EFFECT OF THE LEVEL AND TYPE OF NITROGEN IN THE CONSUMPTION OF SUGAR-CANE FORAGE IN FATTENING BULLS

Data on the consumption of sugar cane dry matter, total crude protein, total natural proteinn from NPN and supplementary natural protein wer e analyzed from the experimental groups of 4 studies published in spec ialized journals. Average weight of fattening bulls was 284 kg. All gr oups had sugar one forage ad Libitum and they were supplemented with d ifferent sources and levels of protein. Regression analyses showed tha t the NPN consumption had no important influence on the sugar cane for age consumption and their relationship is negative. Natural protein ha s a greater effect on sugar cane consumption (r=0.87) compared to the other forms of nitrogen followed by the supplemented natural protein ( r=0.84) in accordance with the quadratic regression analyses This conf irms that sugar cane consumption has a physical limitation which could not be surpassed by nitrogen supplementation and that from the practi cal point of view, the complementation of the sugar cane diet with ano ther protein roughage may minimize the use of protein concentrates.