Angus get hit again, possible new genetic defect.

[legendrockranch]

Possible new genetic defect hits Angus herd in Australia. I high lighted in blue the request is for any breed, but in particular Angus calves.


JEJUNAL ATRESIA - POTENTIAL RECESSIVE HERITABLE CONDITION

CALL FOR CASE REPORTS AND SAMPLES

We are currently investigating several cases of jejunal atresia in a purebred Angus herd in Australia.

Intestinal atresia (of which jejunal atresia is one form) has been reported in many cattle breeds over the years and in other species. The incidence seems to be increasing in some cattle breeds, particularly dairy breeds, although this could be the result of increased reporting.

In man and mouse, recessive inheritance has been demonstrated for some jejunal atresia syndromes. Many cases however are sporadic and environmental factors may also be involved. At one time it was thought that manipulation of the uterus during early pregnancy (for pregnancy diagnosis) was a cause of intestinal atresia in cattle, but this now seems to have been disproven.

The developmental malformation in this syndrome involves either a blockage in the lumen of the jejunum (the middle section of the small intestine) or a complete failure of formation of a section of the jejunum. In both cases there is a blind ending to the upper part of the jejunum and this prevents passage of the intestinal contents which accumulate in the upper bowel and stomach, ultimately causing marked abdominal distension.

CLINICAL SIGNS

Affected calves appear quite normal at birth and establish a normal feeding pattern. No faeces are passed from the anus although there may be some initial passage of a little meconium and ongoing passage of small amounts of mucous produced in the lower bowel. Within a few days of birth the affected calves show signs of increasingly severe abdominal distension. Fluid sloshing sounds may be heard if the abdomen is palpated. Signs of abdominal pain such as licking or kicking the flanks and tenderness on palpation of the abdomen are observed in some cases. Affected calves tend to become inactive or recumbent and die within a few days of birth.

Intestinal atresia should be suspected in any calf that is normal at birth but dies a few days later with a fluid distended abdomen, particularly if there has been no passage of faeces observed.

NECROPSY FINDINGS

Fluid sloshing sounds may be heard when the cadaver is moved. The abdomen is massively enlarged by the upper bowel distended with fluid contents (digested milk). The distended section of bowel ends in the jejunum and the bowel beyond this point is empty. The upper distended section and lower empty section of the jejunum may be connected by a cord of connective tissue but without any connecting lumen or there may simply be a space between the two sections.

FURTHER INVESTIGATIONS

We would appreciate reports of suspected cases of jejunal atresia in calves of any breed, but particularly in Angus calves. Please forward a photograph of the distended bowel showing the blind ending as well as the empty bowel below the blocked area, together with a DNA sample (blood card in the USA or tail hair in Australia).

Suspected cases in Australia can be reported to Dr Laurence Denholm at **[e-mail]**. Suspected cases in Canada or the USA should be reported to Prof. Jonathan Beever at **[e-mail]**

[RedRidge]

Interesting. Sounds a little similar to Pyloric stenosis, which is higher in the digestive tract though involving the esophagus. Thanks for the info.

[wvdexters]

There was a similar case on Dr. Pol last season. It was a Holstein calf on a dairy farm in Mich. Started out well, but quickly became bloated and in great pain. Dr. Pol diagnosed the calf as halving a condition where the intestines were not connected to the rectum at birth. The calf was unable to pass wastes and basically just "filled up". I remember him saying that this was a condition they were seeing now although I don't believe he had a cause.

At post mortem you could see the "end" of the intestine and how it was not connected to the rectum. The calf had no chance of survival.

[kansasdexters]

There are lethal genes in every breed of livestock. As advances are made in testing, more and more genetic defects are identified and tested for.

The Wagyu breed has an excellent fact sheet that describes the lethal genes in their breed and what is being done to manage these:

wagyu.org/uploads/page/Inherited%20Recessive%20Traits%20in%20the%20US%20Red%20%26%20Black%20Wagyu%20Breed_v3.pdf

Wagyu cattle produce a premium meat that commands a high value on the market. Purebred, registered Wagyu breeding stock sell for thousands of dollars, genetic defects and all. Required testing and reporting helps to address breeder concerns with these genetic defects and to manage herds to avoid unnecessary loss of calves.


Patti

[legendrockranch]

It appears that all of the Waygu defects are recessive. Yet some affected animals do die, some live.

While all breeds of livestock have some type of genetic disorder, the Angus folks are extremely fortunate to have the number of animals that researchers can work quickly with to find these disorders.

Added: The Waygu have a great start on reporting their testing results policy also.

Barb

[RedRidge]

Until the Waygu were brought in just down the road I had no idea that breed existed. They are becoming more and more popular apparently but I got the impression from the owner that they'd rather they remain rare.