Evaluation of blood constituents as early markers of performance in young beef bulls of piedmontese breed

The search for physiological attributes serving for early prediction of economically important traits in immature cattle is now mostly oriented towards the determination of metabolites or hormones or growth factors under specific experimental challenges (fasting, refeeding, intravenous administration of hormones or of secretagogues, etc.) and this particularly for early detection of dairy traits (Woolliams and Lcvendhal, 1991). Nevertheless, the determination of blood biochemical variables that are used in clinical diagnosis and which can be cheaply and routinely measured, without the use of radioisotopes, in young bull calves in a Performance Test Station might stili be useful for a better physiologicai understanding of the genetic variability of performances. Particularly so if these blood biochemical variables are considered by a multivariate approach. In fact, with such an approach, blood constituents have shown a better ability to discriminate between beef breeds than somatic or performance traits (Camussi et al.. 1990). In the present work blood constituents were evaluated as early predictors of production performances in a sample of bull calves of the same beef breed.