Within a recorded stud deer herd parentage is vital information for estimating breeding values for commercial (production) traits. Parentage is the basis behind establishing extended pedigree records and associated genetic links on DEERSelect.
Traditionally many breeders single sire mated their hinds and generally also calved them in single sire groups. This worked well, in that the breeder always knew who the sire of the offspring was. The disadvantage of this system was that there was no linkage between groups (sires) which makes it impossible to adjust for environmental effects to estimate breeding values using DEERSelect.
Before laboratory based pedigree testing known sire mating was determined either by the single sire mating (above) or a combination of known sire mating dates (e.g. AI-10 day gap-follow up stag) and ultrasonic pregnancy scan fetal aging or birth date recording was used to determine the sire. This along with direct observation of suckling behavior (calf to hind matching) assigned parentage to the offspring. Breeders also went to the trouble of tagging calves at birth (i.e. usually within 24 hours of), this was often a risky procedure to all involved.
Direct observation can still be used to determine hind-calf matches, and, so long as sire is known, parentage. Direct observation and the linkage issues around single sire mating and associated management issues can make this form of parentage assignment very time consuming. The alternative to this is laboratory-based DNA parentage. Currently two laboratories in New Zealand deliver this service to the deer industry, Genomnz and Genemark.
DNA parentage testing can be completed for around $20 per sample using a range of sample types (hair follicles, ear punch tissue, blood or semen). DNA parentage testing supports optimised farm management practices as well as enhanced DEERSelect genetic analysis, such as adjusting breeding values for environmental effects and sire linkage.
The farm management practices which become possible (recommended) are: multiple-sire-mating, and mixed group calving, as well as minimising disturbance caused by suckling observation of tagging at birth. With DNA pedigree testing, follow up or chaser stags can be introduced to hinds 3 days after artificial insemination, rather than 10-14 days if the sire needed to be determined by ultrasonic fetal aging or calf birth date, which provides a potential advantage of earlier conception of non-synchronized hinds.