Costs and benefits of performance testing in the Whinholme flock

Winner EBLEX progressive flock award 2010 for the Bleu Du Maine sire reference scheme, BLUE SIRES

The Whinholme flock has 100 registered sheep kept on a commercial system using grass that the 130 dairy herd cannot graze. This means the flock is evolving in an environment that mirrors the commercial systems that stock rams will be sold into. The flock has been recorded since 1995, losing one flock in the 2001 foot and mouth cull but re- established in 2002.

The Whinholme flock is performance tested because FORM ALWAYS FOLLOWS FUNCTION. Define a breed in the show ring and the shepherd will tend to select traits for the show ring, which lends to breeding for fashion.

The breeding philosophy in the Whinholme flock has always been that building a flock is like building a wall. Type and correctness is the cement in the foundation and strength between the brick. Bricks are the production traits, every generation another layer of bricks.

The Whinholme Flock

Although the strength of the breed is in the female line, Blue Sires record on a terminal sire index. Recording involves.....

LAMBING INFORMATION...sire, dam, litter size, date of birth and birth weight.

8 WEEK WEIGHT ....the group weight will be adjusted to give a 56 day weight and is a very relevant maternal trait for the Bleu du Maine (BdM).

SCAN and 21 WEEK WEIGHT...the eye muscle is considered to be well developed at around 21 weeks of age and usually a 30% variation can be revealed within the lamb crop.

Measures of eye muscle depth across the loin correlate well with the total yield of muscle within the entire carcase, so an increase in muscling in this area will also lead to increases in muscling throughout the carcase - including the gigot.

Back fat is measured in three places across the loin and an average used in the analysis. Fat depth is not a problem for the B.d.M. which is a relatively lean breed and the analysis helps breeders to select rams with the optimum amount of fat for their particular production system.

When E.B.Vs (estimated breeding values) are given, a percentage accuracy is shown.

Sharing rams across flocks raises the accuracy as flocks become connected.

Table 1.

Trait	2009 EBV	2010 EBV	Whinholme EBV
8 week weight	2.31	2.36	2.75
Mature size	1.33	1.27	1.94
Litter size	-0.01	-0.01	0
Maternal ability	0.52	0.53	0.46
Scan weight	3.56	4.21	4.12
Muscle depth	2.04	2.05	2.41
Fat depth	0.28	0.42	0.45
Terminal sire index	199	194	205

ThThe B.d M. sire reference scheme has increased all production traits in 2010, including back fat. This has kept the index from rising.

Two rams, Churchbridge Commander CHB AC560 (index 289) and Rumwell Diamond JER 0605 (index 280) were no longer used in the scheme, with lower index rams used in their place. However their female young stock (daughters) are there to produce great rams for the future.

Churchbridge Fernando CHB 08934 is the current top sire (index 269) with strong maternal traits and a scan weight EBV at +8.64kg.

Table 2. The COSTS of RECORDING the Whinholme Flock.

Scanning cost, first 100 lamb	£175.00
Invoice for processing 2010 data	£333.00
TOTAL COST	£508.00
Divided by 55 lambs registered	£9.23/lamb