Cattle Names with additional info
AA following a name indicates that the animal has been tested for and has two copies of the Limousin muscling gene F94L and thus inherits the maximum benefit of this gene
Almost all pedigree Limousin have two copies although this is less likely in Limflex and others with diluted Limousin influence. In these cases it is wiser to rely on a DNA test for the gene
Proto is a photosensitive state caused by a recessive gene
Official Pedigrees of Limousin cattle carry one of the following designations relating to Protoporphyria status - PU(untested), PF(free by pedigree) PN (free by test) PC(carrier) PS(suspect)
Animals which have been DNA tested normal have a suffix of PN (Proto Normal) on their names and where an animal is free by pedigree it has a suffix of PF (Proto Free) which occurs where herds have tested their females. Animals which have been tested as carriers have a suffix of PC (Proto Carrier) and the occasional animal which has produced a carrier calf with the other parent being proto normal but is itself untested has a suffix of PS (Proto Suspect). Untested animals whose parents are not tested normal or free by pedigree havea suffix of PU (Proto Untested).
It was being considered removing these designations from the official pedigrees and most recent catalogues have left them out as they tend to be confused with polledness information.
A recent case of several calves sired by Limousin bulls having protoporphyria has prompted a rethink and a serious look at how to deal with this problem and remove it from our herds
Briefly - use a bull tested Proto Normal or Proto Free by pedigree and all progeny should be free from clinical symptoms as it requires two copies of the gene to produce a visible effect.
There is a very low incidence in Limousin cattle and clinical cases are seldom seen as it requires both parents to be carriers to possibly (1 in 4 chance ) produce a calf with clinical symptons. Symptoms are usually a sunburnt nose and ears and the calf will seek shade and be unthrifty. These mild cases will improve with age.
There are some more serious cases which can cause losses.
Action being taken
There is a dna test available in Australia at about $40 NZ ( see "contacts" page to contact the Australian office or visit their webpage http://www.limousin.com.au
A bull tested clear should leave all healthy stock as even if the cow is a carrier it requires both parents to be carriers to cause damage
To be fair to your bull suppliers contact them early to give time for bulls to be tested
All Limousin Bull Trial bulls are now dna tested or free by pedigree
Lots more technical info to come! - watch this space