scholarly journals Modelling of nutrient partitioning in growing pigs to predict their anatomical body composition. 1. Model description

2004 ◽  
Vol 92 (4) ◽  
pp. 707-723 ◽  
Author(s):  
V. Halas ◽  
J. Dijkstra ◽  
L. Babinszky ◽  
M. W. A. Verstegen ◽  
W. J. J. Gerrits

A dynamic mechanistic model was developed for growing and fattening pigs. The aim of the model was to predict growth rate and the chemical and anatomical body compositions from the digestible nutrient intake of gilts (20–105 kg live weight). The model represents the partitioning of digestible nutrients from intake through intermediary metabolism to body protein and body fat. State variables of the model were lysine, acetyl-CoA equivalents, glucose, volatile fatty acids and fatty acids as metabolite pools, and protein in muscle, hide–backfat, bone and viscera and body fat as body constituent pools. It was assumed that fluxes of metabolites follow saturation kinetics depending on metabolite concentrations. In the model, protein deposition rate depended on the availability of lysine and of acetyl-CoA. The anatomical body composition in terms of muscle, organs, hide–backfat and bone was predicted from the chemical body composition and accretion using allometric relationships. Partitioning of protein, fat, water and ash in muscle, organs, hide–backfat and bone fractions were driven by the rates of muscle protein and body fat deposition. Model parameters were adjusted to obtain a good fit of the experimental data from literature. Differential equations were solved numerically for a given set of initial conditions and parameter values. In the present paper, the model is presented, including its parameterisation. The evaluation of the model is described in a companion paper.

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 143-143
Author(s):  
Holland C Dougherty ◽  
Hutton Oddy ◽  
Mark Evered ◽  
James W Oltjen

Abstract Target protein mass at maturity is a common “attractor” used in animal models to derive components of animal growth. This target muscle protein at maturity, M*, is used as a driver of a model of animal growth and body composition with pools representing muscle and visceral protein; where viscera is heart, lungs, liver, kidneys, reticulorumen and gastrointestinal tract; and muscle is non-visceral protein. This M* term then drives changes in protein mass and heat production, based on literature data stating that heat production scales linearly with protein mass but not liveweight. This led us to adopt a modelling approach where energy utilization is directly related to protein content of the animal, and energy not lost as heat or deposited as protein is fat. To maintain continuity with existing feeding systems we estimate M* from Standard Reference Weight (SRW) as follows: M* (kJ) = SRW * SHRINK * (1-FMAT) * (MUSC) * (CPM)* 23800. Where SRW is standard reference weight (kg), SHRINK is the ratio of empty body to live weight (0.86), FMAT is proportion of fat in the empty body at maturity (0.30), MUSC is the proportion of empty body protein that is in muscle (0.85), CPM is the crude protein content of fat-free muscle at maturity (0.21), and 23800 is the energetic content (kJ) of a kilogram of crude protein. Values for SHRINK, FMAT, MUSC and CPM were derived from a synthesis of our own experimental data and the literature. For sheep, these values show M* to be: M* (kJ) = SRW * 0.86* (1-0.3) * 0.85 * 0.21 *23800 = SRW * 2557. This method allows for use of existing knowledge regarding standard reference weight and other parameters in estimating target muscle mass at maturity, as part of a model of body composition and performance in ruminants.


2002 ◽  
Vol 45 (6) ◽  
pp. 535-545
Author(s):  
A. D. Mitchell ◽  
A. Scholz ◽  
V. Pursel

Abstract. The purpose of this study was to evaluate the use of a cross-sectional scan as an alternative to the total body DXA scan for predicting the body composition of pigs in vivo. A total of 212 pigs (56 to 138 kg live body weight) were scanned by DXA. The DXA scans were analyzed for percentage fat and lean in the total body and in 14 cross-sections (57.6 mm wide): 5 in the front leg/thoracic region, 4 in the abdominal region, and 5 in the back leg region. Regression analysis was used to compare total body and cross-sectional DXA results and chemical analysis of total body fat, protein and water. The relation (R2) between the percentage fat in individual slices and the percentage of total body fat measured by DXA ranged from 0.78 to 0.97 and by chemical analysis from 0.71 to 0.85, respectively. The relation between the percentage of lean in the individual slices and chemical analysis for percentage of total body protein and water ranged from 0.48 to 0.60 and 0.56 to 0.76, respectively. These results indicate that total body composition of the pig can be predicted (accurately) by performing a time-saving single-pass cross-sectional scan.


1995 ◽  
Vol 73 (3) ◽  
pp. 452-457 ◽  
Author(s):  
Karol A. Worden ◽  
Peter J. Pekins

Winter is a critical time of year for white-tailed deer (Odocoileus virginianus) in northern regions because their food consumption does not meet their daily energy demands. We measured feed intake, fasting metabolic rate (FMR), and body composition of five captive adult female white-tailed deer from September 1991 through March 1992 in New Hampshire to investigate the relationships between FMR and feed intake to fat deposition and mobilization. Deuterium oxide dilution was used to estimate monthly body composition, indirect respiration calorimetry was used to measure monthly FMR, and metabolizable energy intake (MEI) was calculated from daily feed intake. Mean percent body fat increased from 9.1 ± 1.5 to 24.9 ± 4.4% from September to December, and then declined through March. Mean percent body protein did not change during the study (range 20–21%). Mean MEI peaked during September and October (171.9 ± 8.1 and 168.7 ± 10.3 kcal∙kg body mass−0.75∙d−1, respectively), and declined 54% by February. Mean FMR ranged from 79 to 90 from October through March. Correlations between MEI or FMR and change in body fat were weak. It was estimated that intake rates of free-ranging deer were only 90–110% of winter FMR, and that deer with 20% body fat could balance their daily energy expenditure (1.7 × FMR) with fat stores for about 3 months, or the period of time during which MEI was depressed in captive deer.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 95-95
Author(s):  
Tylo J Kirkpatrick ◽  
Kaitlyn Wesley ◽  
Sierra L Pillmore ◽  
Kimberly Cooper ◽  
Travis Tennant ◽  
...  

Abstract This experiment was designed to quantify the empty body composition of Jersey steers administered an aggressive implant strategy. Jersey steers {n = 30; initial body weight (BW) 183 ± 43 kg} were randomly assigned to one of two implant strategies: negative control (CON), or implanted with Revalor 200 (200 mg trenbalone acetate / 20 mg estradiol 17-β; (REV) every 70 d (d 0, d 70, d 140, d 210, d 280, d 350) during a 420 d feeding period. Steers were harvested on d 421; 6 CON and 6 REV steers were randomly selected for collection of blood, hide, ground viscera, bone, and ground lean and fat to determine empty body composition. Proximate analysis was completed for each sample to determine total body percentages of moisture, crude protein, fat, and ash. Data were analyzed via independent t-test. Percentage empty body moisture (46.48% CON vs 49.69% REV) and empty body protein (15.32% CON vs 17.58% REV) were greater (P < 0.01) in REV cattle. In contrast empty body fat (33.51% CON vs 26.93% REV) was greater (P < 0.01) for CON cattle. Empty body ash did not differ (P > 0.10; 4.69% CON vs 5.80% REV) between treatments. Negative control steers contained a total empty body protein to total empty body fat ratio of 0.44:1 compared to 0.62:1 for REV steers. These data suggest that an aggressive implant strategy alters composition of gain during the finishing of Jersey steers toward increased protein and decreased fat.


1985 ◽  
Vol 5 (9) ◽  
pp. 755-760 ◽  
Author(s):  
Nancy J. Rothwell ◽  
Michael J. Stock

Female dystrophic mice (mdx on C57 Black background) gained weight more rapidly than age-matched controls and had a higher body fat content (% body weight), a slightly lower protein content and a reduced mass of muscle. Chronic treatment (21 d) of the mice with the β2-agonist clenbuterol stimulated weight gain in both genotypes without affecting energy intake. Clenbuterol increased the mass of the gastrocnemius and soleus muscle by 13% and 29% in normal and dystrophic mice, respectively, and raised body protein but depressed body fat. Body water and energy content were unaffected by clenbuterol, but the ratio of protein to fat in the carcasses was enhanced by 17% in normal and 56% in dystrophic mice following clenbuterol treatment. Thus, the β2-agonist restored the body composition of dystrophic mice to normal and enhanced the protein to fat ratio in both these and normal mice.


1965 ◽  
Vol 43 (2) ◽  
pp. 297-308 ◽  
Author(s):  
J. S. Hayward

The body composition in terms of fat, water, and protein has been determined for 115 deer mice (genus Peromyscus) of six racial stocks. The changes in composition that are characteristic of seasonal extremes and that accompany laboratory acclimation are presented. The composition of the fat-free body exhibits the constancy which has been found in other mammals. Body protein averaged 22.97% and body water 69.71% of the fat-free body weight. Body fat levels are shown to vary considerably among individuals and races. The highest fat levels occurred in the desert-adapted race (P. m. sonoriensis). The importance of considering body composition in comparative studies of metabolic rate is discussed.


2017 ◽  
Vol 57 (3) ◽  
pp. 520 ◽  
Author(s):  
A. Casal ◽  
A. L. Astessiano ◽  
A. C. Espasandin ◽  
A. I. Trujillo ◽  
P. Soca ◽  
...  

The aim of this study was to evaluate the effect of controlling the grazing intensity of native pastures, through the herbage allowances (HA) on body composition (water, protein, and fat) of beef cows of different cow genotype (CG; purebred: Angus and Hereford; PU, and crossbred: reciprocal F1; CR). Mature beef cows (n = 32) were used in a complete randomised block design with a factorial arrangement of HA (2.5 vs 4 kg DM/day; LO vs HI) and CG (PU vs CR). The experiment was conducted during 3 years and at the end of the third year at 150, 210, and 240 ± 10 days of gestation and 190 ± 10 days postpartum body composition was estimated using the urea dilution technique. At 192 ± 10 days postpartum cows were slaughtered and all tissues and organs were weighed and samples were collected for chemical composition analyses. During the winter gestation period, body condition score was greater (P < 0.05) in HI than LO cows and in CR than PU cows. Relative body water (g/kg of empty bodyweight) was greater (P ≤ 0.02) in HI than LO cows and in CR than PU cows, whereas relative body protein did not differ between HI and LO, but tended (P = 0.10) to be greater in CR than PU cows. In contrast, relative body fat tended (P = 0.10) to be greater and gross energy content was greater (P < 0.01) in HI than LO cows, whereas they did not differ between CR and PU cows. Relative body water increased (P < 0.01) from 150 to 210 days of gestation for all cows whereas relative body fat decreased (P < 0.05) and body protein increased (P < 0.05) from 150 to 210 days of gestation in PU but not in CR cows. These results suggest that HI maintained greater body condition score and retained gross energy content when compared with LO cows, and CG affected not only body composition (greater body fat and protein in CR than PU cows) but also composition of mobilised/retained weight during the winter gestation period with a greater protein tissue mobilisation in CR than PU cows.


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.


1993 ◽  
Vol 71 (11) ◽  
pp. 2224-2228 ◽  
Author(s):  
William L. Hohman

A method was developed for indexing moulting costs in waterfowl based on intensity of moult and proportional mass of feathers in seven feather regions (ADJMOLT). This method was then applied to an examination of relations between moulting costs and size-adjusted body mass and composition of postbreeding male and female ruddy ducks (Oxyura jamaicensis) collected in southwestern Manitoba, 30 July – 24 August 1985. Moderate to heavy moult (25 to > 50% of moulting feathers) was recorded in all feather regions. The intensity of down moult was greater in males than in females, but no differences between sexes in moult score by contour feather region, overall mean moult score, or ADJMOLT were detected. Relations between ADJMOLT and body fat (FAT), liver protein (LIVER), and size-adjusted body mass (ADJMASS), body protein (ADJPROT), and leg and breast muscle protein (ADJLEG and ADJBR, respectively) were not influenced by sex, but there was a sex effect on the relation of ADJMOLT to gizzard mass (GIZZWT). ADJPROT and ADJBR were negatively associated with ADJMOLT, whereas female GIZZWT was positively related to ADJMOLT. ADJMASS, ADJLEG, FAT, and LIVER were unrelated to ADJMOLT. Female ruddy ducks were structurally smaller and had less ADJMASS, ADJPROT, ADJLEG, and FAT than males, but there were no sex-related differences in ADJBR. I found no evidence of nutritional stress in post-breeding ruddy ducks, but argue that stress associated with moult in waterfowl is most likely to occur in females, especially small-bodied species that are primarily herbivorous.


2011 ◽  
Vol 211 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Luana Lopes Souza ◽  
Aline Cordeiro ◽  
Lorraine Soares Oliveira ◽  
Gabriela Silva Monteiro de Paula ◽  
Larissa Costa Faustino ◽  
...  

n-3 polyunsaturated fatty acids (n-3 PUFA) from fish oil (FO) exert important lipid-lowering effects, an effect also ascribed to thyroid hormones (TH) and TH receptor β1 (TRβ1)-specific agonists. n-3 PUFA effects are mediated by nuclear receptors, such as peroxisome proliferator-activated receptors (PPAR) and others. In this study, we investigated a role for TH signaling in n-3 PUFA effects. Euthyroid and hypothyroid adult rats (methimazole-treated for 5 weeks) received FO or soybean oil (control) by oral administration for 3 weeks. In euthyroid rats, FO treatment reduced serum triglycerides and cholesterol, diminished body fat, and increased protein content of the animals. In addition, FO-treated rats exhibited higher liver expression of TRβ1 and mitochondrial α-glycerophosphate dehydrogenase (mGPD), at protein and mRNA levels, but no alteration of glutathione S-transferase or type 1 deiodinase. In hypothyroid condition, FO induced reduction in serum cholesterol and increase in body protein content, but lost the ability to reduce triglycerides and body fat, and to induce TRβ1 and mGDP expression. FO did not change PPARα liver abundance regardless of thyroid state; however, hypothyroidism led to a marked increase in PPARα liver content but did not alter TRβ1 or TRα expression. The data suggest that part of the effect of n-3 PUFA from FO on lipid metabolism is dependent on TH signaling in specific steps and together with the marked upregulation of PPARα in liver of hypothyroid rats suggest importantin vivoconsequences of the cross-talking between those fatty acids and TH pathways in liver metabolism.


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