Here are some very simple explanations below. For an easy to read article on Linear Appraisal and what it all means, check out Bramblestone Farm's website.
Detailed information can be found on the ADGA & AGS websites.
To look up a ADGA Pedigrees or Linear Scores use ADGA Genetics site.
ADGA - 2nd Generation Doe Earned Milking Star
(Can be earned based on Milk Volume, Butterfat or Protien)
ADGA - Buck who's Dam has a Milking Star & Sire has a *B
or
+B Buck who's Dam
& Sire's Dam have Milking Stars
ADGA - Buck who's progeny have earned Milking Stars
AGS - 2nd Generation Doe Earned Milking Star
AGS - Buck who's Sire & Dam both have Milking Stars
AGS - Buck who's progeny have earned Milking Stars
ADGA - Champion, 3 Grand Champion wins (Legs) under 2 different judges. Usually listed before the goats name.
ADGA - Grand Champion with Milk Star. Usually listed before the goats name.
ADGA - Superior Genetics
The SG designation is given to the top 15% based on
Production Type Index values. Once awarded, it becomes permanent even if the animal
falls below the 15% cutoff
ADGA - Superior Genetics + Grand Champion. Usually listed before the goats name
Does must be in the top 5% and have kidded in the last 2 years and still be alive
Bucks must be in the top 15% and have daughters born within the last 4 years & have a Production Type Index value of 0 or greater
AGS - Champion, 3 Grand Champion wins under 2 different judges. Usually listed before the goats name.
AGS -Grand Champion with Milk Star. Usually listed before the goats name.
Excellent (at least 90% of ideal)
Very Good (85% – 89% of ideal)
Good Plus (80% – 84% of ideal)
Acceptable 70% – 79% of ideal
Fair (60% – 69% of ideal)
Poor (less than 59% of ideal)
The ADGA has two very useful presentation on Evaluation Based Breeding: ADGA
Genetics & Using
Genetic Evaluation Data. PTI
- Frequently Asked Questions. These two will require more than one read through,
but I have finally started to appreciate and understand the basics. You have probably
seen the following two descriptions: Production Type Index (PTI) & Estimated
Transmitting Ability (ETA). These two are derived from Linear Appraisal scores & DHI
Production Records. PTI of a sire is an average number, the best estimate of the sire's
genetic merit. The PTI & ETA indexes are just another tool to use when breeding goats.
Do not despair at a negative rating, look to see what the reliability percentage is and
check to see how many of the goats kids have been evaluated or on test. Remember these
scores change at a minimum yearly as production & linear results are calculated. If all
goats went to linear & did milk tests then the results would be a bit more reliable.
Currently in our herd, the following have received a PTI or ETA Index: Goldie, Lilly,
Tonic & Little.
In order for a doe to have a PTI, she must have at least one completed DHI production
record and have been type evaluated (LA). However, if reliability based on relatives is
high enough, a genetic evaluation can be done with out DHI. Our doe, Goldie, has not
been on DHI test but was given a PTI rating in 2020 after she was evaluated at 2019 LA.
Goldie's grand daughter,AH-MISK-FARMS
GOLDEN GABBY, has had 2 lactations on DHI. Her great-grand daughter, Prima Wara
Farms GD Julia, has 1 lactation on DHI test. Goldie is our best milker and at
the ripe old age of eight could easily qualify on Butterfat, Protein and likely Volume
if she went on test. She would improve upon her current PTI rating. It will be up to
Goldie's daughters, granddaughters & great-granddaughters to prove her worth on DHI when
our herd goes on test.
A buck must have at least 5 daughter records in from the DHI program and at
least 3 daughters with type information (LA) to receive a PTI Index. ETA’s, which are
the basis for screening young bucks in the ADGA-Sire Development Program (SDP) are
estimates (E) of a young buck’s transmitting ability (TA) before he has daughters that
are of an age to contribute information regarding yield and type. ETA’s are based on the
production and type information of his ancestors. For young bucks, an ETA is the PTA
without any daughter information being available. This is how our Tonic, Little & Rapha have received their ETA ratings. Tonic & Little
both currently have negative ratings. Rapha has a postive rating. None of
the three have had daughters on DHI test yet.
Tonic has a negative ETA index, based on his parents. Tonic's Sire, Sugar Moon O
Sky Pilot, has earned his B+. Pilot has a daughter who has earned SG & one who is a GCH.
Eight of his daughters have been on test as of 2021. Pilot has a positive PTI 2:1 & ETA
2:1 which emphases Milk Production over Type. He has a negative PTI 1:2 & ETA 1:2 which
emphases Type over Milk Production. Pilot's girls average FS is 81.3. Only one of
Pilot's 22 sons has been to LA, FS81 @ 01-02. So what does all of that mean? Pilot is
passing great milking traits to his kids. He has not passed on good Type traits to his
kids that have been evaluated. Interestingly, Pilot's son, LARKSTONE
SP GRAND DESIGN was an Elite Bucks in 2020 & 2021. Pilot was also an Elite Bucks
in 2020 & 2021.
Tonic's Dam, Otter Grove Cerulean Moon, has a negative PTI 2:1 &
1:2 rating. She has scored well on Linear Evaluations FS89 (VEEV) @ 07-02 & FS87(+EEE) @
03-02. She earned 2 legs of her permanent championship. She earned her Milking Star but
her Percentile Rank is 13 after 4 lactations. Of her eight registered daughters, two
have had one lactation each on DHI. Three have been evaluated at Linear, Average FS 79.
None of her three registered sons has been to Linear Appraisal. So what does this mean?
Moon did not pass on her good type traits to her 3 girls who were evaluated at LA.
Moon's two girls (littermates) who did DHI, had a Percentile Rank of 43 & 25. When we
purchased Tonic neither his dam or sire had PTI/ETA scores. We purchased him based on
his dam's Linear Scores & his sires impeccable pedigree. Tonic has 2 retained daughters
& son as of 2022. His first born, Mags, will be on the stand in 2022. Mags freshened
with a gorgeous udder! We were very surprised and excited. Her dam scored ok in udder no
major defects but not stellar either. We have retained one of Mag's girls and sold the
other to a show home based on her udder. We also have retained Mag's 1/2 brother based
on her udder. We do think Mags will do very well at Linears & hopefully we will get a
chance to show her in the future. She is a very nice looking goat. I expect we will see
Tonic's PTI ratings rise over his lifetime as his girls mature and go on DHI & are
appraised at Linears.
PTA is the average genetic value for a certain trait that an animal transmits to its offspring. PTAs can change over time as more data becomes available for the calculation. PTA = 0 is given to animals at the average genetic merit for a specific trait
Production has twice the weight as Type. Production component uses PTA of Fat Corrected Milk (FCM). Type component uses PTA of the Linear Appraisal Final Score, a non- linear and semi-subjective trait.
Type has twice the weight as Production. Production component uses PTA of Fat Corrected Milk (FCM). Type component uses PTA of the Linear Appraisal Final Score, a non- linear and semi-subjective trait.
This is an artificial index based on PTIs of Sire & Dam or Dam's Sire. All PTI's of a goat's relatives are calculated into the index. It is an estimate of transmission of genetic merit to offspring.
Production has twice the weight as Type.
Type has twice the weight as Production.
Alpha-s1 casein is one of the four casein proteins found in goat's milk and is the most important of the four for cheese making. The goat alpha-s1 casein gene (CSN1S1) that produces the protein shows polymorphisms which affect the amount of protein and fat produced, with higher levels associated with the best cheese making. Research suggests that low levels of alpha-s1 casein may be associated with reduced milk sensitivities for some people. A goat will inherit one alpha-s1 casein from each parent. Our herd is homozygous for the higher A & B variants. Our goats are either A/A, A/B or B/B. We do not know yet if being homozygous for A or B is the norm for Nigerians. We have noticed as others have that does homozygous for the A variant seem to have the highest fat content in milk. Our goats have not been tested for the A or B sub-variants, which I suspect play a huge role in determining fat & protein content.
Are associated with high content of alpha-S1 casein in milk. Goats with any combination of "high" variants will produce high amounts of alpha-s1 casein.
Are associated with lower content of alpha-S1 casein in milk.
Represents a non-functional variant ("null") that is associated with a lack of alpha-S1 casein production. Goats with two copies of the O1 "null" variant will not produce alpha-s1 casein protein.
Goats with a combination of a "high" variant and a "low" variant will produce intermediate amounts of alpha-s1 casein.
Any combination of "low" variants, with or without "null" will produce low amounts of alpha-s1 casein.