The relationship of feeding behavior to residual feed intake in crossbred Angus steers fed traditional and no-roughage diets1

2008 ◽  
Vol 86 (1) ◽  
pp. 180-186 ◽  
Author(s):  
J. W. Golden ◽  
M. S. Kerley ◽  
W. H. Kolath
Keyword(s):  
Feeding Behavior ◽  
Feed Intake ◽  
Residual Feed Intake ◽  
Relationship Of ◽  
The Relationship

Behavior as a window on physiology: a simple apparatus for recording caterpillar feeding.

1992 ◽  
Vol 262 (6) ◽  
pp. S9 ◽  
Author(s):  
E Bowdan
Keyword(s):  
Feeding Behavior ◽  
Control Mechanisms ◽  
Inexpensive Method ◽  
Simple Apparatus ◽  
Physiological Processes ◽  
Wide Range ◽  
Relationship Of ◽  
The Relationship

Regulation of feeding is a fundamental element of homeostasis. This is reflected in the similarity of control mechanisms in a wide range of animals, including insects and humans. A close examination of feeding behavior can illuminate the physiological processes driving regulation. A simple, inexpensive method for recording fine details of feeding by caterpillars is described. Possible experiments, interpretation of the data, and the relationship of observations to the underlying physiology, are outlined.

Mass to height relationships in annual pastures and prediction of sheep growth rates

2014 ◽  
Vol 54 (9) ◽  
pp. 1305
Author(s):  
S. M. Robertson
Keyword(s):  
Feed Intake ◽  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Sheep Grazing ◽  
Software Model ◽  
Low Mass ◽  
Grazing Systems ◽  
Sheep Production ◽  
Relationship Of ◽  
The Relationship

The relationship between pasture height and mass influences the availability of pasture for grazing, and is important for predicting intake of pasture and liveweight change by sheep. The relationship between pasture mass and structure and sheep production is poorly defined for low-mass, clumpy pastures in low-rainfall regions. Between 2001 and 2004, 480 quadrats of pastures were measured in 23 paddocks throughout the Victorian Mallee. Pasture height was related to live mass for medic (linear; r2 = 0.70; P < 0.001) and grassy medic (asymptotic; r2 = 0.64; P < 0.001) pastures, and prediction of grassy medic pasture height was improved by inclusion of proportion live groundcover. During 2004, pasture dry matter accumulation and liveweight changes in sheep grazing annual pastures were measured and compared with predicted outputs from GrazFeed, a software model used to estimate feed intake and liveweight change in sheep. Improved predictions of liveweight gain in grazing sheep were obtained using measured height rather than the GrazFeed default height. The results show that the height to mass relationship of annual pastures in the Victorian Mallee differs between pasture types, between years, and may differ from other published relationships. This study provides information that may assist in the development of models of grazing systems.

scholarly journals Associations between residual feed intake and apparent nutrient digestibility, in vitro methane-producing activity, and volatile fatty acid concentrations in growing beef cattle1

2019 ◽  
Vol 97 (8) ◽  
pp. 3550-3561 ◽  
Author(s):  
Jocelyn R Johnson ◽  
Gordon E Carstens ◽  
Wimberly K Krueger ◽  
Phillip A Lancaster ◽  
Erin G Brown ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Fatty Acid ◽  
Feed Intake ◽  
Volatile Fatty Acid ◽  
Stepwise Regression ◽  
Rumen Fluid ◽  
Residual Feed Intake ◽  
Nutrient Digestibility ◽  
The Relationship

Abstract The objectives of this study were to examine the relationship between residual feed intake (RFI) and DM and nutrient digestibility, in vitro methane production, and volatile fatty acid (VFA) concentrations in growing beef cattle. Residual feed intake was measured in growing Santa Gertrudis steers (Study 1; n = 57; initial BW = 291.1 ± 33.8 kg) and Brangus heifers (Study 2; n = 468; initial BW = 271.4 ± 26.1 kg) fed a high-roughage-based diet (ME = 2.1 Mcal/kg DM) for 70 d in a Calan-gate feeding barn. Animals were ranked by RFI based on performance and feed intake measured from day 0 to 70 (Study 1) or day 56 (Study 2) of the trial, and 20 animals with the lowest and highest RFI were identified for subsequent collections of fecal and feed refusal samples for DM and nutrient digestibility analysis. In Study 2, rumen fluid and feces were collected for in vitro methane-producing activity (MPA) and VFA analysis in trials 2, 3, and 4. Residual feed intake classification did not affect BW or BW gain (P &gt; 0.05), but low-RFI steers and heifers both consumed 19% less (P &lt; 0.01) DMI compared with high-RFI animals. Steers with low RFI tended (P &lt; 0.1) to have higher DM digestibility (DMD) compared with high-RFI steers (70.3 vs. 66.5 ± 1.6% DM). Heifers with low RFI had 4% higher DMD (76.3 vs. 73.3 ± 1.0% DM) and 4 to 5% higher (P &lt; 0.01) CP, NDF, and ADF digestibility compared with heifers with high RFI. Low-RFI heifers emitted 14% less (P &lt; 0.01) methane (% GE intake; GEI) calculated according to Blaxter and Clapperton (1965) as modified by Wilkerson et al. (1995), and tended (P = 0.09) to have a higher rumen acetate:propionate ratio than heifers with high RFI (GEI = 5.58 vs. 6.51 ± 0.08%; A:P ratio = 5.02 vs. 4.82 ± 0.14%). Stepwise regression analysis revealed that apparent nutrient digestibilities (DMD and NDF digestibility) for Study 1 and Study 2 accounted for an additional 8 and 6%, respectively, of the variation in intake unaccounted for by ADG and mid-test BW0.75. When DMD, NDF digestibility, and total ruminal VFA were added to the base model for Study 2, trials 2, 3, and 4, the R2 increased from 0.33 to 0.47, explaining an additional 15% of the variation in DMI unrelated to growth and body size. On the basis of the results of these studies, differences in observed phenotypic RFI in growing beef animals may be a result of inter-animal variation in apparent nutrient digestibility and ruminal VFA concentrations.

scholarly journals Relationship of Residual Feed Intake on Specific Hematological and Biochemical Parameters in Rambouillet Sheep

2011 ◽  
Vol 10 (9) ◽  
pp. 1112-1116 ◽  
Author(s):  
R.M. Rincon-Del ◽  
H. Gutierrez- ◽  
E.D. Perez-Vazq ◽  
A. Muro-Reyes ◽  
L.H. Diaz-Garci ◽  
...  
Keyword(s):  
Feed Intake ◽  
Biochemical Parameters ◽  
Residual Feed Intake ◽  
Hematological And Biochemical Parameters ◽  
Relationship Of

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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