The effects of body weight and level of nutrition before, during, and after joining on ewe fertility

1967 ◽  
Vol 7 (25) ◽  
pp. 126 ◽  
Author(s):  
ID Killeen
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
Ovulation Rate ◽  
Multiple Birth ◽  
Corpora Lutea ◽  
Body Weights ◽  
Before And After ◽  
Independent Effects ◽  
Experimental Treatments ◽  
High Level

Four experiments were designed to assess the independent effects of body weight and nutritional level on the reproductive performance of Border Leicester x Merino ewes. Ewes in experiments 1, 2, and 3 were joined in summer (December-January) and in experiment 4 in autumn (March-April). The reproductive performance of two groups of ewes in experiment 1, joined at different body weights, was assessed from mating and lambing data. A factorial (3 x 2 x 2) design was used for experiments 2, 3, and 4. The experimental treatments consisted of different levels of nutrition applied before and after mating. The reproductive performance of ewes in experiment 2 was assessed from mating and lambing data. Ewes in experiments 3 and 4 were slaughtered 19-28 days after mating, and their genitalia were observed for presence of corpora lutea and embryos. Body weight at mating and level of nutrition during three weeks before mating independently affected the multiple birth or ovulation rate. High body weight at mating was consistent with a high multiple birth or ovulation rate, and a higher proportion of the ewes receiving a high level of nutrition during the three weeks before mating (i.e. flushed ewes) had multiple births or multiple ovulations. The results also demonstrated that above 90-100 lb, the proportion of ewes mating and becoming pregnant was relatively independent of body weight at joining. The level of nutrition and body weight had only minor effects on early reproductive failure, but there was a higher proportion of egg wastage from multiple ovulation ewes than from single ovulation ewes.

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.

Fertility in Cheviot ewes. 2. The effect of level of pre-mating nutrition on ovulation rate and early embryo mortality in North and South Country Cheviot ewes in moderately-good condition at mating

1979 ◽  
Vol 29 (1) ◽  
pp. 17-23 ◽  
Author(s):  
R. G. Gunn ◽  
J. M. Doney ◽  
W. F. Smith
Keyword(s):  
Food Intake ◽  
Good Condition ◽  
Early Embryo ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Restricted Feeding ◽  
Embryo Mortality ◽  
The North ◽  
Breed Difference ◽  
High Level

ABSTRACTIn two experiments over 2 years, 57 North Country Cheviot and 82 South Country Cheviot hill ewes were differentially group-fed indoors over a 2-month period to achieve either good or moderate body con- dition. Over 5 weeks prior to mating, ewes in good condition were brought down in condition by restricted feeding and ewes in mod- erate condition were raised in condition by a high level of feeding. The ewes were thus in moderately-good condition at mating. After mating, ewes were maintained in this condition until killed either on return to service or at 29 ± 8 days for counts of corpora lutea and viable embryos.Ovulation rate in each breed was positively related to the level of pre-mating food intake at the condition level studied. Embryo mortality, as ova loss, was not influenced overall by the level of pre-mating food intake but loss of multiple-shed ova was greater than that of single-shed ova in ewes which had been on restricted feeding before mating. Although a greater proportion of ewes in the North Country Cheviot breed were not pregnant at slaughter, this could not be identified as a breed difference since the breeds were studied in different years.

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

1988 ◽  
Vol 68 (1) ◽  
pp. 69-81 ◽  
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

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 Ovulation rate of lines of mice selected for testis weight

1976 ◽  
Vol 27 (1) ◽  
pp. 23-32 ◽  
Author(s):  
A. B. M. Mafizul Islam ◽  
W. G. Hill ◽  
R. B. Land
Keyword(s):  
Body Weight ◽  
Reproductive Performance ◽  
Genetic Correlations ◽  
The Body ◽  
Ovulation Rate ◽  
Testis Weight ◽  
Testis Size ◽  
Realized Heritability ◽  
Breeding Programmes ◽  
The Mean

SUMMARYSelection was practised in two replicates for both high and low testis weight in the mouse. Typically 7 males were selected out of 30 recorded for a total of 5 generations. From an initial average of 191 mg the mean divergence between high and low lines reached 112 mg, with a realized heritability of 0·52. The ovulation rate of the lines changed in the same direction as that of selection, the mean divergence was 2·0 eggs in primiparous females in generation 4 and 1·6 in nulliparous females in generation 5. Correlated changes in the body weight of both sexes also occurred but were inadequate to account for the observed change in ovulation rate. The genetic regressions of ovulation rate on testis weight were estimated to be 2·9 and 14 eggs/100 mg in primiparous and nulliparous females, respectively, which, along with data from other experiments, correspond to genetic correlations between testis weight and ovulation rate of 0·50 and 0·25 respectively. There were no correlated changes in litter size. The possibility of using male testis size in breeding programmes to improve female reproductive performance is discussed.

Short-term undernutrition and prenatal mortality in young and mature Merino ewes

1975 ◽  
Vol 84 (1) ◽  
pp. 113-117 ◽  
Author(s):  
A. J. Mackenzie ◽  
T. N. Edey
Keyword(s):  
Ovulation Rate ◽  
Control Group ◽  
Corpora Lutea ◽  
Short Term ◽  
Embryo Survival ◽  
Body Weights ◽  
Cycle Lengths ◽  
The Mean ◽  
Group 2 ◽  
The Right

SUMMARYPrenatal mortality was examined in 74 primiparous Merino ewes which, after hand mating to fertile rams on the second oestrus following synchronization, were allocated to two groups. One group of 38 ewes was confined to yards and restricted to approximately 30% of their maintenance requirement for 14 days while the other group of 36 remained at pasture. The degree and timing of prenatal loss was assessed by corpora lutea counts, pregnancy diagnosis about day 40, returns to service and lambing records.The mean ovulation rate was 1·06 and the 19-day non-return rate was 87·8%. Pregnancy failed in a higher proportion of the underfed ewes (45·0%) than in the control ewes (30·8%) but this difference did not reach significance. Of the ewes returning to service, significantly more did so with cycles longer than 19 days in the underfed group (9/12) than in the control group (2/8), indicating that in the latter stages, the treatment may have been detrimental to embryo survival.In a second experiment, ovulation rate and prenatal mortality, assessed as in the first experiment, were studied in 85 mature Merino ewes subjected to the following nutritional treatments: HH, control; HL, 30% submaintenance feeding for 14 days following mating; LH, 15% submaintenance feeding for 7 days prior to mating; LL, both submaintenance treatments.Acute undernutrition prior to mating (LH) had no effect on ovulation rate or prenatal mortality. Ovulation rates were low over all groups (mean 1·09) and thus precluded any valid examination of ovulation rate and body weight relationships. The right ovary was significantly more active in producing ova than the left in all groups (P < 0·05). Although ova wastage was apparently higher in. the post-mating undernutrition groups (HL, 44%; LL, 48%; LH, 50%) than in the control group (HH, 35%), the differences were not significant. An increased incidence of extended (> 19 days) first-return cycle lengths in group LL provided some evidence of induced prenatal mortality.In so far as the experiments can be considered together, they indicate that if body weights are comparable, primiparous 1½-year-old ewes are not necessarily more susceptible than mature ewes to prenatal mortality induced by severe short-term undernutrition.

scholarly journals Increased ovulation rate in gilts treated with dihydrotestosterone

Reproduction ◽  
2002 ◽  
pp. 527-533 ◽  
Author(s):  
H Cardenas ◽  
WF Pope ◽  
Keyword(s):  
Body Weight ◽  
Androgen Receptor ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Fsh Receptor ◽  
Receptor Mrna ◽  
Preovulatory Follicles ◽  
Early Follicular Phase

Treatment with testosterone increases ovulation rate in pigs. The present study was conducted to examine the effects of 5alpha-dihydrotestosterone (DHT), a non-aromatizable androgen receptor ligand, on ovulation rate and amounts of androgen receptor and FSH receptor mRNAs in postpubertal gilts. In Expt 1, ovulation rate in response to daily i.m. injections of 0, 6, 60 or 600 microg DHT kg(-1) body weight from day 13 of the oestrous cycle (day 0 = day 1 of oestrus) to the following oestrus increased with each dose of DHT (P < 0.05). The mean increase in number of corpora lutea ranged from approximately three to 17 over the three dosages of DHT. In Expt 2, gilts treated daily with 60 microg DHT kg(-1) body weight during the early follicular phase (from day 13 to day 16), coincident with follicular recruitment, or the late follicular phase (day 17 to oestrus), had higher (P < 0.05) rates of ovulation compared with gilts that received vehicle, and were not different from gilts treated with DHT from day 13 to oestrus. Percentage recovery of day 3 embryos was not altered when gilts were treated from day 13 to day 16 or from day 17 to oestrus; however, treatment of gilts with DHT from day 13 to oestrus decreased recovery of day 3 (Expt 1) or day 11 (Expt 2) conceptuses. Daily administration of 6 microg DHT kg(-1) body weight to gilts from day 13 of the oestrous cycle to the following oestrus (Expt 3) did not affect the relative amounts of androgen receptor mRNA, but increased (P < 0.05) the amounts of FSH receptor mRNA in preovulatory follicles as determined by RT-PCR. The results of these experiments indicate that androgens may regulate ovulation rate in gilts. One of the roles of androgens might be regulation of the amounts of FSH receptor mRNA in ovarian follicles.

scholarly journals effect of ascorbic acid as a feed additive on indicators of the reproductive performance of Pulawska breed gilts

2016 ◽  
Vol 72 (6) ◽  
pp. 378-382
Author(s):  
Jerzy Lechowski ◽  
Anna Kasprzyk ◽  
Mirosław Tyra ◽  
Beata Trawińska
Keyword(s):  
Body Weight ◽  
Vitamin C ◽  
Reproductive Performance ◽  
Reproductive Organs ◽  
The Body ◽  
Reproductive Value ◽  
Feed Additive ◽  
Corpora Lutea ◽  
Reproduction Cycle ◽  
Experimental Group

The aim of the study was to determine the effect of vitamin C on indicators of gilts and sows reproductive value. The study was conducted using 64 gilts of the Pulawska breed. The experimental gilts received a supplement of vitamin C in an amount of 2.4 g daily throughout the whole experiment. Sixteen gilts from both control and experimental groups were mated in their third estrus. In order to determine the number of corpora lutea and the state of development of the reproductive organs, other gilts from the control and experimental groups were slaughtered after third estrus between the 5th and 10th day of the following estrous cycle. The results showed that gilts from the experimental group were characterized by higher potential fertility, as well as reared more piglets per litter. In the body weight and backfat thickness of sows during the first reproduction cycle in the control and experimental groups were not statistically significantly different. The piglets in the experimental group had higher body weight in the 1st and 21st day of rearing. Larger contents of protein, immunoglobulins, and vitamin C were recorded in the colostrum and milk from experimental sows.

The effects of inbreeding, maternal handicap, and range in age on 10 fleece and body characteristics in Merino rams and ewes

1967 ◽  
Vol 18 (4) ◽  
pp. 689 ◽  
Author(s):  
J Lax ◽  
GH Brown
Keyword(s):  
Body Weight ◽  
Positive Relationship ◽  
Age Groups ◽  
Fibre Diameter ◽  
Regression Coefficients ◽  
Multiple Births ◽  
Multiple Birth ◽  
Skin Area ◽  
Usual Practice ◽  
Body Weights

Estimates have been made of the influence on 10 fleece and body characteristics of dam's phenotype, range in age of offspring, inbreeding of offspring and dam, type of birth of offspring, and age of dam. The data came from rams 10–11 months old and ewes 15–16 months old, which had previously been shorn as weaners; the animals belong to an unselected control flock run at Cunnamulla, south-western Queensland. The dam's phenotype showed a high positive relationship with that of her offspring in all 10 characteristics, the values of the regression coefficients confirming the levels of heritability previously estimated on the same flock but without removing all the effects included in the present analysis. Younger animals in a group had lower greasy and clean wool weights and body weights, even at 15–16 months, but the effects were slight, except for body weight. For each 1% increase in the offspring's own level of inbreeding, the regression coefficients for rams and ewes respectively were -0.042 and –0,051 lb for greasy wool weight, –0.025 and –0.025 1b for clean wool weight, and –0.431 and –0.541 1b for body weight. These figures represent a decrease of 5–10% in clean wool weight and 8–10% in body weight for the progeny of half-sib matings. Inbreeding of the dam had a negligible effect on the characteristics examined. Animals born in multiple births in this environment suffer penalties which were still evident up to 15–16 months of age, resulting in both sexes in lower wool and body weights, lower wrinkle scores, fewer fibres per unit skin area, and fewer crimps per inch of staple. Fibre diameter was slightly higher for the multiple birth animals, but �he signs for the effects on other characteristics differed between sexes. The handicaps for rams and ewes respectively were 9 and 5% for clean wool weight and 7 and 5% for body weight. Dams were separated into four age groups (2, 3, 4–7, and 8–10 years). Greasy and clean wool weights and wrinkle score rose for offspring of both sexes to a peak at 4–7-year-old dams, then fell slightly. Body weight reached a peak at 3 years for rams and 4–7 years for ewes, while fibre diameter and staple length reached a peak at 3 years for ewes and 4–7 years for rams. In no case was the fall for the older dam age groups sufficient to invalidate the usual practice of adjusting only the progeny of 2-year-old dams. Other characteristics showed no consistent pattern.

Studies in ovine infertility in agricultural regions in Western Australia: the influence of a supplement of lupins (Lupinus angustifolius cv. Uniwhite) at joining on the reproductive performance of ewes

1975 ◽  
Vol 26 (3) ◽  
pp. 567 ◽  
Author(s):  
TW Knight ◽  
CM Oldham ◽  
DR Lindsay
Keyword(s):  
Body Weight ◽  
Western Australia ◽  
Reproductive Performance ◽  
Dietary Supplementation ◽  
Lupinus Angustifolius ◽  
Ovulation Rate ◽  
Mineral Supplement ◽  
Nitrogen Levels ◽  
Wool Growth ◽  
Agricultural Regions

The dietary supplementation of groups of 200 ewes with lupins (0.23 or 0.45 kg per head per day) just prior to and during joining increased the ovulation rate by 8–25 ovulations per 100 ewes and the number of lambs born increased by 5–23 lambs per 100 ewes joined. The increase in the number of lambs born had two components: (i) an increase in number of ewes lambing and (ii) an increase in the number of twin births. Another study suggested that feeding the lupin supplement during joining gave larger increases in the reproductive performance of the ewes, especially in number of ewes lambing, than feeding the supplement of lupins before joining. The increases in reproductive performance following lupin supplementation were not associated with differences or changes in body weight or with differences in the rate of wool growth. The feeding of a barley + urea + mineral supplement that provided 25% more digestible energy than the lupin supplement and similar nitrogen levels, but with 50% of the nitrogen in the form of urea, resulted in no increase in the reproductive performance of the ewes.

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