scholarly journals Body composition and implications for heat production of Angus steer progeny of parents selected for and against residual feed intake

2001 ◽  
Vol 41 (7) ◽  
pp. 1065 ◽  
Author(s):  
E. C. Richardson ◽  
R. M. Herd ◽  
V. H. Oddy ◽  
J. M. Thompson ◽  
J. A. Archer ◽  
...  
Keyword(s):  
Body Composition ◽  
Chemical Analysis ◽  
Feed Intake ◽  
High Efficiency ◽  
Residual Feed Intake ◽  
Whole Body ◽  
Lower Efficiency ◽  
Fat Depots ◽  
The Difference ◽  
Low Efficiency

Yearling Angus steer progeny of parents selected for low residual feed intake (RFI; high efficiency) or high RFI (low efficiency) were evaluated for feed intake, growth and differences in body composition. RFI is the difference between actual feed intake and expected feed intake based on an animal’s size and growth over a test period. Individual intakes of a high grain content ration and growth rates were recorded for 140 days and then the steers were slaughtered for measurement of body composition. All internal organs and non-carcass fat depots were removed, weighed and ground for chemical analysis. Carcasses were kept overnight in the chiller and the left half of every carcass physically dissected into retail cuts, and then into total fat, lean and bone. Carcass fat and lean were then combined and ground for chemical analysis. Steers from low RFI parents ate less (P<0.05) than the steers from high RFI parents, for similar rates of growth. Improvement in RFI was accompanied by small changes in body composition towards greater lean and less fat in the progeny of low RFI parents. Correlations of sire estimated breeding values for RFI with end of test whole body chemical protein, chemical fat and a principal component that condensed information on fat and lean body composition at the end of the test, were statistically significant. These confirmed there was a genetic association between body composition and RFI, with fatness being associated with higher RFI (i.e. lower efficiency). However, the correlations were small and suggested that less than 5% of the variation in sire RFI was explained by variation in body composition of their steer progeny. There was no evidence that a difference in the chemical composition of gain over the test explained the greater intake of metabolisable energy (ME) by the high RFI steers. The results suggest that the difference in ME intake following a single generation of divergent selection for RFI was due to metabolic processes rather than to changes in body composition.

The importance of body composition in explaining variation in feed conversion efficiency and residual feed intake between meat sheep at two different ages

2006 ◽  
Vol 2006 ◽  
pp. 153-153
Author(s):  
S A Knott ◽  
L J Cummins ◽  
B J Leury ◽  
F R Dunshea
Keyword(s):  
Body Composition ◽  
Feed Intake ◽  
Residual Feed Intake ◽  
Feed Conversion ◽  
Lean Tissue ◽  
Tissue Mass ◽  
Physiological Factors ◽  
The Difference ◽  
The Relationship ◽  
Meat Sheep

Residual feed intake (RFI) is a measure of feed efficiency calculated as the difference between an animal’s actual intake and its expected intake based on its liveweight and growth rate over a specified period of time (Richardson, Herd et al. 2002). The efficiency with which an animal utilises energy during growth, is dependent on a number of physiological factors including body composition and the relative proportions of lean tissue mass (LTM) and fat tissue mass (FTM), due to differences in the energy cost of depositing and maintaining these tissues. Protein or lean tissue is continually degraded and resynthesised and thus the rate at which this occurs may contribute to the variation in energy required by an animal for maintenance and growth (Archer, Richardson et al. 1999). The objective of this work was to determine the relationship between feed conversion ratio (FCR, kg feed:kg gain) and residual feed intake (RFI) with body composition in rams at six months of age (6mo), and then again in the same rams at thirteen months of age (13mo).

Genetic parameters and breed differences for feed efficiency, growth, and body composition traits of young beef bulls

2004 ◽  
Vol 84 (2) ◽  
pp. 177-185 ◽  
Author(s):  
F. S. Schenkel ◽  
S. P. Miller ◽  
J. W. Wilton
Keyword(s):  
Body Composition ◽  
Genetic Correlation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Fixed Effects ◽  
Residual Feed Intake ◽  
Backfat Thickness ◽  
Daily Weight Gain ◽  
Feed Conversion ◽  
Beef Bulls

Genetic associations between feed efficiency, growth, and live ultrasound measured body composition traits were studied in purebred beef bulls of six breeds in Ontario bull test stations from 1991 to 2000. Feed traits included average daily feed intake (FI), feed conversion ratio (FCR), and residual feed intake [feed intake adjusted for production alone (RFIp) or production and backfat thickness (RFIb)]. Growth traits were average daily weight gain (ADG), mid-test metabolic weight (MW), hip height (HH), and scrotal circumference (SC). Body composition traits included ultrasound backfat thickness (BF), longissimus muscle area (LMA), and predicted percentage of intramuscular fat (IFAT). Bulls were measured every 28 d for weight and individual feed intake, and at the end of test for ultrasound body composition traits. Number of records per trait ranged from 2284 (FI) to 13 319 (ADG). Fixed effects of test group, breed and end of test age (within breed), and random effects of animal and herd of origin were modeled using REML bivariate analyses for all traits. Heritability estimates were moderate for all traits (0.30 to 0.55), except for IFAT (0.14). The genetic correlation between RFIp and RFIb was high (0.99) within breeds, but breeds ranked differently with respect to RFIp and RFIb. Genetic correlations of RFIb with ADG and backfat thickness were essentially zero, which indicate that selection on residual feed intake could be implemented to reduce feed intake and improve feed conversion without compromising growth or changing levels of subcutaneous fat. Key words: Central test, genetic correlation, heritability, residual feed intake

230 Effect of divergent selection for residual feed intake on whole body protein turnover in growing gilts fed either adequate or lysine deficient diets

2016 ◽  
Vol 94 (suppl_2) ◽  
pp. 108-109 ◽  
Author(s):  
D. J. Hewitt ◽  
C. F. M. de Lange ◽  
T. Antonick ◽  
J. C. M. Dekkers ◽  
A. R. Pendleton ◽  
...  
Keyword(s):  
Feed Intake ◽  
Protein Turnover ◽  
Residual Feed Intake ◽  
Divergent Selection ◽  
Whole Body ◽  
Body Protein ◽  
Selection For

scholarly journals Genetics of steer daily and residual feed intake in two tropical beef genotypes, and relationships among intake, body composition, growth and other post-weaning measures

2009 ◽  
Vol 49 (6) ◽  
pp. 351 ◽  
Author(s):  
S. A. Barwick ◽  
M. L. Wolcott ◽  
D. J. Johnston ◽  
H. M. Burrow ◽  
M. T. Sullivan
Keyword(s):  
Body Composition ◽  
Feed Intake ◽  
Bos Taurus ◽  
Body Condition Score ◽  
Serum Insulin ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Residual Feed Intake ◽  
Genetic Evaluation ◽  
Igf I

Genetic parameters for Brahman (BRAH) and Tropical Composite (TCOMP) cattle were estimated for steer production traits recorded at weaning (WEAN), 80 days post-weaning (POSTW), feedlot entry (ENTRY) and after ∼120 days feedlot finishing (EXIT). The TCOMP was 50% Bos indicus, African Sanga or other tropically adapted Bos taurus, and 50% non-tropically adapted Bos taurus. Data involved 2216 steers, comprising 1007 BRAH by 53 sires and 1209 TCOMP by 50 sires. Individual daily feed intake (DFI) and residual feed intake (RFI) were assessed on 680 BRAH and 783 TCOMP steers over an ~70-day feedlot test. Other traits were liveweight (LWT), average daily gain (ADG), ultrasonically scanned rump (SP8) fat depth, rib (SRIB) fat depth, M. longissimus area (SEMA) and intra-muscular fat % (SIMF), body condition score (CS), hip height (HH), flight time (FT) and serum insulin-like growth factor-I concentration (IGF-I). BRAH were significantly (P < 0.05) lighter at ENTRY and EXIT, and had lower DFI (10.8 v. 13.2 kg/day) and RFI (–0.30 v. 0.17 kg/day), greater SP8 (5.8 v. 5.1 mm) but similar SRIB at ENTRY, lower SRIB (8.2 v. 8.9 mm) but similar SP8 at EXIT, and greater HH than TCOMP. Heritabilities for DFI, RFI, LWT, ADG, scanned body composition, HH and IGF-I measures, across measurement times, were generally in the 20 to 60% range for both genotypes. Genetic variance for RFI was 0.19 (kg/day)2 in BRAH and 0.41 (kg/day)2 in TCOMP, suggesting a clear potential to genetically change RFI in both genotypes. Trait variances and genetic correlations often differed between the genotypes, supporting the use of genotype-specific parameters in genetic evaluation. The genotype differences may be associated with evolutionary changes that have occurred in B. indicus as a part of their adaptation to tropical environments. Measures with potential to be used as genetic indicators of DFI were LWT measures in BRAH and TCOMP, ADG at ENTRY in TCOMP, and SP8 and SIMF at ENTRY in BRAH. Measures with potential to be genetic indicators of RFI were HH and ADG at ENTRY in BRAH, and IGF-I in both genotypes. Taller and faster-growing BRAH steers at ENTRY had genetically lower RFI. IGF-I was negatively genetically correlated with RFI whether IGF-I was measured at POSTW, ENTRY or EXIT. SRIB fatness at EXIT was strongly positively genetically correlated with RFI in TCOMP but only lowly correlated in BRAH. Fatness at ENTRY was lowly and negatively genetically correlated with RFI. The results emphasise the need for a population-specific understanding of trait relationships and of trait differences between measurement times if genetic indicator traits are to be utilised in genetic evaluation of RFI.

scholarly journals Residual feed intake, body composition, and fertility in yearling beef heifers12

2011 ◽  
Vol 89 (4) ◽  
pp. 1028-1034 ◽  
Author(s):  
K. S. Shaffer ◽  
P. Turk ◽  
W. R. Wagner ◽  
E. E. D. Felton
Keyword(s):  
Body Composition ◽  
Feed Intake ◽  
Residual Feed Intake

Dual energy X-ray absorptiometry predicts the effects of dietary protein on body composition of pigs

2006 ◽  
Vol 46 (11) ◽  
pp. 1439 ◽  
Author(s):  
D. Suster ◽  
B. J. Leury ◽  
D. J. Kerton ◽  
F. R. Dunshea
Keyword(s):  
Body Composition ◽  
Chemical Analysis ◽  
Feed Intake ◽  
Dietary Protein ◽  
Dual Energy ◽  
Feed Conversion ◽  
Large White ◽  
X Ray ◽  
Adequate Diet ◽  
Nutritional Studies

The present study investigated the potential of dual energy X-ray absorptiometry to determine the effect of dietary protein on live pig body composition compared with the standard methods. The experiment utilised 48 Large White × Landrace gilts, stratified on liveweight at 17 weeks of age (initial liveweight about 60 kg), and allocated within strata to diets containing either 85 or 100% of dietary protein requirements. The diets were fed ad libitum and contained 14.6 or 16.7% protein, respectively. Pigs were housed individually to allow weekly measurement of feed intake and liveweight. A Hologic QDR4500A dual energy X-ray absorptiometer was used to determine lean, fat and ash composition of pigs initially and 4 weeks later at the end of the experiment. Daily gain was increased by about 200 g in pigs fed the protein-adequate diet, but feed intake was not affected. Therefore, pigs fed adequate protein had a lower feed conversion ratio (2.92 v. 3.52 g/g, P<0.001). Feeding the protein-adequate diet increased lean deposition by about 150 g/day (577 v. 429 g/day, P<0.001) and ash deposition by about 4 g/day (28.7 v. 25.0 g/day, P<0.001), but did not affect fat accretion. This resulted in carcasses with a higher lean content (54.0 v. 50.7 kg, P<0.001) and ash content (2.35 v. 2.28 kg, P<0.05) but unaltered fat content. Therefore, an inadequate level of dietary protein leads to suboptimal growth in lean tissue and bone mineral, with no pronounced effect on fat. These observations were substantiated by chemical analysis and available corrective equations were useful in correcting differences between dual energy X-ray absorptiometry outputs and chemical values. After correction, dual energy X-ray absorptiometry estimates differed less than 5% from the chemical values for lean, protein, water and ash and 10% for lipid. In addition, reduced standard error of the differences around most dual energy X-ray absorptiometry measurements, relative to chemical analysis, allowed small changes in body composition to be detected with increased confidence. These data support the efficacy of using dual energy X-ray absorptiometry in nutritional studies of pigs.

scholarly journals Ingestive behavior and temperament of Nellore cattle classified for residual feed intake

2019 ◽  
Vol 40 (1) ◽  
pp. 457 ◽  
Author(s):  
Julian Aldrighi ◽  
Renata Helena Branco ◽  
Joslaine Noely dos Santos Gonçalves Cyrillo ◽  
Elaine Magnani ◽  
Cleisy Ferreira do Nascimento ◽  
...  
Keyword(s):  
Feed Intake ◽  
Feed Efficiency ◽  
High Efficiency ◽  
Residual Feed Intake ◽  
Serum Cortisol ◽  
Individual Performance ◽  
Flight Speed ◽  
Ingestive Behavior ◽  
Composite Score ◽  
Nellore Cattle

The objective of this study was to evaluate the relationship between ingestive behavior, temperament and residual feed intake (RFI) in Nellore cattle. Sixty-two bulls and 56 heifers after weaning, housed in individual pens, were evaluated in individual performance tests. Animals were classified as low RFI ( 0.135 kg day-1; greater than mean plus 0.5 standard deviation). Ingestive behavior was evaluated for 24 h by direct observation, every 24 days in bulls or every 10 days in heifers. Temperament was assessed by flight speed, reactivity in mobile confinement, composite score, and serum cortisol measurement. The most efficient animals (low RFI, 5.6 kg DM day-1) consumed 7% less feed than animals with medium efficiency (mean RFI, 6.0 kg DM day-1) and 13% less than the least efficient animals (high RFI, 6.34 kg DM day-1). More feed efficient animals spent a longer time feeding and ruminating per kg of DM consumed. Similarly, more efficient animals consumed less DM per hour and ruminated less DM per hour, but made the same number of visits to the feed bunk. High-efficiency animals were 13% and 35% faster to walk 1.77 m after release from the scale than medium- and low-efficiency animals, respectively, suggesting a more reactive temperament without differences in reactivity, composite score, or serum cortisol. Feed efficiency is associated with ingestive behavior and temperament in Nellore cattle. More efficient animals consume and ruminate less feed over the same period of time than animals with medium and low feed efficiency. In addition, more efficient animals exhibit a faster flight speed and are more reactive than less efficient animals.

Differences in residual feed intake are largely explained by changes in body composition

2013 ◽  
pp. 127-128
Author(s):  
M. L. Nascimento ◽  
A. R. D. L. Souza ◽  
A. S. Chaves ◽  
S. R. de Medeiros ◽  
R. R. Tullio ◽  
...  
Keyword(s):  
Body Composition ◽  
Feed Intake ◽  
Residual Feed Intake

Prediction of the body composition of lambs from the composition of their non-carcass components

1995 ◽  
Vol 61 (2) ◽  
pp. 265-268 ◽  
Author(s):  
R. G. Wilkinson ◽  
J. F. D. Greenhalgh
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Specific Gravity ◽  
Crude Protein ◽  
Energy Content ◽  
The Body ◽  
Viable Alternative ◽  
Whole Body

AbstractInformation on the chemical composition of Suffolk × Blackface lambs was collected and used to predict empty body (EB) component weights from empty body weight (EBW) and non-carcass (NC) component weights. EBW accounted proportionately for 0·94, 0·89 and 0·95 of the variation in EB crude protein, fat and energy content. A combination of NC component weights accounted proportionately for 0·94, 0·95 and 0·96 of the variation in EB crude protein, fat and energy content. EBW and a combination of NC component weights together accounted proportionately for 0·97, 0·97 and 0·98 of the variation in EB crude protein, fat and energy content. Chemical analysis of NC components is cheaper and easier than whole body analysis and provides a viable alternative to sample joint or specific gravity analysis.

scholarly journals Meat quality and the calpain system of feedlot steers following a single generation of divergent selection for residual feed intake

2001 ◽  
Vol 41 (7) ◽  
pp. 1013 ◽  
Author(s):  
M. B. McDonagh ◽  
R. M. Herd ◽  
E. C. Richardson ◽  
V. H. Oddy ◽  
J. A. Archer ◽  
...  
Keyword(s):  
Feed Intake ◽  
Shear Force ◽  
High Efficiency ◽  
Subcutaneous Fat ◽  
Residual Feed Intake ◽  
Divergent Selection ◽  
Muscle Area ◽  
Eye Muscle ◽  
Single Generation ◽  
Selection For

Residual feed intake (RFI) is calculated as the difference between an animal’s actual feed intake and its expected feed intake based on its size and growth over a specified test period. Following a single generation of divergent selection for postweaning RFI, Angus steers and Angus × Hereford, Angus×Poll Hereford and Angus × Shorthorn crossbred steers born in 1996 and 1997 were fed in a feedlot. Cohorts of steers were slaughtered at the same age and had attained similar (P&gt;0.05) final liveweights: 467 kg for steers selected for low RFI (high efficiency; HE, n = 91) and 459 kg for steers selected for high RFI (low efficiency; LE, n = 98). The HE and LE steers had similar (P>0.05) carcass weight (247 and 244 kg), dressing percentage (53.1 and 53.2&percnt;) and eye-muscle area (58.9 and 60.3 cm 2 ). The HE steers had slightly less subcutaneous fat over the rib than the LE steers (9.2 v. 10.1 mm, P&lt;0.05), and there was a trend towards less fat over the rump of HE steers (11.5 v. 12.1 mm, P = 0.10). For meat samples taken from the M. longissimus dorsi (LD) there were no differences (P>0.05) between the HE and LE steers in content of intramuscular fat (5.4 and 5.3% fresh weight), marbling scores, meat colour and fat colour. There were also no differences (P>0.05) between HE and LE steers in shear force and compression values for samples of LD aged for 1 day (4.6 and 4.6 kg shear force, 1.45 and 1.44 kg compression), or for 14 days (3.8 and 3.5 kg, 1.36 and 1.32 kg). Myofibril fragmentation index (MFI) measures the breakdown of these structural elements which occurs as an initial step in the process of protein degradation and meat tenderisation. MFI was lower (i.e. less fragmentation; P<0.05) in LD samples from HE steers than from LE steers, both in samples aged for 1 day (67.7 v. 72.5 units) and in samples aged for 14 days (87.8 v. 91.1 units). The rate of decline in MFI between 1 and 14 days post slaughter was similar in the LD samples from both lines of steers. There were no differences (P>0.05) between HE and LE steers in the activity of m-calpain and &micro;-calpain in LD immediately after slaughter (HE steers: 1.9 and 2.3 units, LE steers: 1.8 and 2.1 units). The level of calpastatin in LD from the HE steers was 13% higher than in the LD from the LE steers (5.2 and 4.6 units respectively, P<0.05). Rate of myofibril fragmentation was positively correlated (P<0.01) with the ratios of both m-calpain and µ-calpain to calpastatin, but not (P>0.10) with levels of either calpain or calpastatin. A single generation of divergent selection for RFI produced differences in calpastatin and myofibril fragmentation that may, with on-going selection for low RFI, negatively affect meat tenderness.

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