The phrase "Crop Ear" relates to a genetic fault in Highland cattle that affects the ear shape. Crop ear manifests itself as deformities in the edges of the ear. In some cases it could be as subtle as single indents. In others it could result in ears that look like it has had one too many rugby scrums, resulting in cauliflower ear, or shortened stunted ears. There are no specific health risks to the animal - it's a gene that affects the look of the animal only.
In " A Keen Eye", by Una Flora Cochrane, the origins of crop ear are romantically linked to fairies. Notch eared calves were thought to be the offspring of Crodh-mara - sea cows, or Crodh Shith - fairy cows. These cows were thought to have come ashore in the Obbe area of Harris, at Loscantire. A variation of this myth is that these animals are progeny of the mythical waterbull. Those that came from the waterbull had a severe upper ear crop, whereas the descendants of those from the fairy cows had less scalloping, usually in one ear.
In 1994 there was research done in Germany on 548 Highland cattle on 108 farms. This research looked at the specific genetic inheritance traits of crop ear, but no subsequent research has been done with regards to the prevalence of the gene in New Zealand stock.
This German research was paraphrased by Dr Glen Hastie, an Australian vet, for the Australian Highland Cattle Society. He summarized that the ear defect is inherited by a single autosomal dominant gene, however there is incomplete dominance. 'Autosomal' means not sex-linked and 'incomplete dominance' refers to the fact that animals with the gene will show varying degrees to which they are affected. Some will be so severe that the external ear is barely recognisable and some so mild that the notch at the tip of the ear is barely noticeable.
Crop ear will be present from birth, and will be visible in both ears if the gene is present. Crop ear will never be present in a calf bred from two animals that are free of crop ear. If a calf is born with crop ear, then at least one of the parents MUST have had a gene for crop ear. But there are some circumstances where a calf will come from two apparently normal-eared animals.
Glen's possible explanations for crop eared calves that come from supposed crop ear free animals include:
- One of the parents has mild crop ear (a very small notch) that was not detected. Highlands with very mild crop ear will not be picked up purely on a visual basis. You need to palpate the ears very carefully or even clip the ears to be sure.
- One parent has ears that are smaller than normal but they have no notches. This has been reported anecdotally to occur in animals that have crop-eared offspring.
- There is a very small percentage of animals with one gene for crop ear that have normal ears (no notch and a normal size overall).
- Incorrect parentage identification. Meaning that the recorded parents are not the real parents of the calf.
- A mutation in the calf's genetic make up. This could be possible but would be an extremely rare event for any mutation.
So what's the big deal? If it's a cosmetic issue only, why do Highland animals with crop ear get such a bad rap?
New Zealand has traditionally bred Highlands for a stud purpose. Animals are bred to exhibit the best demonstration of the breed standard set by the parent body, the Highland Cattle Society in the United Kingdom. These animals are selected for their exceptional traits, many of which are related to the unique look of the breed. For an industry like this, any genetic trait that could affect looks is one that should be watched closely.
The original registration body in New Zealand, the New Zealand Highland Cattle Society, decided to mark any female animals in the Herdbook with crop ear with a special CE code that would allow breeders the ability to choose if they wanted to buy an animal carrying this gene. There are also certain animals that won't be registered if they demonstrate any crop ear characteristics. This was to encourage transparency of choice and allow breeders the ability to be better informed about the animals that they are thinking about buying.
Crop Ear is an issue that can be confusing for new breeders of Highlands, and appears to be a gene that is unique to the breed. Careful checking of any animal's ears is always recommended before purchase, and not just to check for any possible crop ear traits - you should also check the animal's identification tags as well, and perhaps you might just spot the odd Gaelic fairy or two!
The New Zealand Highland Cattle Society is the oldest Highland Cattle society in New Zealand, and has been registering cattle since June 1993. The NZHCS Herdbook currently has over 5000 cattle registered, and has over 450 members. For more information please visit their website www.highlandcattle.org.nz