VMD 511: Animal Welfare, Ethics and Jurisprudence (2+0)

CHEMICAL EXAMINATION

Following tests are used

Glycogen test

• Meat of horse contains more of glycogen that the meat of other animals.
• Pig’s liver contains a high percentage of glycogen. Glycogen test should be done whenever a piece of liver is examined.
• Horse flesh is supposed to contain maximum glycogen 2.28 where as in normal mammalian muscles it varies from 0.5 to 1%.

Tests based on fats of the animals

• Sometimes, the fat of horse is mixed with the fat of cattle and sheep. Fat of horse is identified by the presence of 1 to 2 percent linolenic acid.
• In fat of other animals, the percentage of linolenic acid is not more than 0.1 per cent.

Iodine value

• Iodine value is the amount of iodine absorbed by unsaturated fatty acids present in the fat.

Species	Iodine value
Horse	71 to 86
Ox	38 to 46
Sheep	35 to 46
Pig	50 to 70

Refractive Index

• The fat of different animals have different refractive index. For this purpose, the fat of the animal is converted into liquid by heat and refractive index is estimated.
  • Refractive index of horse fat is 35.5
  • Refractive index of ox fat is not above 40
  • Refractive index of pig fat is not above 51.9
• Some other chemical methods are now increasingly being applied in meat inspection. These methods are specific and often the only means available for detection of foreign proteins in the meat or meat products.

Serological tests employed for differentiation of flesh

• Immuno – precipitation test
• Electrophoretic methods
• Isoelectric focusing

Rigor Mortis time Refractive Index and Iodine value – various species

Species	Rigor mortis Time (Min)	Refractive index	Iodine value
Sheep Lamb Ox Pig Horse	80 60 163 50 238	-- -- 40 51.9 53.5	35 to 46 -- 38 to 46 50 to 70 71 to 86