Litter size, ovulation rate and prenatal survival in relation to ewe body weight: genetics review

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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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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Effect of selection for litter size and body weight on hormone-induced ovulation rate in mice2

Journal of Animal Science ◽

10.2527/1991.69114299x ◽

1991 ◽

Vol 69 (11) ◽

pp. 4299-4305 ◽

Cited By ~ 5

Author(s):

D. L. Lubritz ◽

E. J. Eisen ◽

O. W. Robison

Keyword(s):

Body Weight ◽

Litter Size ◽

Ovulation Rate ◽

Induced Ovulation ◽

Selection For

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

Genetics Research ◽

10.1017/s0016672300026252 ◽

1984 ◽

Vol 44 (1) ◽

pp. 73-85 ◽

Cited By ~ 14

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.

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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 ◽

10.3390/agriculture10090403 ◽

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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LH receptor induction and ovulation rate in mice selected for litter size and body weight

Reproduction ◽

10.1530/jrf.0.0840601 ◽

1988 ◽

Vol 84 (2) ◽

pp. 601-609 ◽

Cited By ~ 3

Author(s):

D. Pomp ◽

E. J. Eisen ◽

A. J. Ziecik

Keyword(s):

Body Weight ◽

Litter Size ◽

Ovulation Rate ◽

Lh Receptor

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Ovulation rate, embryo survival and ovarian sensitivity to gonadotrophins in mice selected for litter size and body weight

Reproduction ◽

10.1530/jrf.0.0590329 ◽

1980 ◽

Vol 59 (2) ◽

pp. 329-339 ◽

Cited By ~ 24

Author(s):

B. S. Durrant ◽

E. J. Eisen ◽

L. C. Ulberg

Keyword(s):

Body Weight ◽

Litter Size ◽

Ovulation Rate ◽

Embryo Survival

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An egg transfer study of litter size, birth weight and lamb survival

Animal Science ◽

10.1017/s000335610002242x ◽

1974 ◽

Vol 18 (3) ◽

pp. 249-263 ◽

Cited By ~ 27

Author(s):

G. E. Bradford ◽

C. S. Taylor ◽

J. F. Quirke ◽

R. Hart

Keyword(s):

Body Weight ◽

Birth Weight ◽

Litter Size ◽

Ovulation Rate ◽

Gestation Length ◽

Transfer Experiment ◽

Embryo Survival ◽

Average Litter Size ◽

Breed Differences ◽

Transfer Study

SUMMARYIn an egg-transfer experiment, seven breeds of sheep differing widely in mean mature ewe weight were used: Oxford Down, 96 kg; Borderm Leicester, 77; Finnish Landrace, 55; Southdown, 52; Tasmanian Merino, 42; Welsh Mountain, 34; and Soay, 22. Body weight and gestation length of recipient ewes are briefly examined. Of 60 recipient ewes, 95% became pregnant. Embryo survival averaged 69% and appeared to be independent of breed of embryo. Litter size of Welsh Mountain, Border Leicester and Finnish Landrace ewes each given four eggs averaged 2·6, 2·9 and 2·9 respectively so that most of the normally observed breed differences are mainly due to differences in ovulation rate. Observed birth weights were in general agreement with those predicted from litter size and donor and recipient ewe weights. The maternal capacity of Finnish ewes was close to average. Litter size affected survival mainly through its effect on birth weight. For Oxford lambs in litters of 3 to 5 from Finnish recipients, birth weight was 42% that of normal single-born Oxfords and only 42% survived. For Soays the corresponding values were 59% for birth weight and 85% for survival. Finnish lambs were exceptionally small at birth but had the highest viability of all breeds. Lamb mortality was higher for males (18%) than females (9%) especially in large litters (26 v. 11%) but about the same in both sexes for Finnish lambs.

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269 Effects of high phytase supplementation in lactation diets on sow and litter performance

Journal of Animal Science ◽

10.1093/jas/skaa054.175 ◽

2020 ◽

Vol 98 (Supplement_3) ◽

pp. 101-102

Author(s):

Kelsey L Batson ◽

Hilda I Calderon Cartagena ◽

Robert D Goodband ◽

Jason C Woodworth ◽

Mike D Tokach ◽

...

Keyword(s):

Body Weight ◽

Litter Size ◽

Feed Intake ◽

Control Diet ◽

Small Scale ◽

Body Weight Change ◽

Weaning Weight ◽

Commercial Trial ◽

Quadratic Response ◽

Dietary Treatments

Abstract A total of 109 sows (Line 241; DNA, Columbus, NE) were used in a study to evaluate the effect of increasing phytase concentration in lactation diets on sow and litter performance. On d 107 of gestation, sows were blocked by body weight and parity and allotted to 1 of 3 dietary treatments of increasing phytase concentration (0, 1,000, or 3,000 FYT/kg; Ronozyme HiPhos 2700; DSM Nutritional Products, Inc., Parsippany, NJ). The control diet contained no phytase and was formulated to contain 0.50% standardized total tract digestible phosphorus (STTD P; 0.45% available P) and 0.62% STTD calcium (0.90% total Ca). The same STTD P and Ca concentrations were formulated for the phytase diets considering a release of 0.132 STTD P and 0.094 STTD Ca in both diets. Diets were fed from d 107 of gestation until weaning (d 18 ± 2). Litters were cross-fostered within treatment until 48 h post-farrowing to equalize litter size. Linear and quadratic response to phytase concentration was evaluated using the lmer function in R. There was no evidence for difference in sow body weight change, farrowing performance, wean-to-estrus interval, or litter size among dietary treatments. Sow average daily feed intake from farrowing to weaning tended to increase (linear, P=0.093) as phytase increased. Although not significant (linear, P =0.226), farrowing duration decreased as phytase increased. Litter weaning weight increased (quadratic, P=0.039) and overall litter gain increased (quadratic, P=0.047) with 1,000 FYT of phytase. In summary, sow feed intake tended to increase linearly with increasing phytase; however, feeding 1,000 FYT/kg maximized overall litter gain and weaning weight. This small-scale study suggests sow and litter performance benefits due to high inclusions of dietary phytase; however, a commercial trial with more sows is warranted to confirm these results.

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