1679
Crude Glycerin in multiple supplements for beef cattle in grazing: pH and ammoniacal nitrogen
Crude Glycerin in multiple supplements for beef cattle in grazing: pH and ammoniacal nitrogen
Objective was evaluate the pH and concentration of ruminal ammoniacal nitrogen (NH3-N) in beef cattle receiving multiple supplementation in grazing, with increasing levels of crude glycerin, in the rainy season. It has been utilized five Nellore beef cattle, male, non-castrated. The pastures were divided into five picket of 0.25 ha each, covered with Brachiaria brizantha cv. Marandu. The experiment was divided into 5 x 5 Latin square design, composed by five experimental periods of 19 days each and five animals. The strategy adopted was to provide 4 kg/animal/day of multiple supplements with four levels of crude glycerin (0; 8; 16 and 24%) and the mineral mixture (MM) was offered ad libitum(control). Ruminal liquid samples were collected for measuring the pH and quantification of NH3-N by gavage, in two times (0 and 4 hours after supplementation). The pH values for the time 0 and 4 hours did not differ between the supplements (P> 0.05) (Table 1), with average value of 6.83 and 6.59, respectively. It was verified decrease in measuring 4 hours after the supplementation in comparison to time 0 (P<0.01), demonstrating that there is a normal diurnal variation in the pH value without it being influenced by the multiple supplementation, important fact in the maintenance of ruminal fermentation. The content of NH3-N has not been influenced by the supplementation prior to the concentration being supplied (P>0.05) with average between the treatments of 4.98 mg/dL. It was observed at time four the raise in the content of NH3-N for multiple supplementation regardless the formulation utilized (P<0.01), while the control has not promoted such effect (P>0.05). The average values of NH3-N from animals receiving multiple supplementation was of 11.08 mg/dL, adequate for microbial development and ruminal fermentation.
Table 1. Mean values of pH and concentration of NH3-N (mg/dL) in ruminal fluid
Times |
Supplements |
|
||||
MM |
0% GLYC1 |
8% GLYC1 |
16% GLYC1 |
24% GLYC1 |
SEM2 |
|
Ruminal pH |
|
|||||
T 0 |
6.85Aa |
6.88Aa |
6.86Aa |
6.80Aa |
6.80Aa |
0.10 |
T 4 |
6.68Ab |
6.61Ab |
6.65Ab |
6.51Ab |
6.53Ab |
0.14 |
|
NH3-N |
|
||||
T 0 |
3.72Aa |
6.08Ab |
5.68Ab |
5.03Ab |
4.40Ab |
1.57 |
T 4 |
5.46Ba |
15.64Aa |
11.57Aa |
12.25Aa |
10.50Aa |
3.73 |
Means followed by the same small letter in the column and same uppercase letter in row do not differ at 5% probability by SNK test. 1levels of crude glycerin; 2 standard errors of the mean.
Keywords: Nelore, rainy season, supplementation