Correlation Of Body Weight Research Articles

Correlation of body weight and reproductive characteristics in rainbow trout

Due to a lack of adequate technology to permanently mark individual rainbow trout at the time of the experiment, an attempt was made to estimate genetic correlation coefficients from analyses of full-sib family means. This procedure has provided the first direct estimates of genetic correlations between body weight at various ages and reproductive performance. It was found that most genetic correlations are favorable to the likely goals of selection programs designed to increase market weight. Evidence was found for a negative genetic relationship between number of eggs spawned and egg size. Age at spawning within the spawning season was positively correlated with egg production and post-spawning weight. The estimated correlations indicated that females spawning early in the season are younger and lighter in weight than those spawning later in the season. Estimates of correlated selection responses to direct selection for increased yearling weight in stocks of age-2 or age-3 spawning rainbow trout would all be favorable. Weight at 25 months could be increased by as much as 50% of the expected direct response while egg size and egg number could be expected to increase by about 16% and 29%, respectively, of that expected from direct selection based on individual performance.

Age-Constant Versus Weight-Constant Feed Consumption and Efficiency in Broiler Chickens

Weekly body weights, feed consumptions (FC), and feed efficiencies (FE = gain:feed) of 148 male and 125 female broilers were measured individually between 2 and 7 wk of age. Multiple regression analyses of these traits were performed to examine the influence of body weight, weight gain or feed consumption, age, and individual broiler differences. Four different measures of FC and FE from 4 to 6 wk of age were compared within sex: age-constant FC and FE; weight-constant FC and FE; age-constant-weight-corrected FC and FE; and weight-corrected FC and FE, which estimate weight-constant measures.Much of the variation (85 to 90%) among broilers in FC and FE was due to age and body weight differences. Partial regression coefficients indicated that increased body weight at commencement of testing was associated with increased FC and reduced weight gain and FE. Correlations between age-constant and weight-constant FC were zero. This indicates the two forms have little in common. Correlations of body weights and weight gain with FC were negative (−.5 to −.8) for weight-constant values but positive (.5 to .8) for age-constant values. Hence, correlations of the correct (weight-constant) measure of FC with body weights indicate that faster growth gives rise to lower broiler feed consumption. Age-constant and weight-constant FE values were positively correlated (.8 to .9); however, the latter values had larger correlations with body weights and weight gain. These results emphasize the need to correct age-constant FC and FE for body weight differences in order to evaluate differences in efficiency among broilers more accurately.

Seasonal Abundance of the Exotic Predatory Cladoceran, Bythotrephes Cederstroemi, in Western Lake Erie

The predaceous cladoceran, Bythotrephes cederstroemi, has recently invaded the Great Lakes and basic information on its seasonal abundance and population demographics is lacking. Accordingly, we examined seasonal variation in abundance, length—weight relationships, fecundity, ontogeny of lateral spine production, sex ratio, and incidence of resting vs. subitaneous eggs. Seasonal variation in these parameters was compared with water temperature variation and the presence of a potential competitor, Leptodora kindti. Specimens for these analyses were collected with nocturnal surface tows in the western basin of Lake Erie during summer and fall, 1987. Bythotrephes did not appear until 23 July, had its maximum abundance (111 individuals/m 3) at the surface on the night of 9 October, and persisted at lower numbers in samples through the last sampling date, 14 December. The correlation of body weight with tail spine length varies seasonally, with individuals weighing less in the summer than in the fall. Neonates possess one pair of lateral spines on the tail spine and add a pair during each of the first two molts, enabling determination of instar distribution. Females produce one to 12 subitaneous eggs per brood, with males and resting eggs occurring rarely. Bythotrephes abundance was negatively correlated with water temperature and Leptodora abundance, suggesting that Leptodora abundance or temperature, or both, affect the success of Bythotrephes in the western basin of Lake Erie.

INSULIN-LIKE GROWTH FACTOR 1 IN THE DEVELOPING RHESUS MONKEY

Although the rhesus monkey is an excellent model of human growth hormone physiology, no developmental survey of serum concentrations of the growth hormone dependent somatomedin, insulin-like growth factor 1 (IGF-1), is available. Thus, we studied serum values of IGF-1 collected between birth (NB) and 17 years (17yr) of age in 83 animals in a cross-sectional study and between 3 months (3M) and 4 years (4yr) of age in 6 animals in a longitudinal study. RIA incorporated antibody to IGF-1 (provided by the NHPP), synthetic IGF-1 (provided by Dr. C.H. Li) as radioligand, and pooled rhesus monkey serum as standard. All sera were extracted with acid-ethanol to eliminate the effects of binding proteins. Results from the cross-sectional study were (values in U/ml): Pubertal animals of 2-4 years had significantly higher values than younger or older animals (p<.001). There was a correlation of bodyweight with IGF-1 values in the males (R2=.717, p<.0005). This trend was confirmed in the longitudinal study. In conclusion, the rhesus monkey, like the human being, has higher IGF-1 values during the pubertal period, and should afford a useful model of IGF-1 regulation in human development.

Inter-age correlations of body weight, weight gain and food intake within and between breeds of cattle

ABSTRACTIn a multibreed experiment, 292 heifers from 25 British cattle breeds were fed a standard pelleted diet ad libitum from 12 to 72 weeks of age. Inter-age correlations involving body weight, weight gain, average daily food intake and cumulated food intake were measured across traits at the same age and within and across traits at ages separated by an interval of 12, 24, 36 and 48 weeks. Within-breed correlations were phenotypic but between-breed correlations were genetic.The between-breed inter-age correlations involving body weight, cumulated intake and average daily intake were all very high (range 104 to 0·94) and declined only gradually as the intervening age interval increased from 12 to 48 weeks. Inter-age correlations involving weight gain were lower but usually above 0·7. The within-breed correlations by contrast were invariably lower and declined much more rapidly as the age interval increased. Although the between-breed and within-breed correlations differed in magnitude there was a similarity in their overall pattern.For breed samples, body weight at young ages provided very accurate rankings at later ages for body weight, cumulated intake and average daily intake. Body weight was almost as reliable as food intake itself for predicting cumulated intake.For individuals within breeds predicted rankings at later ages were not very accurate for body weight or cumulated intake and they became worse as the age interval increased. Neither weight gain nor average daily intake could be predicted with any reliability.Inter-age correlations while dependant on age interval did not depend on age itself in the case of body weight and cumulated intake, although they were age-dependant for weight gain and to a lesser extent for average daily intake. Reciprocal correlations between body weight and cumulated intake were very symmetrical whereas those involving weight gain and daily intake were asymmetrical.

Some simple multiple linear regression equations for estimation of maximal aerobic power in healthy Indian males.

An attempt has been made to evolve some simple multiple linear regression equations for the prediction of VO2 max from body weight, time for 3.2 km run and exercise dyspnoeic index ( DIstd Ex%). The predictor variables have been selected by examining the product moment correlations of body weight, relative body weight indices, time for 3.2 km run, chest expansion, height, and DIstd Ex% with VO2 max, based on data collected on 320 healthy Indian males (17-22 years). It has been observed that body weight, time for 3.2 km run and DIstd Ex% attained maximum correlations with VO2 max. Thus, two regression equations with two and three predictor variables have been established in this paper to predict VO2 max. The first regression equation yielded a multiple correlation of 0.608 (P less than 0.001) with a standard error of 0.214 1 X min-1. In this equation, body weight and time for 3.2 km run were considered as significant predictors. To increase the precision of this equation, another multiple linear regression equation based on body weight, time for 3.2 km run and DIstd Ex% as predictors has been developed. This equation yielded a multiple correlation of 0.658 (P less than 0.001) with a standard error of 0.204 1 X min-1. Applications of these regression equations will be of practical importance to biomedical scientists engaged in the development of a simple procedure for indirect assessment of VO2 max, and may serve well as preliminary screening procedures for personnel selection.

Testicular growth in boars of different genetic lines and its relationship to reproductive performance.

Testicular growth of 377 boars was compared by obtaining in situ measurements of testes width and length and excised tissue weights. Two experiments involved a line selected nine generations for ovulation rate (OR) and a control line (CL), and two experiments contained boars of the OR line and two other lines; WL, a Large White-Landrace cross, and a line founded by crossing lines OR and CL and selected six generations for increased average daily gain and decreased backfat (LG line). In situ testes measurements were similar for the OR and CL lines and were curvilinearly related to age. The LG line had smaller in situ measurements than the OR line (P less than .05) when both unadjusted means and means adjusted for body weight were compared. The OR line had 10.5% heavier testes than the CL line at 90.8 kg and a 9 to 15% advantage at 120, 141, 162 and 183 d of age. The OR line had more rapid testicular development from 120 to 183 d of age (P less than .05) than the CL line. The LG line had significantly lower excised testes weights (17 to 50% less), a lower percentage of tubules that showed active spermatogenesis and lower mean diameter of the seminiferous tubules (P less than .05) than the OR line. The relative differences between lines OR, CL and LG suggest that selection for lean growth rate has resulted in less rapid testicular development and increased age at puberty. The correlations of testes weights and in situ testes measurements taken at the time of castration were between .76 and .93. The correlations of testes width and testes length with epididymides weights were slightly lower, and correlations of body weight and testes weight ranged from .51 to .70. Mean diameter of the seminiferous tubules and percentage of tubules with active spermatogenesis were correlated with measurements of testes size (r = .50 to .61) and body weight at the time of castration (r = .29 to .36). Correlations of excised testes weights with number born in the boar's contemporary litter and ovulation rate of full sibs were uniformly positive. The correlations of measurements of testes size and backfat (r = -.09 to .20) suggest that the phenotypic relationship between testes growth and body composition is small. However, the response found in the LG line suggests a negative genetic relationship between lean growth rate and testicular growth rate.

Positive Correlation of Body Weight with Pituitary Tumor Incidence in Rats

Positive Correlation of Body Weight with Pituitary Tumor Incidence in Rats

Obesity and its role in polycystic ovary syndrome.

To examine the mechanism by which obesity influences ovulation, 55 patients with oligo- or anovulation were studied. Parameters measured in serum were sex steroid-binding globulin (SSBG), testosterone (T), PRL, LH, FSH, and estradiol (E2). The women were divided into 2 groups: an obese group (group 1), greater than 145% of ideal body weight, and a normal weight group, less than 120% ideal body weight. SSBG was measured by saturation analysis T, LH, FSH, PRL, and E2 were measured by RIA. SSBG group 1 levels were 7.14 ng dihydrotestosterone bound/ml compared to 14.7 ng dihydrotestosterone bound/ml in group 2 (P less than 0.05). There were no significant differences in FSH, T, or E2. The correlation of body weight vs. SSBG in all patients was r = -0.62. In these 2 groups, the SSBG was significantly lower in the obese patients compared to that in the normal weight patients, independent of T or E2 levels. SSBG correlated negatively with body weight, suggesting that obesity has an influence on SSBG levels independent of hormonal status. When SSBG is lowered, there may be an increase in free T which, by inhibiting follicular maturation, may begin the sequence of events seen in polycystic ovary syndrome.

Heritabilities and Correlations of body weight and Dressing Percentage in Broilers

Data from 958 progeny from five generations produced by 70 sires and 180 dams selected for dressing percentage were used to estimate heritability of body weight and dressing percentage and to estimate correlations between the two traits.Heritabilities based on full sibs were 0.58 and 0.29 for body weight and dressing percentage, respectively.Genotypic, phenotypic, and environmental correlations were 0.28, and 0.04, and −0.13, respectively.

Heritabilities and Correlations for Body Weight and Conformation in a Randombred Population of Turkeys

Abstract INFORMATION concerning the heritability of various physical traits in the turkey are available in the literature (Abplanalp and Kosin, 1952; Goodman et al., 1954; Bumgardner and Shaffner, 1954; McCartney, 1955; Kondra and Shoffner, 1956; and Johnson and Asmundson, 1957). However, similar information concerning genetic correlations between these traits is quite limited. McCartney (1955) found genetic correlations of .90 and .94 between 16 and 24-week body weight for males and females, respectively. Johnson and Asmundson (1957) determined genetic correlations between body weight at 8, 16 and 24-weeks, between body weight at these ages and body measurements (shank length, keel length, body depth, breast width and tibia circumference) and between all the various body measurements. With a few exceptions, the correlations were positive and relatively high. Correlations of body weight with body measurements tended to be higher than those among body measurements. Also correlations between length of bone and breast width…