Gascon calves reared on the mountain pastures in France are sold store at 7-9 months. The younger calves weigh 220-240kg at weaning and the older calves weigh 260-290kg. This equates to an impressive liveweight gain of 1 kg/day from birth, without supplementary feeding, showing good milk production in the dam.
Here in the UK, these figures have been borne out on a hill farm in Sutherland, where this years calves averaged a weight gain of 1.02kg/day (Heifers 0.97kg/day, Steers 1.08kg/day) from birth to weaning at 265 days. These calves were born inside in Jan/Feb and went to the hill with their mothers in April. No creep feed was given to the calves.
Fat Cattle Production
Daily weight gain: 1370g/day*
Carcase weight at 17-19 months: 350kg
Carcase Yield: 59%
Majority classified R+ or U
*Breeding Institute, INRA
Both Limousin x Gascon and Charolais x Gascon bulls have been shown to produce a carcass weight of 325-330kg at 12 months.
A trial with the Blonde D'Aquitaine x Gascon gave the following results: At 12 months, the bulls had a carcase weight of 275-300 kg, with a killing out percentage of 62. Their average daily liveweight gain was 1.2kg/day on a mixture of maize silage and concentrates.
The feed conversion abilities of the Gascon are shown by producers reporting a saving of 200kg of dry matter during the fattening period compared to other hardy breeds.
A study by the French Livestock Institute shows that young Gascon bulls consume 23% less feed than other specialized beef breeds for a comparable daily gain.
Due to differing farming methods between France and the UK, there has been very little trial work on Gascon fat steer production, but the following extract from a mart report, where a Gascon bullock topped the sale, shows their potential. As more information becomes available in the UK, this page will be updated.
Mart X, (March, 20th 2007) sold 56 prime cattle.
Prime bullocks (46) averaged 121.4p (+0.7p) and sold to 130p per kg and £870 gross.
Prime heifers (10) averaged 125.3p (+3.8p) and sold to 133p per kg and £830.80 gross.
Prime bullocks (46) averaged 121.4p (+0.7p) and sold to 130p per kg for a 580kg Gascon, and a 645kg Limousin, and £870 gross for a Charolais cross.
MH Gene management
After a long period of analysis and consideration, the French Gascon Society (Groupe Gascon), has decided that the way forward for the Gascon is to try to reduce
the prevalence of the MH gene within the breed without compromising muscular development. This programme is continuing to show progress and the excellent conformation
of many of the non-carrier bulls (+/+) is very encouraging.
The Gascon Cattle Society in the UK is following this lead, with breeders using +/+ bulls with good conformation and gaining excellent results. No obviously double-muscled Gascon or their progeny will be accepted for registration in the UK herdbook.
The MH (myostatin) gene is still not fully understood. It is a mainly recessive gene with only the MH/MH animals showing extreme muscular development; to complicate matters not all of them do have this muscular development. The gene also has many variants3 with some causing more muscular development than others. 1 The Belgian Blue owes its conformation to this gene.1
The MH/+ animal may show some signs of extra muscular development.1
Many of you will have seen the advertising of the profit gene; this is a variant of the myostatin gene. It is easy to see the advantages of this gene, but there are significant disadvantages also.
It can bring a marked increase in calving difficulty1,2, an increase in perinatal mortality, reduced liveweight gain 2 (slightly offset by a higher killing out %) and an increased susceptibility to pneumonia amongst other things.
The increase in labour involved with difficult calvings, calves that do not get up and suck (in some cases, the tongue can be enlarged due to muscular hypertrophy) and the loss of production in cows with bad calvings are important in the current financial climate.
It is also thought that the MH gene can reduce the palatability of the beef.2 I would certainly query the effect of reduced intramuscular fat (marbling).
I have listed the references below. A search on Google for the myostatin gene in cattle will provide more information also.