scholarly journals Selection for placental efficiency in swine

2004 ◽  
Author(s):  
◽  
Henry Mesa Echeverri
Keyword(s):  
Selection Index ◽  
Genetic Selection ◽  
Reproductive Traits ◽  
Placental Weight ◽  
High Survival ◽  
Genetic Trend ◽  
Crown Rump Length ◽  
Placental Function ◽  
Selection For ◽  
Placental Efficiency

With the overall goal of increasing profitability by increasing litter size, two lines of pigs were divergently selected for four generations on an index of reproductive traits (n = 193 litters). The selection index (SI) included total born (TB), birth weight (BW) and placental weight (PW) and was designed to increase (H line) or decrease (L line) BW:PW (placental efficiency; PE). (Co)variance components were estimated for direct and maternal additive effects by using an animal model with MTDFREML procedures. Breeding values were estimated (EBV) for individual BW (n = 2,111), PW (n = 2,006), PE (n = 1,677), and SI (n = 1,677). Direct heritability estimates were 0.03, 0.25, 0.18, 0.11 and 0.08 for BW, PW, PE, SI, and TB, respectively. Genetic divergence was 20.7 g, 0.24, 0.11, and 0.07 pigs per generation for PW, PE, SI, and TB, respectively (P less 0.01), but not significant for BW. Thus, PW and PE are susceptible to change by genetic selection; however, the genetic trend for TB unexpectedly was positive in the L line The phase two objective was to evaluate correlated responses in conceptus development and placental function in these lines. Sows were remated within line to produce 50 generation-four litters for evaluation at d 30, 50, 70, 90, and 110 of gestation.Fetal weight did not differ between lines from d 30 to 90, but was lower in H than L at d 110 (P = 0.02). Crown-rump length did not differ between lines from d 30 to 70, but was longer in H than L at d 90 (P = 0.09) and shorter at d 110 (P = 0.04). PW did not differ between lines from d 30 to 90, but was lower in H than L at d 110 (P less than 0.01). PE did not differ between lines at any gestational age. These results suggest that in western breeds, a reduction in placental weight through selection is not accompanied by physiological changes to improve placental function and may result in decreased prenatal survival. The farrowing data were used in phase three to determine factors influencing survival at farrowing (FS) and weaning (WS). These traits were considered traits of the piglet and scored 1 for piglets alive at those time points or 0 if dead. Estimates of direct heritability were 0.16 and 0.18 and of maternal heritability were 0.14 and 0.10 for FS and WS, respectively. Logistic regressions indicated BW, PW, their interaction, and TB can be used as predictors FS and WS. In the presence of BW, PE does not improve the prediction of survival. These results suggest possible selection for increased FS and WS. A piglet's BW, PW, its litter average BW, and the individual's deviation from that average can be used to produce piglets with high survival probability.

Opportunities for genetic improvement of lamb survival

2010 ◽  
Vol 50 (12) ◽  
pp. 1017 ◽  
Author(s):  
F. D. Brien ◽  
M. L. Hebart ◽  
D. H. Smith ◽  
J. E. Hocking Edwards ◽  
J. C. Greeff ◽  
...  
Keyword(s):  
Rectal Temperature ◽  
Selection Index ◽  
Genetic Correlations ◽  
Direct Selection ◽  
Reproduction Rate ◽  
Crown Rump Length ◽  
Selection For ◽  
Lamb Survival ◽  
Net Reproduction ◽  
Birth Time

Data on lamb survival and associated traits involving records from 15 192 lambs, 6308 dams and 284 sires from the Sheep CRC’s Information Nucleus were studied. Lamb survival to 3 days of age and to weaning was 85 and 80%, respectively, and heritability (±s.e.) was 0.014 ± 0.010 and 0.010 ± 0.010, respectively. Of the 14 traits recorded at birth, time taken for the lamb to bleat, rectal temperature and crown–rump length had the highest genetic correlations with lamb survival to weaning (–0.43 ± 0.32, 0.56 ± 0.33 and –0.38 ± 0.36, respectively). Under selection for a multi-trait objective including net reproduction rate (but not lamb survival), survival was predicted to decline genetically by 0.25 lambs weaned per 100 lambs born.year, although this was reversed to a gain of 0.20 lambs weaned per 100 lambs born.year by including the trait in the breeding objective and using 50 half-sib and 50 progeny records per selection candidate. Accuracy of selection for lamb survival was improved to 0.735 with a selection index of lamb survival to weaning, lamb ease, birth coat score, time taken to bleat, rectal temperature and crown–rump length, with the addition of 50 half-sibs and 50 progeny records per candidate. Our results suggest that unless actively incorporated into breeding objectives, lamb survival may genetically decline; however, gains are possible with direct selection using half-sib and progeny records. The addition of indirect selection criteria for lamb survival can further improve accuracy, up to 93.4%, but requires further investigation.

126. IMPLICATIONS FOR FETAL AND PLACENTAL DEVELOPMENT FOLLOWING MITOCHONDRIAL PERTURBATION IN THE EMBRYO

2009 ◽  
Vol 21 (9) ◽  
pp. 45
Author(s):  
S. Wakefield ◽  
M. Lane ◽  
M. Mitchell
Keyword(s):  
Mitochondrial Function ◽  
Weight Ratio ◽  
Threshold Effect ◽  
Blastocyst Stage ◽  
Placental Weight ◽  
Placental Development ◽  
Cell Stage ◽  
Crown Rump Length ◽  
Fetal Survival ◽  
Placental Efficiency

The environment an embryo is exposed to can profoundly influence peri- and post-natal development despite having some capacity to adapt. Whilst the mechanisms responsible remain largely unknown, mitochondria are a likely target. In this study we deliberately perturbed mitochondrial function in the mouse embryo, using a model we have established that shows step-wise changes in embryo metabolism and development. The aim of this study was to provide direct evidence implicating mitochondrial dysfunction in the embryo with perturbed fetal and placental development. Zygote stage embryos were recovered from superovulated female mice and cultured in control conditions to the 2-cell stage. Embryos were then allocated to one of three treatments; control media (0μM-AOA), 5μM or 50μM of the known mitochondrial inhibitor, Amino-Oxyacetate, in the absence of pyruvate (5μM-AOA, 50μM-AOA). Embryos were cultured to the blastocyst stage, then transferred to pseudopregnant recipients, with fetal and placental parameters measured on day 18 of pregnancy. Implantation rates and fetal survival for both 5μM-AOA and 50μM-AOA was comparable to control embryos. For 5μM-AOA there was a significant reduction in placental weight (P=0.02) but normal fetal weight, and a significant increase in fetal: placental weight ratio (P=0.002) relative to the control, suggesting increased placental efficiency. When mitochondria were further perturbed (50μM-AOA), the fetuses and placentas were both considerably compromised: that is, decreased fetal and placental weights (P=0.002), reduced placental diameter (P=0.03) and decreased fetal crown rump length (P=0.07). This study demonstrates that mitochondrial function in the embryo impacts on peri-natal development, providing compelling evidence for mitochondrial function involvement in the mechanisms underpinning “embryo programming”. This data suggests a threshold effect, whereby embryos can only adapt up until a point after which development is compromised. Further elucidating these mechanisms is important for understanding how maternal environments and embryo culture systems determine development of future offspring.

Can we breed Merino sheep with softer, whiter, more photostable wool?

2010 ◽  
Vol 50 (12) ◽  
pp. 1089 ◽  
Author(s):  
S. Hatcher ◽  
P. I. Hynd ◽  
K. J. Thornberry ◽  
S. Gabb
Keyword(s):  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Phenotypic Selection ◽  
Quality Traits ◽  
Current Generation ◽  
Merino Sheep ◽  
Initial Cohort ◽  
Selection For

Genetic parameters (heritability, phenotypic and genetic correlations) were estimated for a range of visual and measured wool traits recorded from the 2008 shearing of the initial cohort of Merino progeny born into the Sheep CRC’s Information Nucleus Flock. The aim of this initial analysis was to determine the feasibility of selectively breeding Merino sheep for softer, whiter, more photostable wool and to quantify the likely impact on other wool production and quality traits. The estimates of heritability were high for handle and clean colour (0.86 and 0.70, respectively) and moderate for photostability (0.18), with some evidence of maternal effects for both handle and photostability. The phenotypic correlations between handle and clean colour and between handle and photostability were close to zero, indicating that achieving the ‘triple’ objective of softer, whiter, more photostable wool in the current generation through phenotypic selection alone would be difficult. There was evidence of an antagonistic relationship between handle and photostability (–0.36), such that genetic selection for softer wool will produce less photostable wool that will yellow on exposure to UV irradiation. However genetic selection for whiter wool is complementary to photostability and will result in whiter wool that is less likely to yellow. Genetic selection to improve handle, colour and photostability can be achieved with few detrimental effects on other visual and measured wool traits, particularly if they are included in an appropriate selection index.

scholarly journals 179 Breeding for enhancing feed efficiency in dairy cattle

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 183-184
Author(s):  
Flavio Schenkel ◽  
Luiz Brito ◽  
Hinayah Oliveira ◽  
Tatiane Chud ◽  
David Seymour ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Feed Efficiency ◽  
Selection Index ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Methane Emissions ◽  
Genome Project ◽  
Nutrient Loss ◽  
Breeding Value ◽  
Selection For

Abstract Genetically selecting for improved feed efficiency has been recognized by the dairy cattle industry as an important economic and environmental goal. Improved feed efficiency has the potential to significantly reduce costs, improving dairy farmers’ profitability and, at the same time, minimize environmental impact, for example by reducing nutrient loss in manure and methane emissions. Feed efficiency is recognized as a complex trait that may be define in different ways, but it generally describes units of product output per unit of feed required. An overview of genetic selection for improved feed efficiency and international initiatives to implement genomic selection for feed efficiency in dairy cattle is presented. In general, studies have indicated that feed efficiency, defined and assessed in alternative ways, is moderately heritable and genetic selection could be successfully implemented. Various initiatives around the world have worked collaboratively to carried out research and create reference datasets for joint genomic evaluations. An example is the large international Efficient Dairy Genome Project (EDGP) led by Canada. The EDGP database was developed in 2017 to allow data sharing among the international collaborators. Currently, the database contains genotypes and records on feed intake of 5,289 cows and on methane emissions of 1,337 cows from eight research herds in six countries (Australia, Canada, Denmark, Switzerland, United Kingdom and United States). Genetic parameters (heritability and genetic correlations) were estimated for dry matter intake, metabolic body weight and energy corrected milk at two time-periods: a) 5–60 DIM and b) 60–150 DIM. These parameters provide a basis for development of breeding value estimation procedures and subsequent selection index for feed efficiency, which will incorporate genomic information.

scholarly journals Reproductive Technologies and Genomic Selection in Cattle

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Patrice Humblot ◽  
Daniel Le Bourhis ◽  
Sebastien Fritz ◽  
Jean Jacques Colleau ◽  
Cyril Gonzalez ◽  
...  
Keyword(s):  
Genomic Selection ◽  
Genetic Selection ◽  
Reproductive Traits ◽  
Reproductive Technologies ◽  
Combined Use ◽  
Reproductive Techniques ◽  
Selection For ◽  
Efficiency Of Selection ◽  
Near Future

The recent development of genomic selection induces dramatic changes in the way genetic selection schemes are to be conducted. This review describes the new context and corresponding needs for genomic based selection schemes and how reproductive technologies can be used to meet those needs. Information brought by reproductive physiology will provide new markers and new improved phenotypes that will increase the efficiency of selection schemes for reproductive traits. In this context, the value of the reproductive techniques including assisted embryo based reproductive technologies (Multiple Ovaluation Embryo Transfer and Ovum pick up associated toin vitroFertilization) is also revisited. The interest of embryo typing is discussed. The recent results obtained with this emerging technology which are compatible with the use of the last generation of chips for genotype analysis may lead to very promising applications for the breeding industry. The combined use of several embryo based reproductive technologies will probably be more important in the near future to satisfy the needs of genomic selection for increasing the number of candidates and to preserve at the same time genetic variability.

Genetic selection for nonstructural carbohydrates and its impact on other nutritive attributes of alfalfa ( Medicago sativa ) forage

2021 ◽  
Author(s):  
Annie Claessens ◽  
Marie Bipfubusa ◽  
Caroline Chouinard‐Michaud ◽  
Annick Bertrand ◽  
Gaëtan F. Tremblay ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Genetic Selection ◽  
Nonstructural Carbohydrates ◽  
Selection For

scholarly journals Influence of Genetic Selection for Growth and Broodstock Diet n-3 LC-PUFA Levels on Reproductive Performance of Gilthead Seabream, Sparus aurata

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 519
Author(s):  
Shajahan Ferosekhan ◽  
Serhat Turkmen ◽  
Cathaysa Pérez-García ◽  
Hanlin Xu ◽  
Ana Gómez ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Egg Quality ◽  
Sparus Aurata ◽  
Genetic Selection ◽  
Growth Trait ◽  
High Growth ◽  
Gilthead Seabream ◽  
Commercial Diet ◽  
Selection For ◽  
Broodstock Diet

Genetic selection in gilthead seabream (GSB), Sparus aurata, has been undertaken to improve the growth, feed efficiency, fillet quality, skeletal deformities and disease resistance, but no study is available to delineate the effect of genetic selection for growth trait on GSB reproductive performance under mass spawning condition. In this study, high growth (HG) or low growth (LG) GSB broodstock were selected to evaluate the sex steroid hormones, sperm, egg quality and reproductive performance under different feeding regime of commercial diet or experimental broodstock diet containing either fish oil (FO) or vegetable oil (VO) based diet. Under commercial diet feeding phase, broodstock selected for either high growth or low growth did not show any significant changes in the egg production per kg female whereas egg viability percentage was positively (p = 0.014) improved by the high growth trait broodstock group. The experimental diet feeding results revealed that both growth trait and dietary fatty acid composition influenced the reproductive performance of GSB broodstock. In the experimental diet feeding phase, we observed high growth trait GSB males produced a higher number of sperm cells (p < 0.001) and also showed a higher sperm motility (p = 0.048) percentage. The viable egg and larval production per spawn per kg female were significantly improved by the broodstock selected for high growth trait and fed with fish oil-based diet. This present study results signifies that gilthead seabream broodstock selected on growth trait could have positive role in improvement of sperm and egg quality to produce viable progeny.

Developmental morphology and anatomy of the reproductive structures in sunflower (Helianthus annuus): a unified temporal scale

Botany ◽  
2015 ◽  
Vol 93 (5) ◽  
pp. 307-316 ◽  
Author(s):  
L.I. Lindström ◽  
L.F. Hernández
Keyword(s):  
Disease Resistance ◽  
Helianthus Annuus ◽  
Oil Content ◽  
Genetic Selection ◽  
Reproductive Development ◽  
Developmental Morphology ◽  
Male And Female ◽  
Reproductive Structures ◽  
Selection For ◽  
Growing Conditions

In sunflower (Helianthus annuus L.), there has been an intense genetic selection for achenes with agronomic value, such as greater mass, oil content, and disease resistance. However, the information regarding the anatomical events that control their growth and maturation is surprisingly scarce. The aim of the present work was to study sunflower male and female sporogenesis and gametogenesis, as well as cell division and enlargement and tissue differentiation in the ovary and the embryo, linking the timing of these events to two frequently used phenological scales and a thermal time scale. In addition, we propose an ontogenetic scale that integrates the results of the present work to that of previous studies on sunflower reproductive development. The unified scales presented here provide a framework for others to investigate the relationships uncovered in this study in different genetic backgrounds and under different growing conditions.

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