of the future
Prof. P.L. Leroy
University of Liège
Belgium
pascal.leroy@ulg.ac.be
Belgium is famous for its hyper-developed muscling Belgian Blue cattle and Piétrain pig. Texel DM is a new line which presents all the characteristics of double muscling and is considered the leader in Belgium for terminal crossing.
Texel DM breeders have always selected animals for muscling development when preserving size and structure. The animals are quite different from the other European Texel lines in their muscle development, and especially in their better carcass quality with a lower fat content and higher values of killing-out percentage.
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Scientifically documented
A research project sponsored by the Walloon Region of Belgium has been developedsince the 80's. The study of double muscling in sheep and especially inTexel DM took place in the Department of Genetics of the Veterinary Faculty of the University of Liège (ULg) and in Ciney with the Office de Promotion des Petits Elevages de Wallonie (OPPEW).
The OPPEW has established a recording program and was in charge of the extension work. Conventional Texels and Texel DMs were compared at the research farm of ULg. The research work can be considered as a first scientific documentationof the Texel DM.
Growth
Texel breed is well documented in Belgium. Weights at different ages d with their corresponding daily gains were collected by the OPPEW, standardised to weight at 10, 30, 70, 90 and 130 d and have been studied in order to establish growth curves for analysing several nongenetic factors (herd, sex and birth type, age of the dam, month and year of lambing) affecting growth traits from birth to weaning.
The relative importance of each fixed effects was estimated by eliminating each particular effect from the global model. Values of R2 obtained forthe global model were around 35% for the weights and around 30% for thedaily gains. The relative importance of each effect was as follows: sex-typeof birth (20 %) > herd (10%) > age of dam (5%) > month of lambing( 1%) > year of lambing (<1%) and for daily gains: sex-type of birth(15 %) > herd (10%) > age of dam (2%) > month of lambing ( <1%)> year of lambing (<1%).
Carcass and meat quality
A carcass with incomparable meat qualities can be considered as the main attraction of Texel DM.
The results (means (standard deviation)) of an experiment done at the research station farm of the Veterinary Faculty of the University of Liege on 121 conventional and 28 meaty (DM) Texel rams shows that Texel DM rams, slaughtered at the same average weight, have a better dressing out percentage.
| Conventional | Texel DM | |
| Final Weight | 47.2 (5.2) | 47.7 (3.2) |
| Carcass Weight | 23.6 (3.2) | 24.9 (2.4) |
| Dressing Out % | 49.9 (2.8) | 52.3 (2.8) |
| Skin | 6.4 (1.0) | 5.8 (0.9) |
| Viscera | 9.9 (1.7) | 9.9 (1.0) |
In a comparison with the Bleu du Maine breed, the Texel DM was characterised by carcasses with less fat and bone and a killing out percentage 7.8% higher on average.
| T E X E L | B L E U du M A I N E | |||
| (K°) | Mean | Standard Deviation | Mean | Standard Deviation |
| Final weight | 47.050 | 5.107 | 48.030 | 4.088 |
| Carcass weight | 25.850 | 3.520 | 22.570 | 1.929 |
| Dressing out % | 54.800 | 0.025 | 47.000 | 0.017 |
The complete dissection of the double lumbar L4 indicated that the TexelDM was characterised by a better muscle/total L4 ratio (efficiency), a biggereye muscle, smaller psoas muscles and less fat and bone.
| T E X E L | B L E U du M A I N E | |||
| MEAN | STANDARD DEVIATION | MEAN | STANDARD DEVIATION | |
| Weight | 229.82 | 37.4 | 229.37 | 29.4 |
| Efficiency | 72.40 | 2.5 | 65.25 | 4.1 |
| Surface Eye M. | 1764.05 | 323.1 | 1322.70 | 115.5 |
| Perimeter Eye M. | 184.95 | 17.3 | 169.40 | 8.4 |
| Eye M. | 53.48 | 13.1 | 43.50 | 4.9 |
| Psoas Maj. | 14.06 | 2.5 | 16.90 | 2.3 |
| Psoas Min. | 5.87 | 0.8 | 4.80 | 0.7 |
| Quad. Lumb. | 2.77 | 0.7 | 2.61 | 0.5 |
| Vert. muscle | 12.25 | 2.1 | 10.59 | 2.1 |
| Fat | 21.53 | 7.4 | 28.60 | 14.3 |
| Bone | 41.40 | 3.2 | 51.57 | 4.7 |
For the plasmatic concentration of creatine and creatinine considered as other indicators of muscle development, Texels DM had average values of creatine 25% lower and of creatinine 20% higher than Bleu du Maine sheep.
The analysis of the muscle fibers of the Sartorius muscle has indicated bigger muscular fiber cells with a higher frequency of type II fibers, indicating that the superiority of Texel DM was due to muscular hypertrophy.
Genetic determinism and crossbreeding results
An experiment conducted by ULg and INRA (Toulouse-France) was started in 1996 in order to determine whether the Texel DM entity is monogenic or polygenic. The F1 born from Texel DM rams and Romanov ewes are now being studied; this first trial will be followed by other crossbreeding systems classically used in genetics to track gene(s) linked with muscular development.
Even if we cannot answer the question concerning the genetic determinism at the moment, it is clear that, after comparing different breeding systems used byINRA, the Texel DM is considered the best terminal ram line.
Export success
The best Texel DM rams are used in pure breeding and in crossbreeding. Main exports involve the use of Texel DM as terminal sires on dam lines which are selected for prolificacy.
From an economic point of view, the main interest in crossbreeding is the improvement of carcass quality and this is the main reason why Texel DM isan export success.
For more details,
contact
Prof. P. L. Leroy
Department of Genetics
Faculty of Veterinary Medicine
University of Liege B43
B4000 Liège -Belgium
leroy@stat.fmv.ulg.ac.be
phone +32-4-366 41 20
Fax + 32-4-366 41 22