Growth curves of body weight and their relationship to sexual maturity in laboratory-bred male African green monkeys (Cercopithecus aethiops)

Nonlinear growth models having a three- or four-parameter family were applied to individual body weight data of 5 male African green monkeys for estimating their growth patterns. Body weight was measured from birth to six years of age and 58 to 114 data items per monkey were collected. The average body weight at birth was 360g with the standard deviation of +/- 25g, 4.54 +/- 0.29 kg at five years of age, and 4.50 +/- 0.12 kg at six years of age at which point body weight was judged to have reached a plateau. Five growth models (Gompertz, Logistic, Richards, Bertalanffy and Brody) were applied to the growth data in this study. As a result, two (Gompertz and Logistic) of the five models were found applicable to all data from the five monkeys. However, the coefficient of determination (R2) obtained by application of the two models were not so large (0.919 +/- 0.05 in Gompertz, 0.889 +/- 0.01 in Logistic). Therefore the data were divided into two groups according to monkey age: the first group being from monkeys between birth and 2 years 10 months of age and the second group was from monkeys older than 2 years 10 months of age. The Gompertz model fitted best the data of the first group in four of the five animals (R2 = 0.982 +/- 0.011). The age at the inflexion point in the Gompertz model nearly corresponded to the age of weaning. The Logistic model was most suitable for the date of the second group in all five animals (R2 = 0.955 +/- 0.038).(ABSTRACT TRUNCATED AT 250 WORDS)     

甘肃鼠兔幼子生长的初步研究

根据3 窝14只甘肃鼠兔幼子56 天的生长发育资料初步分析了甘肃鼠兔的生长发育规律。依据逻辑斯蒂曲线的拐点,甘肃鼠兔的体重生长可划分为加速增长相（0～0.5日龄）和减速增长相（20.5日龄以后）。按照瞬时生长率曲线的拐点,体重增长过程可分为3个时期,即缓慢生长期（0～6.5 日龄）、快速生长期（6.5～34.5 日龄）和渐进生长期（34.5 日龄以后）。文章对使用逻辑斯蒂方程和其它“S”形曲线描述动物生长过程存在的一些问题进行了讨论,认为：如果只用1条“S”形曲线描述动物的整个生长过程,就有可能会因为成年期动物生长规律的变化而破坏模型参数的生物学意义,同时引起模型拟合精度的降低。为克服这一问题,作者建议：在使用“S”形曲线拟合动物生长模型时,生长过程的资料最好不要覆盖体重波动较大的成年阶段。     

Management of individual body weight growth of infant squirrel monkey (Saimiri sciureus) in indoor breeding colony

We biometrically analyzed the body weight growth data of new-born squirrel monkeys, obtained during the nursing period from 0 to 12 weeks of age. Body weight (y in grams) could be expressed as a function of birth weight (a in grams) and age (x in weeks) by the following equation: y = a + b x, where b indicates growth rate. This equation corresponded significantly with actual growth curves (R2 = 0.96). The frequency distribution of b values was demonstrated to be abnormal distribution. This value was used to judge whether the body weight growth of each monkey was normal or abnormal. The lower control limit (LCL) was calculated by using a linear equation with the b value of 9.07 (M-1.25 x S.D.) and each birth weight. For the monkeys whose body weight was above the LCL during the first three weeks after birth, it was determined whether the frequency of weighings could be reduced from 13 to 7. Using the same animals, no significant difference was detected between the b value estimated from 13 measurements and that estimated from 7 measurements. Thus, from the standpoint of management's policy to save labor, the frequency of weighings could be reduced. A new daily routine has been established in our primate center to save labor by reducing the number of body weighings of the many infant monkeys. In the new program, newborn monkeys whose body weight is above the LCL are weighed only 7 times during the nursing period of 12 weeks, while those whose weight is below the LCL are weighed 8 to 13 times.     

光倒刺鲃的年龄与生长的初步研究

研究了光倒刺鲃(Spinibarbus hollandi)的年龄与生长规律,结果表明:光倒刺鲃鳞片年轮特征主要为疏密切割型。体长与鳞长呈直线相关L=44.44R-11.69,体重与体长呈指数函数相关W=0.0258L2.9125,4龄以前生长较快,生长指标高,体长指标高,体长和体重的相对增长率大,其生长规律可用Von Bertalanffy方程表达:Lt=67.3[1-e-0.2018(t-0.1338)],Wt=5441.44[1-e-0.2018(t-0.1338)]3。体重生长曲线的拐点位于t=5.678,拐点体长Lr=45.313cm,拐点体重Wr=1660.885g。光倒刺鲃雌性一般在3~4龄性成熟,雄鱼3龄时性成熟。     

Growth retardation in premenarchial female rhesus monkeys during chronic administration of a GnRH agonist (leuprolide acetate)

Abstract: Leuprolide acetate in depot form (0.75 mg/kg body weight/month, im) was administered to four female rhesus monkeys from 18–30 months of age, a period that includes the premenarchial growth spurt. They were compared to eight age matched controls. As anticipated, sexual maturation was blocked in the Leuprolide group and menarche did not occur. Growth was also severely retarded; no weight gain occurred during the study in the Leuprolide group as compared to a 25% weight gain (P = .004) in the control group. The Leuprolide group also lost muscle mass. Food intake normalized for body weight was not affected. Linear growth averaged 35% less in the Leuprolide group. Serum IGF-1 concentrations increased from 486±84 to 965±47 ng/mL (P = .0025) in the Leuprolide group and from 838±139 to 3,006±545 ng/mL (P = .0016) in the control group. These data suggest that premenarchial pituitary/gonadal suppression results in a distinctive pattern of growth retardation in monkeys.     

Synthetic standards for body weight

Growth charts represent body stature, body weight, and body mass index (BMI) from birth to maturity. Due to secular changes in these parameters, growth charts tend to become outdated, and must be revised from time to time. Recently, we developed alternative strategies that facilitate developing and renewing growth charts, and suggested synthetic standards for body stature. The increasing prevalence of obesity has made it necessary to develop similar techniques also for monitoring body weight and BMI. Two-hundred-and-forty historic and modern growth studies (108 studies of male growth, 132 studies of female growth) were selected from 22 European, 6 American, 3 African, and 6 Asian nations, published between 1831 and 2001. The studies contained annual information on weight and stature, either between birth and 6 years, or between 6 years and maturity, or information on the whole age range between birth and maturity. Since historic studies up to the mid-20th century usually ignore the fact that body weight (in contrast to body stature) is not normally distributed, a group of 92 more recent studies (45 male, 47 female), published between 1943 and 2001, presenting centiles for weight, was chosen for additional analysis. Furthermore, the skewness of body weight distributions, was investigated in original raw data of body weight obtained from five well reputed longitudinal growth studies, performed at Jena, Germany, Lublin, Poland, Paris, France, Prague, Czech Republic, and Zürich, Switzerland. Average body stature and average weight differ markedly between different populations. But within the same population, both parameters are closely interrelated. In males, birth length and weight correlated with r = 0.503, stature and weight correlated with r = 0.873 at the age of 2 years; with r = 0.882 at the age of 6 years; with r = 0.935 at the age of 14 years, and with r = 0.891 at the age of 18 years. Similar results were obtained in females. At birth, length and weight correlated with r = 0.619. Stature and weight correlated with r = 0.863 at the age of 2; with r = 0.912 at the age of 6; with r = 0.935 at the age of 12; and with r = 0.918 at the age of 15 years. Tables of linear regression coefficients for relative stature and weight at all ages enable the reversal of the process of the meta-analysis and allow the generation of synthetic growth references for stature and weight. Synthetic reference charts help in the revision of current growth charts without much additional effort, and may be used for populations for which autochthonous growth standards are not available.     

淮河上游南湾湖麦穗鱼年龄与生长的研究

2014年的3月、5月、7月和12月在淮河上游南湾湖采集麦穗鱼(Pseudorasbora parva)样本532尾, 对麦穗鱼的年龄组成与生长进行分析。结果表明样本的体长分布范围为35.82—88.28 mm, 平均体长为(61.61±11.8) mm, 体重的分布范围为3.07—59.17 g, 平均体重为(19.23±10.73) g。雄性个体比雌性个体大, 雌雄性比为0.64鲶1。群体的年龄组成为1—3龄, 其中3龄样本数量占优势为57.38%。体长与体重的关系是雌性W=9.602E–5L2.928 (R2=0.883); 雄性W=4.487E–5L3.116 (R2=0.889), 雌雄样本间存在显著性差异(F=5.241, P<0.05)。麦穗鱼的鳞径与体长之间呈线性关系, 并且雌雄样本的鳞径与体长之间的关系差异性显著(F=78.405, P<0.05)。生长参数分别是雌性: L_∞=107.005, K=0.246, t₀= –0.76; 雄性: L_∞=145.254, K=0.181, t₀= –0.66。生长拐点是雌性3.607龄对应的体长和体重分别为70.46 mm和24.72 g, 雄性5.619龄对应的体长和体重分别为98.64 mm和73.53 g。研究结果表明雌性为匀速生长, 雄性为异速生长; 雄性麦穗鱼比雌性麦穗鱼的生长速度快。     

Pubertal weight gain in female rhesus macaques

In order to describe the timing and extent of accelerated pubertal weight gain in female rhesus, we examined a large colony data base consisting of over 10,000 weight records for animals between 1.5 and 3.0 years of age (menarche occurs at about 2.6 years). Average colony weights were determined by week of age from information on age at weighing. Cross-sectional analyses with linear regression demonstrated an acceleration in weight increase from 196 to 231 weeks (28–33 months) when colony weights increased 381 g/12 weeks as opposed to an average of 193 and 203 g, respectively, during the preceding and succeeding age intervals of the same length. Longitudinal analyses (n = 428) indicated that maximum individual growth velocity averaged 499 ± 18 g/12 weeks and occurred at 119 ± 5.6 weeks (29.7 ± 0.2 months) of age. Nonlinear modeling with the Gompertz function indicated that decelerating growth rates seen at earlier ages were not characteristic of the period of accelerated pubertal growth. © 1996 Wiley-Liss, Inc.     

Association between maternal age at menarche and newborn size

The impact of maternal age at menarche on newborn size was tested using data from 4,996 single births taking place at Vienna, Austria, between 1985 and 1995--so-called teenager pregnancies were excluded from the present analyses. All women experienced pregnancies between the ages of 19 to 42 years. Maturational time was related significantly to infant weight and length independent of maternal age and behavioral variables such as smoking. Early maturation, i.e., age at menarche before the 12th birthday, was significantly associated with decreased newborn weight and size. The incidence of low-weight newborns was significantly higher in early-maturing mothers. The more favorable nutritional status of women whose menarche occurred relatively early was not able to compensate for the negative effects of early maturation on intrauterine growth. Higher circulating estrogen levels in early maturers preserved into adulthood are discussed as possible reasons for intrauterine growth retardation of the offspring of early-maturing mothers.     

Relationship between change in BMI with age and delayed menarche in female athletes

Body mass index (BMI) is widely used as an index of obesity in people from the school age children to adults. However, the relationship between the change in BMI with age and the coming of menarche has not been discussed as there are few reports on the changes in BMI with age. In this study, the change in BMI with age was examined by applying the wavelet interpolation method (WIM), and a critical period for body fat in terms of the coming of menarche was estimated from the growth velocity. We investigated delayed menarche according to the influence of stress in athletes by comparing delayed menarche between athletes and non-athletes in relation to the critical period. Data were obtained from 144 female athletes in their first year at university in the Tokai area, all of whom had competed in a national sports competition in high school (athlete group). Health examination records showing these subjects' heights and weights from the first grade of elementary school to the final year of high school (1984-1995) were collected and BMI was calculated for each grade. Ages at menarche were ascertained from questionnaires. A control group of 73 non-athletes was similarly examined. The age at maximum peak velocity (MPV) derived from the growth (aging) distance curve of BMI was determined in the control group to be 11.96+/-0.97 years old. This age at MPV of BMI was almost the same as the age at menarche (12.11+/-0.93 years old). Therefore, this age at MPV of BMI is estimated to be the critical period of body fat for the coming of menarche. The interval between the age at MPV of BMI and age at menarche was 0.74+/-1.30 years in the athlete group and 0.15+/-0.81 years in the control group, so there was a significant difference (P<0.01) between the two groups. It is suggested that the delayed menarche in athletes is influenced by the stress of regular sports training.     

Growth of the African elephant (Loxodonta africana)

The three-stage desk calculation of the von Bertalanffy equation to describe growth in height and weight with age in the elephant is compared with a new approach to calculating the three coefficients in the function by a computer. The two methods give different results with respect to the weight/age calculations. Theoretical von Bertalanffy equations calculated by both methods to describe growth in height and weight with age in the African elephant in Zambia are compared with previously published equations for the elephant in East Africa. Details are given of growth in height in two known-age African elephants, a female ‘Diksie’ and a male ‘Kartoum’. Theoretical growth in height curves for the female African and Asiatic elephant are compared. The coefficients K and / for growth in height are not transferable to the growth in weight equations. Inherent inaccuracies in the calculation of the coefficients in the von Bertalanffy equation are discussed, and it is concluded that in animals which have a long life-span such as the elephant, the equation serves as a purely empirical representation of weight-at-age data and that there is little biological significance in the parameters it contains. The computer-calculated curves give the best fit to the data. The regression of log age on log shoulder height from 2–20 years of age provides a more realistic approach to comparative growth studies. The increase in adrenal weight with age is linear. Tusk growth in relation to age and sex in Zambia is compared with East Africa. It is concluded that the tusks in Zambia are smaller and are more difficult to sex correctly than their East African counterparts, possibly a consequence of the Zambian elephant having a greater degree of tusk wear. Allometric growth is described with emphasis on the estimation of body weight from shoulder height. The most reliable estimates are obtained from a purely empirical representation of the data, a semilog plot of log body weight on shoulder height.     

人工饲养条件下东方田鼠指名亚种繁殖特性及其幼仔的生长发育

在实验室饲养条件下, 对东方田鼠指名亚种繁殖特性和幼仔生长发育进行了初步观察。该鼠全年均可繁殖, 平均每胎产仔3.8 ±1.5 只, 妊娠期20～21 d , 繁殖间隔期39.3 ±26.4 d , 雌雄比为1.48。幼鼠3 日龄耳壳完全直立, 4 日龄开始长下门齿, 5 日龄长上门齿, 7～8 日龄睁眼, 20 日龄可断奶, 55 日龄左右性成熟。3 种生长模型(Logistic 方程、Gompertz 方程和Von Bertalanffy 方程) 对体重、体长、尾和后足的生长过程的拟合优度均很高,择优选用Von Bertalanffy 方程对体重、体长和尾长进行描述, 选用Logistic 方程对后足长的生长过程进行描述。将该鼠的生长发育过程划分为4 个阶段, 乳鼠阶段: 初生至10 日龄; 幼鼠阶段: 11 日龄至20 日龄; 亚成年阶段: 21至55 日龄; 成年阶段: 56 日龄以后。对指名亚种和长江亚种生长、繁殖特性异同亦作了初步分析。     

人工育幼非洲狮、孟加拉虎、豹幼仔的生长曲线拟合比较

<正>生长曲线(Growth curve)是揭示动物生长发育规律的有效手段之一，反映动物发育指标(包括体重、体尺、体表面积等度量值)与时间之间的关系(盛志廉和吴常信，1995)。生长曲线方程大致可以分为三类：第一类是表示报酬递减规律的方程，如指数函数；第二类是描述光滑S型曲线，     

Richards方程的数学属性及其在兽类生长过程中的应用

通过对Richards方程数学属性的分析表明 ,该方程具有变动的拐点值 ,因而在描绘兽类多种多样的生长过程时具有良好的可塑性。依据其方程参数n取值的不同 ,Richards方程包含了Spillman ,Logistic,Gompertz以及Bertalanffy方程。为了评估Richards方程对兽类生长过程的拟合优度 ,作者引用 1 0组哺乳动物兽类生长数据 ,将它与一些经典的生长模型如Spillman ,Logistic,Gompertz以及Bertalanffy方程共同进行了拟合比较。结果表明 ,Richards方程具有良好的拟合优度 ,适于描绘多种多样的兽类生长模式。     

Correlates and predictors of the age of menarche

In a cross-sectional study of 452 girls between 10 and 16 years of age 36 indices of physical and 50 of mental development were tested for their correlation with age at menarche and chronological age, as well as for their predictive power for estimating menarche by multiple regression analysis. Indices of physical maturity and body weight when adjusted for chronological age showed the highest partial correlation coefficients with age at menarche. Among mental characters which show lower intercorrelations with menarche occurred the highest correlation coefficients for a handmotor factor "Spurennachzeichnen" and a factor "Gruppenabh?ngigkeit" (which indicates a type of social motivation). In general physical and mental factors correlate higher with chronological age than with age at menarche. By multiple regression analysis we determined 14 physical and 25 mental predictors explaining 21% and 17% respectively of the variance of age at menarche. The error of the estimate predicting menarche on body weight without knowledge of onset of menarche is +/- 1 year. Using chronological age in a sample of girls before menarche the error of the estimate only is +/- 6 months. To compare the predictive power of chronological age combined with body weight or with skeletal age the time interval is calculated within which 95% of girls attain menarche. The range of prediction extends from 4.3 to 1 year on chronological age (11-16 years); using mean body weight it can be improved by 1.8 to 6 months, while using mean skeletal age an improvement of 0.2 to 3.9 months is possible compared with body weight. The correlations between age at menarche and physical and mental variables are attributed to a common hormonal influence on rate of development.     

The effects of selection for different combinations of weights at two ages on the growth curve of mice

Summary The weights of mice in lines selected for different combinations of high and low body weights at 5 and at 10 weeks of age were recorded from 3 to 21 weeks of age. The average growth curve for each line was computed using the Gompertz function. The growth curves of lines selected for high or low weight at a single age (ST lines) showed large differences in estimates of mature size and small differences in estimates of maturing rate, i.e. of the relative rate of growth to maturity. The growth curves of lines selected by independent culling for divergent combinations of deviations of opposite sign in 5- and 10-week weights (ICL lines) showed little difference in estimates of mature size and a large difference in estimates of maturing rate. The growth curves of lines selected by index for divergence in 5-week weight with no change in 10-week-weight or for divergence in 10-week-weight with no change in 5-week weight showed large differences in estimates of mature size and large differences in estimates of the maturing rate. The relationship between mature size and maturing rate was affected in different ways by the three types of selection.     

Age at menarche as a fitness trait: nonadditive genetic variance detected in a large twin sample.

The etiological role of genotype and environment in recalled age at menarche was examined using an unselected sample of 1,177 MZ and 711 DZ twin pairs aged 18 years and older. The correlation for onset of menarche between MZ twins was .65 +/- .03, and that for DZ pairs was .18 +/- .04, although these differed somewhat between four birth cohorts. Environmental factors were more important in the older cohorts (perhaps because of less reliable recall). Total genotypic variance (additive plus nonadditive) ranged from 61% in the oldest cohort to 68% in the youngest cohort. In the oldest birth cohort (born before 1939), there was evidence of greater influence of environmental factors on age at menarche in the second-born twin, although there was no other evidence in the data that birth trauma affected timing. The greater part of the genetic variance was nonadditive (dominance or epistasis), and this is typical of a fitness trait. It appears that genetic nonadditivity is in the decreasing direction, and this is consistent with selection for early menarche during human evolution. Breakdown of inbreeding depression as a possible explanation for the secular decline in age at menarche is discussed.     

A comparison of the Schumacher with other functions for describing growth in pigs

This study was undertaken to introduce the Schumacher equation and compare it with established functions for describing growth in pigs. The relationship between live weight (LW) and cumulative feed intake was also investigated. A database was constructed from three independent trials in which LW, age and intake were measured from birth to 937 days. Three growth functions were used for analysis of growth versus age: Gompertz, Schumacher and Weibull; and the Richards and monomolecular equations were used for analysis of cumulative feed intake versus LW. The growth functions have different points of inflexion. Liveweight at inflexion is W_f/e for the Gompertz, where W_f is the final weight, W_f/e² for the Schumacher, and W_f − (W_f − W₀) exp[−(n − 1)/n] for the Weibull, where W₀ is initial body weight and n is a shape parameter. Meta-analysis of the data using mixed model and nonlinear regression procedures was conducted to identify the most appropriate growth function. Functions were compared using F-tests or Bayesian Information Criteria, which give a value based on best fit and number of parameters in the model. The three equations were fitted to five individual pig growth profiles and to the composite data. Although the Weibull had a lower residual mean square, it did not significantly improve the fit compared to the simpler models and appears to be over-parameterised. The results suggest that model selection should be based on the type and amount of data available for analysis. Residuals plot showed that Schumacher and Weibull better predict the initial growth phase, however, all models showed largest magnitude of residuals towards the end of the growth profile. The monomolecular equation was most appropriate for describing LW against cumulative feed intake and may be used to formulate diets based on the efficiency of conversion of feed to LW at various stages of the animal's life span.     

Effect of parental anthropometric parameters on neonatal birth weight and birth length

Data on 550 healthy pregnant women, 550 healthy fathers and their healthy term neonates born from singleton pregnancies (37(+0) through 41(+6) week) during a one-year period were reviewed. Maternal mean age was 27.7 +/- 9.37 years, mean pregestational weight 64.0 +/- 9.50 kg, mean gestational weight gain 15.4 +/- 4.33 kg, mean height 169.7 +/- 5.81 cm, and mean gestational age 40.1 +/- 0.95 weeks. Paternal mean age was 31.4 +/- 6.22 years, mean weight 84.6 +/- 10.35 kg, and mean height 182.8 +/- 6.84 cm. Mean birth weight was 3,709.8 +/- 500.48 g and 3,562.5 +/- 443.02 g, and mean birth length 51.5 +/- 1.91 cm and 50.7 +/- 1.62 cm in male and female newborns, respectively, yielding a birth weight greater by 147.3 g and birth length by 0.8 cm in the former. Study variables showed statistically significant correlations: maternal age contributed to the significant correlation between maternal weight and parity, maternal pregestational weight, weight at delivery, gestational weight gain and body height correlated significantly with neonatal birth weight and birth length, gestational age correlated significantly with neonatal weight and length (p = 0.01 all), parity had no major impact (p > 0.05). Paternal height and weight correlated significantly with neonatal birth weight and birth length (p = 0.01). Study results pointed to a significant correlation of maternal pregestational weight, gestational weight gain and body height, and of paternal weight and height with the neonate birth weight and birth length.     

Age at menarche in urban Argentinian girls: association with biological and socioeconomic factors

Age at menarche is regarded as a sensitive indicator of physical, biological, and psychosocial environment. The aim of this study was to determine the age at menarche and its association with biological and socioeconomic factors in girls from Santa Rosa (La Pampa, Argentina). An observational cross-sectional study was carried out on 1,221 schoolgirls aged 9-15 years. Menarche data were obtained by the status-quo method. Height, sitting height, weight, arm circumference, tricipital and subscapular skinfolds were measured. We also calculated body mass index, measures of body composition and proportions, and fat distribution. To assess socioeconomic factors, parents completed a self-administered questionnaire about their occupation and education, family size, household, and other family characteristics. The median age at menarche - estimated by the logit method--was 12.84 years (95% CI: 12.71, 12.97). Compared with their premenarcheal age peers, postmenarcheal girls had greater anthropometric dimensions through age 12. After this age, only height was higher in the latter group. Data were processed by fitting two logistic regressions, both including age. The first model included anthropometric variables and birth weight, while the second model included the socioeconomic variables. The significant variables derived from each model were incorporated into a new regression: height, sitting height ratio (first model), and maternal education (second model). These three variables remained significantly associated with menarche. The results suggest a relationship between linear growth and menarche and agree with those found in other populations where the advancement of menarche is associated with improved living conditions. In relatively uniform urban contexts, maternal education may be a good proxy for the standard of living.