ABSTRACT
Abstract Background: Assessment of animal growth based on live weight (LW) in traditional sheep production systems is limited by the high cost of purchase and maintenance of livestock scales. Objective: To develop and evaluate equations for LW prediction using heart girth (HG) in growing Pelibuey sheep. Methods: A dataset (n=415) of clinically healthy male Pelibuey sheep from two months to one year of age, with an average LW of 25.96 ± 10.25 kg and HG of 68.31 ± 10.53 cm, were used. Three equations were evaluated: LW (kg) = −37.70 + 0.93 × HG (Eq. 1); LW (kg) = −1.74 + 0.19 × HG + 0.008 × HG2 (Eq. 2); and LW (kg) = 0.003 × HG2.68 (Eq. 3). Results: The correlation coefficient between LW and HG was r = 0.94 (p<0.001). The three equations showed a high concordance correlation coefficient (CCCs≥0.97). However, the random error was the main component of the mean square partition of the prediction error (≥82.78%) only for Eqs. 1 and 2. The test for parameter identity (intercept=0; slope=1) was accepted only for Eq. 2 (p>0.05). On the other hand, for Eqs. 1 and 3 the intercept was different from zero and the slope was different from one (p<0.05). Conclusion: The second-degree equation accurately and precisely estimated body weight of growing Pelibuey sheep using the HG as a sole predictor variable.
Resumen Antecedentes : Debido a las condiciones de los sistemas tradicionales de producción ovina, la evaluación del crecimiento animal en función del peso vivo (PV) está limitada por el alto costo de la báscula ganadera y su mantenimiento. Objetivo: Desarrollar y evaluar ecuaciones para predecir el peso corporal utilizando el perímetro torácico (PT) en ovinos Pelibuey en crecimiento. Métodos : Se utilizó un conjunto de datos (n=415) de ovinos Pelibuey machos clínicamente sanos, de dos meses a un año de edad y peso promedio de 25,96 ± 10,25 kg y PT de 68,31 ± 10,53 cm. Se evaluaron tres ecuaciones: PV (kg) = −37,70 + 0,93 × PT (Ec. 1), PV (kg) = −1,74 + 0,19 × PT + 0,008 × PT2 (Ec. 2) y PV (kg) = 0,003 × PT2,68 (Ec. 3). Resultados: El coeficiente de correlación entre PV y PT fue r=0,94 (p<0,001). Las tres ecuaciones mostraron alto coeficiente de correlación de concordancia (CCCs≥0,97). Sin embargo, el error aleatorio fue el componente principal de la partición cuadrática media del error de predicción (≥82,78%) solo para las Ecs. 1 y 2. Sin embargo, la prueba de identidad de parámetros (intersección = 0; pendiente = 1) solo se aceptó para la ecuación 2 (p>0,05). Por otro lado, el intercepto fue diferente de cero y la pendiente fue diferente de uno (p<0.05) para las Ecs. 1 y 3. Conclusión: La ecuación de segundo grado estima con exactitud y precisión el peso corporal de ovinos Pelibuey en crecimiento utilizando la PT como única variable predictora.
Resumo Antecedentes: Devido às condições dos sistemas tradicionais de produção de ovinos, a avaliação do crescimento animal com base no peso corporal (PV) é limitada pelo alto custo da balança pecuária, bem como pela manutenção sofisticada necessária. Objetivo: Desenvolver e avaliar equações para predizer o PV usando o perímetro torácico (PT) em ovinos Pelibuey em crescimento. Métodos: Um conjunto de dados (n=415) de ovinos Pelibuey machos clinicamente saudáveis de dois meses a um ano de idade, com peso médio de 25,96 ± 10,25 kg e PT de 68,31 ± 10,53 cm foi utilizado para o desenvolvimento das equações. Três equações foram avaliadas: PV (kg) = -37,70 + 0,93 × PT (Eq. 1), PV (kg) = -1,74 + 0,19 × PT + 0,008 × PT2 (Eq. 2) e PV (kg) = 0,003 × PT2,68 (Eq. 3). Resultados: O coeficiente de correlação entre PV e PT foi r = 0,94 (P < 0,001). As três equações apresentaram alto coeficiente de correlação e concordância (CCCs≥0,97). No entanto, o erro aleatório foi o principal componente da partição do quadrado médio do erro de predição (≥82,78%) apenas para as Eqs. 1 e 2. No entanto, o teste de identidade dos parâmetros (intercepto = 0; inclinação = 1) foi aceito apenas para a Eq. 2 (p>0,05). Por outro lado, para a Eq. 1 e 3, o intercepto foi diferente de zero e a inclinação foi diferente de um (p<0,05). Conclusões: A equação de segundo grau estima com precisão e acurácia o peso corporal de ovinos Pelibuey em crescimento usando o PT como única variável preditora.
ABSTRACT
OBJECTIVE: To evaluate the performance of a local fetal weight curve based on the prediction for large gestational age (LGA) newborns in diabetic pregnant women and to compare it to reference curves established for other populations. METHOD: A reference model for estimated fetal weight was created from a local sample of 2211 singleton low-risk pregnancies. The estimated fetal weight from 194 women with gestational diabetes mellitus was then plotted on this curve, and the results were compared to those obtained by Intergrowth 21st and Hadlock curves. RESULTS: The sensitivity of the proposed model to predict LGA fetuses was 55.6%, the specificity was 82.1%, and the accuracy was 74.7%. The sensitivity, specificity, and accuracy for the Intergrowth 21st curve were 46.3%, 87.9%, and 76.3%, respectively, and no statistically significant difference was observed compared to the proposed model. Conversely, significant differences were observed for the Hadlock curve, which presented a lower sensitivity (24.1%), higher specificity (97.1%), and similar accuracy (76.8%). CONCLUSION: The sensitivity of the proposed model was higher compared to the Hadlock curve for the screening of LGA newborns in diabetic pregnant women. However, no significant differences were observed in comparison to the Intergrowth 21st curve.
Subject(s)
Diabetes Mellitus , Infant, Newborn, Diseases , Birth Weight , Female , Fetal Growth Retardation/diagnosis , Fetal Weight , Fetus/diagnostic imaging , Gestational Age , Humans , Infant, Newborn , Infant, Small for Gestational Age , Pregnancy , Pregnant Women , Ultrasonography, Prenatal/methodsABSTRACT
La ecografía obstétrica se ha posicionado como un apoyo importante al control prenatal, incluso por matronas y médicos generales que controlan pacientes en atención primaria. Sin embargo, la disponibilidad de ecografía realizada por médico obstetra en el sistema público es relativamente escasa, lo que ha llevado a médicos y matronas a capacitarse en ecografía obstétrica. El objetivo de este trabajo es evaluar la utilidad de realizar ecografías obstétricas de rutina en etapas posteriores al primer trimestre, basándose en la capacidad de predicción de peso y sexo fetales. Para ello, se revisaron 1.703 ecografías obstétricas realizadas en el Hospital de Calbuco entre los años 2005 y 2008. Los resultados muestran buena capacidad para predecir sexo fetal, no así en el caso del peso fetal, donde las diferencias entre los pesos estimados y reales superan los estándares aceptados. Estos datos nos pueden ayudar a dimensionar de mejor manera los alcances de las ecografías obstétricas que realizamos a nivel primario.
Obstetric ultrasound has emerged as an important support to prenatal care, including its use by midwives and general practitioners in primary health care. However, the availability of ultrasound performed by obstetric physician in the public health system is relatively low, which has led to the training of general doctors and midwives in obstetric ultrasound. The objective of this study is to evaluate the usefulness of routine obstetric ultrasound after the first trimester, based on its predictability of fetal weight and sex. With this aim, 1703 obstetric ultrasounds performed in Calbuco Hospital between 2005 and 2008 were reviewed. The results show good capacity of predicting fetal sex, but not in the case of fetal weight, where the differences between estimated and actual weights exceed accepted standards. This data can help us to better dimension the scope of obstetric ultrasound performed at the primary health level.