scholarly journals 224 A method for estimating the target for protein energy retention in sheep

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.

1983 ◽  
Vol 36 (3) ◽  
pp. 415-423 ◽  
Author(s):  
R. G. Campbell ◽  
A. C. Dunkin

ABSTRACTForty-five piglets were used to study the effects of feeding diets containing 153, 239 or 321 g crude protein per kg dry matter between 1·8 and 6·5 kg live weight, and low and high protein diets subsequent to 6·5 kg live weight on growth performance, body composition and the cellularity of skeletal muscle to 45 kg live weight.Reducing dietary crude protein between 1·8 and 6·5 kg live weight depressed growth performance and at 6·5 kg live weight increased body fat content but reduced body protein, body water and the weight and DNA content of the adductor muscle. The effects of dietary protein content before 6·5 kg live weight on body composition at the latter weight were still evident in pigs killed at 11·5 kg live weight whilst the differences in muscle DNA persisted to 45 kg live weight.On the lower protein treatment subsequent to 6·5 kg live weight there was a tendency for pigs given the lowest protein diet before 6-5 kg live weight to exhibit better growth performance and deposit protein at a faster rate than those given the higher protein diets. However, these responses were reversed on the higher protein treatment subsequent to 6·5 kg live weight.The effects of dietary protein content subsequent to 6·5 kg live weight on growth performance, body composition and the cellularity of muscle tissue were qualitatively the same as those for the live-weight phase 1·8 to 6·5 kg.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 144-144
Author(s):  
Holland C Dougherty ◽  
Mark Evered ◽  
James W Oltjen ◽  
Hutton Oddy ◽  
Roger Hegarty

Abstract The nutritional effects of variation in feed supply and subsequent compensatory gain can play a significant role in cattle and beef production, due to their effects on carcass quality and feed costs. A system that predicts changes in fat and protein content of muscle and viscera in animals of different life stages and nutritional histories could therefore assist management to optimize performance and reduce costs of feed. A method has been developed to simultaneously estimate body composition and nutrient requirements of ruminants. This method estimates body composition from the difference in energy balance derived from ME intake, and heat production from ME intake and protein content of muscle and viscera, but requires information on protein content of fat free mass in viscera and non-viscera “muscle” tissue. Data from the literature was combined with unpublished data from a study conducted in growing lambs. This experiment tested the effects of ad libitum intake of diets of varying energy density and added RUP on performance and carcass composition of lambs that had been previously restricted or unrestricted prior to a 12–13 week finishing phase, and both carcass and viscera components were chemically analyzed on an individual basis. On a fat-free basis, muscle crude protein averaged 20.8%; this value is in agreement with literature values, which lie between the range of 20–24% and which do not appear to vary substantially with age in postweaning sheep. In the same sheep, crude protein content of viscera averaged 15.6% on a fat-free basis; while data on visceral composition in the literature is limited, these values are within the range of available data. This data is use to parameterize functions describing growth of viscera and changes in heat production over time. This contributes to the method we have developed to estimate nutritional effects on body composition.


2019 ◽  
Vol 59 (11) ◽  
pp. 1970 ◽  
Author(s):  
V. H. Oddy ◽  
H. C. Dougherty ◽  
J. W. Oltjen

Increased market pressure to improve meat yield and quality require improved methods of predicting body composition in growing animals. Current systems of animal nutrition based on nutrient supply and animal characteristics predict animal growth from nutrient inputs, but, as of yet, do not accurately predict body composition. The present paper explores the evidence and data required to support an existing model of the effects of energy intake on visceral and muscle protein mass and energy expenditure to predict heat production, growth and body composition of sheep. While parameters of the model related to energetic costs of protein in muscle and viscera can be supported by independent studies, parameters associated with energetic costs of protein gain, particularly in viscera, are harder to reconcile with independent measurements. The range of available data on systematic changes in visceral organ mass over time in response to feed intake is limited, which may constrain generalisation of the parameters of the model with regard to the wide range of production situations faced by the sheep and cattle industries. However, sufficient data exist in the literature to test, and if required, revise the current framework.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 143-144
Author(s):  
Phillip A Lancaster

Abstract Previous research indicates that animals of similar weight but greater protein mass have greater metabolic rate. The objective was to quantify the relationship between fasting heat production (FHP) and empty body composition in ruminants. A literature search was conducted to compile data on FHP and empty body composition. Seven studies using sheep or cattle consisting of 49 treatment means were found reporting FHP and chemical empty body composition. Data were analyzed with R statistical packages using mixed model methodology with study as a random variable. Given the strong correlations (r > 0.7) and high degree of multicollinearity (VIF > 30) among EBW, empty body protein (EBP) and empty body fat (EBF), LASSO regression was used to reveal that EBP was the important predictor of FHP. Allometric models (a*X^b) gave significant (P < 0.001) values for a and b of 74.3 ± 10.4 and 0.74 ± 0.02 for X = EBW (R2 = 0.963, RMSE = 432 kcal, AIC = 737), 227.7 ± 21.1 and 0.86 ± 0.02 for X = EBP (R2 = 0.972, RMSE = 375 kcal, AIC = 724), and 270.8 ± 75.9 and 0.75 ± 0.07 for X = EBF (R2 = 0.702, RMSE = 1219 kcal, AIC = 839), respectively. Log transformed models (lnFHP = lnX) gave significant (P < 0.001) values for intercept and slope of 4.47 ± 0.13 and 0.69 ± 0.02 for X = EBW (R2 = 0.979, RMSE = 0.088 lnkcal, AIC = -62.6), 5.61 ± 0.11 and 0.74 ± 0.03 for X = EBP (R2 = 0.973, RMSE = 0.096 lnkcal, AIC = -45.1), and 6.44 ± 0.19 and 0.33 ± 0.02 for X = EBF (R2 = 0.894, RMSE = 0.125 lnkcal, AIC = -13.8), respectively. A log transformed model including both EBP and EBF resulted in significant intercept (5.79 ± 0.14; P < 0.0001), lnEBP coefficient (0.56 ± 0.08; P < 0.0001) and lnEBF coefficient (0.09 ± 0.04; P = 0.02) with VIF of 8.3. The R2, RMSE and AIC of this model were 0.970, 0.088 lnkcal and -43.5; not improved over the model with EBP alone. In conclusion, EBP explained the variation in FHP as well or slightly better than EBW, and EBF did not significantly improve the prediction.


2006 ◽  
Vol 82 (2) ◽  
pp. 169-174 ◽  
Author(s):  
K. Engin ◽  
C. G. Carter

AbstractThis study investigated the effects of 100 g/kg increments of crude protein (approx. 250 (P25) to 550 (P55) g/kg of crude protein) in paired iso-energetic diets on the growth performance of the juvenile Australian short-finned eel (1·83 (s.e. 0·01) g average wet weight). The highest growth response was obtained with treatment P45 followed by P35, P55 and P25. It appeared that food efficiency ratio (FER) increased with increasing crude protein content in low energy diets (treatments P25 and P35). However, 100 g/kg increase in dietary crude protein content (from 450 to 550 kg crude protein per kg diet) in high energy diets resulted in lower FER for treatment P55 than for the treatment P45. The protein efficiency ratio (PER, %) was higher in low protein:low energy diets (treatments P25 and P35) than that of high protein:high energy diets (treatments P45 and P55). The protein productive values (PPV, %) for treatments followed a similar trend to PER in this experiment. The lowest PPV was obtained by the treatment P55 and it was significantly different from that of the other three treatments. A proportional increase in dietary crude protein content in paired iso-energetic diets did not significantly change the whole body protein content. However, a small increase in whole body protein content with increasing dietary crude protein in each group was detected. In conclusion, the present study showed protein sparing effects of lipids and carbohydrates in the diets of the short-finned eel. Further studies specifically investigating the effects of dietary carbohydrate to lipid ratios at different protein levels would improve diet formulation and reduce nutrient impact in intensive recirculation systems.


Author(s):  
M.R. Cropper ◽  
D.P. Poppi ◽  
A.M. Nicol

In a market where high levels of fat on lamb carcases are not favoured, the supposition that a lamb, given adequate feeding, will grow protein preferentially to gaining lipid, holds interest. However, this idea runs counter to the evidence that body composition is not manipulable in sheep. Therefore, an experiment was undertaken to implement extreme treatments of protein and energy supply to determine to what extent the contrasting views on body composition changes in growing lambs are justified.Seventy-two Coopworth ram lambs (mean liveweight, (LW) 30.4, s.d. 1.1 kg) were given one of the three feeds of different digestible crude protein (DCP) content at one of three allowances (ad libitum (AL), 1.2 (H) or 0.8 (L) kg/day). The feeds (H, M and L) were formulated as shown in Table 1. Feed M was a mixture of 0.55 Feed H and 0.45 Feed M. The proximate composition, measured DCP and estimated metabolisable energy (ME) content of the feeds is given in Table 1. ALH and ALM lambs were also choice-fed with ad libitum access to feed L. 8 lambs at the start of the experiment and 4 lambs per treatment at 6 and 12 weeks were slaughtered for analysis of body protein (PR), lipid (LP) and wool protein (WP).


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.


1997 ◽  
Vol 65 (3) ◽  
pp. 509-513 ◽  
Author(s):  
N. Quiniou ◽  
J. Noblet

AbstractThe effect of energy supply between 45 and 100 kg body weight (BW) on the contribution of lean tissue (muscle plus intermuscular adipose tissue) to total protein mass was studied in Large White castrated males (cLW), crossbred Piétrain × Large White castrated males (cPPx) and boars (bPPx). The pigs were allocated to four energy levels (0·70, 0·80, 0·90 or 1·00 ad libitum) and kept in metabolism cages in experiment 1 or given food ad libitum and kept in individual pens in experiment 2. Daily protein supplies were calculated to be non-limiting for growth and identical for all pigs in experiment 1. Temperature was 23°C in both experiments. The pigs were slaughtered at 100 kg BW and physically dissected; the body tissues were chemically analysed. Taking into account housing conditions, the food intake of pigs in experiment 2 corresponded to 1·20 of ad libitum intake of pigs in experiment 1; data of both experiments were combined. The energy supply and the type of pig influenced significantly the protein content of empty BW (eBW) (170 g/kg on average), of lean (184g/kg on average) and non-lean compartment (eBW minus lean, 152 g/kg on average), the proportion of total protein deposited in lean (604 g/kg of total protein, on average) but not the protein content in fat-free eBW (209 g/kg on average). The fat-free eBW can be predicted as 4·8 times the body protein mass.


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