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

1981 ◽  
Vol 32 (2) ◽  
pp. 227-229 ◽  
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.

scholarly journals Active immunization against the proregions of GDF9 or BMP15 alters ovulation rate and litter size in mice

Reproduction ◽  
2012 ◽  
Vol 143 (2) ◽  
pp. 195-201 ◽  
Author(s):  
C Joy McIntosh ◽  
Steve Lawrence ◽  
Peter Smith ◽  
Jennifer L Juengel ◽  
Kenneth P McNatty
Keyword(s):  
Litter Size ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cross Reactivity ◽  
Full Length ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Immunization Group

The transforming growth factor β (TGFB) superfamily proteins bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9), are essential for mammalian fertility. Recent in vitro evidence suggests that the proregions of mouse BMP15 and GDF9 interact with their mature proteins after secretion. In this study, we have actively immunized mice against these proregions to test the potential in vivo roles on fertility. Mice were immunized with either N- or C-terminus proregion peptides of BMP15 or GDF9, or a full-length GDF9 proregion protein, each conjugated to keyhole limpet hemocyanin (KLH). For each immunization group, ovaries were collected from ten mice for histology after immunization, while a further 20 mice were allowed to breed and litter sizes were counted. To link the ovulation and fertility data of these two experimental end points, mice were joined during the time period identified by histology as being the ovulatory period resulting in to the corpora lutea (CL) counted. Antibody titers in sera increased throughout the study period, with no cross-reactivity observed between BMP15 and GDF9 sera and antigens. Compared with KLH controls, mice immunized with the N-terminus BMP15 proregion peptide had ovaries with fewer CL (P<0.05) and produced smaller litters (P<0.05). In contrast, mice immunized with the full-length GDF9 proregion not only had more CL (P<0.01) but also had significantly smaller litter sizes (P<0.01). None of the treatments affected the number of antral follicles per ovary. These findings are consistent with the hypothesis that the proregions of BMP15 and GDF9, after secretion by the oocyte, have physiologically important roles in regulating ovulation rate and litter size in mice.

The effect of melatonin treatment during the seasonal anoestrus on the superovulatory response and embryo production of high-prolificacy Rasa Aragonesa ewes before culling

2003 ◽  
Vol 2003 ◽  
pp. 82-82
Author(s):  
F. Forcada ◽  
J.A. Abecia ◽  
J.A. Valares
Keyword(s):  
Embryonic Development ◽  
Breeding Season ◽  
Litter Size ◽  
Direct Effect ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Melatonin Treatment ◽  
Embryo Production ◽  
Spring Equinox

The efficacy of melatonin implants inserted around the spring equinox to improve fertility and ovulation rate or litter size in Mediterranean ewes has been previously reported (Chemineau et al., 1996; Forcada et al., 2002a.), indicating the ability of the hormone to regulate the hypothalamic activity (Viguié et al., 1995). Moreover, a direct effect of melatonin on corpora lutea and embryonic development has been also reported (Wallace et al., 1988; Abecia et al., 2002). The use of prolific Rasa Aragonesa (RA) ewes (a Mediterranean breed) before culling as embryo donors has been previously tested in the breeding season (Forcada et al., 2002b.). The aim of this experiment was to improve embryo production during the seasonal anoestrus period in selected superovulated RA ewes at the end of their reproductive lives through the use of melatonin.

scholarly journals Litter size components traits in two Algerian rabbit lines

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

<p>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 3<sup>rd</sup> 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; <em>P</em>&lt;0.0001). Synthetic line displayed a higher number of implanted embryos (10.00±0.25 vs. 7.85±0.25 embryos; <em>P</em>&lt;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; <em>P</em>&lt;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 1<sup>st</sup> PC. Resorbed embryos and foetal survival were located in the 2<sup>nd</sup> PC. Ovulation rate and embryonic survival were the predominant variables defining the 3<sup>rd</sup> PC. The body weight of females was located in the 4<sup>th</sup> 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.</p>

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

1967 ◽  
Vol 10 (1) ◽  
pp. 73-80 ◽  
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.

Genetic studies of prolificacy in New Zealand sheep

1998 ◽  
Vol 67 (2) ◽  
pp. 289-297 ◽  
Author(s):  
G. H. Davis ◽  
C. A. Morris ◽  
K. G. Dodds
Keyword(s):  
Litter Size ◽  
Heritability Estimate ◽  
Ovulation Rate ◽  
The Other ◽  
Relationship Matrix ◽  
Research Station ◽  
Embryo Survival ◽  
Genetic Studies ◽  
Average Litter Size ◽  
Likelihood Model

AbstractData on ovulation rate, embryo survival and litter size have been analysed from the 1988-96 records collected at AgResearch's Woodlands Research Station on 2180 elite (highly prolific) ewes of three breeds: Romney, Coopworth and Perendale. The Romneys included a subgroup found to carry the sex-linked Inverdale high prolificacy gene. Foundation animals for all breeds were screened on high litter size (lambs born, alive or dead, per ewe lambing) from industry flocks. Prior to being transferred to Woodlands between 1979 and 1984, their average litter size was 2·66. Ovulation rates for descendants of the foundation ewes averaged 2·15 (Romney), 2·43 (Coopworth), 2·15 (Perendale) and 2·96 for the Romney subgroup carrying the Inverdale gene. Embryo survival averaged 0·84 except for a low value in Inverdales (0·76). Using a restricted maximum likelihood model, with full relationship matrix, the within-breed heritability of ovulation rate over all ages and breeds (excluding Inverdale) was 0·14 (s.e. 0·03), with repeatability 0·26 (s.e. 0·02). Litter size averaged 1-80 (Romney), 2·05 (Coopworth), 1·76 (Perendale) and 2·17 (Inverdale). The heritability estimate for litter size (excluding Inverdale) was 0·073 (s.e. 0·018), from data for all ages. The genetic correlation between ovulation rate and litter size was 0·91 (s.e. 0·08). The standard deviation for ovulation rate in the Inverdales was 1·75 times as great as the average of the other three breeds. Embryo survival to term for ewes conceiving to two, three or four ovulations averaged 0·89, 0·77 and 0·64, respectively, and was significantly different among breeds fP < 0·001). The greater ovulation rate in Inverdales than Romneys was sufficient to explain the Inverdale effect on reduced embryo survival. The highest embryo survival was observed in the Coopworth breed (P < 0·001).

Pre- and peri-pubertal feed intake: effects on age at puberty and potential litter size of replacement gilts

2017 ◽  
Vol 57 (6) ◽  
pp. 1040
Author(s):  
W. H. E. J. van Wettere ◽  
M. Mitchell ◽  
D. K. Revell ◽  
P. E. Hughes
Keyword(s):  
Litter Size ◽  
Dietary Restriction ◽  
Feed Intake ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Short Term ◽  
Large White ◽  
Embryo Number ◽  
Age At Puberty

The effect of moderate restriction of pre- and peri-pubertal liveweight gain on puberty attainment and potential litter size was investigated. At 69 days of age, 48 Large White/Landrace crossbred gilts (28.3 ± 0.3 kg), were fed to attain a liveweight of 70 kg (LIGHT) or 100 kg (HEAVY) at 161 days of age (n = 24 gilts/treatment). At 161 days of age, half the gilts in each group were fed to gain liveweight at 0.5 (LOW) or 1.0 (HIGH) kg/day until puberty (n = 12 gilts/treatment). From 175 days of age, gilts received 20 min/day of full, physical boar contact. Gilts were artificially inseminated at the pubertal oestrus, with reproductive tracts collected 22 ± 0.1 days later, and the number of corpora lutea and viable embryos recorded. LIGHT-LOW gilts were older (P < 0.05) at puberty compared with LIGHT-HIGH, HEAVY-LOW and HEAVY-HIGH gilts; 207.7 ± 3.50 versus 191.7 ± 3.65, 193.1 ± 3.50 and 192.5 ± 3.65, respectively. Treatment (HIGH vs LOW) increased (P < 0.05) pubertal ovulation rate (15.2 ± 0.43 vs 13.1 ± 0.47), oestradiol at oestrus (13.4 ± 1.87 vs 9.1 ± 1.22 pg/mL) and progesterone 72 h post-oestrus (7.1 ± 0.48 vs 4.6 ± 0.50 ng/mL). Embryo number (10.8 ± 0.46) and survival (77.0 ± 3.21) were unaffected (P > 0.05) by treatment. To conclude, puberty was delayed by chronic, but not acute, dietary restriction. Although short-term, moderate increases in feed intake increased pubertal ovulation rates, embryo numbers and survival were unaffected.

scholarly journals Effects of flush feeding strategy before breeding on reproductive performance of modern replacement gilts: impacts on ovulation rate and litter traits

2020 ◽  
Vol 98 (6) ◽  
Author(s):  
André L Mallmann ◽  
Lidia S Arend ◽  
Gabriela S Oliveira ◽  
Ana P G Mellagi ◽  
Rafael R Ulguim ◽  
...  
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Feeding Strategy ◽  
Early Embryo ◽  
Ovulation Rate ◽  
Breeding Cycle ◽  
Corpora Lutea ◽  
Embryo Survival ◽  
Estrous Cycles ◽  
Litter Traits

Abstract AbstractThe effects of two feed levels offered during two estrous cycles before insemination were evaluated on the reproductive performance of gilts. A total of 93 gilts (PIC Hendersonville, TN) were individually housed and manually fed twice a day with 2.1 or 3.6 kg/d of a corn and soybean meal-based diet (3.15 Mcal ME/kg and 0.64% standardized ileal digestible lysine), during two estrous cycles before breeding (cycle 1, between first and second estrus; cycle 2, between second and third estrus). Gilts were weighed at the beginning of the experiment, at second and third estrus, and at slaughter (30.2 ± 1.2 d of gestation). Follicles were counted at second estrus, and the embryo-placental units and the corpora lutea were individually counted, measured, and weighed at slaughter. Gilts fed 3.6 kg/d had greater BW gain during cycle 1 and cycle 2 (P &lt; 0.001; + 9.8 kg and + 10.0 kg, respectively) becoming heavier at second and third estrus (P &lt; 0.001). At second estrus, gilts fed 3.6 kg/d had 1.6 more medium-large follicles (P = 0.074) but no difference in follicle size (P = 0.530) was observed. Gilts fed 3.6 kg/d in cycle 1 or cycle 2 had a greater ovulation rate at third estrus (P &lt; 0.016) than those receiving 2.1 kg/d. Also, 3.6 kg/d in cycle 2 increased early embryo mortality (P = 0.006; 2.3 vs. 1.1 dead embryos) and consequently reduced total embryo survival (P = 0.002; 84.6 vs. 90.1%). Gilts fed 3.6 kg/d during cycle 1 had two more total embryos (P &lt; 0.001; 17.2 vs. 15.1) and two more vital embryos on day 30 (P &lt; 0.001; 16.7 vs. 14.5) in comparison with gilts fed 2.1 kg/d. The coefficient of variation for placental length was greater for gilts fed 3.6 kg/d during cycle 1 (P = 0.003). No further significant effects of feeding levels were observed on embryo and placental traits (P ≥ 0.063). These results suggest that the feeding level during the first cycle after pubertal estrus is crucial to set ovulation rate and potential litter size for breeding at next estrus. However, flush feeding gilts before insemination can negatively impact litter size by reducing embryo survival when breeding at third estrus.

scholarly journals Effects of selection on growth, body composition and food intake in mice: II. Correlated responses in reproduction

1984 ◽  
Vol 44 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Forbes D. Brien ◽  
Gillian L. Sharp ◽  
William G. Hill ◽  
Alan Robertson
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Food Intake ◽  
Litter Size ◽  
Reproductive Performance ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Primary Reason ◽  
Correlated Responses ◽  
Fat Percentage

SummaryFemale reproductive performance is reported in mice selected for ten generations for one of three criteria: either appetite (A), fat percentage (F) or total lean mass (P). For each criterion lines were selected for high (H) or low (L) performance, with contemporary unselected controls (C). In the A and P lines, litter size changed in the direction of the selected criterion, the changes being larger and more rapidly established in the A than in the P lines. At generation 10, the differences in litter size between high and low lines were 2·6 live young born in the A lines, and 1·0 live young born in the P lines. The differences in 6-week weight between the high and low lines were 3·5 g in the A lines, 6·5 g in the P lines. Changes in ovulation rate were the primary reason for changes in litter size, the differences between the high and low lines being 3·8 corpora lutea for the A lines, and 3·1 corpora lutea for the P lines. Fitting body weight at mating as a covariate within lines in the analysis of ovulation rate and live foetus number removed the differences between the high and low selected P lines, but not those in the A lines. The high and low selected A and P lines did not differ in prenatal survival. There were no consistent differences in litter size, ovulation rate or pre-natal survival in the F lines.

REPEATABILITY OF OVULATION RATE, NUMBER OF LAMBS BORN AND OVA LOSS IN SHEEP WITH DIFFERENT OVULATION RATES

1989 ◽  
Vol 69 (2) ◽  
pp. 307-314 ◽  
Author(s):  
M. H. FAHMY
Keyword(s):  
Key Words ◽  
Litter Size ◽  
First Record ◽  
Linear Increase ◽  
Genetic Group ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Genetic Groups ◽  
Quadratic Relationship

Ovulation and lambing records of 214 ewes from nine genetic groups varying in ovulation rate (OR) from 1.8 to 3.2 corpora lutea (CL) and number of lambs born (LB) from 1.2 to 2.1 were analyzed to study the relation between OR, LB, ova loss (OL) and their repeatabilities. The nine genetic groups were DLS, Finnsheep (F) and seven crosses from these two breeds ranging from 1/8 to 7/8 Finnsheep breeding. Intrayear repeatability of OR averaged 0.59 for all genetic groups combined. It ranged from −0.20 for DLS to 0.93 for 5/8 F. Interyear repeatability averaged 0.38 and ranged from 0 for DLS to 0.54 for 3/8 F. OR showed a linear increase (b = 0.22 ± 0.02) with increase in Finnsheep breeding whereas repeatabilities showed a significant quadratic relationship. Repeatability of OR was more associated with variability than with mean OR. Repeatability of OR for ewes which had 1, 2, 3 or 4 CL at first record and averaged 2.3 ± 0.5,2.5 ± 0.7,3.4 ± 1.0 and 3.4 ± 1.3 CL at the following two records was, −0.09, 0.33, 0.42 and 0.42, respectively. Lambs born increased with the increase in Finnsheep breeding from 1.2 for DLS to 2.1 for Finnsheep. Ova loss averaged 35% and was fairly constant in the different genetic groups. Repeatabilities for LB and OL for each genetic group were generally small and mostly nonsignificantly different from zero. For the genetic groups combined the estimates were 0.15 and 0.14 for LB and OL, respectively. The correlation between OR and LB (0.25) was lower than that between OR and OL (0.58) and LB and EM (−0.62). Key words: Ovulation rate, litter size, ova loss, repeatability, Finnsheep crosses, DLS sheep

scholarly journals The Ovulation Rate, Plasma Leptin Concentration, and Litter Size of a Local Ewe Breed Kept in a Barn Versus Those Kept under an Overhead Shelter

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 403
Author(s):  
Ewa Kuźnicka ◽  
Małgorzata Kunowska-Slósarz ◽  
Mirosław Gabryszuk
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Negative Impact ◽  
Pearson Correlation ◽  
Ovulation Rate ◽  
Housing System ◽  
Control Group ◽  
Average Litter Size ◽  
Condition Score ◽  
Plasma Leptin

The effect of housing system on ovulation rate, leptin concentration, body weight, condition score and litter size of Żelażnieńska ewes was investigated. The observations were carried out during three successive years on 36 ewes between 2 and 4 years of age. The animals were divided into groups: the experimental group kept in a cold environment under an overhead shelter, and the control group kept in a warm barn. In both groups were ewes with similar age and reproductive performance nearing that of the flock. The average litter size was 1.53 and 1.59, respectively. This difference was not significant. The observation was carried out on the same ewes each year; thus, ewe age varied from 2 to 6 years. The ovulation rate was tasted by laparoscopy (L) on 16 September and 5 October. Blood was taken from each ewe after feeding one day before laparoscopy. The lower number of corpus lutea (p ≤ 0.01) and leptin concentration (p ≤ 0.01) at first L compared with second L was confirmed. The highest litter size (1.8) was shown by ewes at the age of 4 years (p ≤ 0.01). The Pearson correlation of ewe age and plasma leptin concentration was noted (p ≤ 0.05). The Spearman correlation of the condition score with ewe body weight (p ≤ 0.01) and with ewe age (p ≤ 0.05) was confirmed. Żelaźnieńska sheep may be housed in semiopen sheds with no negative impact on their reproduction. This may encourage breeders to develop this branch of livestock production avoiding the high expenses of construction of massive, warm barns.

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