UREA POLYMER AND UREA SALT AS SOLUBLE NITROGEN SOURCE IN RUMEN: RUMINAL AND PLASMA PARAMETERS

Abstract

Ruminal (pH, N-NH3) and plasmatic (urea) parameters were evaluated in crossbred cows no lactiferous (Holstein x Zebu), canulated in rumen and inoculated with 28 g/animal/day of nitrogen no protein. The animals had been estabulated and supplied with water, mineral supplement and ground hay of Brachiaria brizantha”, ad libitum”. The treatments were: TC (control - without inoculation of nitrogen source in rumen); TU (inoculation of urea source) and TUP (inoculation of urea polymer source. The times of observations were: 0; 0.5; .1.0; 1.5; 2.0; 2.5; 3.0; 3.5; 4.0; 4.5; 5.0; 5.5; 6.0; 9.0; 12 and 24 hours after the inoculation of nitrogen source in rumen. The experimental design was Latin square 3x3 duplicate. The comparison between the averages was done the test of Scott-Knott in 5% of probability. The values of N-NH3, in treatment TUP was higher (P<0.05) than treatments TC and TU at times of 2.0 to 6.0 hours after the inoculations of the nitrogen sources in the rumen. In the time of 6 hours, the TUP it was significantly higher (P<0.05) than TC e TU, with value of 36.43 mg of N-NH3/dL. The ruminal pH was significantly lesser (P<0.05) for TUP at times of 5.5 and 6 hours (6.54 and 6.59) in relation the TC (6.76 and 6.83) and TU (6.80 and 6.86). In the time of 0.5 hours, TU presented a significantly higher (16.70 mg/dL) plasmatic urea level (P<0.05) than others treatments. The urea polymer presents a ruminal provided stability in pH and higher concentration of N-NH3 during the times of observations.

KEY WORDS: Additive, ammonia, NNP, pH.