ANNEX
METHODS FOR GRADING PIG CARCASES IN LATVIA
Part I
INTRASCOPE (OPTICAL PROBE)
1.
The rules provided for in this Part shall apply when the grading of pig carcases is carried out by means of the apparatus termed ‘Intrascope (Optical Probe)’.
2.
The apparatus shall be equipped with a hexagonal-shaped probe of a maximum width of 12 mm (and of 19 mm at the blade at the top of the probe) containing a viewing window and a light source, a sliding barrel calibrated in millimetres, and having an operating distance of between 8 and 50 mm.
3.
The lean meat content of the carcase shall be calculated according to the following formula:
ŷ = 66,6708 – 0,3493 × F where:
ŷ = the estimated percentage of lean meat in the carcase,
F = the thickness of back fat (including rind), measured on the left side of the carcase behind the last rib 6 cm off the midline of the carcase (in millimetres).
The formula shall be valid for carcases weighing between 60 and 110 kilograms.
Part II
MANUAL METHOD (ZP)
1.
The rules provided for in this Part shall apply when the grading of pig carcases is carried out by use of the manual method (ZP).
2.
The method may be implemented using a ruler with the grading determined on the basis of the prediction equation. It is based on the manual measurement on the midline of the split carcase of the thickness of the back fat and of the thickness of the muscle.
3.
The lean meat content of the carcase shall be calculated according to the following formula:
ŷ = 60,5214 – 0,2579 × G + 0,0525 × M
where:
ŷ = the estimated percentage of lean meat in the carcase,
G = the thickness of muscle on the midline of the split carcase, measured at the shortest distance between the cranial end of the m.gluteus medius and the edge of the canalis vertebralis (in millimetres),
M = the thickness of the back fat (including rind) on the midline of the split carcase, measured at the narrowest place over the m.gluteus medius muscle (in millimetres).
The formula shall be valid for carcases weighing between 60 and 110 kilograms.
Part III
PORK GRADER (PG200)
1.
The rules provided for in this Part shall apply when the grading of pig carcases is carried out by means of the apparatus called ‘Pork Grader (PG200)’.
2.
The apparatus shall be equipped with a measuring probe fitted to the gun-shaped case, a data sheet printer and a gage-test block as well as with an 8-9 mm wide blade and a LED light with an adjacent light receiver (photodetector).
3.
The lean meat content of the carcase shall be calculated according to the following formula:
ŷ = 64,4502 – 0,4364 × F + 0,0381 × M where:
ŷ = the estimated percentage of lean meat in the carcase,
F = the thickness of back fat (including rind), measured behind the last rib, 7 cm of the midline of the carcase (in millimetres),
M = the thickness of the muscle, measured behind the last rib, 7 cm of the midline of the carcase (in millimetres).
The formula shall be valid for carcases weighing between 60 and 110 kilograms.
Part IV
OPTIGRADE-MCP
1.
The rules provided for in this Part shall apply when the grading of pig carcases is carried out by means of the apparatus known as ‘OptiGrade-MCP’.
2.
The apparatus shall be equipped with an optical probe of 6 mm in diameter, one infrared photodiode and a photo transistor. The results of the measurements shall be converted into estimated lean meat content by means of a computer.
3.
The lean meat content of the carcase shall be calculated according to the following formula:
ŷ = 66,7787 – 0,4464 × F + 0,0018 × M
where:
ŷ = the estimated percentage of lean meat in the carcase,
F = the thickness of back fat (including rind), measured between the last rib and the second to last rib, 7 cm of the midline of the carcase (in millimetres),
M = the thickness of the muscle, measured between the last rib and the second to last rib, 7 cm of the midline of the carcase (in millimetres).
The formula shall be valid for carcases weighing between 60 and 110 kilograms.