Ovulation rate and early embryonic survival rate in female rabbits of a synthetic line and a local Algerian population

A higher litter size at birth has been reported in female rabbits from a Synthetic line than in those of the Local Algerian population. The aim of this work was to analyse whether this difference in litter size was due to a higher ovulation rate and/or embryonic survival rate in Synthetic line than in Local Algerian population. In total, 24 multiparous female rabbits from Synthetic line and 23 from Local population were used in this experiment. Litter size at birth was recorded up to the first 3 parities. Litter size was 20% higher in Synthetic line than Local population. At their 4th gestation, the females were euthanized at 72 h post coitum. Synthetic line females had 50% more ova and embryos than those of Local population (+4.42 ova and +3.92 embryos, respectively). Synthetic line displayed a lower percentage of normal embryos and a larger number of unfertilized oocytes than Local population (–2.81% and +0.64 oocytes, respectively), but differences were not relevant. Synthetic line showed a lesser embryonic stage of development at 72 h post coitum, showing a higher percentage of early morulae (31.50 vs. 8.50%) and a lower percentage of compact morulae (51.45 vs. 78.65%) than Local population. No relevant difference was found for early embryonic survival rate between Synthetic line and Local population. In conclusion, the difference in litter size was mainly due to a higher ovulation rate in the Synthetic line, allowing more embryos to develop in this line.

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Litter size components traits in two Algerian rabbit lines

World Rabbit Science ◽

10.4995/wrs.2021.14247 ◽

2021 ◽

Vol 29 (1) ◽

pp. 51

Author(s):

Rafik Belabbas ◽

Maria de la Luz García ◽

Hacina AinBaziz ◽

Ali Berbar ◽

Maria José Argente

Keyword(s):

Body Weight ◽

Litter Size ◽

Principal Components ◽

Local Population ◽

The Body ◽

Ovulation Rate ◽

Phenotypic Correlation ◽

Limiting Factor ◽

Corpora Lutea ◽

Synthetic Line

The aim of this study was to estimate the limiting litter size components in rabbit females from a Synthetic line (n=32) and a Local population (n=34). Ovulation rate, number of implanted and live embryos were counted by laparoscopy at 12 d after mating. Prolificacy (total newborn, number born alive and mortality) and embryonic, foetal and prenatal survival at day of birth of the 3rd gestation were measured. The analysed traits were body weight of the female at mating, ovulation rate, implanted, live and resorbed embryos, embryonic, foetal and prenatal survival, as well as total newborn, number born alive and mortality at birth. Synthetic line females had a higher ovulation rate compared to the Local population (11.03±0.23 vs. 8.41±0.23 corpora lutea; P<0.0001). Synthetic line displayed a higher number of implanted embryos (10.00±0.25 vs. 7.85±0.25 embryos; P<0.0001). No difference was found between groups for number of resorbed embryos. Similar embryonic, foetal and prenatal survival rates were reported between the Synthetic line and the Local population. Additionally, total newborn was higher in the Synthetic line than in the Local population (+1.46 kits; P<0.05). A principal components analysis was performed. The first four principal components (PC) explained more than 90% of the total variation in both lines. Total newborn, number born alive and live embryos were the main variables defining the 1st PC. Resorbed embryos and foetal survival were located in the 2nd PC. Ovulation rate and embryonic survival were the predominant variables defining the 3rd PC. The body weight of females was located in the 4th PC. The phenotypic correlation between total newborn and its components were high and positive in both lines, except for ovulation rate and total newborn, where it was moderate in Synthetic line. In conclusion, the females from Synthetic line have a higher total newborn than those from Local population, as a consequence of a higher number of released oocytes and embryos that successfully reach implantation. However, a higher uterine crowding in Synthetic line seems to limit survival of foetuses that reach term of gestation, while ovulation rate is the principal limiting factor of total newborn in Local population.

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THE ACCUMULATIVE EFFECT OF FINNSHEEP BREEDING IN CROSSBREEDING SCHEMES: REPRODUCTIVE PERFORMANCE

Canadian Journal of Animal Science ◽

10.4141/cjas88-007 ◽

1988 ◽

Vol 68 (1) ◽

pp. 69-81 ◽

Cited By ~ 6

Author(s):

MOHAMED H. FAHMY ◽

JACQUES J. DUFOUR

Keyword(s):

Body Weight ◽

Mortality Rate ◽

Key Words ◽

Litter Size ◽

Reproductive Performance ◽

Conception Rate ◽

Ovulation Rate ◽

Genetic Groups ◽

Linear Regressions ◽

Size At Birth

Reproductive performance and body weight were studied on 361 ewes, representing Finnsheep (F), DLS (a population of 1/2 Dorset, 1/4 Leicester, 1/4 Suffolk) and seven combinations ranging from 1/8 to 7/8 Finnsheep breeding. Conception rate in yearlings was 61.5% for DLS compared to 89.0% for F with the crosses being intermediate. Conception rate in older ewes was similar in the different genetic groups (avg. 94%). Ovulation rate and litter size at birth of DLS ewes were 1.72 and 1.44 lambs, which was less than half those of F ewes (3.51 and 2.86 lambs, respectively). Both traits increased progressively with an increase in F breeding in crosses and with advances in age. DLS ewes weaned 1.22 lambs compared to 2.03 lambs for F ewes and 1.84 lambs for 4/8 F ewes. The heaviest litters at weaning (31.7 kg) were raised by 4/8 F ewes, followed by 7/8 F (30.8 kg) while those raised by DLS ewes weighed 23.0 kg and F ewes 29.1 kg. Percentage of ova lost per ewe mated averaged 24% and ranged between 18% (DLS and 1/8 F) and 29% (6/8 F). About 3.6% of lambs were born dead and a further 13.8% died before weaning. Preweaning mortality rate was highest in F (22.9%) and lowest in 3/8 F (9.4%). Average kilograms of lambs weaned per ewe exposed was highest in 4/8 F (27.6 kg) followed by F (26.0 kg), whereas that of DLS was the lowest at 18.1 kg. The 4/8 F cross showed 25% heterosis in kg of lambs weaned per ewe exposed and 52.5% increase over DLS. Significant positive linear regressions were calculated for ovulation rate, litter size and preweaning mortality rate on proportion of Finnsheep breeding in crosses. The relation was quadratic for percent ova lost and lamb mortality at weaning. Yearling DLS females weighted 36 kg compared to 44 kg for F yearlings. However, at 5 yr of age DLS ewes weighed 62 kg, 5 kg heavier than F ewes. The heaviest ewes at all ages were the 4/8 F (45 kg at 1 yr, 65 kg at 5 yr). Key words: Reproduction, DLS sheep, Finnsheep, crossbreeding, heterosis, repeatabilities

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The effect of energy or protein supplementation on embryo survival rate in ewes

Proceedings of the British Society of Animal Science ◽

10.1017/s0308229600028233 ◽

1995 ◽

Vol 1995 ◽

pp. 55-55

Author(s):

M.G. Diskin ◽

J.P. Hanrahan

Keyword(s):

Survival Rate ◽

Litter Size ◽

Protein Supplementation ◽

Ovulation Rate ◽

Reproductive Efficiency ◽

Protein Supplement ◽

Embryo Survival ◽

Rumen Undegradable Protein

Embryo survival rate is a major factor determining litter size and overall reproductive efficiency in sheep. In sheep, as ovulation rate increases the proportion of embryos surviving decreases. There is evidence, from cattle, that feeding a rumen-undegradable protein supplement enhances embryo survival rate. The objective of this experiment was to determine the effect on embryo survival rate in high prolific ewes of feeding an energy or protein supplement.

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A note on ovulation rate and embryonic survival in D'man ewes

Animal Science ◽

10.1017/s0003356100025071 ◽

1981 ◽

Vol 32 (2) ◽

pp. 227-229 ◽

Cited By ~ 8

Author(s):

A. Lahlou-Kassi ◽

M. Marie

Keyword(s):

Litter Size ◽

Ovulation Rate ◽

Corpora Lutea ◽

Embryonic Survival ◽

Average Litter Size ◽

Simultaneous Activity

ABSTRACTThe elements of prolificacy have been analysed for the D'man sheep, a prolific Moroccan breed, by laparotomy on 38 animals. The average ovulation rate was 2·50 (s.e.0·45); a slight difference was observed between nulliparous and multiparous ewes due to high simultaneous activity by both ovaries in the latter group. Embryonic survival (42% overall) was 94% (87 to 100%) for multiparous and 44% (36 to 52%) for the nulliparous ewes at one ovulation, decreasing with increasing numbers of corpora lutea. The average litter size showed an optimum at four ovulations.

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The effects of inbreeding on the components of litter size in mice

Genetics Research ◽

10.1017/s0016672300010776 ◽

1967 ◽

Vol 10 (1) ◽

pp. 73-80 ◽

Cited By ~ 23

Author(s):

J. C. McCarthy

Keyword(s):

Litter Size ◽

Inbreeding Depression ◽

First Generation ◽

Inbreeding Coefficient ◽

Ovulation Rate ◽

Corpora Lutea ◽

Base Population ◽

Pregnant Females ◽

Sib Mating ◽

Size At Birth

Twenty-four lines were bred from a base population of outbred Q mice by continued full-sib mating. Inbreeding depression in litter size at birth was observed. This decline in litter size was analysed in terms of ovulation rate, the incidence of preimplantation mortality and the incidence of postimplantation mortality. Pregnant females were dissected at 17½ days' gestation and the numbers of corpora lutea, or eggs, and of live and dead embryos were counted. Matings were arranged so that separate estimates of the effects of inbreeding in the mother and in the litter on the components of litter size could be obtained.In the first generation of inbreeding when the inbreeding coefficient of the litter was raised from 0 to 25% decline in litter size was attributable to an increased incidence of preimplantation mortality.In the second and fourth generations decline in litter size was attributable to (1) a reduction in the number of eggs ovulated by the inbred mothers, (2) an increased incidence of preimplantation mortality which resulted from inbreeding in the mother. No evidence of significant effects on mortality of inbreeding in the litter was obtained in the later generation of inbreeding.These findings are discussed in the context of previous work on the effects of inbreeding and crossing on litter size and its components in mice and pigs.

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Reproductive Biology of the Booroola Merino Sheep

Australian Journal of Biological Sciences ◽

10.1071/bi9840163 ◽

1984 ◽

Vol 37 (3) ◽

pp. 163 ◽

Cited By ~ 45

Author(s):

BM Bindon

Keyword(s):

Reproductive Biology ◽

Litter Size ◽

Single Gene ◽

Ovulation Rate ◽

Physiological Characteristics ◽

Merino Sheep ◽

Sheep Breeds ◽

The World ◽

Lamb Survival ◽

Size At Birth

This paper reviews the genetic and physiological characteristics of the Booroola Merino, one of the four most prolific sheep breeds in the world, and which was acquired by CSIRO in 1958 from a commercial sheep property, 'Booroola', Cooma, N.S.W. The exceptional prolificacy of this genotypee. g. mean flock ovulation rate in 1982 of 4�2 (range 1-10) and mean litter size of 2� 5 (range 1-7)is largely attributable to a single gene (F) of uncertain origin which increases ovulation rate. Crosses of the Booroola with other Merinos produce progeny which have a 47-87% increase in ovulation rate, a 45-56% increase in litter size at birth, and a 1-33% reduction in lamb survival relative to control Merinos. This represents a 16-37% increase in the number of lambs weaned per ewe joined in favour of the Booroola crosses.

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Effect of divergent selection for uterine capacity on embryonic survival and development at 30 h post-mating in unilaterally ovariectomized rabbit females

World Rabbit Science ◽

10.4995/wrs.2015.3592 ◽

2015 ◽

Vol 23 (4) ◽

pp. 241 ◽

Cited By ~ 1

Author(s):

R. Peiro ◽

M. Gallego ◽

A. Blasco ◽

M.A. Santacreu

Keyword(s):

Reproductive Traits ◽

Divergent Selection ◽

Ovulation Rate ◽

Cell Stage ◽

Embryonic Survival ◽

Stage Of Development ◽

High Line ◽

Morphological Criteria ◽

Survival And Development ◽

Selection For

Uterine capacity has been proposed as an indirect way to increase litter size. The aim of this work is to study the effect of a divergent selection for uterine capacity (UC) on reproductive traits at 30 h post mating in unilaterally ovariectomized (ULO) females. A total of 62 ULO females from the high line (selected to increase UC) and 39 ULO females from the low line (selected to decrease UC) were used. Ovulation rate was estimated as the number of corpora haemorrhagica and early embryonic survival was estimated as the ratio between number of embryos and ovulation rate. No differences in ovulation rate and early embryonic survival at 30 h post mating were found between high and low lines. Selection for UC did not change the embryonic stage of development either, the majority of embryos being at 4-cell stage. Additionally, the embryos were evaluated according to morphological criteria and more than 95% of the embryos were evaluated as good or fair quality. No differences in embryonic morphological criteria between high and low lines were found either. Thus, selection for UC did not modify the early embryonic survival and development in ULO females at 30 h post mating.

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Growth performances, carcass traits, meat quality, and blood metabolic parameters in rabbits of local Algerian population and synthetic line

Veterinary World ◽

10.14202/vetworld.2019.55-62 ◽

2019 ◽

Vol 12 (1) ◽

pp. 55-62 ◽

Cited By ~ 1

Author(s):

Rafik Belabbas ◽

Maria de la Luz Garcia ◽

Hacina Ainbaziz ◽

Nadia Benali ◽

Ali Berbar ◽

...

Keyword(s):

Meat Quality ◽

Growth Traits ◽

Local Population ◽

Carcass Traits ◽

Daily Weight Gain ◽

Feed Conversion ◽

Local Conditions ◽

Algerian Population ◽

Lower Protein ◽

Synthetic Line

Aim: The objective of this work was to study the growth performance, slaughter traits, meat quality, and metabolic profile in rabbits of local Algerian population and a synthetic line. Materials and Methods: In total, 120 weaned rabbits were used (60 per group). Growth traits were recorded from weaning (35 days) to slaughter (91 days). At slaughter, carcass traits, meat quality, and metabolic profiles were measured. Results: The synthetic line showed heavier total weight and faster daily weight gain than the local population (+15% and +19%, respectively), better feed conversion (3.92 vs. 4.81 g/g), and heavier weight of cold carcass, and perirenal fat (+15%). No differences were found between the two groups in dressing out percentage, muscular pH, weight of liver, or scapular fat. Wider intestinal villi were found in the synthetic line (+20%, p<0.0001) allowing better absorption surface in this line. The synthetic line also showed higher fat content (3.41% vs. 2.22%, p<0.0001) in the meat and lower protein content (22.02% vs. 18.98%, p=0.0002). Glucose level was 19% higher in the local population than in the synthetic line. Conclusion: The synthetic line is well adapted to the local conditions of Algeria. This line has shown better growth, daily gain, and feed conversion, due to its better intestinal absorption surface.

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EFFECT OF LIGHT ON THE DEVELOPMENT OF MARKET PIGS AND BREEDING GILTS

Canadian Journal of Animal Science ◽

10.4141/cjas68-055 ◽

1968 ◽

Vol 48 (3) ◽

pp. 425-430 ◽

Cited By ~ 13

Author(s):

J. Dufour ◽

C. Bernard

Keyword(s):

Litter Size ◽

Average Daily Gain ◽

Ovulation Rate ◽

Significant Difference ◽

Yorkshire Pigs ◽

Daily Gain ◽

Size At Birth ◽

Effect Of Light

A total of 176 Yorkshire pigs (112 barrows and 64 gilts) were raised from weaning to market weight, second estrus or parturition, in a piggery maintained under normal daylight conditions or in darkness. Average daily gain and feed required for gain were not affected by the treatments. There was no significant difference in total backfat or loin eye area between barrows housed in darkness and barrows housed in normal daylight conditions. Gilts raised in darkness reached puberty 11 days earlier than gilts raised in daylight (P < 0.01). Ovulation rate and litter size at birth were not affected by the treatments. Optical enucleation delayed the onset of estrus by 14 days, but had no other detectable effects.

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The effects of lactation feed level on subsequent ovulation rate and early embryonic survival in the sow

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600013945 ◽

1984 ◽

Vol 1984 ◽

pp. 30-30

Author(s):

P. E. Hughes ◽

R. W. Henry ◽

D. W. Pickard

Keyword(s):

Litter Size ◽

Ovulation Rate ◽

Embryonic Survival ◽

Embryo Mortality ◽

Low Level

Low level feeding during lactations of greater than thirty five days duration has been shown to result in an extended weaning to remating interval and a reduction in subsequent litter size. The aim of this experiment was to examine whether this effect was a consequence of a reduction in ovulation rate and/or increased embryo mortality following such treatment.

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