 |
 |
Understanding Records
Official Records
Tagging animals at birth with a lifetime identification and supplying Livestock Improvement with the details through MINDA Software or on paper Animal Detail Forms, supplied as part of the MINDA service, ensures that all the ancestry and future performance records are linked to the right animal. Sire and dam information is therefore recorded.
Using that ancestry information, each animal's potential is calculated and expressed as the Breeding Worth and Production Worth (BW and PW). All evaluations are given a reliability, and generally, the more ancestry information available, the more reliable the figure.
Once an animal is lactating, herd testing will provide actual performance records, and so the accuracy and the reliability of the figures will increase.
A recorded animal is one with a MINDA identity tag in its ear and the related detail recorded in the LIC national database.
The fact that a cow is identified does not necessarily make her better than an unidentified one. "Records" mean that we know the details about the animal and can therefore predict, with varying degrees of reliability, future production trends. They take the guesswork out of making purchase decisions.
Evaluating Animals: BW, PW, Reliability
Farmers must be able to gauge the breeding potential and know the productivity of individual animals, to make significant genetic progress. If farmers use the LIC MINDA service, they have information expressed as a BW (Breeding Worth) to show the animal's relative value for breeding and a PW (Production Worth) to show the animal's relative worth as a producer.
Breeding Worths have been proven to indicate the productive potential of a herd.
The Breeding Worth or BW gives an indication of an animal's likely worth for breeding. It is based on what is known about an individual cow's relations, and any herd test information for the individual.
If a farmer is considering buying a herd with a large number of unrecorded animals, the Recorded Ancestry figure is of great importance. This is because the Herd BW will be less accurate in an unrecorded herd (which will have a greater number of animals, which have been given the average BW for unrecorded animals of their age and breed).
Finances are often a limiting factor. Herds with little recording are often cheaper than well recorded herds.
If a farmer is buying individual cows, look at the individual PW and BW and associated reliabilities. The PW reflects what the animal can produce, the BW indicates its breeding potential.
Production Worth (PW)
PW information appears on most MINDA reports, and can be used to compare all cows regardless of breed.
The PW is the simplest way to judge the animal's performance within the breed nationally, and it can be compared with the PW of a farmer's own animals.
Recorded Ancestry
Recorded Ancestry means the percentage of the herd with officially recorded sires. Ideally this percentage should be in the vicinity of 70% or greater if the Herd BW is to be regarded with confidence. If the percentage is lower, the Herd BW will not be as reliable an indication of how good or bad this herd really is. An unidentified animal will get the average BW for unrecorded animals of her age and breed.
Reliability is important - an evaluation without a reliability figure, or with a very low reliability, is meaningless.
Liveweight
The Animal Evaluation system can estimate the evaluations of unweighed animals in exactly the same way as heifers can be evaluated before they are tested. In both situations, ancestry data can be used to produce an evaluation.
However, more information always means more accurate and more reliable evaluations. So animals which have actual liveweight records for themselves and/or their progeny will have more reliable evaluations than those with just ancestry data.
Liveweight evaluations are calculated for all dairy animals in herds using the MINDA service.
|
|
|
