Cryptorchidism in the Karagouniko breed of sheep and its economic consequences


Published: Jan 25, 2018
Keywords:
sheep cryptorchidism testicular aplasia Karagouniko breed
Th. LAINAS (Θ. ΛΑΪΝΑΣ)
K. DELIGIANNIS (Κ. ΔΕΛΗΓΙΑΝΝΗΣ)
Abstract

The aim of the present study was to evaluate the frequency of cryptorchidism in the Karagouniko breed of sheep. The animals used were derived from the sheep flock at the Agricultural Research Station of Palamas (Karditsa), consisting of 500 breeding ewes and 15 rams of the Karagouniko breed and from two hundred and seven flocks of Karagouniko breed genetic nucleus. In addition 14.107 carcasses of Karagouniko male lambs, slaughtered at the abattoir of Karditsa and the size and weight of testicles and epididymides of 18 cryptorchidic and 7 normal lambs were examined. Finally, the economic impact of this defect was also evaluated. The results showed that cryptorchidism is a defect with a high frequency (23.81% of male lambs, P<0.001) in the Karagouniko breed and it is associated with polledness. The frequency of cryptorchidism is increased in sheep flocks where inbreeding is applied. Cryptorchidism was found to be bilateral or unilateral (20:1 respectively, P<0.001). The most common type of unilateral defect was found to be the right one (10:1, P<0.001). Bilateral was of abdominal or inguinal type(400:l,P<0.001). Testicular aplasia was found to be rare (0.02% of total examined male lambs or 0.09% of cryptorchid ones). The weight of "hidden" testicles and epididymides was lower than that of normal (-14.06% and -22.99% respectively, P<0.001). However, until the age of 4 months, there was no difference in weight between cryptorchidic and normal lambs. Males with bilateral cryptorhidism were not able to produce semen. Cryptorchidism causes a considerable decrease in sheep breeders' income (P<0.001), as it deprives them of the opportunity to sell male lambs as breeding animals at the higher than usual price. It is concluded that the high frequency of cryptorchidism in the Karagouniko sheep significantly retards the genetic improvement of the breed and decreases the farmer's income.

Article Details
  • Section
  • Research Articles
Downloads
Download data is not yet available.
References
Alvi A.S. (1981). Der Einiluss der partiellen Kastration und des induzierten Kryptorchismus auf die Entwicklung mannlicher Eigenschaften bei Schafen. SH. Fleischwirtschaft: 61:5:796-800.
Bishop, M.W.H. (1972). Genetically determined abnormalities of the reproductive system. J. Reprod. Fertil. Suppl. 15/51.
Blackshaw A.W. and Samisoni J.J. (1967). The testes of cryptorchid ram. Res. Vet. Sci., 8:2:187-194.
Busse Η. (1951) Kryptorchismus in der Merinofleischschafzucht und Vererbung des Homes. Dissertation, Univ. Halle/S (A.B.A. 21:No 782).
Claxton, J.H. and Yeates, N.T.M. (1972). The inheritance of cryptorchidism in a small crossbred flock of sheep. J. Hered., 63:3:141-144.
Dolling C.H.S. and Brooker M.G. (1964). Cryptorchidism in Australian Merino sheep. National Fieldstation, Gilruth Plains, G.S.I.R.O., Cunnamula Queensland, Australia. Nature, 203:49-50.
Giannakopoulos A. (1994). Analysis of Experimental Biological Data. Aristotelian University of Thessaloniki Press.
Glembockii J.R. (1941). Kriptorhizm u ovec porodyprekos i borjbas nim. Agricultural State Publishing House, Moscow, Ref. A.B.A., 33: No 1945.
Glembockii J.R. and Moissev S.B. (1935). Usp. Zootechn. Nauk, Moscow, 1,5. Ref. Anim. Breed. Abstr., 1936,4: 313.
Hamori D. (1983). Constitutional disorders and hereditary diseases in domestic animals.Developments in Animal and Veterinary Sciences 11, pp 221-225.
Hobday, F.T.G. (1903). The castration of Cryptorchid Horses and the Ovariotomy of Troublesome Mares. William R. Jenkins, New York.
Jacob, W.K. (1972). Mh. Vet. Med. 27,1: 33-37 in Hamori (1983). Koutsouris C. (1981). Selection of rams for reproduction. Artificial Insemination Center. Ionia. Thessaloniki.
Koch P., Fischer, H., Schumann,H. (1957). Erbpathologie der landwirtschaftlichen Haustiere. Paul Parey, Berlin.
Koechetkova, L.P. (1936). Probi. Zivotn. 10, 81 in Hamori (1983). Kuest D. and Schactz F. (1977). Fortpfanzungsstoerungen bei den Haustieren. Ferdinand Enke Verlag Stuttgart.
Lunstra D.D. and Schanbacher B.D. (1988). Testicular function and Leyding cell Ultrastructure in Long-Term Bilaterally Cryptorchid Rams. Biology of Reproduction 38, 211-220.
Lush I.L., Jones, J.M. and Dameron, W.H. (1930). The inheritance of cryptorchidism in goats. Texas Agr. Exp. Sta. Bull., p. 407.
Moore C.R. and Oslund, R. (1924). Testicular reactions in experimental cryptorchidism. Amer. J. Physiol. 67: 595.
Otto H. (1924). Diss. Muenchen in Hamori (1983). Papadopoulos F. (1975). General Surgery of Domestic Animals. Aristotle University of Thessaloniki. (In Greek).
Rae AL. (1956). The genetics of the sheep. Adv. Genet. 8:189-265. Romberts S.J. (1956). Veterinary obstetrics and genetical disease, pp. 444-445 (S. Romberts Ithaca, N.Y., Edwards Brothers, Inc. Ann.Azboz).
Tsakalof P.N.(1982). Pathology of reproduction and Pathology of Mammary Glands of Domestic Animals. Aristotle University of Thessaloniki. (In Greek).
Wendt K, Pohl I. and Mrosk H. (1960). Mh. Vet. Med., 15:309-311 in Hamori (1983). Wiesner E. and Willer S. (1974). Veterinaermedizinische Pathogenetic. Gustav Fissher Verlag, Jena.
Most read articles by the same author(s)