Íslenskar landbúnaðarrannsóknir - 01.03.1970, Síða 108

Íslenskar landbúnaðarrannsóknir - 01.03.1970, Síða 108
106 ÍSLENZKAR LANDBLJNAÐARRANNSÓKNIR The white X mouflon was white. A back-cross of the Fx to mouflon gave 3 white, 3 mouflon and in addition 3 badger- face, which would not been produced if the two patterns badgerface and mouflon were given by allelic genes. Similarly, white X black gave white F1( which when backcrossed to black gave 9 white, 5 black and one badgerface, of which the last one would not have been expected if the genes for white, badgerface and black were al- lelic. In these experiments, no case was report- ed of animals showing both the badgerface and the mouflon pattern, and the badger- face pattern was regarded to be completely dominant. The variation of the badgerface pattern, on the other hand, was enormous. Some of the animals were almost complete- ly black, and 4 cases are reported (Roberts and White, 1930 a), where it was doubtful whether the lambs were black or badger- face. During the purchase of animals for the foundation of the experimental flock, very heavily pigmented types were exclud- ed, but owing to the difficulties in secur- ing sufficiently large numbers, some ani- mals with reduced pigmented areas were included. In some cases the ventral area was grey, and in the most extreme cases only the bars between the eyes were found, a little black on the ears, muzzle lightly pigmented, a black area on the lower jaw, and greyish legs (Roberts, 1924). The de- scription of the type with extreme reduc- tion of pigment in the foundation stock resembles considerably the colour of the black badgerface-mouflon animals founcl in the present study. It shoukl also be noted that this type witli reduced pigment seems to have been produced in the experi- ments, but it is not mentioned how fre- quent it was nor whether it was more frequent in some matings than others. The occurrence of two badgerface sheep hetero- zygous for that factor and either hetero- zygous or homozygous for the mouflon patt- ern, with whiter chin than in ordinary badgerface, is mentioned, but at the same time it is stated that all other animals of similar genetic constitution appeared in- distinguishable from ordinary badgerfaces (Roberts and White, 1930 a). It is also clear from the description of the founda- tion stock that the rams used showed the typical pattern, while the ewes were more variable (Roberts, 1924). Some of the photographs of the modi- fication of the badgerface and mouflon patterns (Roberts, 1924, Roberts and White, 1930 a) indicate that some of the modified types might have shown both patterns. Tlie type showing extreme reduc- tion of pigment (Roberts, 1924, Plate XX, 1) could possibly have been a lightcoloured type of badgerface-mouflon, but due to the clear head pattern it would have been de- scribed as badgerface. On the other hand, the modification of the mouflon type (Ro- berts and White, 1930 a) shown in Plate VIII, 3, could have been a badgerface- mouflon, where the badgerface pattern was on the dark side. This lamb was described as a mouflon, presumably because the characteristic head pattern was absent and the white belly of the mouflon pattern present. The lamb shown in fig. 5 in the same plate seems to have all the character- istics of a dark badgerface as shown in Plate VI, 6, of the same paper, while the characteristic features of the mouflon patt- ern, light belly and light colour inside the ears, are absent. As this lamb was from a mating where the badgerface pattern was not expected, it seems reasonable to assume that the dam might have been a dark badgerface-mouflon, classified as mouflon, and the sire a mouflon, carrying the mou- flon pattern in a simplex state. The description of the variation in the patterns and the photograps given in the above mentioned studies therefore indicate
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