Íslenskar landbúnaðarrannsóknir - 01.03.1970, Page 75

COLOUR INHERITANCE IN ICELANDIC. SHEEP 73
TABLE 35
Effect of colour genotypes of ewes and rarns on variation in fertility
of two year old ewes
Source ot' variation DF SS MS F
1. Number of lambs per ewe lambing
Between farm-years 115 94.1043 0.8183 5.96**
Between matings 3 6.1749 2.0583 14.98**
Between ewes ign. rams 1 5.8081 5.8081 42.27**
Between ewes el. rams 1 3.6847 3.6847 26.82**
Between rams el. ewes 1 0.3518 0.3518 2.56
Interaction ewes X rams 1 0.0150 0.0150 0.11
Interaction farm-years X nratings 173 34.0166 0.1966 1.43**
Error 2208 303.3099 0.1374
2. Number of lambs per mating
Between farm-years 115 147.3322 1.2811 5.00**
Between all matings 11 10.1063 0.9188 3.59**
Between all parent genotypes 5 8.9786 1.7957 7.01**
Interaction ewes X ranrs all genotypes .... 6 1.1277 0.1880 0.73
Between ewes ign. rams 2 7.5296 3.7648 14.70**
Between ewes el. rams 2 4.1076 2.0538 8.02**
Between wh. and nonwh. ewes el rams .. . 1 4.0361 4.0361 15.76**
Among wlrite ewes el. rams 1 0.0715 0.0715 0.28
Between rams el. ewes 3 1.4490 0.4830 1.89
Between wh. and nonwlr. rams el. ewes . . 1 1.2137 1.2137 4.72*
Among white rams el. ewes 2 0.2353 0.1176 0.46
Between matings, white vs. nonwhite 3 8.7376 2.9125 11.37**
Between parent genot., wh. vs. nonwh. .. . 2 8.7373 4.3686 16.99**
Interaction ewes X rams, wh. vs. nonwh. . . 1 0.0003 0.0003 0.001
Interaction ewes X rams, other parent genot. 5 1.1274 0.2255 0.88
Interaction farm-years X matings 345 97.2163 0.2818 1.10
Error 2361 604.6575 0.2561
*) P < 0.05; **) P < 0.01
ly both ewes and rams were divided into
two groups only, white and nonwhite.
The results from the analyses for 2 year
old ewes are shown in tables 34 and 35,
while results obtained for 3 and 4 year old
ewes are shown in tables 36 and 37.
The conclusions that can be drawn fronr
the results shown in tables 34—37 are much
the same as those drawn fronr tables 32
and 33, as far as the ewes are concerned.
The Aj-allele in ewes shows again a highly
significant effect on fertility, both on
nunrber of lambs per ewe lambing and
number of lanrbs per mating. The least
scjuares estinrates of ewe genotype effects
in table 34 are sonrewhat lower tlran tlre