Linear and generalized linear models for the detection of QTL effects on within-subject variability

The present study was conducted on changes in the coefficient variations of live birth weight and in the proportion of singleton live birth weight by gestational age using vital statistics compiled by the Japanese government from 1969 to 1985. The coefficient variations of live birth weight declined between 1969 and 1977-78 and then increased. The coefficient variations of live birth weight were affected by the percentage of low birth weight infants. The decline in the coefficient variations depends on the decrease of low birth weight infants, while the increase in the coefficient variations depends on the increase of low birth weight infants. Recently, the proportion of low birth weight infants has increased in Japan. Perinatal mortality rates, which indicate the level of maternal and child health, have decreased annually.

Familial correlations in birth weight and gestational age have been explained by fetal and maternal genetic factors, mainly in studies on offspring of twins. The aim of the present intergenerational study was to estimate and compare fetal and maternal genetic effects and shared sibling environmental effects on birth weight and gestational age and also on crown-heel length and head circumference. The authors used path analysis and maximum likelihood principles to estimate these effects and, at the same time, to adjust for covariates. Parent-offspring data were obtained from the Medical Birth Registry of Norway from 1967 to 2004. For the analysis of birth weight and crown-heel length, 101,748 families were included; for gestational age, 91,617 families; and for head circumference, 77,044 families. Assuming no cultural transmission and random mating, the authors found that fetal genetic factors explained 31% of the normal variation in birth weight and birth length, 27% of the variation in head circumference, and 11% of the variation in gestational age. Maternal genetic factors explained 22% of the variation in birth weight, 19% of the variation in birth length and head circumference, and 14% of the variation in gestational age. Relative to the proportion of explained variation, fetal genes were most important for birth length and head circumference.

<p>The aim of this study was to determine the effect of performance of the parent parity of hybrid piglets, and to know the parity that produces good performance of the hybrid piglets. This research was conducted for four months in the company of CV. Adhi Farm in Kebakkramat, Karanganyar. The material were three boars (Landrace, Duroc and Hampshire), 21 Landrace sows, piglets from the marriage, and the data from the company. The design of experiments was nested design. The variables that were observed or estimated included birth weight, littersize, the correlation of littersize to the birth weight, and birth weight variation in birth. The data showed the influence, then followed by Least Significant Difference Test (Least Significant Difference) for parity nested in males and Duncan's Multiple Range Test for parity. The results showed that parity and male parity nested exerted a highly significant (P <0.01) for birth weight and littersize. Between birth weight and littersize were compared from each parity and each male parity nested were significantly different (P<0.05). Balanced birth weight and hybrid piglets littersize were at parity 1. The correlation between weight birth and littersize were -0,17. The variation in birth weight per littersize was 0,02 to 0,16. The conclusion of this study is the influence of the parity sow has effect on birth weight of piglet’s performance of hybrids and littersize.</p><p>Keywords: performance, piglets, sow parity</p>

What factors determine birth weight and do they have any biological significance for the future health and welfare of the individual?These are important questions for all paediatricians and four groups...

Background and Aim:Low birth weight and within-litter variations are major challenges in swine production, often exacerbated by highly prolific sow lines. Nutritional interventions such as amino acid and probiotic supplementation have shown promise, but their combined effects remain unexplored. This study aimed to evaluate the individual and interactive effects of Bacillus subtilis QST 713 and L-arginine supplementation during late gestation on reproductive performance in sows.Materials and Methods:A randomized trial was conducted on 247 Landrace × Yorkshire sows allocated to four dietary groups from day 85 of gestation to farrowing: (1) Basal diet (control), (2) basal diet + B. subtilis, (3) basal diet + L-arginine, and (4) basal diet + both supplements. Reproductive outcomes–including individual birth weight (IBW), total litter birth weight (TBW), born-alive birth weight (NBABW), proportion of runt (<1.1 kg) and large piglets (>1.5 kg), and within-litter coefficient of variation in birth weight [CVBW])–were assessed. Linear and generalized linear mixed models were used for analysis.Results:Co-supplementation with B. subtilis and L-arginine significantly increased IBW (1434.7 g vs. 1310.0 g, p < 0.001), TBW (19.6 kg vs. 16.9 kg, p < 0.001), NBABW (18.1 kg vs. 15.9 kg, p = 0.006), and the proportion of large piglets (33.7% vs. 19.5%, p = 0.0002), while reducing runt piglet incidence (4.0% vs. 14.4%, p < 0.001). Neither supplement alone produced significant improvements. No treatment significantly affected litter size, CVBW, stillbirth, or mummification rates.Conclusion:Co-supplementation of sows with B. subtilis and L-arginine during late gestation produces synergistic impro-vements in piglet birth weight and litter quality. This strategy offers a practical and cost-effective approach to enhance swine reproductive efficiency.

Simple SummaryArginine is one of the functional amino acids that enhances the growth of fetus and placenta development. Since the fetal growth and the nutrient requirement for fetuses are increased hugely during the late gestation period in high-prolific sows, supplementation of L-arginine could have a positive influence on the reproductive performance of sows and piglet uniformity. In the present study, increasing inclusion level of L-arginine linearly increased alive litter weight at birth and litter weight gain during lactation. However, the piglet uniformity at birth decreased linearly, as dietary arginine level increased in the late gestation period. We concluded that the inclusion level of arginine in the diet for late gestating sows, by up to 1.5%, could improve the alive litter weight and weight gain of their progeny. The piglet uniformity at birth was decreased due to the increase of survival for piglets with light birth weight.This study was conducted to evaluate the effects of L-arginine supplementation levels during late gestation on reproductive performance and piglet uniformity in high prolific sows. A total of 60 F1 multiparous sows (Yorkshire × Landrace), with an average body weight of 238.2 kg, were allotted to one of three treatment groups in a completely randomized design. The dietary treatments were divided by the supplementation level of arginine during the late-gestation period, from day 70 to farrowing, as follows—(1) CON: corn-soybean meal-based basal diet (Arg 0.72%), (2) Arg10: basal diet + L-Arg 0.28% (Arg 1.0%), and (3) Arg15: basal diet + L-Arg 0.79% (Arg 1.5%). The same lactation diet was provided ad libitum to sows during the lactation period. There were no significant differences in body weight and backfat thickness in sows during late-gestation and lactation. Dietary arginine levels had no significant influences on the number of total born, stillbirth, and born alive. However, increasing inclusion level of L-arginine supplementation tended to increase (p < 0.10) alive litter weight linearly, and also linearly increased (p < 0.05) the piglet weight gain and litter weight gain during the lactation period. In piglet uniformity, the standard deviation of piglet birth weight (p < 0.05) and the coefficient of variation for piglet birth weight (p < 0.10) increased linearly, as dietary arginine levels increased in the late gestation period. Increasing L-arginine supplementation to late gestating sows linearly increased (p < 0.05) the blood concentrations of arginine and ornithine at day 90 and day 110 of gestation. On the other hand, dietary arginine levels in late gestation did not affect the blood parameters related to the nitrogen utilization. Increasing dietary arginine levels for the late gestating sows did not affect the milk composition for colostrum and milk at day 21 of lactation. In conclusion, the inclusion level of arginine in the diet for late gestating sows, by up to 1.5%, could improve the alive litter weight at birth and litter weight gain during lactation, whereas the piglet uniformity at birth was decreased due to the increase of survival for fetuses with light birth weight.

BackgroundMaternal metabolism during pregnancy is a major determinant of the intra-uterine environment and fetal outcomes. Herein, we characterize the maternal urinary metabolome throughout pregnancy to identify maternal metabolic signatures of fetal growth in two subcohorts and explain potential sources of variation in metabolic profiles based on lifestyle and clinical data.MethodsWe used 1H nuclear magnetic resonance (NMR) spectroscopy to characterize maternal urine samples collected in the INMA birth cohort at the first (n = 412 and n = 394, respectively, in Gipuzkoa and Sabadell cohorts) and third trimesters of gestation (n = 417 and 469). Metabolic phenotypes that reflected longitudinal intra- and inter-individual variation were used to predict measures of fetal growth and birth weight.ResultsA metabolic shift between the first and third trimesters of gestation was characterized by 1H NMR signals arising predominantly from steroid by-products. We identified 10 significant and reproducible metabolic associations in the third trimester with estimated fetal, birth, and placental weight in two independent subcohorts. These included branched-chain amino acids; isoleucine, valine, leucine, alanine and 3 hydroxyisobutyrate (metabolite of valine), which were associated with a significant fetal weight increase at week 34 of up to 2.4 % in Gipuzkoa (P < 0.005) and 1 % in Sabadell (P < 0.05). Other metabolites included pregnancy-related hormone by-products of estrogens and progesterone, and the methyl donor choline. We could explain a total of 48–53 % of the total variance in birth weight of which urine metabolites had an independent predictive power of 12 % adjusting for all other lifestyle/clinical factors. First trimester metabolic phenotypes could not predict reproducibly weight at later stages of development. Physical activity, as well as other modifiable lifestyle/clinical factors, such as coffee consumption, vitamin D intake, and smoking, were identified as potential sources of metabolic variation during pregnancy.ConclusionsSignificant reproducible maternal urinary metabolic signatures of fetal growth and birth weight are identified for the first time and linked to modifiable lifestyle factors. This novel approach to prenatal screening, combining multiple risk factors, present a great opportunity to personalize pregnancy management and reduce newborn disease risk in later life.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-016-0706-3) contains supplementary material, which is available to authorized users.

Birth weight is a robust predictor of valued life course outcomes, emphasizing the importance of prenatal development. But does birth weight act as a proxy for environmental conditions in utero, or do biological processes surrounding birth weight themselves play a role in healthy development? To answer this question, we leverage variation in birth weight that is, within families, orthogonal to prenatal environmental conditions: one's genes. We construct polygenic scores in two longitudinal studies (Born in Bradford, N=2008; Wisconsin Longitudinal Study, N=8488) to empirically explore the molecular genetic correlates of birth weight. A 1 standard deviation increase in the polygenic score is associated with an~100-grams increase in birth weight and a 1.4 pp (22 percent) decrease in low birth weight probability. Sibling comparisons illustrate that this association largely represents a causal effect. The polygenic score-birth weight association is increased for children who spend longer in the womb and whose mothers have higher body mass index, though we find no differences across maternal socioeconomic status. Finally, the polygenic score affects social and cognitive outcomes, suggesting that birth weight is itself related to healthy prenatal development.

This study reports pregnancy outcomes for 105 addicted women enrolled in New York Medical College's Pregnant Addicts and Addicted Mothers Program. Three classes of variables are examined: prenatal care variables, obstetrical outcomes, and neonatal outcomes. As a first step, percentage distributions are shown for all variables within each class. With respect to the second and third classes, comparisons are made when possible to findings reported elsewhere on heroin-addicted, methadone-maintained, and drug-free populations. Zero-order correlations are then shown for the prenatal care variables versus the neonatal outcomes. It is found that the mother's number of prenatal medical visits correlates significantly with the neonate's gestational age at birth and birth weight, and that her methadone dose at time of delivery correlates significantly with the neonate's withdrawal status. The effect of the prenatal care variables on the two key neonatal outcomes--gestional age at birth and birth weight--is then examined via a stepwise regression analysis. It is found that two of the variables--gestional duration at first prenatal visit and number of prenatal visits--together account for 18.5% of the variance in birth weight and 26.9% of the variance in gestational age at birth, while maternal methadone dose has virtually no effect on these outcome measures. The findings indicate that better neonatal outcomes are associated with the mother's joining the program relatively early in pregnancy and coming in relatively often for prenatal care.

Death risk and preweaning growth rate of piglets in relation to the within-litter weight distribution at birth

Do Early Fetal Measurements and Nuchal Translucency Correlate With Term Birth Weight?

Ethnicity Modifies Seasonal Variations in Birth Weight and Weight Gain of Infants

This study was designed to determine if feeding β-hydroxy-β-methylbutyrate (HMB) to pregnant mice would improve birth weight uniformity and growth performance of offspring. Dams (Agouti Avy) were assigned to one of four treatments: control (CON; n = 13), low-level HMB (LL; 3.5 mg/g; n = 14), high-level HMB (HL; 35 mg/g; n = 15), and low-level pulse dose fed from gestational days 6 to 10 (PUL; 3.5 mg/g; n = 14). Randomly selected dams (n = 27) were euthanized on gestational day 18 to collect placentae and pup weights. The remaining dams gave birth and lactated for 28 days. Dams only received HMB during gestation. Dietary HMB did not influence the performance of dams. Dietary treatment during gestation did not affect litter size or birth weight of pups. Variation was not different among treatments in terms of birth weight of offspring. Placental weights were not affected by treatments. Overall, growth performance of offspring after weaning was similar among all treatments. Body composition of offspring at 5 and 8 weeks of age was similar regardless of HMB treatment during gestation. In conclusion, dietary HMB supplementation in pregnant mice did not affect birth weight, variations in birth weight, or growth performance of offspring.

Effect of increasing feed intake during late gestation on piglet performance at parturition in commercial production enterprises

Crossbreeding experiment with beef and dual-purpose sire breeds on Danish dairy cows