|
24th January 2012
British Texel breeders drive towards increased loin muscling
Commercial sheep farmers using recorded Texel sires to produce
prime lambs will see an increase in the lean meat yields in the
most expensive primal loin cuts in their lambs thanks to some recent
adjustments to the Signet Texel index.
The Society’s Performance Recorded Texel Committee (PRT) asked
Signet to review the weightings within the Texel index due to a
very small number of sheep with low Muscle Depth EBVs appearing
higher than expected within the overall ranking of Texel sheep.
As a result of this Signet has reviewed the weightings within
the index to establish whether greater influence could be placed
on muscle depth EBV without having a detrimental effect on the
other growth and carcass traits.
The previous breeding index was targeted at optimising meat yields
in the carcasses of Texel sired lambs. Penalties also continue
to be applied to animals with low fat depth EBVs to ensure sires
are not rewarded for being over lean, further rewards are given
to animals with superior gigot EBVs to balance the weightings of
the index for this important terminal sire.
In adjusting the index Signet will be maintaining these objectives,
but placing a much higher weighting on the Muscle Depth EBV.
Commenting on the changes to the index British Texel Sheep Society
chief executive John Yates said it was important to continually
review the Signet Texel index in line with industry needs. “As
a breed we have to reflect and respond to commercial sheep farmers
needs. Texels naturally have a high meat to bone ratio, especially
within the loin area and the new
index will help breeders ensure this remains the case while also
continuing the massive improvements in growth achieved by recorded
flocks.”
At an overall population level the new index has a relatively
small impact, increasing muscling across the loin with little impact
on other traits, adds Signet breeding services manager Sam Boon.
“This will enable breeders to continue to make major gains in the
economically important carcass and meat yield traits. However,
there will be some significant changes to the indices of individual
animals.”
The table below shows the type of changes in index breeders can
expect. The two high Muscle Depth EBV rams have seen big increases
in their indexes, whilst Rams E and F, with low Muscle Depth EBVs
will see decreases in their indexes.
Ram |
8
Week Weight EBV |
Scan
Weight EBV |
Muscle
Depth EBV |
Fat
Depth EBV |
CT
Lean Weight EBV |
CT
Fat Weight EBV |
CT
Gigot EBV |
Current
Index |
New
Index |
|
Ram A |
5.09 |
10.26 |
6.54 |
-0.30 |
3.42 |
0.88 |
4.54 |
325 |
410 |
Biggest riser |
Ram B |
7.57 |
15.23 |
3.04 |
0.26 |
4.58 |
2.09 |
7.44 |
408 |
410 |
|
Ram C |
4.37 |
12.94 |
0.37 |
0.65 |
3.12 |
1.66 |
8.73 |
314 |
281 |
Faller |
Ram D |
2.57 |
3.79 |
-1.71 |
-0.22 |
1.48 |
0.67 |
0.78 |
163 |
117 |
Biggest faller |
|