Reduced energy expenditure after ventromedial hypothalamic lesions in female rats

1984 ◽  
Vol 247 (1) ◽  
pp. R183-R188 ◽  
Author(s):  
T. R. Vilberg ◽  
R. E. Keesey

Activity, O2 consumption, and body composition were measured in female rats with lesions of the ventromedial hypothalamus (VMH). One group of lesioned rats was food restricted to maintain body weights at control levels. O2 consumption of these food-restricted VMH-lesioned rats was 13% lower than that of nonlesioned rats. About half this energy savings accrued from reduced activity; the remainder resulted from a decline in resting metabolic rate (RMR). Though matched in weight to controls, the body composition of the restricted VMH-lesioned rats was abnormal. Their carcass protein was reduced by 12%, whereas fat was elevated 200%. The replacement of lean metabolically active tissue by carcass fat appears to underlie the reduction in RMR, an interpretation supported by multiple-regression analysis of carcass composition. Ad libitum-fed VMH-lesioned rats did not show this carcass protein decline, though their fat was elevated 895%. These results confirm that reduced activity contributes to energy savings and weight gain after VMH lesions. Likewise, restricting weight of VMH-lesioned rats to control levels reduced RMR, apparently because carcass protein declines. But, since ad libitum-fed female VMH-lesioned rats do not display reduced carcass protein, the historic assumption that RMR reductions contribute to their obesity appears unwarranted.

2007 ◽  
Vol 30 (3) ◽  
pp. 232-241 ◽  
Author(s):  
Julie Demars ◽  
Juliette Riquet ◽  
Marie-Pierre Sanchez ◽  
Yvon Billon ◽  
Jean-François Hocquette ◽  
...  

Quantitative trait loci (QTL) influencing many traits including backfat thickness and carcass composition have been detected on porcine chromosome 7 (SSC7) in an F2 cross between Large White (LW) and Meishan (MS) pigs. However, the genes and controlled pathways underlying the QTL effects on body phenotype remain unknown. This study aimed at investigating the tissue characteristics at metabolic and cellular levels in pigs that were either homozygous or heterozygous for a body composition SSC7 QTL. A backcross pig (BC3) was first progeny tested to confirm its heterozygoty for the SSC7 QTL; results on all offspring ( n = 80) confirmed the QTL effects on body fatness. This boar was then mated with three sows known to be heterozygous for this QTL. In the subset of pigs per genotype, we found that heterozygous LWQTL7/MSQTL7 pigs had smaller adipocytes in backfat, together with a lower basal rate of glucose incorporation into lipids and lower activities of selected lipogenic enzymes in backfat isolated cells, compared with homozygous LWQTL7/LWQTL7 pigs. A higher number of adipocytes was also estimated in backfat of LWQTL7/MSQTL7 animals compared with LWQTL7/LWQTL7 pigs. The SSC7 QTL did not influence oxidative and glycolytic metabolisms of longissimus and trapezius muscles, as estimated by the activities of specific energy metabolism enzymes, or the myofiber type properties. Altogether, this study provides new evidence for an altered adipocyte cellularity in backfat of pigs carrying at least one MS allele for the SSC7 QTL. Some candidate genes known for their functions on adipocyte growth and differentiation are suggested.


Author(s):  
A J Kempster ◽  
G L Cook ◽  
M Grantley-Smith

1The relationship between diet and health is now a major factor in the development of production and marketing strategies for the British meat industry, following Government recommendations that people should be encouraged to eat less fat. It has emphasised the need for accurate information on the body composition of national livestock populations and the fat content of the meat and meat products derived from them. This paper collates the information available for cattle, sheep and pigs, and provides base-line (1984) estimates of national lean and fat production. Changes that have taken place over the past ten years are also examined.2The basic framework for making estimates was the distribution of carcasses between fatness ranges in the national carcass classification schemes operated by the Meat and Livestock Commission (MLC). The distribution for cattle was obtained from a random 1 in 3 sample of beef carcasses classified (0.25 of all clean beef carcasses were classified).3A computer spread-sheet was constructed relating the midpoint means of the fatness ranges to carcass tissue proportions and chemical composition. Regressions for predicting carcass lean and fat content were calculated from accumulated data from surveys of commercial carcasses and breed evaluations for cattle (Kempster, 1986), for sheep (Kempster, Jones and Wolf, 1986a) and for pigs (Diestre and Kempster, 1985). Key regressions are given in Table 1. Carcass lean and fat are defined as in the standard MLC tissue separation procedure. Regressions for estimating carcass lipid content: were obtained using data from several studies. The principal study involved carcasses from breed comparison trials (MAFF/MLC, 1982). Details of the other data sets are given by Kempster, Cook and Grantley-Smith (1986b). Key relationships are given in Table 2.4Estimates of the composition of carcasses in different classification fatness ranges are given in Table 3. These are for 'clean' cattle, sheep and pigs, but estimates were also made for cull cows and cull ewes.5National estimates of carcass composition and the weights of lean and fat produced in 1975/77 and 1984 are given in Table 4. The carcass composition of beef was the same in 1974/76 and 1984 but the average carcass weight has increased by 20kg. The implication of this is that changes in breed and production system have created the potential for leaner carcasses but that the beef industry has preferred to exploit this potential by increasing carcass weights. An increase of 20kg is equivalent to about 15gAg separable fat in carcass on the basis of typical regressions within breed and system.The carcasses of clean sheep in 1984 were estimated to be slightly lighter and leaner than those in 1977. Information on marketing patterns suggests that there has been little change in production methods (as far as they affect composition) and that lambs are now being slaughtered early, possibly stimulated by the pattern of Guide Prices in the EEC Sheep Meat Regime.In marked contrast to cattle and sheep, the separable fat content of the average pig carcass has fallen from 274g/kg in 1975 to 228g/kg in 1985, with a small increase in carcass weight. It is estimated that the increase in the use of entire males has contributed 5g/kg to the overall change.6The estimates in the paper are considered to be the best available with current information but because of the limitations of the data may be subject to error. Possible sources of error are discussed by Kempster et al (1986b). The authors would be pleased to know of data relating physical and chemical composition that could be used to refine the estimates.


1970 ◽  
Vol 75 (1) ◽  
pp. 19-26 ◽  
Author(s):  
R. P. Andrews ◽  
E. R. Ørskov

SUMMARY1. In an experiment with ninety-nine lambs the effects on the body composition of male and female lambs were examined when five diets containing different concentrations of crude protein (in the range 10–20%) were given at three levels of feeding and lambs were slaughtered at two live weights (27·5 and 40 kg).2. With lambs slaughtered at 27·5 kg there were significant increases in the rate of both nitrogen and fat retention with increases in levels of feeding. There were also linear increases in the rate of protein deposition and decreases in fat deposition with increases in the concentration of crude protein. This effect was particularly marked at the high level of feeding.3. With lambs slaughtered at 40 kg live weight there were also linear increases in fat and in nitrogen deposition with increasing feeding level but the effect of increasing the protein concentration on increases in nitrogen retention departed from linearity.4. While at 27·5 kg there were no significant effects of feeding level on nitrogen and ether-extract content of the bodies at slaughter, with animals slaughtered at 40 kg there was a significant linear decrease in ether-extract content with increasing feeding level and a corresponding linear increase in nitrogen content with increased level of feeding.5. Male lambs deposited more nitrogen and less fat than females. This was true of both rate of deposition and of carcass composition at 40 kg live weight.


1994 ◽  
Vol 58 (1) ◽  
pp. 41-47 ◽  
Author(s):  
D. C. Patterson ◽  
C. A. Moore ◽  
R. W. J. Steen

AbstractBulls (½ Blonde d'Aquitaine ⅜ Charolais) were used in a 2 × 3 factorial design experiment with two planes of nutrition in the finishing period and three slaughter weights. High and low planes of nutrition were based on diets with similar forage to concentrate ratio (0·40 of dry matter (DM)) offered ad libitum or at 0·78 of ad libitum DM intake at equal live weight respectively. The target slaughter live weights were 550, 625 and 700 kg. Twelve bulls were taken to each slaughter point and an additional five animals were killed as a pre-experimental slaughter group. Mean initial live weight was 412 (s.e. 5·3) kg at a mean age of 342 (s.e. 2·5) days. No significant interactions were found between the main factors. For the high and low planes, live-weight and estimated carcass gains were 1251 and 989 (s.e. 47·7), and 816 and 668 (s.e. 35·3) g/day respectively, the reduction in gains being similar to the proportional degree of nutritional restriction. Plane of nutrition had no effect on live-weight or carcass gain per unit of energy intake. The low plane of nutrition produced significant decreases in body cavity fat depots, subcutaneous fat in the sample joint and increased the proportions of both saleable beef and high-priced joints in the carcass.With increase in slaughter weight, energy intake per unit of live weight0·75 and rates of both live-weight and carcass gain tended to decline. The dressing proportions were 583,579 and 609 (s.e. 9·1) g/kg for the slaughter live weights of 550, 625 and 700 kg. Carcass conformation improved while fat depots in the body cavity and estimated concentration of separable fat in the carcass increased with increase in slaughter weight, and both estimated lean and bone concentrations decreased. Forequarter as a proportion of total side tended to increase with increase in slaughter weight. Slaughter weight had no effect on concentration of saleable meat or ultimate pH of carcass muscle. It is concluded that bulls of this genotype can be taken to high slaughter weights on diets having a relatively high proportion of forage as grass silage, with high rates of growth and acceptable carcass leanness.


1964 ◽  
Vol 6 (3) ◽  
pp. 309-319 ◽  
Author(s):  
S. K. Stephenson

1. Body shape and carcass composition have been measured in a dated series of Romney-Southdown cross and Australian Merino sheep foetuses.2. Large differences in shape exist between the two breed groups and these result from growth rate differences in certain components of the bone and muscle tissue.3. Carcass composition at any particular foetal weight, however, is more uniform. In relation to body weight, the Merino has a higher proportion of bone in the body but the proportion of muscle is the same in both breed groups. Nevertheless, the distribution of muscle tissue is changed as there s i a higher proportion of muscle in the hind limb of the Romney-Southdown cross.


1987 ◽  
Vol 44 (3) ◽  
pp. 371-385 ◽  
Author(s):  
J. France ◽  
M. Gill ◽  
J. H. M. Thornley ◽  
P. England

ABSTRACTA simple dynamic model of metabolism in growing beef cattle is described; the scheme is based on carbon and nitrogen fluxes. There are six state variables, three relating to blood metabolite levels and three to body composition. The blood metabolite variables are acetyl-coenzyme A equivalents, glucose equivalents and amino acids, and the body composition ones are ash, lipid and protein. The fluxes in the model are based on nine biochemical transactions, six of which are catabolic and three biosynthetic. The model simulates changes in carcass composition in response to changing nutrient input and gives a measure of agreement with comparative slaughter data. It also highlights the need for more complete data on profiles of nutrient absorption in association with comparative slaughter experiments.


1975 ◽  
Vol 85 (2) ◽  
pp. 193-204 ◽  
Author(s):  
K. R. Drew ◽  
J. T. Reid

SUMMARYForty-eight cross-bred wether lambs were used to measure the effects of severe feed restriction and realimentation on the body and carcass composition of immature sheep. Ten of the total number of sheep were used as an initial slaughter group, 12 were continuously fed (six at the ad libitum level of intake and six at 70% ad libitum), 26 were progressively underfed and 18 of them were realimented after a mean loss of about 25% empty body weight (EBW).Shrunk body weight (SBW = weight after an 18-h fast with access to water) was a good predictor of empty body weight (EBW = SBW minus gastro-intestinal contents) and the EBW of continuously growing sheep was a good predictor of body water, protein, fat, energy and ash, but it was not precise after realimentation, particularly in the early stages of refeeding. Restricted continuous supermaintenance feeding did not alter the body composition of the sheep from that of the sheep on the ad libitum intake at any given EBW except slightly to increase the carcass protein content.Although underfeeding to produce an EBW loss of 25% generally produced changes in the chemical body components which were similar to a reversal of normal growth, body fat did not decrease during the first half of the submaintenance feeding and did not increase during the first 2 weeks of realimentation. Under all circumstances percentage body fat was very closely related to percentage body water.Sheep realimented at 26 kg (after losing 25% EBW) contained, at 45 kg EBW, more bodywater and protein and less fat and energy than continuously-fed animals of the same EBW. The treatment effects were greater in the carcass and had little effect on the non-carcass EBW, with th e result that the refed sheep had 1800 g more water × protein in a carcass that weighed 700 g more than one from a normally grown sheep of the same EBW. The regression of calorific value of th e ash-free dry matter on body fat as a percentage of ash-free dry matter gave calorific values of body protein and fat as 5·652 and 9·342 kcal/g of ash-free dry matter, respectively.


2003 ◽  
Vol 51 (3) ◽  
pp. 305-319 ◽  
Author(s):  
Kinga Fodor ◽  
L. Zöldág ◽  
S. Gy. Fekete ◽  
A. Bersényi ◽  
A. Gáspárdy ◽  
...  

An experiment was carried out with young male New Zealand White (NZW) rabbits to establish live body weight changes, body measurements, body composition and sexual maturity as a function of feeding intensity. Animals in Group 1 ('AL', n = 10) were fed ad libitum, while those in Group 2 ('RS', n = 10) received restricted feeding corresponding to 70% of the ad libitum level. The starting liveweights were practically the same (0.907 ± 0.146 and 0.911 ± 0.147 kg in Group AL and Group RS, respectively). The feeding trial lasted from 6 to 22 weeks of age. The average body weight was significantly higher in Group AL from 7 to 22 weeks of age. At 22 weeks of age the body weight of RS rabbits was 85.64% of the weight of AL animals (3.22 ± 0.52 kg and 3.76 ± 0.33 kg, respectively). Average body weights of RS males at 8, 9, 11, 19 and 21 weeks of age were similar to those of ad libitum fed (AL) animals at 7, 8, 10, 15 and 16 weeks of age, respectively. The growth of bucks fed restricted tended to be allometric. The most significant difference was found at 16 and 18 weeks of age, while the lowest difference occurred at 6, 12, 15 and 19 weeks of age. It can be stated that low-intensity feeding up to slaughtering weight causes backwardness in rear cannon length and this backwardness remains also after the 15th week, which is well over the optimal slaughtering age. Based on the present data, the 70% restricted feeding cannot be recommended either for the future breeding bucks or for broiler males reared for slaughter. To determine the major chemical components of the body, rabbits were euthanised. Original dry matter and crude fat content of the body significantly (P < 0.05) decreased under restricted feeding (41.42%; 32.48% and 16.73%; 7.35%) while the percentage of protein within the dry matter increased (49.6%; 65.0%) and fat decreased (40.17%; 22.1%) significantly. Libido unambiguously decreases as a consequence of feed deprivation. The most conspicuous difference was found in the level of blood testosterone. Although a few RS bucks produced semen but only much later than the rabbits fed ad libitum. On the other hand, there was no difference in the motility of spermatozoa and ejaculate volume in comparison with AL animals. There was no relationship between the body fat content and the reproductive status of bucks in the present trial.


1995 ◽  
Vol 75 (4) ◽  
pp. 517-524 ◽  
Author(s):  
K. L. Hammell ◽  
J. P. Laforest ◽  
J. J. Dufour

Data from approximately 850 commercial pigs tested in 12 trials, from 1987 to 1990 at the Beaumont test station in Québec were used to determine the effect of growth rate and body composition on growth performance, carcass yield and lean meat colour. Pigs were housed four to a pen and were fed commercial diets. Feed intake and growth rate were measured during the test, and carcass measurements were taken at slaughter and at 24 or 72 h following slaughter. The different groups of pigs were defined according to a 2 × 2 factorial, with one factor being the growth rate [fast growth (FG) or slow growth (SG)] and the second factor being the body composition of the carcass [fat (F) or lean (L)]. The FG commercial pigs reach market weight at a younger age with lower overall feed consumption and generally a better feed conversion than SG pigs. Furthermore, FG pigs have more backfat, longer carcasses and a slightly darker meat. The L commercial pigs had similar growth performances with a better lean meat yield than the F commercial pigs. Growth variables and composition of the carcass had little effect on the meat characteristics measured. The proportion of barrows compared to gilts was higher in the FG and F groups than in the SG and L groups, which could account for some of the differences observed between groups. However, the rate of growth and the type of body composition affected the growth and feed consumption performances as well as the carcass yield in a similar way for both sexes. Overall, less than 3% and less than 2% of the pigs produced meat with a colour standard of 1 (extremely pale) or 5 (extremely dark), respectively. The SG-L group had a slightly higher proportion of pigs with a pale meat colour compared to the other groups. Key words: Pig, backfat, growth rate, carcass composition, meat colour


1987 ◽  
Vol 38 (5) ◽  
pp. 971 ◽  
Author(s):  
AJ Ash ◽  
BW Norton

The effects of plane of nutrition (ad libitum and 75% ad libitum) and dietary crude protein concentration (11.3, 16.0 and 20.9% crude protein) on body composition of male and female weaner goats were studied in a comparative slaughter experiment. The initial chemical composition of the body (water, ash, protein, fat) and dissectible tissue fractions of the carcass (muscle, fat, bone) of the experimental goats were estimated from regression equations, derived from a group of twelve comparable kids. The final chemical composition and carcass tissue distribution were determined directly by chemical and dissection analyses. There was no effect of dietary crude protein concentration on the chemical composition of the empty body weight (EBW) gain or on carcass tissue distribution. The lack of any response to dietary protein was attributed to similar levels of protein/energy available at the small intestine despite large differences in crude protein intake. Ad libitum feeding, however, resulted in significantly more fat (31.0 v. 22.6% of EBW gain) and less water (51.1 v. 56.4% of EBW gain) in the composition of the gain compared with restricted feeding. There was no effect of feeding level on protein or ash content of the body. Goats fed ad libitum had significantly less muscle (60.1 v. 62.5%) and more dissectible fat (19.5 v. 16.3%) in their carcasses than kids restricted in their intake. Females had significantly more fat (32.7 v. 22.4% of EBW gain) but less water (48.4 v. 57.9% of EBW gain) and nitrogen (2.2 v. 2.8% of EBW gain) in their body gain than did males. Similarly, the carcass of females contained more dissectible fat (22.6 v. 13.2%) but less bone (15.8 v. 19.3%) and muscle (58.5 v. 64.1%) than males. The efficiency of utilization of dietary energy for growth and fattening (kf) was similar (0.32) for all groups of kids.


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