The Genetics of the Sheep

Rae, A. L.

doi:10.1016/s0065-2660(08)60503-9

Cited by 27 publications

(11 citation statements)

References 134 publications

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“…Our results, however, are in agreement with other studies (Busse 1951, Rae 1956, Blackshaw and Samisoni 1967.…”

Section: εξέλιξη του βάρους των όρχεων και των επιδιδυμίδωνsupporting

confidence: 94%

“…Concerning the type of cryptorchidism, the results of the present study are in agreement with previous ones on Merinos breed and sub-breeds (Glembockii 1941, Busse 1951, Kuest and Schactz 1977, Claxton and Yeates 1972, Koechetkova 1936, Romberts 1956, Rae 1956, Wendt et al 1960. However, other studies reported differences concerning the different manifestations of the defect (bilateral, unilateral, right, left).…”

Section: εξέλιξη του βάρους των όρχεων και των επιδιδυμίδωνsupporting

confidence: 93%

“…Σε ό,τι αφορά τη μορφή με την οποία εμφανίζεται η κρυψορχιδία (αμφοτερόπλευρη-ετερόπλευρη), πολλοί ε ρευνητές, που οι παρατηρήσεις τους έγιναν κυρίως στη φυλή Merinos και στις υποφυλές της, διαπίστωσαν, την ύ παρξη τόσο αμφοτερόπλευρης όσο και ετερόπλευρης κρυ-ψορχιδιας (Glembockii 1941, Busse 1951, Kuest and Schactz 1977, Claxton and Yeates 1972, Koechetkova 1936, Romberts 1956, Rae 1956, Wendt et al 1960). …”

Section: εξέλιξη του βάρους των όρχεων και των επιδιδυμίδωνunclassified

“…Η υψηλή ό μως συχνότητα εμφάνισης της αμφοτερόπλευρης κρυ ψορχιδίας που διαπιστώθηκε στον παρόντα πειραματισμό συμφωνεί με τα ευρήματα αρκετών ερευνητών (Busse 1951, Rae 1956, Blackshaw and Samisoni 1967.…”

Section: εξέλιξη του βάρους των όρχεων και των επιδιδυμίδωνunclassified

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Cryptorchidism in the Karagouniko breed of sheep and its economic consequences

Lainas

Deligiannis

2018

J Hellenic Vet Med Soc

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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.

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“…Our results, however, are in agreement with other studies (Busse 1951, Rae 1956, Blackshaw and Samisoni 1967.…”

Section: εξέλιξη του βάρους των όρχεων και των επιδιδυμίδωνsupporting

confidence: 94%

Section: εξέλιξη του βάρους των όρχεων και των επιδιδυμίδωνsupporting

confidence: 93%

Section: εξέλιξη του βάρους των όρχεων και των επιδιδυμίδωνunclassified

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Cryptorchidism in the Karagouniko breed of sheep and its economic consequences

Lainas

Deligiannis

2018

J Hellenic Vet Med Soc

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“…This pattern has been attributed to inbreeding depression (Rae 1956;Doney 1957;Pattie 1965;Lax & Brown 1967). Within flocks, live-weight change over the mating period was greater for ewes lambing multiples than for singles, which in turn was greater than for dry ewes.…”

Section: Discussionmentioning

confidence: 99%

Hill country sheep production

Hight¹,

Jury²

1973

New Zealand Journal of Agricultural Research

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Mean live weights at four times of the year are given for Romney and Border Leicester X Romney ewes grazed on hill country from 1959 to 1967. Flock, ewe age, and seasonal influences are summarised.There was a marked increase in mean pre-tupping live weight from Romney (43.7 kg) to first-cross ewes (50.0 kg) and a decrease with interbreeding to second-(46.5 kg) and third-cross (44.7 kg) ewes. A similar pattern was evident in ewe live weights post-tupping, pre-lambing, and at weaning. Ewe live weights increased with age and as the experiment progressed from 1959 to 1967. Statistically significant differences in weight were found between lambing classes when ewes were classified as having 0, 1, or 2 or more lambs. Ewes having multiple births were heaviest pre-and post-tupping and pre-lambing, but were lighter at weaning. Relationships between fertility ratios and live weight calculated by grouping ewes in live-weight ranges are also presented.It is concluded that the difference in fertility between Romney and first-cross Border Leicester X Romney ewes, or between age-of-ewe groups, could not be attributed to liveweight differences alone.The effects on flock productivity of culling on the basis of pre-tupping live weight are discussed.

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Spontaneous congenital developmental abnormalities observed at necropsy in a large survey of newly born dead lambs

1972

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In a systematic necropsy study of 4408 newly born dead lambs derived from 79 flocks over two lambing seasons malformation considered sufficient to impair viability was observed in 80 carcasses. Agnathia was observed in 25 carcasses and comprised the major component of congenital lethal malformations. Lambs of both sexes were affected. Its occurrence was often associated with anotia, ear displacement, or ear malformation. Factors thought to be associated with this abnormality are reviewed and attention drawn to the lack of knowledge concerning the embryonic development of the first branchial arch and related structures in sheep. Developmental defects of the muscular and skeletal systems, central nervous system, cardiovascular system (particularly ventricular septal defects), and imperforate intestinal tract were the next most common malformations.

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The Genetics of the Sheep

Cited by 27 publications

References 134 publications

Cryptorchidism in the Karagouniko breed of sheep and its economic consequences

Cryptorchidism in the Karagouniko breed of sheep and its economic consequences

Hill country sheep production

Spontaneous congenital developmental abnormalities observed at necropsy in a large survey of newly born dead lambs

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