What is Linear Appraisal, DHIR, & ADGA Plus?


Dairy herd improvement registry (DHIR)

DHIR is an ADGA advanced registry program for evaluation of milk production.  Through production testing, goats can earn milk stars and other production awards for exceeding  benchmarks set by ADGA.

So how does it work?

There are many test programs.  The ADGA guidebook is the best reference for the different test options and what awards each test type qualifies a goat for. The 3 main options are: supervised test, owner sampler, & one-day competition.

My herd is on ADGA IPT02-APCS which is a supervised test.  My supervising DHIA (Dairy Herd Improvement Association) is Minnesota DHIA, who tests both cattle and goat herds.  My tester from MN DHIA comes to my farm once a month, alternating AM and PM, to collect and weight one of the that days milk samples.  I provide the weight for the other milking.  Once a year, a verification test is completed, where 3 consecutive milkings are witnessed and weighted by at least two different testers from the DHIA.

The benefits of milk testing are not limited to production awards.  Milk testing provides analysis of the milk for protein content, butterfat content, and somatic cell count (SCC).  An inverted butterfat to protein ratio (protein inversion, where % protein is greater than % butterfat) can indicate acidosis.  Acidosis is a condition in which the rumen is overly acidic resulting in improper absorption of nutrients, processing of feed, and general weakened immunity.  SCC is a bacterial cell count from the sample which can indicate mastitis or inflammation from other sources (CAE, for example). 

One nice thing about DHIR is the records belong to the goat.  The records are kept in the CDCB (Council on Dairy Cattle Breeding) database and can be searched by anyone with an account (free, just need to sign up).  As long as the milk weights/samples were acquired with honesty and integrity, there is no question regarding the production of the animal in question.  Just like Linear Appraisal is the comparison of an animal to the IDEAL animal (not just other animals in the ring),  DHIR is a comparison of an animal to a benchmark.