scholarly journals Maternal factors and the prediction of dystocia in beef heifers

1993 ◽  
Vol 73 (2) ◽  
pp. 431-435 ◽  
Author(s):  
B. D. King ◽  
R. D. H. Cohen ◽  
S. McCormac ◽  
C. L. Guenther
Keyword(s):  
Birth Weight ◽  
Discriminant Analysis ◽  
Key Words ◽  
Caesarian Section ◽  
Stepwise Discriminant Analysis ◽  
Gestation Length ◽  
Maternal Factors ◽  
Beef Heifers ◽  
Factors Associated ◽  
Pelvic Area

Stepwise discriminant analysis was used to determine maternal factors associated with dystocia in 564 2-yr-old heifers bred to bulls with below breed average birth weights. Calf birth weight (n = 556) was consistently the most significant (P < 0.001) factor correlated (R2 = 0.31) with dystocia. Other significant (P < 0.001) factors were weight at breeding (n = 376) and calving (n = 559; R2 = 0.11 for both traits). Other factors considered were age at breeding (n = 446), pelvic area at breeding (n = 112) and pregnancy evaluation (n = 297), heifer birth weight (n = 564), gestation length (n = 467) and age at calving (n = 559) but none were significant (P > 0.05). Heifers requiring caesarian section were heaviest (P < 0.05) at breeding and their calves were heaviest (P < 0.05) at birth. Unassisted heifers were heavier at calving (P < 0.05) than assisted heifers. It was concluded that none of the factors examined in this study was a reliable predictor of dystocia in beef heifers but that heifers should be bred at 75–80% of their expected calving weight to reduce the risk of dystocia. Key words: Dystocia, heifer, discriminant analysis

Risk factors associated with dystocia in a tie stall dairy herd

2016 ◽  
Vol 96 (2) ◽  
pp. 135-142 ◽  
Author(s):  
I. López Helguera ◽  
A. Behrouzi ◽  
J.P. Kastelic ◽  
M.G. Colazo
Keyword(s):  
Risk Factors ◽  
Birth Weight ◽  
Dairy Herd ◽  
Cold Season ◽  
Gestation Length ◽  
Factors Affecting ◽  
Factors Associated ◽  
Twin Pregnancies

The aims of the study were to: (1) investigate factors affecting calf birth weight (CBW) and gestation length (GL); and (2) determine risk factors associated with dystocia in 1019 Holstein heifers and cows in a tie stall dairy herd. Calf sex (CS), sire, and GL were related to CBW in primiparous and multiparous cows, with no significant effect of season, age of primiparous cows (AGE) or days in milk (DIM) of multiparous cows at conception. Gestation length was affected by CS in primiparous, with a shorter GL for female versus male calves (275.7 ± 0.5 vs. 278.3 ± 0.4; P < 0.001). Also, GL was shorter in multiparous cows that calved during the cold season compared to those that calved in mild or warm seasons. Primiparous cows had a higher prevalence of dystocia compared to multiparous cows (32.1 vs. 8.5%; P < 0.001), but it was highly variable depending on sire (24.4%–60.0% for primiparous and 0%–21.1% for multiparous). In conclusion, CS, sire, and GL were related to CBW, whereas GL was affected by CS in primiparous and season in multiparous. The CBW was the major factor affecting dystocia in primiparous cows, whereas sire and twin pregnancies were factors related to dystocia in both primiparous and multiparous cows.

scholarly journals Improving preterm newborn identification in low-resource settings with machine learning

2018 ◽  
Author(s):  
Katelyn J. Rittenhouse ◽  
Bellington Vwalika ◽  
Alex Keil ◽  
Jennifer Winston ◽  
Marie Stoner ◽  
...  
Keyword(s):  
Machine Learning ◽  
Birth Weight ◽  
Preterm Birth ◽  
Preterm Infants ◽  
Preterm Newborn ◽  
Maternal Factors ◽  
Factors Associated ◽  
Improve Accuracy ◽  
Hiv Serostatus ◽  
Twin Delivery

AbstractBackgroundGlobally, preterm birth is the leading cause of neonatal death with estimated prevalence and associated mortality highest in low‐ and middle‐income countries (LMICs). Accurate identification of preterm infants is important at the individual level for appropriate clinical intervention as well as at the population level for informed policy decisions and resource allocation. As early prenatal ultrasound is commonly not available in these settings, gestational age (GA) is often estimated using newborn assessment at birth. This approach assumes last menstrual period to be unreliable and birthweight to be unable to distinguish preterm infants from those that are small for gestational age (SGA). We sought to leverage machine learning algorithms incorporating maternal factors associated with SGA to improve accuracy of preterm newborn identification in LMIC settings.Methods and FindingsThis study uses data from an ongoing obstetrical cohort in Lusaka, Zambia that uses early pregnancy ultrasound to estimate GA. Our intent was to identify the best set of parameters commonly available at delivery to correctly categorize births as either preterm (<37 weeks) or term, compared to GA assigned by early ultrasound as the gold standard. Trained midwives conducted a newborn assessment (<72 hours) and collected maternal and neonatal data at the time of delivery or shortly thereafter. New Ballard Score (NBS), last menstrual period (LMP), and birth weight were used individually to assign GA at delivery and categorize each birth as either preterm or term. Additionally, machine learning techniques incorporated combinations of these measures with several maternal and newborn characteristics associated with prematurity and SGA to develop GA at delivery and preterm birth prediction models. The distribution and accuracy of all models were compared to early ultrasound dating. Within our live‐born cohort to date (n = 862), the median GA at delivery by early ultrasound was 39.4 weeks (IQR: 38.3 ‐ 40.3). Among assessed newborns with complete data included in this analysis (n = 458), the median GA by ultrasound was 39.6 weeks (IQR: 38.4 ‐ 40.3). Using machine learning, we identified a combination of six accessible parameters (LMP, birth weight, twin delivery, maternal height, hypertension in labor, and HIV serostatus) that can be used by machine learning to outperform current GA prediction methods. For preterm birth prediction, this combination of covariates correctly classified >94% of newborns and achieved an area under the curve (AUC) of 0.9796.ConclusionsWe identified a parsimonious list of variables that can be used by machine learning approaches to improve accuracy of preterm newborn identification. Our best performing model included LMP, birth weight, twin delivery, HIV serostatus, and maternal factors associated with SGA. These variables are all easily collected at delivery, reducing the skill and time required by the frontline health worker to assess GA.

scholarly journals BREED OF DAM, AGE OF DAM AND SEX OF CALF EFFECTS IN THE CANADIAN SIMMENTAL YOUNG SIRE PROVING PROGRAM

1984 ◽  
Vol 64 (1) ◽  
pp. 1-8
Author(s):  
R. A. KEMP ◽  
L. R. SCHAEFFER ◽  
J. W. WILTON
Keyword(s):  
Birth Weight ◽  
Key Words ◽  
Mixed Model ◽  
Genetic Relationships ◽  
Residual Effects ◽  
Gestation Length ◽  
Calving Ease ◽  
Sire Evaluation ◽  
Unbiased Estimates ◽  
Best Linear Unbiased

Canadian Simmental Association Young Sire Proving Program records (1978–1982) were used to estimate breed of dam by age of dam by sex of calf effects for several traits. Two models were used. Model 1 included fixed herd-years, breed of dam by age of dam by sex of calf (BAX) plus random sire and residual effects. Model 2 included fixed herd-year by sex of calf and breed of dam by age of dam (BA) plus random sire and residual effects. Both models included additive genetic relationships among sires and maternal grandsires. Traits used with Model 1 were gestation length (GL), calving ease (CE), birth weight (BW), gain on dam (GD) and 200-day weight (WW). Model 2 was used for gain on test (GT) and 365-day weight (YW). Mixed model techniques were used to obtain best linear unbiased estimates of BAX and BA from models 1 and 2, respectively. Hypothesis tests were conducted using two breed of dam groups ([Formula: see text] Simmental (S) and [Formula: see text] British breeds (B)) and four age of dam groups (2, 3, 4 and 5 + yr which correspond to < 31, 31–42, 43–54 and > 54 mo, respectively). Three-way subclasses (BAX) were significant (P < 0.01) for GL, CE, BW, GD and WW as were two-way subclasses (BA) for YW. Estimated differences for breed of dam by age of dam by six of calf subclasses (for GL, CE, BW, GD, WW) and breed of dam by age of dam subclasses (for YW) generally increased as age of dam increased. Accounting for breed of dam, age of dam, sex of calf and interaction effects are important in sire evaluation. Estimated differences of these effects, a by-product of sire evaluation, can be used to increase the accuracy of procedures for individual and dam evaluation. Key words: Breed of dam by age of dam by sex of calf effects, sire evaluation, mixed model techniques

scholarly journals Maternal factors associated with low birth weight: a case control study in rural Kerala

2017 ◽  
Vol 4 (10) ◽  
pp. 3793 ◽  
Author(s):  
Anant Pawar ◽  
Durgesh Kumar
Keyword(s):  
Risk Factors ◽  
Birth Weight ◽  
Low Birth Weight ◽  
Case Control Study ◽  
Case Control ◽  
Maternal Risk Factors ◽  
Maternal Factors ◽  
Maternal Risk ◽  
Factors Associated ◽  
Control Study

Background: Low birth weight (LBW) continues to remain a major public health problem worldwide. There are numerous factors contributing to LBW both maternal and foetal. The maternal risk factors are biologically and socially interrelated. The mortality of low birth weight can be reduced if the maternal risk factors are detected early and managed by simple techniques. This study was conducted to study the maternal risk factors associated with low birth weight. Methods: A retrospective record based case control study was conducted. Retrospective data collection was done using registers from medical record section of Obstetrics and Gynaecology department. After applying exclusion criteria and checking for completeness of records, we selected 60 cases and 124 matched controls. Data was entered in Microsoft excel and analyzed using SPSS version 16. Students ‘t’ test, chi-square test and odds ratio were used to find out the factors associated with low birth weight. Results: In the present study, 60 cases and 124 controls were studied. Mean age of mothers in the case group was 24.4±4.7 yrs. and in the control group was 24.8±4.42 yrs. Mean weight of the cases was 62.5±6.89 kg and of the controls was 65.04±7.16 kg. A total of 35% of the cases and 20% of the controls suffered from pregnancy related diseases. Conclusions: Maternal factors like Socio-economic status, weight, haemoglobin and parity were significantly associated with LBW. Maternal diseases like hypertension, diabetes can result in LBW baby. 

A STUDY OF SOME OF THE FACTORS INFLUENCING EASE OF CALVING IN RANGE BEEF HEIFERS

1983 ◽  
Vol 63 (2) ◽  
pp. 255-262 ◽  
Author(s):  
M. MAKARECHIAN ◽  
R. T. BERG
Keyword(s):  
Birth Weight ◽  
Key Words ◽  
Significant Influence ◽  
Threshold Effect ◽  
Phenotypic Correlation ◽  
Relative Importance ◽  
Beef Heifers ◽  
Factors Influencing ◽  
Condition Score ◽  
Calving Performance

This study was performed in two parts. In the first part, 349 calving records of 2-yr-old heifers in 1979, 1980 and 1981 were analyzed by least-squares to assess the effects of lowering sire birth weight on calf birth weight and ease of calving. The study demonstrated that using sires with lower birth weight in 1981 compared to 1979 and 1980 (31.12 vs. 40.12 and 40.17 kg, respectively), reduced the average calf birth weight (32.65 vs. 36.04 and 34.62 kg, respectively) which in turn improved calving performance of the heifers in 1981 compared to the previous years. In the second part, 128 calving records of 2-yr-old heifers in 1981 were analyzed to study the relative importance of hip height, area of pelvic opening, condition score and weight at calving on calving performance. The results indicated that heifer weight at calving had a significant influence of calving performance (P < 0.01). Calving performance improved with increases in heifer weight at calving. Height at hip was phenotypically correlated with weight at calving, area of pelvic opening and calf birth weight. Phenotypic correlation between weight at calving and area of pelvic opening was also highly significant. The area of pelvic opening might exert a threshold effect on calving performance in 2-yr-old heifers. Key words: Cattle, dystocia, range beef heifers

The influence of zeranol implantation on growth and reproduction of beef heifers

1991 ◽  
Vol 71 (4) ◽  
pp. 1249-1252 ◽  
Author(s):  
R. N. Kirkwood ◽  
R. D. H. Cohen ◽  
B. D. King ◽  
P. A. Thacker
Keyword(s):  
Key Words ◽  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Growth Enhancement ◽  
Beef Heifers ◽  
Pelvic Area ◽  
Effect Of Treatment ◽  
Growth And Reproduction

Crossbred beef heifers received a 36-mg implant of zeranol at 60 d of age (R1; n = 35) or at both 60 and 197 d (weaning; R2; n = 32) or received no implants (C; n = 35). R2 heifers were heavier and had greater pelvic areas (P < 0.05 for both) at breeding compared with controls. There was no effect of treatment on the calving rates (78.1 vs. 80.0 vs. 74.3%) or on mean pelvic area at the time of calving (261.1 vs. 260.4 vs. 257.6 cm2) for R2, R1 and C heifers, respectively. We conclude that zeranol can be successfully used for growth enhancement from 60 d of age without detriment to subsequent reproductive performance. Key words: Zeranol, heifers, pregnancy rate, pelvic area

Maternal Factors Associated with Small-for-Dateness Among Twins

1982 ◽  
Vol 31 (3-4) ◽  
pp. 241-245 ◽  
Author(s):  
Denis Hemon ◽  
Colette Berger ◽  
Philippe Lazar
Keyword(s):  
Risk Factors ◽  
Birth Weight ◽  
Gestational Age ◽  
Maternal Risk Factors ◽  
Maternal Factors ◽  
Maternal Weight ◽  
Smoking During Pregnancy ◽  
Maternal Risk ◽  
Factors Associated ◽  
Twin Pregnancies

The maternal risk factors that correlate with small-for-dateness among twins have been analyzed using a sample of 659 twin pairs and a matched sample of singletons. Non-marital status, job involvement, and the previous delivery of a low-birth weight (<2,500g) infant present a negative interaction with twinning, as low gestational age-adjusted birth weight does not correlate significantly with these risk factors among twin gestations, while it does among singleton gestations. On the other hand, the effects of parity, habitual maternal weight, smoking during pregnancy, and twinning are additive on gestational age-adjusted birth weight. Indeed, the decrease in adjusted birth weight associated with these risk factors is of the same magnitude among twins and singletons and is statistically significant in both cases. These findings suggest that exposure of twin pregnancies to these latter risk factors, and particularly to smoking during pregnancy, can lead to the delivery of newborns with extremely low birth weights.

Repeatability estimates of pelvic diameters measured by Rice pelvimeter in beef heifers

1993 ◽  
Vol 73 (4) ◽  
pp. 977-980
Author(s):  
U. Paputungan ◽  
M. Makarechian ◽  
M. F. Liu
Keyword(s):  
Key Words ◽  
Intraclass Correlation ◽  
Correlation Method ◽  
Reliable Estimate ◽  
Residual Variance ◽  
Beef Heifers ◽  
Single Measurement ◽  
Pelvic Area ◽  
Beef Heifer

Vertical (VP) and horizontal (HP) pelvic diameters were measured with Rice pelvimeter four times in a 3-wk period by the same operator in 143 bred beef heifers (18 ± 0.5 mo old). Pelvic area (PA) was estimated by VP × HP. Pelvic diameters of 30 open beef heifers (19 ± 0.3 mo old) were also measured by two experienced and two inexperienced operators. Repeatability of pelvic measurements was estimated by the intraclass correlation method. The estimates of repeatability of pelvic measurements were relatively moderate (0.53 ± 0.04, 0.46 ± 0.04 and 0.55 ± 0.04 for VP, HP and PA, respectively), indicating that a single measurement may not provide a reliable estimate of pelvic diameter. Between-operator variance was much smaller than the residual variance for each measurement (0.02 vs. 0.39 for VP, 0.06 vs. 0.36 for HP and 38.15 vs. 276.18 for PA). Key words: Beef heifer, pelvic diameters, repeatability

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