) during growth from hatching to adulthood (32 weeks of age), we evaluated kinetics of fattening, growth rate, reproduction parameters and body composition of the animals by using non-invasive tools such as medical imaging and blood sample analysing. The use of CT scanner allowed us to monitor the development of body composition on the same animals who are sleeping (fatness, bone, muscle, ovary and testis growth). These analyses were associated with biochemical blood analysis. Parental broilers fed the recommended diet by breeders. The analyses were performed with a CT scanner of bio-medical grade (Siemens As Definition ; 100K Volta and 120 mA / s). Five hundred images were performed every 0.6 mm, 0.45 Pitch and reconstruction filter Safire I26 was used to characterize fat tissues, skeletal and muscle. Image processing by thresholding was used to quantify and monitor the tissues from 4 weeks to 32 weeks of age. The acquired data were used to compare males and females. A significant difference in volume of adipose tissue was observed between male and female. From 20 weeks of age, shortly before the onset of lay, the females had 1.6 fold more adipose tissue than males (P < 0,001). In the female group, the increase in adipose tissue is associated to elevated plasma triglycerides levels (average 8 fold more in comparison to male at the beginning of the laying period. In addition, females, from 16 weeks of age, present a slow bone development in comparison to male (P < 0,001). The ratio bone/bodyweight is 30% lower in female compared to male chicken at 32 weeks of age. A section of the pectoral muscle volume was also analysed but no difference has been noted between both sexes. The correlation between the number of yellow follicles of hens and volume of ovarian adipose tissue determined in vivo was 0.80. In conclusion, the use of CT scanner and ultrasound system has permitted to follow the body composition of an actual parental breed without dissectio