1258
Effect of diet without forage on beef quality in Bos Taurus and Bos Indicus young bulls
The objective was to evaluate beef quality of finishing young bulls Nellore or Aberdeen Angus fed a whole grain corn diet without roughage (WR, 85% of whole corn and 15% of commercial pellet) or a traditional diet containing 30% of corn silage and 70% of concentrate (30:70). Thirty-six animals, with average initial body weight of 381.2 ± 11.87 kg, were used in a 2 x 2 factorial design (2 breeds and 2 diets). Both diets had 12.5% crude protein and 2.88 Mcal/kg of ME. Animals were fed for 82d after a 28d adaptation period and slaughtered at the end. Samples were taken from the Longissimus dorsi muscle between the 12nd and 13rd ribs for centesimal composition analyses, color (L*, a*, b*), cooking weight loss (CWL) and shear force (SF). The model included the effects of breed, diet and their interaction and was analyzed using PROC GLM in SAS 9.1. The moisture, ashes, protein, CWL, a * and b * were not affected by breed and diet. However, Angus bulls showed higher muscle ether extract in WR than Nellore animals. Angus animals showed greater tenderness when compared to Nellore, and WR had a tendency to increase tenderness. Nellore presented a higher brightness (L *) when compared to Angus animals. Angus animals and diet with whole grain corn increased the levels of ether extract and the use of Angus animals improved meat tenderness.
Table 1. Centesimal composition (%), color (L*, a*, b*), cooking weight loss (CWL), and shear force (SF) of beef from young bulls Nellore and Angus receiving diets with or without roughage.
Atributes |
Nellore |
|
Angus |
SEM |
P Value |
||||
30:701 |
WR2 |
|
30:70 |
WR |
Breed |
Diet |
B*D |
||
Moisture (%) |
73.7 |
74.4 |
|
73.9 |
73.51 |
1.08 |
0.77 |
0.88 |
0.56 |
Ashes (%) |
1.2 |
1.2 |
|
1.2 |
1.3 |
0.15 |
0.81 |
0.61 |
0.87 |
Protein (%) |
17.1 |
16.7 |
|
17.0 |
17.2 |
0.20 |
0.82 |
0.88 |
0.67 |
Ether extract (%) |
4.9 |
4.1 |
|
4.1 |
6.2 |
0.04 |
0.04 |
0.05 |
<.0001 |
CWL(%) |
27.4 |
27.4 |
|
27.7 |
25.6 |
1.58 |
0.30 |
0.11 |
0.14 |
SF (Kgf) |
6.0 |
5.8 |
|
5.8 |
5.2 |
0.47 |
0.05 |
0.07 |
0.41 |
L* |
49.2 |
48.7 |
|
48.3 |
47.7 |
0.51 |
0.02 |
0.97 |
0.56 |
a* |
7.3 |
7.5 |
|
7.7 |
7.8 |
0.48 |
0.16 |
0.44 |
0.92 |
b* |
9.7 |
9.5 |
|
9.4 |
9.2 |
0.42 |
0.1003 |
0.2745 |
0.8556 |
1 Diet containing 30% roughage and 70% concentrate (30:70); 2 diet with 85% corn grain
and 15% commercial pellet (Without roughage, WR).
Keywords: color, shear force, beef