Home Articles Links
Color Variation & Reproduction in the
West African Dwarf Goat
Maxine Kinne
This is a brief summary of a study by reseachers in Nigeria was published in Small Ruminant Research (Feb., 1998), of the performance averages for a number of traits. Both the Nigerian Dwarf and Pygmy are descended from the WADG, but they have been selected toward different standards here in the U.S.
Reproductive performance and preweaning growth in 720 WAD goats were studied based on coat color. Fertility (number of kiddings per year) was not affected by coat color. Prolificacy (litter size) and fecundity (number of kids per year) and preweaning growth rates were highly affected by coat color. Age at first kidding and birth weight increased in lighter colored goats. Black does gave birth for the first time at younger ages than brown and white does. Black does had the largest litters at birth and at weaning. They also weaned the heaviest kids at 120 days of age. Mortality was higher among white does (41%).
Dark-colored animals (various livestock species studied) grow faster in the tropics and subtropics, and survival and growth are less in lighter colored animals. Conversely, lighter colored sheep in the tropics seem to have increased milk yield.
For this study, the goats were grouped into 4 color groups:
1) black/chocolate brown [probably our dominant brown in the US]
2) light brown [probably our recessive brown in the US]
3) white to dark tan
4) spotted [white patches on a pigmented background]
Additionally, the goats were divided into sub-groups based on the genetics of their coat color. (This gets confusing, folks, as it involves the alleles responsible for coat color, so I'm not going into this one. All we need to know is the basic 4 groups.)
|
Reproductive Performance by Coat
Color |
|||
| Fertility % | Prolificacy % | Fecundity % | |
| (Overall mean) | (150 +/- 15) | (182 +/- 31) | (273 +/- 34) |
| Black/Dark Brown | 162 +/-11 | 210 +/- 24 | 330 +/- 39 |
| Lighter brown | 150 +/-14 | 180 +/- 30 | 270 +/- 29 |
| White/Tan | 142 +/-16 | 162 +/- 31 | 240 +/- 35 |
| Spotted | 148 +/- 17 | 188 +/- 29 | 282 +/- 36 |
|
|
|||
| Age First Kidding | Kidding Interval | Gestation Length | |
| (Overall mean) | 16.08 | 8.05 | 148.54 |
| Black/Dark Brown | 14.94 | 8.05 | 148.01 |
| Lighter brown | 15.55 | 8.54 | 145.52 |
| White/Tan | 17.30 | 8.00 | 149.93 |
| Spotted | 16.03 | 7.81 | 148.88 |
|
Litter Size |
Litter Size |
Birth Weight |
Weaning Weight |
Mortality % |
|
| (Overall Mean) |
1.82 |
1.56 |
6.30 (2.86) |
30.16 (13.68) |
27.5 |
| Black/Dark Brown |
2.20 |
1.74 |
6.50 (2.95) |
32.99 (14.96) |
24.5 |
| Light Brown |
1.80 |
1.64 |
6.30 (2.86) |
31.05 (14.08) |
26.3 |
| White/Tan |
1.64 |
1.42 |
6.10 (2.77) |
21.14 (12.76) |
35.0 |
| Spotted |
1.88 |
1.56 |
6.10 (2.77) |
30.08 (13.64) |
24.0 |
None of these statistics are reported to be significant in small goat breeds in the U.S. I thought it was an interesting study and worth passing along. It would be interesting to see whether these original forebears have any reproductive similarity to our goats.
Maxine Kinne, Chairperson
Health, Education & Research Committee
National Pygmy Goat Association
maxinekk@aol.com
| © |
Copyright 1998 |