INCORPORATION OF ENTIRE MILK IN A FATTENI NG DIET BASED ON SUGAR-BEETPULP IN GROWING FATTENING BULLS WHICH WERE EITHER BUCKET FED OR SUCKLING CALVES IN THEIR YOUNG AGE

A fattening diet based on dried sugar beet pulp, cereals and cakes and supplemented with entire milk was offered to 2 groups of 4 Belgian Bl ue-dual purpose type bulls of 10 months age. The first group was made of bulls which were bucket fed in their young age (BF) while in the se cond group the animals were suckling calves (SC). During the fattening period, all animals were offered entire milk in a bucket at a rate of 8 1 in one meal. The fattening diet was distributed ad libitum. Dry m atter degradation in the rumen of sugar beet pulp and straw was lower in the SC group (P<0.05) while the degradation of linseed meal was hig her (P<0.05). The concentration of total volatile fatty acids, of buty ric acid and of ammonia was also greater in the group which was suckli ng in their young age (P<0.05). The rumen liquid was whiter after the meal with milk in the SC group while it was normally colored in the BF group; such findings suggested that milk offered to the bulls of SG f ell into the rumen by contrast to the BF bulls in which milk entered i nto the abomasun after closure of the oesophageal groove. There were n o differences between the 2 groups of bulls on the animal performances , on slaughter characteristics or on meat quality. By contrast, perire nal and intramuscular fats in the group SC were characterized by a low er concentration in C18:1 and a higher C16:0 and / or C18:0. Such chan ges were also attributed to a different metabolism in the rumen betwee n the 2 groups.