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Nigerian Productivity Scoring (NPS): A Tool for Breeders
How do you
compare the productivity of a Nigerian doe that is 23 inches tall to that
of a tiny doe of 20 inches? What about one who is chubby but putting a
lot of milk into the pail? Breeders of Nigerian Dwarf Dairy goats have a
constant challenge regarding breeding for animals that are good milker,
great show animals and who also do not go overheight.
You might
have concluded that a Nigerian Dwarf doe who is just below the height
limit is quite likely to produce sons who mature over the breed standard
of 23.5 inches. A doe who is overheight does not qualify for top-ten milk
production awards, but if she is a good milker with qualities that might
produce offspring who do well in the show ring and at linear appraisal
then you are unlikely to cull her from your program. But is she really
the top milker you think she is?
For the past year I have been trying
to develop a set of objective criteria to help us evaluate the
productivity of our Nigerian does. We want our breeding program to
produce Nigerians that are within breed standard, but also producing an
appropriate volume of milk for their size. What we finally came up with
what we call Nigerian Productivity Scoring or NPS. I would
like to share it with you as I feel it could be helpful for the breeder
struggling to develop a productive commercial herd while still attempting
to breed within the height standard.
Below you will find our NPS
scorecard and several examples of how it works using a few of our does as
examples. You will find four traits on the scorecard: Milk production (#
of milk), height (in inches), age (yearling first freshener or older) and
body conditioning score (BCS range 1-5).
Milk Production: Giving one
point per one hundred pounds of milk (or fraction thereof) means that
there will never be a perfect goal score and allows for continued increase
of you goal production over time.
Height: You can select your
own goal height and BCS. We have set our ideal height at 21.5 inches (one
inch below the current maximum limit for Nigerian Dwarf does). We find
that does who are 21-22 inches tall have advantages over the smaller does
in the following areas: They are easier to assist during labor and milk
pails and sheep inflations fit under them and still leave room for your
hands.
Age: Under the trait of age,
the scorecard gives credit to does who freshen as yearlings. (If it were
to be used on animals past their prime years, a credit could be given then
as well, but I feel that most of us will have determined by then if an
animal is worth keeping in our breeding programs)
BCS: Our ideal body condition
score (BCS) is 3. It may seem like the scorecard encourages a lower number
BCS by giving points, but it is more of a handicapping credit than a
reward. It is often the doe who has just freshened or truly puts all she
eats into milk production that is too thin. The extra point is meant to
compensate her under these conditions. BCS information can be found
online. In a nutshell, BCS scores a dairy animal based on a scale of 5
points with 1 meaning too thin and 5 meaning too fat. (A person could go
by weight, but most of us do not have scales and a weight tape for
Nigerians has not been developed).
Nigerian Productivity Scoring
|
Trait |
Score |
|
Milk Production |
1 point per 100#
milk |
|
Height |
< 21.5 inches add
1 point per inch
> 21.5 inches
subtract 1 point per inch |
|
Age |
Yearling first
freshener add 1point |
|
Body Conditioning
Score (BCS)
|
With 3 being the
average, subtract or add 1 point per point of deviation up or down. |
|
|
Total = Higher
is better |
NPS Example # 1
|
Trait |
Data |
Score |
|
Milk Production |
820 # |
8.20 |
|
Height |
23 in. |
-1.50 |
|
Age |
2nd freshener |
n/a |
|
BCS |
3.5 |
-0.50 |
|
Total |
|
6.20 |
NPS Example # 2
|
Trait |
Data |
Score |
|
Milk Production |
460 # |
4.60 |
|
Height |
20.5 in. |
+ 1.00 |
|
Age |
1-04 |
+1.00 |
|
BCS |
2 |
+1.00 |
|
Total |
|
7.60 |
NPS Example # 3
|
Trait |
Data |
Score |
|
Milk Production |
860 # |
8.60 |
|
Height |
21.25 in. |
+0.25 |
|
Age |
1-11 |
+0.50 |
|
BCS |
4 |
-1.00 |
|
Total |
|
8.35 |
As you can see from these
examples, the doe that produced the most milk (#1), is actually the most
inefficient and poorest producer- for her size, age and condition. We are
using this tool to help us evaluate our first fresheners. So far the
scores are similar for does in their 2nd lactation (even though
they are taller and older).
As a commercial dairy using
registered Nigerian Dwarf goats, we hope to continue to strive for
achieving breed and ADGA scorecard standards while at the same time
increasing our productivity. I think that NPS will assist us in our
breeding program and our buyers in their evaluation of our genetics and
herd potential. Here’s to little does who can fill the pail -even if it
is a really small pail!
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