Evaluation of urinary creatinine excretion to estimate in vivo body composition of Belgian Blue double-muscled bulls

Autor: Sam De Campeneere, C. V. Boucque, L. O. Fiems, José Vanacker
Rok vydání: 2000
Předmět:
Zdroj: Annales de Zootechnie. 49:335-342
ISSN: 1297-9651
0003-424X
Popis: Urinary creatinine excretion (UCE) and chemical body composition of 18 Belgian Blue double-muscled bulls were determined. Partly due to the large fasted live weight (fLW) range (308-710 kg), kg water and protein in the empty body were quite accurately predicted (adjR 2 = 0.94 and 0.97) by UCE. The precision of the prediction of kg empty body fat was less good (adjR 2 = 0.77). However, the empty body composition of the bulls varied only slightly and linearly with increa- sing live weight so that the fLW was the best parameter to estimate empty body water and protein with an adjR 2 value of 0.99 for both. The empty body fat was estimated from fLW with an adjR 2 = 0.75. The equations predicting relative body composition from UCE had much smaller adjR 2 values, varying from 0.53 for % empty body water to 0.30 for % empty body protein. However, the coeffi- cients of variation were much smaller. The prediction of the relative composition based on UCE was always somewhat better than based on fLW, but the improvement was not enough to justify the work involved in determining UCE. Conclusively, due to the small compositional changes, UCE did not significantly improve the estimation of the body composition from fLW. From the compari- son of the results with other studies, it can be concluded that the double-muscled bulls have an extre- mely high urinary creatinine concentration, which cannot entirely be explained by their increased protein content.
Databáze: OpenAIRE