Use of Wholecrop Sorgum Silage to Fatten Gascon Bulls    C.E.E.S.O. B2 86

Number of animals
Initial Weight (Kg)
Final Weight (Kg)
Duration (days)
DLWG (gr/head/day)
Carcase Weight (Kg)
Killing out Percentage (%)
Kidney Fat (Kg)

Feed Intake (Kg DM/head/day)

Maize Silage
Sorgum Silage
Soya Protein 48 %
Bruised Wheat
C.M.V.

TOTAL DM/HEAD/DAY (Kg)

Appetite (DMI 100 Kg LW) (Kg)
I.C (DM/Kg of weight gain) (Kg)

Feeding Costs/bull/day (Fr) Price
0.35 Maize Silage
0.29 Sorgum Silage
2.00 Soya Protein 48 %
1.40 Bruised Wheat
4.00 CMV
TOTAL (Fr)
Cost per Kilo weight gain (Fr)

LOT Il
Sorgum « Aralba »

20
246.6
558.7
240
1300
323.0
57.8
5.500

-
6.32
0.88
0.55
0.12

7.87

1.95
6.05 (+ 4 %)

-
1.83
1.76
0.77
0.48
4.84
3.72 (-7 %)

LOT I
Control(maize silage)

20
243.6
553.2
241
1285
324.4
58.6
5.750

5.86
-
0.90
0.58
0.12

7.46

1.87
5.80

2.05
-
1.80
0.81
0.48
5.14
4.00

PRINCIPAL CONCLUSIONS (B2 86)

25,000 Gascon cows are farmed in the Pyrenees, mainly producing weaned calves for which the principal market is Italy. For some years, the department of ARIÈGE, under the impetus of BOVIN-SUD has tried to bring an added value to these calves by fattening locally. This is therefore the first trial of this type to compare maize silage with sorgum silage because the department offers these two possibilities.

The results are as follows:

GROWTH RATES:

These are slightly higher on sorgum silage (1300 g/head/day) compared to maize silage (1285g/head/day) +3%

For this breed, these growth rates are surprising because they are similar to those of the best meat breeds of France, despite the overall weights of the bulls being less (250-550kg)

FEED INTAKE:

Feed intake of sorgum silage was 5 % higher, confirming the excellent palatability of this product.

MEASURES OF FEED INTAKE:

With the best growth rate (+ 3 %) but higher DM intake (+ 5 %) the weight gain/kg DM intake is a little poorer (- 4 %) with the sorgum silage. The analysis of the feeding regime shows that concentrates only play a small part (about 20%); this shows the digestive capacity of the Gascon bull for rough forage.

ECONOMICS:

By consuming so little concentrates, these Gascon bulls have low feeding costs, especially on the sorgum silage (- 7 % compared to maize silage). By comparison with Blonde d'Aquitaine bulls, the Gascon feeding costs are 23% lower on maize silage and 20% less on sorgum silage.