Genome‐wide epistatic interactions of litter size at birth in Chinese indigenous pigs

2021 ◽  
Author(s):  
Z. Chen ◽  
Y. Li ◽  
Z. Zhang ◽  
W. Zhao ◽  
Z. Zhang ◽  
...  

2014 ◽  
Vol 17 (4) ◽  
Author(s):  
Raymond K. Walters ◽  
Charles Laurin ◽  
Gitta H. Lubke

Epistasis is a growing area of research in genome-wide studies, but the differences between alternative definitions of epistasis remain a source of confusion for many researchers. One problem is that models for epistasis are presented in a number of formats, some of which have difficult-to-interpret parameters. In addition, the relation between the different models is rarely explained. Existing software for testing epistatic interactions between single-nucleotide polymorphisms (SNPs) does not provide the flexibility to compare the available model parameterizations. For that reason we have developed an R package for investigating epistatic and penetrance models, EpiPen, to aid users who wish to easily compare, interpret, and utilize models for two-locus epistatic interactions. EpiPen facilitates research on SNP-SNP interactions by allowing the R user to easily convert between common parametric forms for two-locus interactions, generate data for simulation studies, and perform power analyses for the selected model with a continuous or dichotomous phenotype. The usefulness of the package for model interpretation and power analysis is illustrated using data on rheumatoid arthritis.



2021 ◽  
Author(s):  
S. T. Amorim ◽  
N. B. Stafuzza ◽  
S. Kluska ◽  
E. Peripolli ◽  
A. S. C. Pereira ◽  
...  


1977 ◽  
Vol 25 (2) ◽  
pp. 255-258 ◽  
Author(s):  
A. N. Howard ◽  
W. C. Smith

SUMMARYIn an analysis of data from 211 litters in a Pietrain herd, litter size at birth and at weaning was lower than is generally found in indigenous breeds. Mortality in growing and breeding pigs was high with circulatory failure accounting for 23% and 95% of deaths respectively. Pietrains, fed ad libitum over the live-weight range 27 to 87 kg, grew more slowly by 130 g/day than contemporary Large Whites on the same feeding regime, had higher killing-out percentages (by 3 to 4 units) and larger eye muscles in cross-section (by 9·9 cm2) but tended to have higher feed conversion ratios. There was no breed difference in backfat measurements but Pietrain carcasses were shorter by 83 mm and their muscle quality was markedly inferior to that of the Large Whites.



2021 ◽  
Vol 27 (1) ◽  
pp. 11-18
Author(s):  
Marykutty Thomas ◽  
G. Radhika ◽  
T.V. Aravindakshan ◽  
R. Thirupathy ◽  
K. Raji ◽  
...  


1988 ◽  
Vol 68 (1) ◽  
pp. 69-81 ◽  
Author(s):  
MOHAMED H. FAHMY ◽  
JACQUES J. DUFOUR

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



Author(s):  
Katherine D Vande Pol ◽  
Austin L Laudwig ◽  
Aaron M Gaines ◽  
Beau A Peterson ◽  
Caleb M Shull ◽  
...  

Abstract Litter sizes in commercial pig production have increased substantially over recent years; however, farrowing pen sizes have generally not changed over the same time period. The objective of this study was to evaluate the effect of farrowing pen size on piglet pre-weaning growth and mortality. Differences in pen size were created by varying the width of pens of the same length, increasing the creep area available to the piglets. The study used a total of 1,786 litters in a randomized complete block design to compare two Farrowing Pen Size treatments (FPS): Standard (pen width 1.52 m) and Increased (pen width 1.68 m). Litter sizes were equalized across treatments (12.9 ± 1.95 piglets) at 24 h after birth using cross-fostering. Litter weights were collected at birth and weaning (21.3 ± 2.08 d); pre-weaning mortality was recorded. The experimental unit was the litter; models included FPS and replicate. Farrowing Pen Size had no effect (P > 0.05) on litter size at birth (12.8 and 13.0 for the Standard and Increased FPS, respectively), after cross-fostering (12.9 for both treatments), or at weaning (11.2 and 11.3, respectively). There was no effect (P > 0.05) of FPS on total litter or average piglet weight at birth, after cross-fostering, and at weaning. These results suggest no benefit in piglet performance from increasing the width of farrowing pens. As litter sizes continue to increase in commercial production, further research is warranted to re-evaluate the impact of farrowing pen size on pre-weaning mortality.



2021 ◽  
Vol 13 (1) ◽  
pp. 23-28
Author(s):  
Iva Mardiani Fatimah ◽  
Nita Opi Ari kustanti ◽  
Edya Moelia Moeis

The aim of this study is to find out reproctive performance of New Zealand doe in UD. Alastika Jaya. This study use 35 of 51 doe population as the sample and field survey to take primary and secondary data from observation and interview as the research method.  The result of observation and data analysis of study indicate that average value of service per conception (S/C), long of days open, gap of bred after whelped, interval of birth, litter size at birth, and litter size at weaning in a row is 2,17+0,57, 33,33+16,56 days, 32,6+22,14 days, 65,67+16,54 days, 6,65+2,54 kits, dan 4,24+2,05 kits



2021 ◽  
Vol 19 ◽  
pp. 114-119
Author(s):  
I. K. Odubote ◽  
J. O. Akinokun

Records of 848 West African Dwarf goat kids and 220 kiddings over a period of eight years (1982-1989) were analysed. The records were used to provide heritability and repeatability estimates for litter size at birth, kidding interval (repeatability estimate alone) and body weight at birth, weaning, 3 months, 6 months, 9 months and 1 year of age. Heritability estimates of 0.28±0.005, 0.18±0.003, 0.14±0.003, 0.29±0.005, 0.11±0.003 and 0.17±0.004 were obtained for litter size at birth, body weight at birth, and at weaning, 3 months, 6 months, and 9 months of age respectively. Corresponding repeatability estimates were slightly higher than the heritability estimates. However, repeatability estimates of 0.04±0.030 was obtained for kidding interval.



2020 ◽  
Vol 375 (1806) ◽  
pp. 20190543 ◽  
Author(s):  
I. Satokangas ◽  
S. H. Martin ◽  
H. Helanterä ◽  
J. Saramäki ◽  
J. Kulmuni

All genes interact with other genes, and their additive effects and epistatic interactions affect an organism's phenotype and fitness. Recent theoretical and empirical work has advanced our understanding of the role of multi-locus interactions in speciation. However, relating different models to one another and to empirical observations is challenging. This review focuses on multi-locus interactions that lead to reproductive isolation (RI) through reduced hybrid fitness. We first review theoretical approaches and show how recent work incorporating a mechanistic understanding of multi-locus interactions recapitulates earlier models, but also makes novel predictions concerning the build-up of RI. These include high variance in the build-up rate of RI among taxa, the emergence of strong incompatibilities producing localized barriers to introgression, and an effect of population size on the build-up of RI. We then review recent experimental approaches to detect multi-locus interactions underlying RI using genomic data. We argue that future studies would benefit from overlapping methods like ancestry disequilibrium scans, genome scans of differentiation and analyses of hybrid gene expression. Finally, we highlight a need for further overlap between theoretical and empirical work, and approaches that predict what kind of patterns multi-locus interactions resulting in incompatibilities will leave in genome-wide polymorphism data. This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers’.



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