General Definitions for all Grading Systems
1. The skin
The crown is the area with quill markings on the skin, excluding the neck area down to the wing folds as well as the flank areas.
For grading purposes divide the crown area into four quarters as displayed on the ostrich skin diagram – Figure 1 The vertical line “A-B” on the diagram will stretch from the base of the neck between the wing folds, down to the bottom of the crown. The horizontal line “C-D” on the diagram will stretch between the widest quill markings on either side of the crown area
Unless requested otherwise by the buyer, cut skins according to Figure 2
Defects occur in various sizes with three sizes (circular) defined, namely 40, 80 and 120 mm in diameter. A defect can be:
Holes or cuts through the skin
Scars and wounds (open or healed)
A scar is any defect that disturbs the natural grain pattern.
Scratches (open or healed)
Scratches are the same as a scar and caused by sharp-edged objects like thorns.
A partially healed wound that causes a distinctive disturbance of the natural grain layer
Rough Surface (sunburn, chaffing, feather pecking, etc)
A rough surface is open grain damage normally associated with scuffing and is not the same as sueding caused by bacterial decay.
Loose grain (separation of grain layer from skin)
Bacterial damage (open grain, sueded grain)
Disease (rash, grown-in feathers, pit marks, marks from inoculation, etc)
Well-defined small holes +/- 1 mm in diameter, with swollen edges and usually occur behind a quill
Wrinkles on the crown area are a defect if obvious.
In general, all defects or blemishes, regardless of size or whether open or healed, will be taken in account for grading purposes as they do influence the value to the customer.
World Ostrich Association
Green Skin and Finished Leather Grading
A healed wound that blends in with the surrounding natural grain pattern and is no larger than the distance between two quills is not a defect for grading purposes (it will not be prominent and is normally not the result of a large, deep wound).
Bacterial decay causes Pinholes (not hair follicles), and an extensive occurrence in at least two (or more) quarters will result in a down-grade of at least one grade.
A torn skin is a skin where the tear extends into the crown. This skin will be down-graded by one grade.
4. Opening Lines
Figure 1 shows the skin removed from the bird and the shape it should be. Figure 2 shows the cutting lines on the bird. The length of the upper flank “E” on the diagram – Figure 1 and the length of the lower flank “F” on the diagram must be equal. If the difference is obvious and affects the cutting value, it will be reason for a down-grade by one grade. This will apply to wrong opening lines in general.
5. Genetically caused defects1
Grain definition that does not resemble what is normally associated with farmed ostriches will be regarded as a defect and taken into account for grading purposes
The occurrence of hair roots causes hair follicles, is natural and believed genetic in origin. An extensive occurrence of it in at least two (or more) quarters of the quill area will be a reason for a down-grade by one grade.
Vein marks are natural, but if they are obvious and cover a substantial area of the skin, it will be reason for a down-grade by one grade.
6. Quill development
A ripe feather, when harvested, will leave a full-bodied round quill; this is the ideal. Green feather quills tend to be opened/flat/prolonged. A sunken quill is the opposite of a green feather and is a quill with no body and a distinctive hole in the centre. Extensive occurrence of under-developed quills in more than two quarters will be reason for a down-grade by one grade.
7. Skin sizes
Areas of skins for different size groups are as follows:
A+ = 156+ square decimetres
A = 130 to 155 square decimetres
B = 120 to 129 square decimetres
C = 100 to 119 square decimetres
D = 80 to 99 square decimetres
Trim the neck through the distinctive line where the quill area ends and the more non-distinctive smooth area on the neck starts. Trim the leg through the last distinctive line (10cm) above the middle of the knee.