الفهرس 
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Abstract
Present study included two experiments, first experiment that
aimed to study the effect of re-mating interval after first kindling only and
breed and their interaction on body weight, body scores, some hormones,
metabolites, milk yield, litter traits, ovary activity and reproductive
performance in APRI line and Baladi Black breed rabbit. The rabbit does
after the first parturition (primiparous) were allocated to: group 1 (PP): remating
interval 1-day post kindling, group 2 (PS): re-mating interval 11
days post kindling and group 3(PW) re-mating interval after 35 days post
kindling (after weaning).
The intermediate score was based for bone protrusions and muscle
fullness on the lion and rump, the highest value at mating in PW group at
1st parity and during next parities. The highest (P≤0.05) value of leptin
was recorded by PW group at mating during 1st Parity and 2nd Parity.
there were significant differences on milk yield, the highest values were
recorded by PW group during 3rd week of lactation while the lowest were
recorded by PP group during 3rd and 4th weeks of lactation. The highest
values of litter size (LS) were recorded in PW group. Data of comet test
presented no significant effects were observed between groups. Result in
1stparity there is superiority for APRI line at kindling. APRI rabbits at
1stparity and next parities had significantly (P≤0.05) higher in all litter
size and litter weight traits than Baladi Black rabbits. Intermediate score
was the highest values comparing to other scores during all parities and
APRI rabbits at mating taken the highest value. Interaction between
genotypes and re-mating interval had significant effect on plasma leptin,
and insulin concentrations during 1st and 2nd parities. During 1st parity,
there were significant differences on milk yield during all lactation
periods studied except during 1st week of. During next parities, there were
significant differences during all lactation periods. At first parity, there
were significant differences in litter size at 21 days and at weaning due to
the interaction. During next parities, all litter traits were significant
differences except litter size and weight at 21 days. The interaction
between breed and interval groups had a significant effect on kindling
interval (KI) while it had not significant effect on number of services per
conception (NSC) and gestation length (GL). In conclusion: delay the remating
after first kindling resulted to improve reproductive performance
in rabbit does.
Second experiment aimed to compare three breeding systems
that differed in terms of reproductive rhythm and age of females at first
mating on rabbit litter, reproductive traits and productivity in nulliparous
does. Two genotypes APRI and Baladi Black were divided into three
different groups; groupW24, 24 wk with 52 d; group W27, 27 wk with 42d
and group W30, 30wk with 32d, according to reproductive rhythm and
age of females at first mating, respectively. The effect of breeding system
on litter traits separately for both APRI and BB breeds. There were
significant differences on litter size at birth, Individual litter weights at
birth and weaning for APRI rabbits. Breeding system had affected
significant on NSC and KI in APRI rabbits does. The parity had a
significant effect on all LS traits in APRI line. Mean bunny weight at
weaning was highest in W24 group during all parities in APRI rabbit
line. In the BB rabbits breed the mean weight at weaning was lightest in
W30 group comparing with W24 and W27 groups. The productivity at
weaning in APRI rabbit line was the highest for W30 group (11.7
kg/year) and the lowest for group W24 (10.5 kg/Year). Productivity in
Baladi Black rabbit breed showed that at weaning in W24 group was the
highest values (9.20 kg/year) and the lowest for group
W30(7.05kg/Year).
In conclusion, an early 1st mating (24 week) associated with an extensive
reproduction rhythm (52 d) resulted in higher productivity (kg/year) at
weaning in APRI line. An intensive reproduction rhythm (32 d) combined
with a 1st mating at 30 weeks, for females of Baladi Black breed to
improve their productivity (kg/year) at weaning.
Key words: Rabbits does, Postpartum, Re-mating interval, Hormones,
Blood biochemicals, Litter traits, Weaning age,
Reproductive performance, Milk yield, Body condition
score, Ovary, Comet, Breeding system, Age at first mating,
Individual litter weight, Mean bunny weight, Productivity,
and Parity.