scholarly journals Growth Curves for Body Weight of the Laboratory Rat

1969 ◽  
Vol 22 (4) ◽  
pp. 1077 ◽  
Author(s):  
PJ Pahl
Keyword(s):  
Body Weight ◽  
Body Fat ◽  
Growth Rates ◽  
Growth Curves ◽  
Tail Length ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Second Stage ◽  
Weight Growth ◽  
Laboratory Rat

Body weight growth of rats, bred and reared in small cages, occurs in two main stages, which overlap to a degree. During the first stage, when rats develop to maturity, all parts of the animal (e.g. head, body, limbs, tail) grow, resulting in high relative growth rates. During the second stage, one of post-maturity growth, there is an increase in body weight, unaccompanied by corresponding significant changes in such measures as limb and tail length. It is thought that the increase in body weight during the second stage is due to an increase in body fat; however, further experimentation is required to verify this contention.

Comparative breed studies of beef cattle. I. Changes in body weight

1963 ◽  
Vol 14 (6) ◽  
pp. 882 ◽  
Author(s):  
NM Tulloh
Keyword(s):  
Body Weight ◽  
Growth Rates ◽  
The Other ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Breed Differences ◽  
Weaning Age ◽  
Absolute Growth ◽  
The Mean ◽  
One Year

A comparative growth study was made of Hereford, Aberdeen Angus, and beef Shorthorn cattle reared and kept together throughout their lives on irrigated perennial pastures at the Metropolitan Farm, Werribee, Vic. Records of body weight as a function of age were obtained on 404 Hereford, 172 Aberdeen Angus, and 127 Shorthorn cattle, representing cattle born in 1955, 1957, 1958, 1959, and 1960. At birth, male calves were significantly heavier than females, and Hereford calves were significantly heavier than Shorthorn and Aberdeen Angus calves, the birth weights of Shorthorn and Aberdeen Angus calves being similar. Up to the age of 5 years, the younger and lighter 2-year-old cows produced lighter calves than cows which were both older and heavier. At weaning age (9.5 months) steers were significantly heavier than heifers. Herefords were significantly heavier than Aberdeen Angus in two years out of three; and in one year out of three, Herefords were significantly heavier than Shorthorns. Shorthorns were significantly heavier than Aberdeen Angus in one year out of three. When the steers were finally weighed off grass at the mean age of either 20 months (1958, 1959, and 1960 cattle) or 25 months (1957 cattle), Herefords were significantly heavier than Aberdeen Angus in four successive years, and in one year out of four the Herefords were significantly heavier than Shorthorns. In three years out of four, Shorthorns were significantly heavier than Aberdeen Angus. Breed differences between the mean weights of breeding cows were not significant and, up to the age of 5 years, as breeding cows grew older they became heavier. Body weight growth curves indicated that the cattle experienced a severe check in growth during the winter months (June, July, August). At other times of the year, growth rates were satisfactory. Cattle born in some years grew better than cattle born in others. This was thought to be due partly to differences between years in the quality and quantity of pasture available, even though the pastures were irrigated. Average absolute and average relative growth rates were calculated for the 1957 and 1958 steers before and after weaning. Breed differences in absolute growth rates before weaning were not statistically significant, but after weaning, rates were significantly the highest for Herefords in both years. The breed differences in average relative growth rates were in the same direction as those for absolute growth rates. However, the pre-weaning relative growth rate of Shorthorns was significantly higher than those of the other breeds among the 1957 steers. When due allowance was made for the smaller size of Aberdeen Angus steers at birth and at weaning, the relative growth rates of this breed were less than those of the other breeds. Absolute and relative growth rates were higher for all breeds before weaning than afterwards. This was mainly a reflexion of low post-weaning growth rates during the winter months. Rank correlation coefficients between birth weight and weight at subsequent ages were low and variable in different breeds and in different seasons. However, coefficients calculated between subsequent ages, beginning at weaning age, were generally highly significant. The breed and sex differences presented in this paper have been compared with the limited data from the literature and, in general, the results are similar.

Effects of Photoperiods on the Growth Performance of Juvenile Trichogaster lalius (Hamilton, 1822)

2017 ◽  
Vol 65 ◽  
pp. 16-21 ◽  
Author(s):  
Madhu Awasthi ◽  
Pragya Gupta ◽  
Farah Bano ◽  
Mohammad Serajuddin
Keyword(s):  
Body Weight ◽  
Growth Performance ◽  
Growth Rates ◽  
Juvenile Fish ◽  
Maximum Growth ◽  
Light Conditions ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Light Duration ◽  
The Mean

Juvenile of Trichogaster lalius was reared under three photoperiod conditions (0L:24D, 12L:12D, 16L:08D) for 60 days to examine the growth performance under laboratory conditions. The maximum growth was observed in the juvenile of T. lalius exposed to 16:00 hrs. light. The mean body weight of different groups of juvenile fish exposed to different light conditions were significantly different (p<0.05) from each other which was observed from 20thday of the experiment. The absolute, specific, and relative growth rates were found to be maximum in the group exposed to 16:00 hrs. light duration. The present study indicated that 16:00 hrs. light duration was considered to be better for the growth of juvenile of T. lalius under controlled condition.

ANALYSES OF GROWTH CURVE PARAMETERS OF N’DAMA CATTLE RAISED IN THE HUMID TROPICS

2021 ◽  
Vol 34 (1) ◽  
pp. 1-13
Author(s):  
M. O. Ozoje ◽  
S. O. Peters ◽  
S. I. Ojikuku
Keyword(s):  
Body Weight ◽  
Growth Curve ◽  
Growth Rates ◽  
Growth Traits ◽  
Negative Relationship ◽  
Growth Function ◽  
Individual Growth ◽  
Early Maturity ◽  
Relative Growth ◽  
Relative Growth Rates

Individual growth curve parameters are suitable phenotypic variable for the assessment of growth course and early maturity. This study focused on the analyses of growth curves parameters of N’Dama cows derived from the Richarads growth function. Data consist of field records of weight measurements from birth to 36 months old of 98 N’Dama cows born and raised between 1992 and 1998. The coefficient of variation was moderately high in both the curve and predicted parameters except for point of inflation (m). The estimates of heritability for maturing traits ranged from 0.18 to 0.30. While those for body weights and growth traits ranged form 0.21 to 0.47. High correlation coefficients were observed between mature weight parameter (A) and body weight at 180 days. 365days and 550days of age. A negative relationship was observed between A and maturing rate index k,(0.51) and between A and all maturing parameters associated with stages of growth (degrees of maturity and relative growth rates). Sire variation was an important source of variation (P < 0.05) for all the parameters studies except for residual means squares (RMS). Year of birth was also a significant (P < 0.05), source of variation for A, K, RMS, degrees of maturity at 180days of age and the relative growth rates at 180days and 365 of age, while age of dam significantly (P < 0.05) affected the constant of integration b, the maturing rate index k, body weight and degree of maturity at 180days of age. Season of birth affected the point of inflation (m) RMS body weight at 180day and absolute growth rate at 365days of age. The interaction between year of birth and age of dam was significant (P < 0.05), affecting only the A and the K parameters

Selection for biomass production based on respiration parameters in eucalypts: effects of origin and growth climates on growth rates

1996 ◽  
Vol 26 (9) ◽  
pp. 1556-1568 ◽  
Author(s):  
Thimmappa S. Anekonda ◽  
Richard S. Criddle ◽  
Lee D. Hansen ◽  
Mike Bacca
Keyword(s):  
Temperature Dependence ◽  
Growth Rates ◽  
Heat Rate ◽  
Eucalyptus Species ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Metabolic Heat ◽  
Respiratory Parameters ◽  
Metabolic Heat Rate ◽  
Different Climates

Seventeen Eucalyptus species and 30 rapid-growing Eucalyptuscamaldulensis trees (referred to as plus trees), growing in a plantation were studied to examine relationships among measured plant growth and respiratory parameters, geographical origins, and growth climate. The respiratory parameters measured at two different temperatures by isothermal calorimetry were metabolic heat rate, rate of CO2 production, and the ratio of heat rate to CO2 rate. Metabolic heat rate was also measured as a continuous function of temperature by differential scanning calorimetry in the range of 10 to 40 °C. Tree growth was measured as rates of height and stem volume growth. The values of respiratory and growth variables of Eucalyptus species are significantly correlated with latitude and altitude of origin of their seed sources. The maximum metabolic heat rate, the temperature of the maximum heat rate, the temperature coefficients of metabolic rate, and the temperatures at which the slopes of Arrhenius plots change are all genetically determined parameters that vary both within and among species. Measurement of growth rate–respiration rate–temperature relationships guide understanding of why relative growth rates of Eucalyptus species and individual genotypes differ with climate, making it possible to identify genotypes best suited for rapid growth in different climates. The temperature dependence of respiration rates is an important factor determining relative growth rates of eucalypts in different climates. To achieve optimum biomass production the temperature dependence of individual plants must be matched to growth climate.

Studies on the sowing dates of cotton in the Sudan Gezira: I. The influence of date of sowing on plant growth and development

1967 ◽  
Vol 69 (3) ◽  
pp. 305-315 ◽  
Author(s):  
J. E. Jackson
Keyword(s):  
Growth Rates ◽  
Slow Growth ◽  
Seasonal Pattern ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Research Division ◽  
Sowing Dates ◽  
Net Assimilation ◽  
State Growth ◽  
Sudan Gezira

Growth analysis of cotton crops sown in the Sudan Gezira at monthly intervals between August and May revealed a marked seasonal pattern of growth. Irrespective of plant age and fruiting state growth of non-senescent plants was slowest during the cool winter months. Relative growth rates of young plants were highest in August, September and early October due to the high specific leaf areas and fairly high net assimilation rates found then. They were lowest when minimum temperatures were lowest. Net assimilation rates were also lowest in the coolest months, probably as a result of restricted growth. High temperatures in the spring reduced fruiting. It is concluded that low minimum temperatures and high evaporation rates are both associated with slow growth, and play a large part in determining the characteristic decline of growth rates of cotton sown at the usual date in August.I wish to thank the Chief of the Research Division, Ministry of Agriculture, Sudan, for permission to publish this paper and to record my gratitude to the team of field and laboratory assistants, especially Salih Saad and Hassan Osman, who helped in the work.

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