Growth performance, feed digestibility, body composition, and feeding behavior of high– and low–residual feed intake fat-tailed lambs under moderate feed restriction1

2016 ◽  
Vol 94 (8) ◽  
pp. 3382-3388
Author(s):  
H. Rajaei Sharifabadi ◽  
A. A. Naserian ◽  
R. Valizadeh ◽  
M. R. Nassiry ◽  
W. G. Bottje ◽  
...  
Keyword(s):  
Body Composition ◽  
Feeding Behavior ◽  
Growth Performance ◽  
Feed Intake ◽  
Residual Feed Intake ◽  
Feed Digestibility

Effect of divergence in residual feed intake on feeding behavior, blood metabolic variables, and body composition traits in growing beef heifers1

2010 ◽  
Vol 88 (1) ◽  
pp. 109-123 ◽  
Author(s):  
A. K. Kelly ◽  
M. McGee ◽  
D. H. Crews ◽  
A. G. Fahey ◽  
A. R. Wylie ◽  
...  
Keyword(s):  
Body Composition ◽  
Feeding Behavior ◽  
Feed Intake ◽  
Residual Feed Intake ◽  
Metabolic Variables

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

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

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.

scholarly journals Association between residual feed intake and enteric methane emissions in Hereford steers

2018 ◽  
Vol 3 (1) ◽  
pp. 239-246 ◽  
Author(s):  
Yoana Dini ◽  
Cecilia Cajarville ◽  
José I Gere ◽  
Sofía Fernandez ◽  
Martín Fraga ◽  
...  
Keyword(s):  
Feeding Behavior ◽  
Methane Emission ◽  
Feed Intake ◽  
Sulfur Hexafluoride ◽  
Quantitative Polymerase Chain Reaction ◽  
Daily Intake ◽  
Residual Feed Intake ◽  
Live Weight ◽  
Repeated Measurements ◽  
Ch4 Production

Abstract The objective of this study was to quantify the emissions of enteric CH4 from growing Hereford steers raised under feedlot conditions based on contrasting levels of residual feed intake (RFI). A repeated measurements experiment was conducted over 20 d to determine CH4 production from two groups of nine Hereford steers, with contrasting RFI values (mean ± SD): low RFI (LRFI group; −0.78 ± 0.22 kg DMI/d) vs. high RFI (HRFI group; 0.83 ± 0.34 kg DMI/d). Steers were selected from a larger contemporary population in which the RFI was evaluated. Steers were maintained under confined conditions with ad libitum access to water and feed, comprising a total mixed ration of 55% sorghum silage, 21% barley silage, 21% corn grain, and 3% protein–mineral–vitamin–premix, provided twice a day. Before the beginning of CH4 measurements, the live weight of both groups of animals was determined, which on average (±SEM) was 357.0 ± 5.11 and 334.0 ± 10.17 kg in the LRFI and HRFI groups, respectively. Methane emission (g/d) was measured on each animal with the sulfur hexafluoride (SF6) tracer technique, during two consecutive periods of 5 d. Individual daily intake and feeding behavior characteristics were measured using a GrowSafe automated feeding system (Model 6000, GrowSafe Systems Ltd, Airdrie, Alberta, Canada). Methanogens in the ruminal content were quantified using quantitative polymerase chain reaction with primers targeting the mcrA gene. Methane emission was near 27% lower in animals with LRFI when expressed in absolute terms (g/d; 26.8%; P = 0.009), by unit of dry matter intake (g CH4/kg; 27.9%, P = 0.021), or as % of gross energy intake (26.7%; P = 0.027). These differences could not be explained by differences in amount of total of methanogens (average = 9.82 log10 units; P = 0.857). However, there were some differences in animal feeding behavior that could explain these differences (e.g., LRFI animals tended to spend less time in feeders). Our results suggest that, in Hereford steers, the selection by RFI values is a promising mitigation strategy for the reduction of the emission of enteric CH4.

Feeding Behavior of Yorkshire Pigs Selected for Residual Feed Intake

2009 ◽  
Author(s):  
Jennifer Young ◽  
Weiguo Cai ◽  
Daniel S. Nettleton ◽  
Jack C.M. Dekkers
Keyword(s):  
Feeding Behavior ◽  
Feed Intake ◽  
Residual Feed Intake ◽  
Yorkshire Pigs
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