الفهرس 
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Abstract
S.SUMMARY
This study was carried out in Gizereit El-Sheir Experimental Station at EIKanater
El-Khairia, 12 Kilometer to the north of Cairo. Data collected on 967
purebred litters and 3076 progeny produced by BR, Band NZW rabbits during
three consecutive years of production (1984/85, 1985/86 & 1986/87) were used to
investigate some genetic and non-genetic effects on litter traits (litter size and
weight at birth and at weaning, number born alive, pre-weaning mortality percent
and gestation length) and individual body weight and mortality at different ages up
to weaning. The most important results obtained could be summarized as follows:-
S.I.Litter traits
5.1.1. Litter Size
Differences in litter size due to breed effects were found to be significant
(P<O.OSor p<O.OI) at birth and at weaning. BR rabbits produced the
largest litters at birth and at weaning.
Doe effects contributed significantly (P<O.OSor P<O.OOl)to the variance
of litter size at birth in the three breeds (BR, B & NZW) and only for
litter size at weaning in NZW rabbits.
Litter size at birth and at weaning differed with parity, month of kindling
and year of production. Significant differences were noticed for the effect of
month of kindling on litter size at both ages (P<o.05) in B and NZW
rabbits only and for the effect of year of production on litter size at weaning
in BR (P<O.Ol)and NZW (P<O.05) rabbits.
Litter size at weaning increased significantly (P<O.OOl)with the increase of
litter size at birth.
5.1.2. Number J!!mIIIiR
Breed contribUled non-significantly to the variance in number born alive.
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Doe effects on number born alive proved significant (P<O.Ol or P<O.OOl)
in the three breeds studied.
Number born alive differed with parity, month of kindling and year of
production, the differences proved significant (P<O.05 or P<O.Ol) for
month-of-kindling and year-of-production effects on number born alive in B
and NZW rabbits only.
Differences in number born alive due to litter size at birth were significant
(P<O.OOl) in the three breeds. Number born alive increased with the
increase of litter size at birth.
5.1.3. Litter wei2ht
Breed effects did not contribute significantly to the variance in litter weight
at birth and at weaning.
Effects of doe on litter weight were significant (P<O.Ol) only in B rabbits at
birth, and non-significant in the thee breeds (BR, B, NZW) of the study at
weaning.
Litter weight at birth differed according to parity, month of kindling and
year of production, the differences were not significant in the three breeds s
tudied at birth. Significant (P<O.Ol) effects on litter weight at weaning were
detected for parity and year of production in NZW rabbits and for month of
kindling in B rabbits.
Litter size at birth was a significant source of variation in litter weight at
birth in the tIu’ee breeds (P<O.OOl) and in litter weight at weaning in
NZW rabbits only (P<O.Ol). Utter weight increased with the increase of
litter size at birth.
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5.1.4. Pre-weanini: litter mortality
Differences among breeds in pre-weaning litter mortality were significant
(P<O.OOl).The highest pre-weaning litter mortality percent was recorded
by B rabbits, while the smallest percent was shown by NZW ones.
Doe effects on pre-weaning litter mortality percent were non-significant in
the three breeds in the study.
Pre-weaning litter mortality percent differed with parity, month of kindling
and year of production, the differences due to months of kindling were
significant (P<O.05or P<O.Ol)only in Band NZW rabbits.
Pre-weaning litter mortality differed non-significantly with the size of the
litter at birth.
5.1.5. Gestation length
Gestation length varied among breeds with significant (P<O.Ol) differences.
Gestation length was not affected significantly by doe effects in the three
breeds studied.
Gestation length changed with parity, month of kindling and year of
production, the differences were found to be significant for the effects of
month of kindling (P<O.(X)l)in the three breeds and for the effects of year
of production (P<O.05)only in BR rabbits.
Litter size at birth affected gestation length (P<O.Ol) only in DR rabbits b
ut not in either B or NZW ones.
5.2. Individual trJ1tl
5.2.1. ~ weii:ht
Sire effects did not constitute a signiflC3llt source of variance in individual
body weight at all ages studied in the three breeds except for body weight at
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one week of age in Band NZW rabbits which proved significant (P<O.OS or
P<O.Ol).
Individual body weight at birth, one, two, three and four weeks of age
varied among breeds significantly (P<O.OOl).
Differences in individual body weight due to dam effects were significant
(P<O.OOl) at alJ ages studied in the three breeds.
Individual body weight differed with parity, month of birth, year of birth
and litter size at birth. The differences due to parity, month of birth and
litter size at birth at all ages ~re mostly significant (P<O.05 or P<O.OOl),
while those caused by year-of-birth effects were significant (P<O.05) only at
one week in B rabbits.
5.2.2. mortality
Individual mortality differed among breeds and the differences for all ages
up to weaning were significant (P<O.OO1).
Dam effects on individual mortality up to one, two, three and four weeks of
age were significant (P<O.OOl) in all breeds of the study.
Individual pre-weaning mortality up to one, two, three and four weeks of
age varied significantly (P<O.05 or P<O.OOl) with parity effects only in BR
and NZW rabbits. Month-of-birth effects on pre-weaning individual
mortality up to the ages studied were mostly significant (P<O.Ol or
P<O.OOl). Year-of-birth differences did not contribute significantly to the
variance of individual mortality up to different ages in the three breeds
except for B rabbits up to two weeks which proved significant (P<O.05).
Litter size at birth effects on individual mortality percent were significant
(P<O.05, P<O.Ol or P<O.OOl) in DR and NZW rabbits up to all ages
studied and in B rabbits only up to three weeks of age.