Birth Weight Values Research Articles

Genetic analysis of growth traits in Salem Black goats under farm conditions.

In this study, data on pedigree, production traits for 19years (2002-2022) of Salem Black goat from the Mecheri Sheep Research Station, Tamil Nadu, India was used. Various growth traits viz., birth weight (BW), weaning weight (WW), 6-month weight (6W), 9-month weight (9W), 12-month weight (YW), pre- and post-weaning average daily gain (ADG) (3-6, 6-9, 9-12 and 3-12months) were analyzed. Univariate analysis was carried out after correcting for significant non-genetic factors. (Co)variance components for different production and functional traits were estimated by Restriction Maximum Likelihood method (REML) using WOMBAT. Heritability estimates for most of the growth traits were medium providing better scope for selection. Direct heritability estimates for BW, WW, 6W, 9W and YW, pre- and post-weaning ADG (3-12) were 0.177 ± 0.066, 0.094 ± 0.055, 0.111 ± 0.068, 0.123 ± 0.082, 0.181 ± 0.122, 0.118 ± 0.060 and 0.188 ± 0.126 respectively. Through bivariate analysis genetic and phenotypic correlations between growth traits were obtained. Positive, medium to high genetic correlation was observed in post-weaning body weight traits which would support multistage selection. Similar positive and medium to high genetic correlation between pre- and post-weaning ADG (3-6 and 3-12months) with post- weaning body weight traits would facilitate indirect selection. Breeding values (EBV) for BW, WW, 6W, 9W, YW, pre- and post-weaning ADG (3-12months) were estimated. High genetic variability was observed in weaning and post- weaning body weight traits. The findings of this study could further aid in the improvement of the breeding programme.

Some Yield and Growth Traits of Anatolian Buffaloes and the Effects of First Calving Age and Calving Interval on These Traits

Numerous in-depth studies have described the fertility traits, growth performance and milk yield traits of dairy animals, which are considered indicators of welfare, but there are limited studies examining these traits within the framework of cause-effect relationships, especially in buffaloes. The aim of this study was to determine the changes in some milk, growth and fertility traits of Anatolian buffaloes over the years in some dairy farms where the Buffalo Breeding Project in Public Conditions was implemented in Samsun province and, to investigate the effects of first calving age (FCA) and calving interval (CI) on milk and growth traits. The study was conducted in 27 buffalo farms (3295 buffalo cows and 3317 buffalo calves) located in Bafra district, the region with the highest buffalo population in Samsun province, Türkiye. The data was taken from records previously kept within the scope of the relevant project. The data such as growth characteristics [birth weight (BW), 6th and 12th-mo live weight (LW) values of calves born between 2013-2020] and lactation traits of cows [lactation milk yield (LMY) and lactation duration (LD)] and FCA and CI values were analyzed by analysis of variance. The effect of years on LMY of buffalo cows was found to be significant, and significant positive changes were determined from year to year. In addition, the BW, 6th-mo, and 12th-mo LW values of calves also varied from year to year. As the FCA value of buffaloes increased, the BW, 6th-mo, and 12th-mo LW values of calves and LMY of cows increased. Similarly, CI values affected the BW values of calves (P<0.01), and LMY and LD values increased in parallel with the increase in CI values. Consequently, determining the lactation and growth traits of buffaloes could benefit developing herd management practices that would optimize these performance indicators.

The generation interval and season of birth do not affect age at first calving, birth weight and calving interval of Mozambican Angoni cattle.

The Angoni cattle breed's contribution to the country's economy is crucial, as it significantly contributes to animal draught power and meat supply, despite not being primarily used for milk production. Despite its importance, there is a lack of comprehensive research conducted to characterize this breed. This study aimed to investigate the impact of the generation interval (GI) and season of birth (SB) on key reproductive parameters, including age at first calving (AFC), birth weight (BW), and calving interval (CI) in angoni cattle. Data sourced from the Angónia Research Station (ARS) included records for 425 heifers' AFC, 1684 calves' BW, and 1272 cows' CI. The study calculated overall averages and explored the relationships between generation intervals, the season of birth, and the aforementioned reproductive traits. The mean values for AFC, BW, and CI were determined as 1475.40 days, 18.49kg, and 634.62 days, respectively. The analysis revealed that both generation interval and season of birth exhibited weak relationships, and their influence did not yield significant effects on the reproductive traits under investigation (P > 0.05). The observed variability ranged from 0.37 to 0.46% for AFC, 0.10-0.01% for BW, and 0.11-0.26% for CI. In conclusion, this study determined that neither generation interval nor birth season significantly affected the age at first calving, birth weight, or calving interval in Angoni cattle.

Reproductive and productive behavior of hair sheep under an intensive production system

Objective: To evaluate the reproductive and productive behavior of four hair sheep breeds in an intensive production system.
 Design/Methodology/Approach: Data recorded over 4 years (2016-2019) from a production unit that works with Blackbelly, Pelibuey, Dorper, and Katahdin breeds were analyzed. The following variables were evaluated: fertility, prolificacy, birth weight (BW), weaning weight (WW), weaned lamb yield (WLY), daily weight gain during lactation (DWGL), offspring born alive (OBA), male offspring (MO), and female offspring (FO). All information was analyzed using Chi-square tests and analysis of variance.
 Results: The fertility, BW, WW, and WYL variables recorded different values between breeds (P<0.05). The greatest fertility and prolificacy were recorded by Blackbelly, while Dorper recorded the lowest values (P<0.05). BW and WW were highest in Dorper and lowest in Blackbelly (P<0.05). Finally, the sheep that recorded the highest WYL were the Blackbelly, while the Dorper registered the lowest values (P<0.05). BW and DWGL values reached maximum values (P<0.05) in Dorper rams, followed by Katahdin. The greatest number of OBA was observed in Blackbelly and Pelibuey (P<0.05).
 Study Limitations/Implications: Further studies should be carried out to validate this research.
 Findings/Conclusions: Blackbelly ewes produced more kilograms of weaned lambs per lambing ewe. The Dorper and Katahdin rams in the pre-weaning period recorded higher weight at weaning.

Genetic parameters for birth and weaning weight in a herd of Mediterranean buffaloes under tropical conditions

The objectives of the present study were to estimate variance components and genetic parameters for birth weight (BW) and weaning weight (WW). The data comes from Mediterranean buffalo calves born during the period from August 2003 to December 2021 on the Livestock Farm “Hacienda Caño Negro”, located near the population of Santa Barbara del Zulia, Venezuela. A total of 2225 records collected for BW and WW were included in the analysis. Variance components and genetic parameters were estimated by REML using the MTDFREML program, applying a bivariate animal model that includes direct, maternal, and permanent maternal effects. The population average BW of Buffalo calves was 42.7±0.1 kg, whereas for males, 43.9±0.2 and for females, 41.7±0.2 kg. The population average for WW was 174.5+0.9 kg. According to sex, the WW parameters were 178.5±1.3 kg and 170.5±1.1 kg in males and females, respectively. The direct heritability estimates were 0.03 and 0.23 for BW and WW, respectively, whereas maternal heritability values were 0.78 for BW and 0.24 for WW. The estimated total heritability for both characters was 0.23 (BW) and 0.32 (WW). The genetic correlation between BW and WW was 0.57, while the maternal genetic correlation for BW and WW was 0.01. The results indicated moderate total heritability value for BW and WW; further analysis is needed to estimate the genetic parameters, perhaps including other breed herds.

Maternal Age at Menarche Gene Polymorphisms Are Associated with Offspring Birth Weight.

In this study, the association between maternal age at menarche (AAM)-related polymorphisms and offspring birth weight (BW) was studied. The work was performed on a sample of 716 pregnant women and their newborns. All pregnant women underwent genotyping of 50 SNPs of AAM candidate genes. Regression methods (linear and Model-Based Multifactor Dimensionality Reduction (MB-MDR)) with permutation procedures (the indicator pperm was calculated) were used to identify the correlation between SNPs and newborn weight (transformed BW values were analyzed) and in silico bioinformatic examination was applied to assess the intended functionality of BW-associated loci. Four AAM-related genetic variants were BW-associated including genes such as POMC (rs7589318) (βadditive = 0.202/pperm = 0.015), KDM3B (rs757647) (βrecessive = 0.323/pperm = 0.005), INHBA (rs1079866) (βadditive = 0.110/pperm = 0.014) and NKX2-1 (rs999460) (βrecessive = -0.176/pperm = 0.015). Ten BW-significant models of interSNPs interactions (pperm ≤ 0.001) were identified for 20 polymorphisms. SNPs rs7538038 KISS1, rs713586 RBJ, rs12324955 FTO and rs713586 RBJ-rs12324955 FTO two-locus interaction were included in the largest number of BW-associated models (30% models each). BW-associated AAM-linked 22 SNPs and 350 proxy loci were functionally related to 49 genes relevant to pathways such as the hormone biosynthesis/process and female/male gonad development. In conclusion, maternal AMM-related genes polymorphism is associated with the offspring BW.

Estimates of genetic parameters and genetic trend for growth traits and Kleiber ratio of Holstein-Friesian calves

Growth traits of calves, which are quantitative characteristics determining cattle business profitability, vary according to genetic and environmental factors. In other words, growth traits depend on the genetics of the individual and vary with farm management. The aim of this study was to investigate the effective environmental factors, genetic parameters, and genetic trends for some growth traits and the Kleiber ratio (KR) in Holstein-Friesian calves. For this purpose, the records of 724 calves, progeny of 566 dams and 29 sires, reared between 2017 and 2019 on a private dairy farm in Türkiye, were used. MTDFREML software was utilized to estimate genetic parameters and genetic trends of growth traits and KR. In this study, regarding weight, the mean of birth weight (BW), 60-day weight (W60), and 90-day weight (W90) were 39.76 ± 6.15 kg, 69.23 ± 10.93 kg, and 95.76 ± 16.48 kg, respectively. Concerning weight gain, 1-60 daily weight gain (DWG1-60), 60-90 daily weight gain (DWG60-90), and 1-90 daily weight gain (DWG1-90) were 0.49 ± 0.16 kg, 0.91 ± 0.34 kg, and 0.63 ± 0.17 kg, respectively. With respect to KR, 1-60 daily KR (KR1-60), 60-90 daily KR (KR60-90), and 1-90 daily KR (KR1-90) were 2.03 ± 0.48, 2.93 ± 0.89, and 2.02 ± 0.34, respectively. As a result of the GLM analysis, only the effect of the birth season on all traits was significant (p < 0.05 or p < 0.01). In addition, it was detected that sex had a significant effect on BW and W60 (p < 0.05 or p < 0.01). For all traits, only the effect of parity on KR1-60 was not significant. In REML analysis, direct heritability differed between 0.26 ± 0.16 and 0.81 ± 0.27 obtained at DWG1-90 and DWG1-60, respectively. Also, the highest repeatability (0.100) was obtained in DWG1-60. It was detected that mass selection could be used in all traits for breeding program. In BLUP analysis, the current population had an increasing trend for BW and W90 and a decreasing trend for W60. However, there was no significant change in other weight gain traits and KR over the years. Calves with high breeding values for BW, W60, W90, DWG1-60, DWG60-90, and DWG1-90 should be chosen for selection programs. But for KR1-60, KR60-90, and KR1-90, calves with low breeding values should be selected for efficiency. Also, KR evaluated would contribute to the literature and other research should be studied regarding KR.

Assessment of growth and population structure revealed sufficient genetic diversity among lambs of Mecheri sheep in Tamil Nadu, India

This study was designed to evaluate various genetic parameters for growth characteristics, genetic progression, and to find out the genetic constitution of a population of Mecheri sheep, a tropical breed native to Tamil Nadu, southern India. Data for this study were various records from 2768 lambs, which were a result of mating of 110 sires and 748 dams during a period of 10 years, between 2010 and 2019. Among the evaluated traits included body weights at various stages of growth such as birth weight (BWT), as well as weight at weaning (WWT), at 6-months (6WT), at 9-months (9WT), and at one-year-old (12WT). Estimated genetic parameters included additive direct and maternal heritabilities and genetic correlations, genetic changes, inbreeding, and generation interval. Among the software required for various analyses were the ENDOG (version 4.8) and Restricted Maximum Likelihood (REML). Mean ( ± SE) values of weight at birth and at 12 months were 2.37 ± 0.02 and 21.34 ± 0.34 kg respectively. Direct heritability values estimated at birth, six months, as well as 12 months were respectively 0.14 ± 0.05, 0.07 ± 0.03, and 0.08 ± 0.03. Maternal heritability value for BWT was 0.28 and whereas low and varied values between 0.03 and 0.05 were obtained for both weaning and post-weaning traits. Overall, genetic improvement was low at birth (−0.0025 kg) and highest (0.1314 kg) around weaning age. Average inbreeding coefficient value was 0.16 % and the effective population size of founders was 100.35, while mean generation interval ( ± SE) was 3.44 ± 1.15 years. Effective number of founders was 18.01 % and indicates that Mecheri sheep have their origin from a moderate genetic base. The observed fe/fa ratio was 1.00 and is linked to presence of sufficient founding ancestors, less bottlenecks, and possibly implementation of rotational mating scheme at the farms. In summary, our study revealed that there are high correlations between WWT and post-weaning weights. Based on heritability values, the WWT could be used as an important trait which can facilitate improvement in body weight of Mecheri lambs. Further, the present genetic parameter values for different variables advocates that the genetic progress for body weight at various stages of growth is feasible in Mecheri sheep thorough genetic selection strategies. We conclude that sufficient genetic diversity is maintained within Mecheri sheep.

High birth weight and risk of multiple sclerosis: A multicentre study in Argentina

BackgroundMultiple sclerosis (MS) is now recognized as a multifactorial disease in which genetic and environmental factors intervene. Considerable efforts have been made to identify external risk factors present in childhood, adolescence and youth, though only a few perinatal risk factors have been positively associated with MS. Previously, we found an association between high birth weight and MS in male patients in a small study in Argentina. The present research was designed to further assess the association between high birth weight and MS in a larger sample of patients, using an extensive and validated general population database as control. MethodsWe present an analytical observational, multicentre, population-based, and case-control study. A total of 637 patients (cases) with confirmed MS diagnosis attending five MS specialized centres in Argentina were included. Birth weight (BW) data was recalled by the patient's mother, which is a validated approach. A two-way comparison was performed. First, we used the standard categories of high, adequate and low BW in grams. Then, we applied the weight percentile distribution to provide reproducible results for further research. For a proper assessment and comparison of variables, we adopted the guidelines of the American Academy of Pediatrics for neonate classification according to gestational weeks and to BW in grams. The neonate's BW distribution of the general population was used as control. For the purposes of the study, we adapted Urquía's et al. curves, which are based on an extensive database of all the live births registered in the country from 2003 to 2007. To measure the magnitude of the proportional differences between low, adequate and high BW, the odds ratio (OR) and their 95% confidence interval (CI) were estimated. The mean BW and percentile values for each sex were compared using a z-Normal test. The respective MS patients and general population BW distribution curves by sex were compared between each other. ResultsCases and controls were comparable in their demographic, geographic and environmental characteristics. Males showed higher BW than females both in the MS patients and the general population groups. When we applied the sex stratified analysis separately, we found that males in the MS group showed an almost seven times higher risk of high birth weight than males from the general population (OR 6.58 [95% CI 4.81–8.99]). Female patients showed an almost five times higher risk of high BW than their respective controls (OR 4.5 [95% CI 3.06–6.58]). The comparison based on the BW percentile distribution confirmed that MS patients showed higher BW than the general population. This result reached statistical significance from the 75th percentile onwards for both sexes. ConclusionIn summary, our findings suggested that high BW could be one of the earliest risk factors for MS in life. If this results were reproduced in other centres, high birth weight would emerge as a novel and very early risk factor, potentially modifiable in utero or immediately postpartum, representing a unique opportunity to prevent the disease in future generations.

30 Predicting gestational age improves newborn screening for congenital adrenal hyperplasia

Abstract Background Newborn screening for congenital adrenal hyperplasia is performed using a two-tier approach. The first tier involves comparison of neonate 17-hydroxyprogesterone levels to gestational age (GA)-based thresholds. When GA is unreported, which occurs in approximately 5% of births, birth weight (BW)-based thresholds are the only available option. However, these have a lower specificity and result in more false positive results. Recently, a predictive model was developed to estimate GA based on newborn demographics and the screening analytes measured in a blood sample. Objectives The objective of this study was to determine whether supplying a predicted GA to newborns with unreported GA, and subsequent GA-based screening, has a higher positive predictive value than BW-based screening. Design/Methods Screening data was obtained for approximately 700,000 births that occurred in Canada between 2011 and 2015. Predicted GA was calculated using a model composed of demographic and screening analyte factors. The positive predictive values of BW- and predicted GA-based screening were calculated for newborns with unreported GA. A sequential approach was then developed whereby newborns with unreported GA were first screened by BW-based screening. Newborns that screened positive were then supplied with their predicted GA and screened using GA-based thresholds. Results First-tier CAH screening using GA-based 17-hydroxyprogesterone thresholds had a higher positive predictive value than using BW-based thresholds (1.30% vs. 0.82%). In the study time period, 3.61% of newborns had an unreported GA. For these newborns, predicted GA-based screening had a higher positive predictive value than BW-based screening (0.83% vs. 0.76%) and correctly identified the 2 infants with CAH whose GA was unreported. A sequential screening approach was then used: BW-based screening and, for the screen positive population, predicted GA-based screening. This further increased the positive predictive value compared to BW-based screening (0.95% vs. 0.76%), reduced the false positive rate, and correctly identified true positive cases. Conclusion Reducing the false positive rate of CAH screening is important to prevent unnecessary second-tier screening and referrals. For newborns with unreported GA (4-5% of all births), BW-based screening is the only currently available approach. However, this approach has a poor specificity and a high false positive rate compared to GA-based screening. This study is the first to demonstrate an alternative screening strategy with a higher positive predictive value for newborns with unreported GA.

Estimation of (co)variance components for birth weight in Nellore cattle using alternative data editing criteria.

The aim of this study was to estimate the (co)variance components and breeding values for birthweight (BW) in Nellore cattle by considering or not identical weights that exhibit a high frequency within the contemporary group (CG). A total of 175,258 BW records of Nellore cattle born between 2002 and 2018 were used. The CG was formed by farm, year of birth, sex and feeding regime at birth. CGs with more than 16% of identical BW values were eliminated, generating a data file called BWd. Another file was created without removing these animals (BWt). A mixed linear model was used for statistical analysis, which included fixed and random effects. In both data files analysed, single-trait analysis was performed by Bayesian inference. The mean direct and maternal heritability for BW and the correlation between direct and maternal effects were 0.27, 0.07 and -0.07 for BWt, respectively, and 0.30, 0.093 and -0.07 for BWd. This method should affect the estimation of genetic merits of animals for BW, providing greater safety in the choice of sires.

Growth patterns and associated risk factors of congenital malformations in twins

BackgroundThe rate of twinning continues to increase due to the combined effect of a rise in parental age and increased use of assisted reproductive technology. The risk of congenital anomalies in twins is higher than in singletons, but it is less well reported in relation to growth patterns. We focused to the auxological outcome of twin pregnancies when one or both of twins are affected by one or more malformations.MethodsWe conducted a retrospective observational study reviewing the clinical charts of twins admitted in the period between January 2003 and December 2018 at the University Hospital of Palermo. The associations between malformations and anthropometric variables at birth were analyzed by comparison within each twin pair and regarding each variable as ordered difference between the two twins.ResultsWe studied data of 488 neonates (52% females) from 244 pregnancies. The rate of major congenital anomalies was 11%, affecting significantly the smaller twin (p = .00018; Odds ratio 3.21; 95% CI 1.65 6.59). Malformation class distribution was as following: genitourinary (24%), gastrointestinal (20%), cardiovascular (18.5%), musculoskeletal (11%), central nervous system (9%), syndromic (9%), ocular (5.5%) and diaphragmatic hernia (2%). The most predictive value, the Birthweight (BW) difference mean ratio in malformed versus not malformed neonates (− 0.31 vs 0.02; p = .0016) was distributed equally lower than zero in all malformed twins, except for those with congenital heart defects (p = .0000083).Microcephaly (head circumference < 2 standard deviation, SD) was present in 3% of symmetrically smaller twin, and severe microcephaly (< 3 SD) was present in 0.6%. We found that an intertwin BW discordance of 18% or greater identified 50% of neonates with microcephaly, but only 11% of malformed twins.ConclusionsIn case of one twin with a BW < 10th centile, a concomitant intertwin BW discordance ≥18% could reveal an increased risk for microcephaly but not for malformation. Lower values of BW, Ponderal index, Body mass index but above all negative value of BW difference mean ratio are associated with malformations in twin pairs.

Genetic parameters and principal components analysis of breeding value for birth and weaning weight in Egyptian buffalo.

ObjectiveThe objectives of the current study were to study the main environmental factors affecting birth weight (BW) and weaning weight (WW), estimate variance components, genetic parameters and genetic trend and to evaluate the variability and relationships among breeding value of BW and WW using principal components analysis (PCA).MethodsA total of 16,370 records were collected from 8,271 buffalo calves. Genetic parameters and breeding values were estimated using a bivariate animal model which includes direct, maternal and permanent maternal effects. These estimates were standardized and used in PCA.ResultsThe direct heritability estimates were 0.06 and 0.41 for BW and WW, respectively whereas direct maternal heritability values were 0.03 and 0.14, respectively. Proportions of variance due to permanent environmental effects of dam were 0.455 and 0.280 for BW and WW respectively. The genetic correlation between BW and WWs was weak approaching zero, but the maternal correlation was 0.26. The first two principal components (PC1 and PC2) were estimated utilizing the standardized breeding values according to Kaiser method. The total variance explained by the first two PCs was 71.17% in which 45.91% and 25.25% were explained by PC1 and PC2, respectively. The direct breeding values of BW were related to PC2 but those of WW and maternal breeding values of BW and WWs were associated with PC1.ConclusionThe results of genetic parameters and PCA indicate that BW and WWs were not genetically correlated and improving growth traits of Egyptian buffaloes could be achieved using WW without any adverse effect by BW.

Relationship between litter size at birth and within-litter birth weight characteristics in laboratory mice as pilot animal for pig.

We investigated the relationship between litter size at birth and within-litter birth weight (BW) characteristics of laboratory mice as a pilot mammal for pig. We obtained records of number born alive (NBA) and total and mean litter BW (LWB, MWB), and maximum and minimum values of within-litter BW (MaxIWB, MinIWB), range and standard deviation (Range, SDIWB), skewness (Skew), and kurtosis (Kurt) of within-litter BW for 656 litters at first parity. Pearson's correlations of NBA were highly positive with LWB (0.92), weakly negative with MWB (-0.31), MaxIWB (-0.19), and MinIBW (-0.33), and those of MWB were negligible with Range, SDIWB, Skew, and Kurt (-0.10 to 0.06). Estimated heritabilities, treated as dam traits, were 0.32 for NBA, 0.39 for LWB, 0.24 for MWB, 0.28 for MaxIWB, 0.05 for MinIWB, 0.16 for Range, 0.17 for SDIWB, and 0.00 for Skew and Kurt. Estimated genetic correlation between NBA and LWB was high (0.95). Therefore, LWB could be promising for efficiently improving NBA. The estimated genetic correlation of NBA was negligible with MWB (0.00), positive with MaxIWB (0.10), Range (0.48), and SDIWB (0.36), and negative with MinIWB (-0.36), suggesting that selection for increased NBA brings larger SDIWB and lighter MinIWB.

Rescue High-Frequency Oscillatory Ventilation in Neonatal Respiratory Failure Unresponsive to Conventional Mechanical Ventilation

Background: High-frequency oscillatory ventilation (HFOV) has been shown to result in less lung injury. HFOV is also used in critically ill newborns when conventional mechanical ventilation (CV) fails, especially in units with lack of nitric oxide (NO) and extracorporeal membrane oxygenation. Objectives: There are no recent data on the response of newborns to rescue HFOV (rHFOV) in the literature. The aim of this study was to evaluate the risk factors that affect the response to rHFOV in newborns who had CV failure in respiratory support. Methods: Newborns who still had a respiratory failure in case of CV and switched to rHFOV were grouped as survived and died. The characteristics of the patients such as birth weight (BW), gestational age (GA), and disease, in addition to ventilator settings, arterial blood gas analysis, ventilation duration, and side effects were compared between the groups. Results: 84 patients with a mean GA of 32.1 ± 5.3 weeks and a mean BW of 1901 ± 1135 g were enrolled in the study. The patients were switched to rHFOV at median 28.5 hours of life. Infants who died had lower BW (1345 ± 935 g vs. 2557 ± 1035 g, P = 0.0001) and lower GA (31.7 ± 4.9 weeks vs. 34.8 ± 4.4 weeks, P = 0.03) in comparison with infants who survived. Prematurity (OR: 7.73, 95% CI: 2.1 - 24.7, P = 0.001) and having BW < 1500 g (OR: 7.02, 95% CI: 2.6 - 18.6, P < 0.001) increased mortality significantly. Cut-off values for BW and GA were found to be 1875 g and 32.5 weeks with 75% sensitivity and 78% specificity. There were no differences in the initial ventilation settings between the groups and no correlation between the side effects such as intraventricular hemorrhage, retinopathy of prematurity, and bronchopulmonary dysplasia could be demonstrated with the duration of rHFOV. Conclusions: rHFOV in case of CV failure is more effective in patients with greater GA and BW, independent of the disease and initial rescue ventilator settings.

The influence of maternal height on offspring's birth weight in Merida, Mexico.

To analyze the influence of maternal height (MH) on offspring's birth weight (BW) in infants born from January 2016 to May 2017, in Merida, Mexico. A total of 3462 singletons born at term in a public hospital were analyzed. Data extracted from hospital records were MH; number of previous births; and infant's sex, BW, and gestational length. MH was divided into 4 categories at quartile points: Q1:129-147, Q2:148-151, Q3:152-155, and Q4:156-180 cm. BW data were transformed to z-score values using the WHO Child Growth Standard. The association between MH and infants' BW was analyzed through a multiple regression model in which gestational length, infant's sex, maternal age, ethnicity, and number of previous birth were included as covariates. Mean values of MH and infants' BW were 151.43 cm (SD = 6.32) and 3172 g (SD = 401) (corresponding to -0.29 SD in BW z-score), respectively. The regression model showed that the shortest quartile of MH was associated with -0.43 (95% CI -0.35 -0.51) SD in infants' BW compared with the highest quartile. The second and third shortest quartiles of MH were associated with -0.24 (95% CI -0.16 -0.32) and -0.17 (95% CI -0.09 -0.25) SD of infants BW, respectively. MH remains an important factor for infant BW even in the presence of other determinants. The influence of MH on infants' BW in this population is similar to that found in other populations in low-, middle-, and high-income countries.

Wymiary ciała noworodków urodzonych na Mazowszu w jednym ośrodku w latach 2011–2015

We present the assessment of birth body measurements of neonates born during the years 2011–2015 in one hospital maternity unit in the administrative region of Masovia. The measurements were compared against the WHO Child Growth Standards and the locally published reference standards. AimTo determine mean body measurements in a cohort of neonates and compare them against the WHO standards and local standard reference values used in Poland. Material, methodsData were collected on the gender, birth weight (BW) [g; measured on electronic neonatal scales], birth length (BL) [cm; measured using a measuring tape], birth head circumference (BHC) [cm; measured using a measuring tape], gestational age (GA) [weeks; as estimated by an obstetrician] and mother's parity among 22 315 neonates born during the period of five consecutive years at one centre. ResultsBW, BL and BHC measurements were assessed in a cohort of 22 247 live births, including 11 519 males (M) and 10 0728 females (F; 48.2% of all neonates); most infants (92.8% of males and 93.9% of females) were born at term. Conclusions(1) The mean BW value in the study cohort was similar to that observed in Poland over the past several decades. (2) The mean birth length of a Masovian cohort cannot be compared against the standards set by the WHO because of the differences in the measurement methods. Birth length measurements should be based on the principles of anthropology and the use of a measuring tape should be discontinued.(3) The BHC value in the Masovian cohort did not differ from the standards set by the WHO or the standards published in Poland. A tendency for the BHC to increase with a simultaneous decrease in the BL has been observed however, it requires further studies.

Influence of genetic and non genetic factors on growth traits of Bharat Merino sheep in sub-temperate climate of Kodai hills of Tamil Nadu, India

In the present study, the data on 1649 Bharat Merino (BM) lambs; progeny of 144 sires over the year from 2000 to 2014 available at Southern Regional Research Centre (SRRC), Central Sheep and Wool Research Institute, Mannavanur were considered for the analysis. The different economic growth traits used for the analysis were birth weight (BWT), weaning weight (3MWT), 6 month weight (6MWT), 12 month weight (12MWT) and greasy fleece yield (GFY). The overall least-square means for weights (in kg) were 3.28±0.02, 19.08±0.23, 25.00±0.35, 34.79±0.59 and 2.13±0.07 for BWT, 3MWT, 6MWT, 12MWT and GFY respectively. Different non genetic factors such as year, sex, type of birth and dam’s age had significant (P less than 0.01) influence on BWT and 3MWT. Season influenced the BWT (P less than 0.05) while it had no significant effect on 3MWT. Six month weight was also significantly (P less than 0.05) influenced by all non-genetic factors taken under present study. Twelve month weight was significantly affected by year (P less than 0.01), sex and season (P less than 0.05). Similarly, analysis of variance showed that the year, sex of the lambs (P less than 0.01) and season (P less than 0.05) were important sources of variation on GFY of Bharat Merino sheep. Lambs born single had higher values of BWT and 3MWT than that of the lambs born as twins. The trend of the increase in BWT and 3MWT of the lambs is being observed up to the period when the age of their corresponding dams is 4-5 years. The findings of the present study showed that non - genetic factors play an important role in the expression of genetic potential in the lambs as well as growth performance of Bharat Merino sheep under sub temperate conditions of Kodai hills of Tamil Nadu, India. The genetic parameters estimated of 6MWT indicate that it is most suitable for use as selection criterion. Improvement of body weight of BM sheep seems feasible in selection programs, as some of the related traits are moderately heritable and those traits specially are well correlated, which could suggest that these traits are useful in selection programs.

Postnatal weight gain in very low birth weight infants in Beijing and the risk of retinopathy of prematurity.

To analyze the low weight gain (WG) from birth to 4 and 6wk of life to predict the development of retinopathy of prematurity (ROP) among very low birth weight (VLBW) preterm babies. Three hundred and three newborns with VLBW were analyzed. Body weight measurements were recorded weekly. In all patients, the proportion of the WG was defined as the preterm weight measured at the 4(th) and 6(th) weeks of life minus the birth weight (BW) divided by the BW. Other risk factors for ROP were also analyzed. Mean gestational age and mean BW of the whole cohort were 29.56±1.44wk and 1270.58±176.18g respectively. WG proportion at 4wk postnatal age (18.89%±13.58%) were significantly lower in infants with ROP (P=0.003). WG proportion at 6wk was not different between ROP and no ROP group (42.48%±20.36% vs 46.43%±15.65% P=0.118). When all the other risk factors significant for ROP were included in the logistic regression poor WG did not arise as an independent risk factor. Area under the ROC curve was 0.591 (95%CI: 0.515-0.666; P=0.016). For ROP, the best discriminative cutoff of 18.06% of the proportional WG at the 4(th) week over the BW, sensitivity and specificity values were 67.3% and 50.0% respectively. Low WG proportion in the first 4wk of life is maybe an additional predictor of ROP in very low BW infants. Preterm babies with low BW and low WG proportion should be followed closely for ROP.

Estimates of genetic parameters of growth traits of Nellore cattle in the Midwest region of Brazil

Records of birth weight (BW) and weights standardized to 210 (W210); 365 (W365) and 550 (W550) of age in the Nellore breed were used to estimate variance components of genetic effects and predict genetic values of sires. The model included the fixed effects of contemporary group and cow age at calving as co-variable, and the additive and maternal genetic, permanent maternal environmental, and temporary environmental random effects. Estimates of means and standard deviations for BW, W210; W365 and W550 were 32.76 ± 3.74; 184.30 ± 29.02; 240.31 ± 41.85 and 322.12 ± 60.77, respectively. A significant additive genetic variability was detected for all weights. The permanent maternal environmental variance showed greater relevance on weaning weight, and it was practically inexistent after weaning. For the maternal genetic variance, the estimate for birth weight was more significant as compared with weaning weight. The estimated heritability values for BW, W210; W365 and W550 were 0.37 ± 0.02; 0.36 ± 0.03; 031 ± 0.01 and 0.38 ± 0.02, respectively. Genetic correlations between birth weight and other weights were of low magnitude, with high values of weights at other ages. The use of sires of higher genetic value for total maternal effect makes it possible to use sires that are more positive for weaning weight and also for year and yearling weight.