Black Wagyu Sire Guide

This guide will help you gain knowledge of some of the many Black Wagyu lineages. Brief description of bulls to give you a understanding of breeds.

Wagyu Genetic Disorders

Factor XI Deficiency (F11)
This mutation affects the efficiency of the clotting factor F11. Affected cattle suffer from mild
hemophilia‐like bleeding tendencies, either spontaneously or following trauma and surgical
procedures. It is also possible that Affected animals have increased difficulty producing viable
fertilized embryos and full‐term pregnancies and are often Repeat Breeders.
1- Repeat Breeders are Cows that are cycling normally, with no clinical abnormalities, which have failed to conceive after at least two successive inseminations or embryo transfers. From a clinical perspective, there are two types of repeat breeders:
2 – Early repeats ‐ Cows that come into heat within 17‐24 days after insemination or embryo
transfer. In these animals the luteal function has been shorter than normal or typical for the
physiological estrus cycle in non bred cows. In these cows the most probable event is either
failure of fertilization (delayed ovulation, poor semen quality etc.) or early embryonic death
(delayed ovulation, poor embryo quality, unfavorable uterine environment, precocious
3 – Late repeats ‐ Cows that come into heat later than 25 days after insemination or embryo
transfer. In these animals the luteal function was maintained for longer than the physiological
luteal phase in non bred cows. Fertilization and initial recognition of pregnancy probably took
place but for some reason (inadequate luteal function, inadequate embryo signaling, infectious
diseases, induced luteolysis) luteolysis was induced and pregnancy lost. Breeding may be considered 40% with 60% conception being an industry average. It has been reported that factor 11 increased rebreeding by 50% in the Canadian Holstein breed, so now instead of 60% conception we will get 40% conception with 60% of the animals open to be rebred.

Bovine Blood Coagulation Factor XIII Deficiency (F13)
This disorder is where one of the proteins needed to form blood clots is missing or reduced.
Symptoms include severely prolonged bleeding time, bruising from castration/branding, and severe anemia. Death occurs in most cases. NOTE, this test is still in R&D as a positive control animal has not been identified in the US or Australia. We will continue to run this test and report the results to the American Wagyu Association (the “Association”), and if and when a Positive animal is identified by the test, staff from iGenix will work with the breeder and the Association to validate the results. When the validation is complete iGenix will begin reporting on this disorder to the member. If you have an animal that has symptoms as described above, please collect a blood sample (purple top blood tube) or nasal swab and contact the iGenix lab.

Chediak‐Higashi Syndrome (CHS)
Affected cattle have a deficiency in cells that make up a functional immune system. As a result,
these calves are often more susceptible to disease and infection. These cattle may also have a light coat color, and slight coagulation problems (hemorrhaging). This disorder is usually not lethal.

Erythrocyte Membrane Protein Band III Deficiency (Spherocytosis) (Band 3)
Affected cattle (cattle with two copies of the causative mutation) are morbidly anemic. The
mutations affect a protein necessary for proper shape and function of red blood cells. Calves are typically born weak and small (40‐55 lbs birth weight) with severe anemia, labored breathing, palpitations, and not able to stand or suckle at birth. This disorder is often lethal, but some affected cattle survive to adulthood, although with severely retarded growth.

Claudin 16 Deficiency (CL16)
This mutation causes a buildup of fibrous tissue in the kidneys as well as other tissues. Affected
cattle suffer from a severe risk of kidney failure throughout their lives. Other symptoms include
growth retardation, increased blood urea nitrogen and creatinine values, diarrhea and overgrowth of hooves. It may or may not be lethal, but affected cattle tend to have atypically short lives.