1560
Sulfur sources in protein supplements and their influence upon amino acid profiles
Sulfur sources in protein supplements and their influence upon amino acids profile
The present experiment was performed to evaluate the effect of different sulfur sources in protein supplements for cattle in the amino acids profile with respect to the abomasal digesta. Crossbred steers were fed with Brachiaria dictyoneurahay, applying different sulfur sources in the protein supplement: 70S elementary sulfur - byproduct (ES70S); 98S elementary sulfur - flowers of sulfur (ES98S); hydrated calcium sulfate (HCS); anhydrous calcium sulfate (ACS) and ammonium sulfate (AS). The dietary treatments were applied at 11:1 nitrogen:sulfur ratio. Five steers which were fistulated in the rumen and abomasum were used in a 5 x 5 Latin square design. The experiment had five 16-d periods, in which the first 10 d were for adaptation period and the subsequent 6 d were utilized to obtain the experimental data. The concentration of available amino acids in the abomasal digesta (g/kg DM) remained with very similar values (P>0.05) in the evaluated diets. The amino acids evaluated in the abomasal digesta remained with the same quantitative profiles, suggesting that their properties do not depend on the sulfur sources encountered in the respective diets.
Table 1 – Amino acid profile in abomasal digesta in different treatments and their coefficient of variation (CV%)
Essentials amino acids |
E70S |
E98S |
HCS |
ACS |
AS |
CV(%) |
mg/kg of DM |
||||||
Valine |
19.52 |
18.80 |
18.64 |
18.96 |
19.40 |
10.65 |
Methionine |
20.40 |
19.82 |
19.70 |
19.94 |
20.30 |
11.36 |
Isoleucine |
5.46 |
5.60 |
5.68 |
5.52 |
5.70 |
18.03 |
Leucine |
18.16 |
18.38 |
18.72 |
18.58 |
20.22 |
17.22 |
Phenylalanine |
32.04 |
30.68 |
31.86 |
31.74 |
32.46 |
13.68 |
Histidine |
541.54 |
541.76 |
529.08 |
552.12 |
590.66 |
14.16 |
Valine |
7.22 |
7.02 |
7.12 |
7.42 |
7.56 |
13.24 |
Lysine |
34.92 |
33.72 |
34.04 |
35.28 |
36.22 |
14.83 |
Arginine |
18.52 |
18.04 |
18.80 |
18.78 |
19.16 |
10.28 |
Nonessential amino acids |
mg/kg of DM |
|||||
Aspartic acid |
45.34 |
44.06 |
44.30 |
43.80 |
44.96 |
12.08 |
Serina |
100.42 |
101.24 |
107.62 |
149.18 |
114.10 |
32.64 |
Cystine |
5.58 |
5.44 |
5.00 |
5.24 |
5.54 |
12.66 |
Glutamic acid |
45.82 |
46.38 |
45.64 |
45.30 |
46.98 |
15.72 |
Proline |
20.30 |
19.74 |
19.74 |
20.20 |
20.76 |
13.34 |
Glycine |
21.06 |
19.98 |
20.68 |
19.64 |
19.86 |
15.15 |
Alanine |
26.66 |
25.06 |
25.18 |
24.98 |
26.02 |
12.45 |
Keywords: beef steers, amino acid profiles, sulfur nitrogen ration