Íslenskar landbúnaðarrannsóknir - 01.03.1977, Page 81

INHERITED FERTILITY DEPRESSION 79
TABLE 1. REPRODUCTIVE HISTORY OF THE EWE STEINKA 6600, BORN
IN 1966.
Record year Mating date (D) and mating interval (I) Date of lambing Gest- ation, days Number of lambs Sex of lamb
D I D I D
1966/67 Nc t mate d ... 0 ...
1967/68 Re peat edly m atec . . . 0 . ..
1968/69 .. . . .. 1 M
1969/70 . .. 1 M
1970/71 .. . . . . 1 M
1971/72 29/12 20/5 143 1 M15
1972/73 20/12 13/5 144 1 M
1973/74 26/12 19 14/1 11/6 148 1 M
1974/75 20/12 17 6/1 17 24/1 17/6 144 1 m2)
1975/76 25/12 20/5 147 1 b3)
1976/77 21/12 16 6/1
1) Grettir 215. 2) Bolli 236. 3) Loki 245.
TABLE 2. MATING RESULTS OF THE RAMS GRETTIR 215, DRAUPNIR AND DURGUR
AND NORMAL RAMS FOR COMPARISON (T = EWESWITH TWINS,
iV*
S = EWES WITH SINGLES, R = EWES RETURNING ON HEAT, ORy= NOT
LAMBING).
Com- parison 'Rams Ewe group. xi xi AU classes
T S R(N) Total T: S T + S : R
i Grettir 21.5 Normal rams 5 20 16(2) 41 78 58 11(0)147 11.80*** 25.93*** 35.01***
ii Draupnir Nörmal rams 42 79 63(6)184 240 142 3302)415 29.49*** 65.46*** 90.77***
iii Durgur Normal rams 2 23 15(1) 40 106 86 16(7)208 19.54*** 27.25*** 42.11***
*** P < 0.001