scholarly journals Growth, efficiency and body composition of mice selected for post-weaning weight gain on ad libitum or restricted feeding

1986 ◽  
Vol 48 (2) ◽  
pp. 101-109 ◽  
Author(s):  
D. J. S. Hetzel ◽  
F. W. Nicholas

SummaryAfter seven generations of selection, a line of mice selected for post-weaning (21–42 days) weight gain on full feeding (SF) showed significant increases of 49% in weight gain, 31% in efficiency and 14% in food intake, when compared with its control on full feeding between 21 and 42 days. After day 42, SF mice continued to eat more food and were 28% heavier than control mice at 91 days. Because SF mice were heavier than control mice at almost all ages, they were fatter on an age basis. There was, however, no change in the rate of deposition of fat, protein and ash relative to body weight. On restricted feeding between 21 and 42 days, SF mice showed a non-significant increase in weight gain, and hence in efficiency, of 12%. They deposited more fat than control mice during the feeding period but there was no significant difference when comparisons were made on a weight basis.A contemporary line of mice selected for post-weaning (21–42 days) weight gain on restricted feeding (SR) had significant increases of 12% in weight gain, 17% in efficiency but no significant change in food intake, when compared with its control on full feeding between 21 and 42 days. SR mice were the same weight as control mice at all ages except day 21, when they were significantly lighter due to direct genetic effects rather than maternal effects. SR mice had a lower (P<0·10) rate of fat deposition per unit body weight and became less fat relative to their control as body weight increased. The rate of deposition of other components was not altered by selection. On restricted feeding, SR had a significant increase in weight gain, and hence in efficiency, of 37%. Changes in body composition were similar to those on full feeding.It was concluded that the use of a restricted feeding regime had enabled the exploitation of heritable variation in the partitioning of energy for growth. This variation was independent of genetic variation for appetite and body weight.Overall performance at each level of feeding was best improved by selection on that feeding level. The realized genetic correlation between post-weaning weight gain on full and restricted feeding was estimated to be 0·28 ± 0·08, indicating a very different genetic basis for the same character in the two feeding environments.

1996 ◽  
Vol 63 (1) ◽  
pp. 149-157 ◽  
Author(s):  
J. A. Archer ◽  
W. S. Pitchford

AbstractFood intake and body weight of 119 mice was measured from 3 to 18 weeks of age. Residual food intake was calculated for each week as the variation in food intake independent of variation in weight gain, weight maintained and sex. Growth efficiency and maintenance requirement were calculated by fitting curves to data from 3 to 18 weeks. The repeatability of residual food intake was low in young mice, but increased as they matured. Growth efficiency was correlated with residual food intake in very young mice. Residual food intake was not correlated with maintenance requirement in young mice, but as mice matured the correlation of residual food intake with maintenance requirement increased to 0·6. Body composition at maturity was correlated with residual food intake and maintenance requirement of mature mice, but a large proportion of the variation in residual food intake and maintenance requirement was independent of body composition. The results suggest that the age at which residual food intake is measured is important if it is to be used as a criterion for selection for efficiency.


1997 ◽  
Vol 92 (5) ◽  
pp. 481-486 ◽  
Author(s):  
A. C. Hackney ◽  
W. Hezier ◽  
T. P. Gulledge ◽  
S. Jones ◽  
D. Strayhorn ◽  
...  

1. As an ancillary study carried out during the recently completed Multicenter Study of Hydroxyurea, we examined the effect of hydroxyurea on the body weight, body composition and exercise capacity of adult patients with sickle-cell anaemia. 2. The subjects received either hydroxyurea (six males and four females) or placebo (eight males and six females). Data for each subject were generated during four separate 24 h admissions to the General Clinical Research Center. These admissions occurred at baseline and then at 6, 12 and 18 months after the start of study drug (hydroxyurea or placebo) administration. During each admission, body composition was measured by using a dual X-ray absorptiometer, and exercise testing was performed by cycle ergometry. Anaerobic performance was assessed according to a ‘Wingate’ protocol (20 s at maximal intensity against a cycling resistance of 7.5% body weight). Aerobic performance was examined using a steady state submaximal exercise protocol (10 min cycling time). 3. At baseline, no significant difference in any parameter was found between the hydroxyurea- and placebo-treated groups. At 18 months, the hydroxy-urea-treated subjects exhibited an average weight gain of 3.16 kg. The mean weight gain in the placebo-treated subjects was 1.82 kg. Body composition analysis showed that the additional weight in both groups involved both lean and fat body mass components. In anaerobic performance, the subjects given hydroxyurea showed an increase in peak muscle power of 104.9 W. The placebo group also showed an increase, but theirs was a more modest gain of 57.7 W. The most marked improvement in anaerobic performance was observed in the hydroxyurea-treated men (P < 0.05). In aerobic performance, the hydroxyurea-treated subjects exhibited a decrease in peak heart rate response to a standardized workload of 15.2 beats/min, as compared with a decrease of only 4.3 beats/min in the placebo-treated patients. 4. Taken together, the overall weight gain, combined with increases in both anaerobic muscular performance and aerobic cardiovascular efficiency, provides objective data to support the subjective impression that hydroxyurea administration produces an improvement in the physical capacity of patients with sickle-cell anaemia.


2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 541-541
Author(s):  
Brandon McGuire ◽  
Azra Dees ◽  
Anna Ogilvie ◽  
Sue Shapses

Abstract Objectives Serum calcidiol is inversely associated with BMI in obese individuals and murine research has shown that vitamin D deficient diets (VDD) increase body weight. Alcohol intake doesn't necessarily increase body weight despite its caloric density but has been associated with VDD. The objective of this study was to determine the effect of vitamin D deficiency with or without alcohol on body weight, body composition, glucose tolerance, and energy expenditure in seven-month-old female mice. Methods Seven-month-old female retired breeder C57BL/6J mice (n = 40) were weight-matched and randomized to one of four diets: control (normal purified AIN-93 diet), vitamin D deficient (VDD, 0 intake of vitamin D), alcohol (Alc, 10% ethanol), or vitamin D deficient and alcohol (VDD + Alc). Mice were fed ad libitum for 8 weeks. Body weight and food intake were recorded weekly and body composition was measured at baseline and final time points using EchoMRI. Glucose tolerance and energy expenditure (EE) were assessed by an oral glucose tolerance test (OGTT) and Oxymax/CLAMS unit at week 8. Results Body weight at baseline was 27.4 ± 1.8 g and did not differ between groups. Mice drinking alcohol had a decreased food intake (p &lt; 0.001). When liquid calories were accounted for, total caloric intake did not differ between groups. Weight gain throughout the study increased more in the VDD groups (p &lt; 0.05). Increases in weight were 0.81 ± 2.9, 0.82 ± 2.0, 2.0 ± 1.7, and 3.6 ± 2.9 g, in the control, Alc, VDD, and VDD + Alc groups, respectively (p &lt; 0.05). Lean body mass was also increased due to VDD (p &lt; 0.05). The total fat mass did not differ significantly between groups, however, VDD groups gained more fat mass over time (p &lt; 0.05). Two-way ANOVA showed an interaction between vitamin D and alcohol for EE (p &lt; 0.05). Positive incremental area under the curve (IAUC) for blood glucose was decreased due to alcohol intake (p &lt; 0.05). Conclusions In conclusion, alcohol intake decreased blood glucose and food intake, but there was no effect on total caloric intake, body weight or body composition. VDD led to greater increases in body weight and soft tissue compartments compared to other groups that were not explained by caloric intake or EE. Understanding mechanisms that are causing excess weight gain due to VDD is currently a focus in the lab. Funding Sources USDA-NIFA (NJAES).


Author(s):  
Abere DV

The study investigated the effect of feeding high and low saturated fatty acid based diets to feed female albino rats (Rattusnorvegicus) with a view to evaluating the effects of the fatty diets on the feeding patterns, weight and body composition of the rats. Seven months old female Rattus norvegicus were used for the experiment. The weights of the rats were taken for twelve weeks using Salter balance (Model 250). Four experimental diets were formulated which were made up of 2.5 and 5.0 g of margarine (blue band), 2.5 and 5.0 g canola oil each mixed with the basal diet. The control diet was grower feed and the resultant experimental diets were fed to the experimental rats kept in cages at the rate of 12 rats per cage. The rats were fed with the diets at the rate of 3% of body weight for a period of twelve weeks. The highest weight gain was recorded in the group fed with 5.0 g margarine, followed by 5.0 g canola, 2.5 g margarine, 2.5 g canola and least in the rats fed the control.The mean weight gain of the rats fed with 5.0 g margarine and 5.0 g canola were significantly different (p<0.05) from the mean weight of 2.5 g margarine, 2.5 g canola and the control. The food intake of the rats fed 5.0 g margarine and 5.0 g canola was also significantly different (p<0.05) from the food intake of rats fed 2.5 g margarine, 2.5 g canola and the control. The proximate composition of the carcass of the rats fed the different experimental diets showed that fat content of the rats fed 5.0 g margarine was higher than in the rats fed the other diets. The histology of the liver of rats fed 5.0 g margarine and 5.0 g canola showed greater fat accumulation in the rat’s liver compared to rats fed 2.5 g margarine, 2.5 g canola as well as the control. Rats with the highest body weight gain were considered obesity-prone; those with the lowest body weight were regarded as obesity-resistant while others were considered intermediate. The study concluded that the kind of fat consumed contributes to the weight gained by the rats.


1977 ◽  
Vol 107 (9) ◽  
pp. 1715-1723 ◽  
Author(s):  
Pi-Yao Lin ◽  
Dale R. Romsos ◽  
Gilbert A. Leveille

1975 ◽  
Vol 20 (3) ◽  
pp. 315-335 ◽  
Author(s):  
L. S. Monteiro

SUMMARYA model is proposed to establish a functional relationship between food intake, weight gain and body composition during growth, based on the differential energy requirements for fat, fat-free tissues and contents of the digestive tract. If constant specific nutrient requirements are assumed for fat and fat-free tissues, these requirements can be directly estimated from changes in food intake and body composition during growth. By introducing an allometric function relating changes in fat-free tissue to changes in body weight, the model is extended to include situations where direct measures of body composition are not available. This enabled the model to be fitted to data on food intake, body weight and growth rate up to 2 years of age in Friesians and Jerseys fed ad libitum on a complete diet. The nonlinear model is contrasted with a linear relationship where food intake i s related to body weight and weight gain. The linear model was unable to account for the changes in food intake over the whole period of growth. The non-linear model allowed a gradual decline n i maintenance requirements per unit weight and indicated an increase in the net conversion coefficient of food into gain, consistent with an increase from early to late growth in proportion of fat deposited.For the period studied the Jerseys were less efficient in transforming food into weight gain than Friesians. On the non-linear model, about half of the difference was attributable to the higher metabolic rate per unit weight of Jerseys, the remainder to poorer utilization of nutrients for weight gain. If, as the model indicated the conversion coefficients of food into body constituents were the same in the two breeds, the difference in efficiency may be attributable to a higher proportion of fat in the overall gain of Jerseys. The pattern of estimated fat deposition also differed in the two breeds with Jerseys appearing to be less mature in fat percentage at all stages.


2011 ◽  
Vol 106 (S1) ◽  
pp. S19-S23 ◽  
Author(s):  
Lucille G. Alexander ◽  
Carina Salt ◽  
Gaelle Thomas ◽  
Richard Butterwick

To understand the effects of neutering on food intake, body weight (BW) and body composition in kittens, data from an unrelated study were subjected topost hocanalysis. A total of twelve pairs of 11-week-old female littermates were randomly assigned to either a neutered group (neutered at 19 weeks old) or an entire group (kept entire) and offered free access to a dry diet until the age of 1 year. Neutered kittens exhibited increased food intake and increased BW after neutering (bothP < 0·00 001). Food intake (per kg BW) peaked 10 weeks after neutering; the mean intake of neutered kittens was 17 (95 % CI 8, 27) % more than entire littermates (P = 0·00 014). The intake was then reduced until there was no significant difference between the groups 18 weeks post-neutering. By 52 weeks of age, the neutered kittens were 24 (95 % CI 11, 39) % heavier than entire littermates (P < 0·0001) with a body condition score (BCS) 16·6 (95 % CI 0·9, 34·8) % higher (P = 0·0028). Neutered kittens continued to grow significantly fatter after neutering (allP < 0·0014), while entire kittens showed no significant change after 18 weeks of age. As neutered kittens consumed similar amounts of energy to their entire littermates from 18 weeks post-neutering, while their BW, BCS and percentage fat continued to increase, we suggest that neutered kittens have a reduced metabolisable energy requirement, and should therefore be fed to maintain an ideal BCS rather thanad libitum.Moreover, to maintain an ideal BCS, entire kittens consumed 93 (95 % CI 87, 100) % of their theoretical intake at 26 weeks of age, and 79 (95 % CI 72, 87) % at 52 weeks of age, suggesting that the current energy recommendation is inappropriate for these kittens.


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