[Concentrates for rearing calves: pelleted or extruded-flaked]
1997
Morel, I. (Station federale de recherches en production animale, Posieux (Switzerland))
Until weaning female rearing calves (Simmental and Brown Swiss) were offered two concentrates of identical composition but treated in two different ways. The first concentrate type (P) was fed as pellets, while the second concentrate (E) was partly flaked (cereals) and partly extruded (protein sources and further ingredients). Compared with the pelleted feed type, extrusion of protein sources tended to reduce crude protein degradability, which fell from 75.4 % (P) to 71.4 % (E). Flaking of cereals resulted in a higher degree of gelatinised starch, which rose from 11 % in feed type P to 14 % in feed type E. However, the extent of these improvements in protein quality and starch availabiltiy was too small to lead to detectable differences in animal performances (growth, feed conversion ratio). Total intake of extuded-flaked concentrate was higher in the first trial, but without statistical significance (P = 0.09). This tendency could not be confirmed in the second trial. The different technological treatments of concentrates did not have any significant effect on body development, health status, and blood parameters
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