Nigerian Dwarf Goat Color Genetics
The Basics
Nigerian Dwarf goats have some of the most complex color genetics in the goat world. Multiple gene systems work independently but interact visually to create the final coat color. Think of it like layers in image editing software - each gene is a layer that modifies what's underneath.
The Main Gene Systems
1. Extension (E) Locus - The Black Switch
Controls whether black pigment is distributed through the coat.
- E^D = Dominant black (black pigment ON)
 - e = Recessive (allows other colors to show)
 
| Genotype | Result | ||
|---|---|---|---|
| E | D/E | D | Black base (but patterns can modify this) | 
| E | D/e | Black base, carries non-black | |
| e/e | No black - allows red/tan/cream base | 
2. Agouti (A) Locus - The Pattern Maker
Creates banding patterns on individual hairs and body patterns. Only visible on black-based goats (E^D carriers).
- A^wt = Wild type (Swiss marked/grey pattern)
 - A^b = Badgerface (black belly, tan body)
 - A^t = Tan points (black body, tan trim)
 - a = Recessive black (solid black, no pattern)
 
3. Brown (B) Locus - Chocolate Modifier
Converts black pigment to brown/chocolate.
- B = Normal black
 - b = Brown/chocolate (recessive)
 
4. Spotting (S) Locus - White Patches
Creates white markings independent of base color.
- S = Solid color
 - s = Spotted/pied (recessive)
 
5. Dilution Genes
Various genes can lighten or modify colors (cream, silver, etc.). These are less well understood in goats.
How They Work Together
Key concept: The genes act in ORDER:
- Extension determines if you START with black or red/tan
 - Agouti creates PATTERNS on black
 - Brown converts black to chocolate
 - Spotting adds white patches
 - Dilution lightens everything
 
Example Combinations
| Extension | Agouti | Brown | Spotting | Visual Result | |||
|---|---|---|---|---|---|---|---|
| E | D/E | D | a/a | B/B | S/S | Solid black | |
| E | D/e | A | wt/a | B/B | S/S | Grey/Swiss marked (agouti pattern) | |
| E | D/E | D | A | wt/a | b/b | S/S | Chocolate with grey pattern | 
| e/e | any | B/B | S/S | Red/tan/cream (no black to pattern) | |||
| E | D/e | A | b/a | B/B | s/s | Badgerface with white spots | |
| E | D/E | D | a/a | B/B | s/s | Black with white spots | 
Why Surprises Happen
Two grey/cream parents can produce black kids because:
- Both parents are E^D/e (carry black)
 - Their grey/cream comes from agouti patterns or dilution genes
 - Kid inherits E^D from BOTH parents = E^D/E^D
 - Kid also inherits a/a (no pattern) = solid black appears
 
The math: When two E^D/e parents breed:
- 25% E^D/E^D (can show as black)
 - 50% E^D/e (carries black, may look grey/tan)
 - 25% e/e (no black possible)
 
Practical Breeding Notes
- You cannot predict Nigerian colors with certainty without genetic testing
 - Keep detailed records across generations to spot carriers
 - “Hidden” genes can appear after several generations
 - White spotting is completely independent - can appear on ANY base color
 - Newborn kids often darken or lighten significantly in first few months
 
Further Reading
- UC Davis Veterinary Genetics Laboratory - Goat Coat Color Testing
 - American Dairy Goat Association - Color genetics resources
 
Last updated: 30 October 2025
