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

2010 ◽  
Author(s):  
Kevin S. Shaffer
Keyword(s):  
Body Composition ◽  
Feed Intake ◽  
Residual Feed Intake ◽  
Beef Heifers

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.

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

scholarly journals Feed efficiency and meat quality of crossbred beef heifers classified according to residual feed intake

2015 ◽  
Vol 16 (3) ◽  
pp. 632-642 ◽  
Author(s):  
Simone Frotas dos REIS ◽  
Daiane Aparecida FAUSTO ◽  
Sergio Raposo de MEDEIROS ◽  
Pedro Veiga Rodrigues PAULINO ◽  
Sebastião de Campos VALADARES FILHO ◽  
...  
Keyword(s):  
Meat Quality ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Residual Feed Intake ◽  
Beef Heifers ◽  
System A ◽  
Fat Thickness ◽  
Ad Libitum ◽  
Sorghum Silage

AbstractThis study aimed to evaluate feed efficiency and meat quality of 31 three-crossbred beef heifers during 84 days in a feedlot system. A 60:40 concentrate and sorghum silage ration on DM basis (ME = 2.73Mcal/kg of DM, CP = 11.90% DM) was fed ad libitum. Based on residual feed intake (RFI) calculations, the heifers were ranked in three groups of feed efficiency: High RFI (average mean = 0.776; n = 9), medium RFI (average mean = -0.010; n = 11), and low RFI (average mean = - 0.624; n = 11). High RFI heifers consumed 4.56% more DM per day than low RFI heifers (P <0.05). The ADG did not differ (P> 0.05) among RFI groups (1.40kg/day). No differences (P>0.05) were detected for digestibility of the nutrients: DM (64.00%), CP (60.01%), crude fat (72.90%), NDF (54.80%) and non-fibrous carbohydrate (NFC) (78.91%). There were no differences between low and high RFI groups for slaughter weight (475.00 vs. 479.55kg), hot carcass weight (259.09 vs. 261.44kg), Longissimus dorsi (LD) area (69.02 vs. 68.11 cm2), back-fat thickness (5.74 vs. 6.26 cm), shear force (5.45 vs. 5.19kg), sensorial traits of LD muscle, LD color (intensities L=40.47 a*=24.74 and b*=16.13) or commercial cuts yield. Low RFI heifers presented similar meat quality and carcass traits as high RFI heifers, however low RFI heifers consumed less DM (kg/d).

Methane and carbon dioxide emissions and grazed forage intake from pregnant beef heifers previously classified for residual feed intake under drylot conditions

2020 ◽  
Author(s):  
Ghader Manafiazar ◽  
Thomas K. Flesch ◽  
Vern S. Baron ◽  
Lisa McKeown ◽  
Brittany Byron ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Co2 Emissions ◽  
Feed Intake ◽  
Carbon Dioxide Emissions ◽  
Residual Feed Intake ◽  
Beef Heifers ◽  
Once Daily ◽  
Forage Intake ◽  
Carbon Dioxide Co2 ◽  
Fecal Sampling

Objectives were to quantify the effect of post-weaning residual feed intake (RFI) on subsequent grazed forage intake, methane (CH4) and carbon dioxide (CO2) emissions. Beef heifers classified for RFI adjusted for off-test backfat (RFIfat; 55 high and 56 low) at nine mo of age were monitored seven mo later for CH4 and CO2 emissions using the GreenFeed Emissions Monitoring system. Fifty-six of these heifers were also monitored as high and low RFIfat groups using Open Path Fourier-Transform Infrared Spectroscopy (OP-FTIR). Heifers were dosed with one kg of C32 labelled pellets once daily for 15 d, with twice daily fecal sampling the last eight d to determine individual grazed forage intake using the n-alkane method. Low RFIfat pregnant heifers consumed less forage (10.25 vs. 10.81 kg DM d-1; P < 0.001), and emitted less daily CH4 (238.7 vs. 250.7 g d-1; P = 0.009) and CO2 (7578 vs. 8041 g d-1; P < 0.001) compared with high RFIfat animals. Results from the OP-FTIR further confirmed that low RFIfat heifers emitted 6.3% less (g d-1; P = 0.006) CH4 compared to their high RFIfat cohorts. Thus, selection for low RFIfat will decrease daily CH4 and CO2 emissions from beef cattle.

Methane and carbon dioxide emissions from yearling beef heifers and mature cows classified for residual feed intake under drylot conditions

2020 ◽  
Vol 100 (3) ◽  
pp. 522-535 ◽  
Author(s):  
G. Manafiazar ◽  
V.S. Baron ◽  
L. McKeown ◽  
H. Block ◽  
K. Ominski ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Feed Intake ◽  
Carbon Dioxide Emissions ◽  
Body Weight Gain ◽  
Residual Feed Intake ◽  
Individual Performance ◽  
Feed Consumption ◽  
Beef Heifers ◽  
Air Temperatures ◽  
Rapid City

This study quantified methane (CH4) and carbon dioxide (CO2) production from beef heifers and cows classified for residual feed intake adjusted for off-test backfat thickness (RFIfat) and reared in drylot during cold winter temperatures. Individual performance, daily feed intake, and RFIfat were obtained for 1068 crossbred and purebred yearling heifers (eight trials) as well as 176 crossbred mature cows (six trials) during the winters of 2015–2017 at two locations. A portion of these heifers (147 high RFIfat; 167 low RFIfat) and cows (69 high RFIfat; 70 low RFIfat) was monitored for enteric CH4 and CO2 emissions using the GreenFeed Emissions Monitoring (GEM) system (C-Lock Inc., Rapid City, SD, USA). Low RFIfat cattle consumed less feed [heifers, 7.80 vs. 8.48 kg dry matter (DM) d−1; cows, 11.64 vs. 13.16 kg DM d−1] and emitted less daily CH4 (2.5% for heifers; 3.7% for cows) and CO2 (1.4% for heifers; 3.4% for cows) compared with high RFIfat cattle. However, low RFIfat heifers and cows had higher CH4 (6.2% for heifers; 9.9% for cows) and CO2 yield (7.3% for heifers; 9.8% for cows) per kilogram DM intake compared with their high RFIfat pen mates. The GEM system performed at air temperatures between +20 and −30 °C. Feed intake of heifers and mature cows was differently affected by ambient temperature reduction between +20 and −15 °C and similarly increased their feed intake at temperatures below −15 °C. In conclusion, low RFIfat animals emit less daily enteric CH4 and CO2, due mainly to lower feed consumption at equal body weight, gain, and fatness.

Relationships among performance, residual feed intake, and temperament assessed in growing beef heifers and subsequently as 3-year-old, lactating beef cows1

2013 ◽  
Vol 91 (5) ◽  
pp. 2254-2263 ◽  
Author(s):  
T. E. Black ◽  
K. M. Bischoff ◽  
V. R. G. Mercadante ◽  
G. H. L. Marquezini ◽  
N. DiLorenzo ◽  
...  
Keyword(s):  
Feed Intake ◽  
Residual Feed Intake ◽  
Beef Heifers
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