Follow these steps:
Divide by two
Add the two percentages together
1. Bred to a doe that is 25%, or ¼ Boer: 100% plus 25%=125 divided by 2 equals 62.5%, or equivalent to 5/8 Boer.
2. Bred to a doe that is 50%, or ½ Boer: 100% plus 50%= 150 divided by 2 equals 75%, or equivalent to ¾ Boer.
3. Bred to a doe that is 75%, or ¾ Boer: 100% plus 75% =175 divided by 2 equals 87.5%, or equivalent to 7/8 Boer.
4. Bred to a doe that is 87.5% or 7/8 Boer: 100% plus 87.5%=187.5 divided by 2 equals 93.75%, or equivalent to 15/16 Boer.
5. Bred to a doe that is 93.75%, or 15/16 Boer: 100% plus 93.75%=193.75 divided by 2 equals 96.875%, or equivalent to 31/32 Boer.
The above samples were simplified by having only parent be a mixture. What do you do if it is not quite so? If both parents are crossbreeds, it still is relatively simple to calculate if you follow these steps:
1. Convert the breed percentages of both buck and doe to eighths.
2. Divide the percentages in half.
3. Add the percentages of like breeds together to find the resulting offspring.
Example:
The buck is ¾ Savanna and ¼ Boer. The doe is ¾ Boer and ¼ savanna. Follow the steps listed above.
Buck converts to 6/8 Savanna and 2/8 Boer. Doe is 6/8 Boer and 2/8 savanna.
For the buck, division results in 3/8 Myotonic and 1/8 Boer. For the dam, the result is 3/8 Boer and 1/8 savanna.Total is 4/8 savanna and 4/8 Boer. If you reduce the fractions, the end result is an offspring that is ½ savanna and ½ Boer. (50% savanna and 50% Boer)
The buck is ½ Savanna and ½ Boer. The doe is ¾ savanna and ¼ Boer.
1. Buck converts to 4/8 savanna and 4/8 Boer. The doe is 6/8 savanna and 2/8 Boer.
2. For the sire, division results in 2/8 savanna and 2/8 Boer. For the doe, the result is 3/8 savanna and 1/8 Boer.
3. Total is 5/8 savanna and 3/8 Boer. (62.5% savanna and 37.5% Boer)
The third scenario, while it looks complicated, still uses the same calculations to obtain the percent of crossbreeding.
Let’s work through it:The buck is ¾ Boer and ¼ kalahari. The dam is ½ mubende and ½ Boer.
1. The buck converts to 6/8 Boer and 2/8 kalahari. The doe converts to 4/8 mubende and 4/8 Boer.
2. For the buck, division results in 3/8 Boer and 1/8 kalahari. For the doe, the result is 2/8 mubende and 2/8 Boer.
3. Total is 5/8 Boer, 1/8 kalahari and 2/8 (or ¼) mubende (62.5% Boer, 12.5% kalahari and 25% mubende)
Test your knowledge:The buck is ½ savanna, ¼ mubende and ¼ Boer. The doe is ¼ savanna and ¾ Small E.A.
1. The buck converts to 4/8 savanna, 2/8 mubende and 2/8 Boer. The dam converts to 2/8 savanna and 6/8 Small E.A.
2. For the buck, division results in 2/8 savanna, 1/8 mubende and 1/8 Boer. For the dam, the result is 1/8 savanna and 3/8 Small E.A.
3. Total is 3/8 savanna, 1/8 mubende, 1/8 Boer and 3/8 small E.A. (37.5% savanna, 12.5% mubende, 12.5% Boer and 37.5% small E.A)
Here’s one more example to make sure you really have it:
The sire is ½ Savanna and ½ Nigerian dwaf goat. The doe is ¼ savanna and ¾ Boer. The sire is ½ Savanna and ½ Nigerian dwaf goat. The doe is ¼ savanna and ¾ Boer.
1. The buck converts to 4/8 savanna and 4/8 mubende. The doe converts to 2/8 savanna and 6/8 Boer.
2. For the buck, division results in 2/8 savanna and 2/8 Nigerian dwaf goat. For the doe, the result is 1/8 savanna and 3/8 Boer.
3. Total is 3/8 savanna, 2/8 (or ¼) Kalahari red, and 3/8 Boer. (37.5% savanna, 25% Kalahari red and 37.5% Boer)
This formula will come in handy any time you wish to calculate percentages of breeds in a crossbred animal. Remember: if the outside influence is less than 5%, this is not genetically significant. In other words, a goat that is 31/32 (greater than 95%) of a specific breed is considered a full blood.