NON-FREEMARTIN RATE IN HOLSTEIN (Q) HETEROSEXUAL n 0 "'O L.C. BUDEN, T.Q. ZHANG, A.F. WEBER & ~...... (JQ G.R RUTH g University of Minnesota College of Veterinary Medicine 8► St. Paul, MN 55108, U.SA. (D .....'"i . () INTRODUCTION The program of § cytogenetically testing Holstein Bovine freemartinism is the calves for potential 00► sexual modification of a female 00 freemartinism began in 1978; 0 by in utero exchange of since then 667 blood samples ()...... blood from a male fetus. This from heifer heterosexual twins condition was first described by were submitted and examined for a...... 17791 0 Hunter in and was well cytogenetic abnormalities. ::::s known to result in sterility. Chromosome preparations of 0 The freemartin syndrome occurs · lymphocytes were made from 10 I-!; in around 92% of bovine females drops of whole blood, which was td born as a result of heterosexual cultured for 72 hours in RPMI- 0 2 < twin pregnancies , which 1640 medium containing 20% fetal s· indicates 8% of female calf serum and 3% Pokeweed (D heterosexual twins will be mitogen. The cultured cells were normal. The diagnosis of ~ harvested following 2 hours ~ freemartinism can be established treatment with Colcemid (0.01 () by one of the following methods: ,-+. µg/ml), followed by 15 minutes ,-+...... 1) clinical genital ...... of O. 07 5 M KCL hypotonic 0 abnormalities; 2) presence of treatment, and fixed using 3:1 ::::s (D sex chromatin bodies in methanol acetic acid. Chromosome '"i circulating leukocytes in male spreads were made, Giemsa­ 00 co-twin; 3) presence of sex s ta in e d, and observed 0 chromosome chimerism (XX/XY) of "'O microscopically for the presence (D hemopoietic cells; 4) blood or absence of chromosomes of ::::s typing; and 5) skin grafting. both sexes. The animals with ~ In order to promote the () both 60XY and 60XX cells were () preservation of ideal genetic identified to be freemartins (D 00 traits in newborn heterosexual while the individual 00 co-twin heifer calves in the heterosexual twins with only 0...... Holstein breed, the American 60XX cell were determined to be 00 Holstein Association authorized normal heifers; more than 100 q our laboratory to metaphases were further examined s.: cytogenetically test calves for in order to confirm the non­ I= ,-+...... potential freemartinism. The existence of the XY cells. purpose of this paper is to 0p review the cytogenetical results RESULTS AND DISCUSSION of testing Holstein heifer heterosexual twins referred to In our laboratory, 667 cas~ our laboratory in the last 13 of female heterosexual twins years. were chromosomally examined over the last 13 years, 1978-1991. MATERIALS AND METHODS out of these, 553 (82.9%) cases

Vol. I - 300 showed the sex-chromosomal clinical signs, therefore, is chimerism (XX/XY) and were not completely reliable. (Q) diagnosed ten ta ti vely as erythrocyte typing involves a freemartins. The remaining 114 large number of antibodies and n 0 (17 .1%) cases had only XX cells is time consuming and expensive, "'O and thus were potentially plus the necessity of ~rtile. To date no instances of interpreting the results of ~...... inaccurate diagnosis have been blood typing in cattle with (JQ brought to our attention. caution for twins. This is not a g The figure of 17.1% is practical routine diagnostic substantially higher than 10% method for early recognition of 8► reported earlier by others. This the freemartin. Although skin (D .....'"i . higher percentage of potentially grafting can be performed soon (") "normal" ( non-freemartin) after birth, the time and effort § heifers occurred probably for the technique renders the because the cases selected by procedure impractical for 00► veterinarians to be examined routine diagnosis of the bovine 00 0 cytogenetically were nearly freemartin condition. The use of (") normal based on other clinical sex chromatin in diagnosing ...... criteria, especially vaginal freemartinism is not possible a...... length. because drumsticks of 0 According to Eldridge et al. 3 neutrophils are unreliable, and ::::s 0 although there are five methods non-blood cells do not cross the I-!; available to make a diagnosis of placental circulations. In td freemartinism, each, including comparison with the four methods 0 the cytogenetic method has some described previously, an < 96% s· disadvantages. The clinical accuracy of in the diagnosis (D signs of the bovine freemartin of the non-freemartin condition such as abnormal development of can be achieved by the ~ ~ the , the small vulva, cytogenetic method for the (") the short length of the , females born co-twin to bulls. .-+-...... and the lack of estrus, are Based on the above we think that .-+-...... 0 helpful in the diagnosis of a chromosome analysis of ::::s freemartin. However, many of lymphocytes is a reliable aid (D '"i these phenotypes do not manifest and useful for routine early 00 themselves at birth. diagnosis of the bovine 0 Furthermore, variability in freemartin. However, to reduce "'O development of the freemartin examination costs, we suggest (D ::::s reproductive tract would result that dairy farmers send samples ~ in false diagnoses in many cases to a cytogenetics laboratory for (") (") where only clinical signs are a final diagnosis only from (D employed. The insertion of a 00 those co-twin heifers suspected 00 lubricated test tube into the to be non-freemartin animals by vagina of a suspected freemartin 0...... the clinical method performed at 00 is a common early test for a three to six weeks after birth. q normal vagina. Many freemartin In the U.S. about 200,000 s.: calves have short where dair{ twin calves are born each I= a 150 X 18 mm test tube can be year . The incidence of dizygotic .-+-...... inserted only 5 to 6 cm. The twins is 93 to 95 percent of all 0p tube test is unreliable since twins, and half of the dizygous 2 some freemartins possess a twins will be heterosexual • This vagina of approximately normal means that more than 93,000 length but have anatomical female heterosexual twins are abnormalities in the , produced annually. Among them, oviducts, or , resulting 86,000 freemartins and 7,000 in sterility. Early diagnosis of normal heifers are expected, the bovine freemartin by respectively, according to the

Vol.1 - 301 incidence of freemartinism examined for freemartinism. Out reported previously2 • If the of these, 553 (82%) and 114 above estimated figures are ( 17 .1%) cases were diagnosed to (Q) acceptable a total of about be freemartins and normal n 1,118,000 freemartins and 91,000 heifers respectively. The normal 0 normal heifers have been heifer figure of 17.1% is "'O produced in the last 13 years; substantially higher than 8% ~...... thus our cases account only for reported previously by others. (JQ less than 0.06% of all the This is probably due to the g heterosexual dairy twins born in possibly normal cases being that period. Based on the selected by veterinarians based 8► information shown above, the on other clinical criteria. The (D .....'"i . degree of application of the data also show that less than (") cytogenetic test approach in 0. 06% of all the heterosexual diagnosis of freemartinism is dairy twins were examined § very small, even though it is cytogenetically to rule out 00► well known to be quite reliable freemartinism, which implies a 00 and simple. These data also certain number of freemartins 0 imply that a substantial number were subjectively kept or (")...... of freemartins were subjectively clinically misdiagnosed to be a...... kept or clinically misdiagnosed normal heifers. We think that 0 to be normal heifers, which chromosome analysis of ::::s 0 would result in uncalculated ·lymphocytes is a reliable aid I-!; economical losses to dairy and useful for routine early td farmers. ·diagnosis of the bovine 0 freemartin, and encourage that < ACKNOWLEDGEMENTS dairy farmers send samples only s· from possibly non-freemartin (D This work was sponsored by animals for a final diagnosis by ~ Minnesota agriculture Experiment cytogenetic evaluation. ~ (") Station (Grant Nos. Min-61-085 .-+-...... and Min V-65-008). ZUSAMMEKFASSUNG .-+-...... 0 ::::s REFERENCES "Freemartinism" wurde (D '"i zwischen 1978 und 1991 an 667 00 1 . Hunter, J. , Account of the Blutproben von weiblichen 0 free-martin. Philosophical Holstein Zwillingen getested. "'O Transactions of the Royal Dabei wurden 553 (82%) als (D Society, B 69:279-293. 1779. 2. positiv und 114 (17 .1%) als ::::s ~ Marcum, J.B., The freemartin negativ beurteilt. Der 17.1% (") syndrome. Animal Breeding Anteil ist wesentlich hoher als (") (D Abstracts. 42:227-239. 1974. 3. in frUheren Arbeiten publiziert. 00 Eldridge F.E. & Blazak, W.F., Dies beruht vielleicht darauf, 00 Chromosomal analysis of fertile dass Veterinarpraktiker zur 0...... female heterosexual twins in zytogenetischen Beurteilung auch q00 cattle. Journal of Dairy Proben von normalen Zwillingen s.: Science. 60:458-463. 1977. 4. mi tbenutzten. Unsere Ergebnisse I= Roberts, S. J. , Veterinary betreffen ferner nur 0.06% aller .-+-...... Obstetrics & Genital Diseases. weiblichen Zwillinge in USA, die 0 pp. 95. 1986. zytogenetisch geprUft wurden. p Moglicherweise sind daran SUMMARY klinisch-diagnostische Fehler oder Fehlbeurteilungen Between 1978 and 1991 a total beteiligt. Wir glauben, dass der of 667 blood samples from zytogenetische Test Vorteile Holstein heifer heterosexual bietet, und empfehlen ihn twins were submitted and Viehbesitzern zur Anwendung.

Vol.1- 302 RESUMEH

Entre 1978 y 1991, un total de (Q) 667 muestras de sangre de n becerras Holstein provenientes 0 de nacimiento gemelar "'O heterosexual, fueron enviadas y ~...... examinadas para detectar (JQ freemartinismo. De todas el las, g 553 (82%) y 114 (17 .1%) de los casos fueron diagnosticados 8► becerras freemartines y normales (D respectivamente. La f igura de .....'"i . las becerras normales de 17 .1% (") es substancialmente mas alta que § el 8 % reportado por otros 00► previamente. Esto es debido 00 probablemente, a que los casos 0 normales que son seleccionados (")...... por el veterinario estan basados a...... en otros criterios clinicos. La 0 informaci6n muestra ademas que ::::s 06% 0 menos del O. de todos los I-!; gemelos heterosexual es td provenientes de vacas lecheras 0 fueron examinados < citogeneticamente para descartar s· freemartinismo, lo cual implica (D que un cierto numero de ~ freemartines fueron ~ (") subjetivamente dejados en los .-+-...... hatos o no fueron diagnosticados .-+-...... clinicamente y fueron 0 ::::s diagnosticados como vacas (D '"i normales. Nosotros pensamos que 00 el analisis cromosomal de 0 linfocitos es una ayuda "'O confiable y util para el (D diagnostico temprano de rutina ::::s ~ de freemartinismo bovino y (") recomendamos a los ganaderos de (") (D vacas lecheras enviar muestras 00 solo de animales no freemartines 00 para un diagnostico final usando 0...... evaluaci6n citogenetica. 00 s.:q I= .-+-...... 0p

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