Íslenskar landbúnaðarrannsóknir - 01.09.1975, Side 61

Íslenskar landbúnaðarrannsóknir - 01.09.1975, Side 61
OCCURRENCE AND INIIERITANCE 59 TABLE 3. Classification of lamb pelts at weaning in relation to score for tan colour at birth. Birth No. of lambs in pelt class score A-fB C D Total 1 40 64 18 122 2 57 408 210 675 3 12 65 65 142 4 2 15 38 55 5 1 2 5 8 Total 112 554 336 1002 The difference between scores for tan colour at birth w. r. t. pelt classification is highly significant (%28 = 117.21;P<0.001), showing that the degree of tan colour at weaning is to a considerable extent predic- table from the score for tan colour at birth. The relationship between pelt classifica- tion of lambs at weaning and the classifi- cation of the fleeces of the same animals at shearing 5—6 months later together with average wool weight by pelt and wool classes were examined in one investigation on 90 female lambs kept for breeding at Hólar and Reykhólar in 1963 (Adalsteinsson, 1964). The results are shown in table 4. TABLE 4. Classification of wool fleeces in relation to classi- fication of lamb pelts at weaning, and average fleece weight by wool and pelt classes. Pelt No. of ewe lambs in wool class Average class A B C Total fleece wt. kg A+B 16 6 2 24 2.05 C 0 14 14 28 2.06 D 1 2 35 38 2.06 Total 17 22 51 90 Av. fleece wt. kg. 2.04 2.11 2.04 2.06 The connection between pelt class and wool class is highly significant (X \ = 71.35;P<0.001) showing that the amount of tan colour present at weaning is clearly reflected at shearing 5—6 months later. The fleece weight in this investigation has been unaffected by pelt class and wool class. Pelt classes of progeny from matings with known pelt classes of parents were examined in 1963 and 1964 in the experiments at Hólar and Reykhólar (Adalsteinsson, 1965). The numbers of progeny in each pelt class according to mating are shown in table 5. TABLE 3. Distribution on pelt classes of progeny from parents with known pelt classes. -c c Number of white s >* o G G ö Pelt progeny in pelt o <D —( <D bj) bt) o *-> o classes class. o £ Q.H o. of parents A+B C D Total (A+B)xA+B) 38 24 7 69 5 74 (A+B)xC 32 48 14 94 12 106 (A+B)xD 23 81 69 173 10 183 CxC 12 32 9 53 3 56 CxD 13 36 49 98 1 99 DxD 8 28 78 114 3 117 Total 126 249 226 601 34 635 Comparison of the distribution of progeny in table 5 with expectation under the hypo- thesis that pelt class of progeny is unaffected by pelt classes of parents shows a high- ly significant deviation from expectation (X210 = 146.99;P<0.001). This shows that a clearcut relationship exists between pelt classes of parents and progeny.

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