Rit Landbúnaðardeildar : B-flokkur - 01.10.1953, Blaðsíða 83

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15 ewes wliich wrere barren as yearlings and reared singles, when 2 years old. Lot C
was made up of 39 ewes wliich reared one lamb each as yearlings and again when 2
years old. Lot D consisted of 5 ewes which reai-ed one lamb each as yearlings and
twins when 2 years old. In lot E there were 5 ewes which reared one lamb as yearlings
and were barren or lost their lambs at birtli when 2 years old.
3. The average live-weight increase of the ewe lambs from 4 to 11 months was
in the barren lots (A and B) 2.98 kilos and in the pregnant lots (C, D and E) 6.72
kilos or practically the same as in comparable lots (A and C) ín Part I. The average
gain in live-W'eight over the year from 4 to 16 months was 20.00 kilos in tlie former
and 13.09 kilos in the latter.
The lambs reared by the yoarling ewes (lots C, D and E), when killed 4 montlis
old dressed out with an average carcass weight of 13.61 kilos, kidney and caul fat 0.92
kilos and skin with w'ool 2.96 kilos.
4. At 16 months of age the average live-w'eight of tlie ewes in lot B was 7.87 kilos
greater than of the ewes in lot C. From 16 to 28 months the mean difference in live-
weight between these lots decreased by 62.5% and remained at 28 months only 2.95
kilos. During the same period the mean live-weight of the ewes in lots A and E which
were barren in their 2nd year, increased by 7.70 kilos and 9.40 kilos respectively,
whereas tiiose which reared lambs in their second year gained only 3.19 kilos in lot C,
1.40 kilos in lot D and lost 1.73 kilos in lot B in average live-weight.
5. As in Part I the difference in the mean live-weight between the lots, when
killed, was found to be primarily due to difference in the weight of dressed carcass,
loose fat and skin with wool.
6. The dressed carcass weight of the ewes in lot A was significantly greater than
in any of the other lots. The ewes in lot E had significantly heavier carcass than those
in lots C and D, but only 0.87 kilos heavier than those in lot B w'hich is not signi-
ficant. Tlie ewes in lot C had 2.02 kiios or 8.6% lighter dressed carcass than those in
lot B, this difference being significant at tlie 5% point, but amounting to only 38.7%
of the difference observed between comparable lots at 16 montlis (lot C and A, Part I).
Thcre was no difference in dressed carcass weight between lots C and D.
7. There was only slight and insignificant difference in the avcrage weight of
kidney- and caul fat between the lots which reared lambs as two tooths (lots B, C
and D), though lightest in lot D. The loose fat in lot E was significantly heavier than
in lots B, C and D and significantly lighter than in lot A.
8. There was no significant difference between any of the 5 lots in the following
external carcass measurements, T, F and Th. Neither was there any significant dif-
ference between any of the lots which rearcd lambs as two tooths (B, C and D) in the
other external carcass measurements, except that the ewes in lot B had significantly
greater widtli of thorax (W) than the ewes in lot C. The G-, W- and U-measurements
were significantly greater in lot A than in lots B, C and D. In lot E these tliree mea-
surements were shorter than in lot A and grcater than in lots B, C and D, though not
significantly so except the differenccs in all these measurements between lots E and
C being significant at the 5% point.
9. There were no significant differences between tlie 5 lots in any of the cannon
bone measurements.
10. Much greater differences were between the lots in the internal carcass mea-
surements than in the cannon bone- and the external carcass measurements. These
differences however are more dependant on whether the ewes did suckle lambs or not
in their second jear than if they reared lambs or were barren as yearlings.
11. There was no significant difference between the lots in the “length” of the
“eye-muscle” (A). The depth of the “eye-muscle” (B) was greater and nearly signi-
ficantly so in the lots which did not rear lambs as tw'o tooths (A and E) than in the
other lots (B, C and D), while therc was practically no difference belween the former
and the latter lots inter se.