scholarly journals The use of n-alkanes for estimating feed intake in beef cows

1995 ◽  
Vol 44 (Suppl. 1) ◽  
pp. 239-239
Author(s):  
M. Oliván ◽  
K. Osoro
Keyword(s):  
Feed Intake ◽  
Beef Cows

scholarly journals Influence of Residual Feed Intake and Cow Age on Dry Matter Intake Post-Weaning and Peak Lactation of Black Angus Cows

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1822
Author(s):  
Cory T. Parsons ◽  
Julia M. Dafoe ◽  
Samuel A. Wyffels ◽  
Timothy DelCurto ◽  
Darrin L. Boss
Keyword(s):  
Milk Production ◽  
Feed Intake ◽  
Dry Matter ◽  
Free Choice ◽  
Residual Feed Intake ◽  
Beef Cows ◽  
Age Effect ◽  
Dry Matter Intake ◽  
Intake Rate ◽  
Two Stages

We evaluated heifer post-weaning residual feed intake (RFI) classification and cow age on dry matter intake (DMI) at two stages of production. Fifty-nine non-lactating, pregnant, (Study 1) and fifty-four lactating, non-pregnant (Study 2) commercial black Angus beef cows were grouped by age and RFI. Free-choice, hay pellets were fed in a GrowSafe feeding system. In Study 1, cow DMI (kg/d) and intake rate (g/min) displayed a cow age effect (p < 0.01) with an increase in DMI and intake rate with increasing cow age. In Study 2, cow DMI (kg/d) and intake rate (g/min) displayed a cow age effect (p < 0.02) with an increase in DMI and intake rate with increasing cow age. Milk production displayed a cow age × RFI interaction (p < 0.01) where both 5–6-year-old and 8–9-year-old low RFI cows produced more milk than high RFI cows. For both studies, intake and intake behavior were not influenced by RFI (p ≥ 0.16) or cow age × RFI interaction (p ≥ 0.21). In summary, heifer’s post-weaning RFI had minimal effects on beef cattle DMI or intake behavior, however, some differences were observed in milk production.

scholarly journals 127 Predicting Dry Matter Intake of Gestating and Lactating Beef Cows

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 58-58
Author(s):  
Megan A Gross ◽  
Claire Andresen ◽  
Amanda Holder ◽  
Alexi Moehlenpah ◽  
Carla Goad ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Milk Yield ◽  
Feed Intake ◽  
Beef Cows ◽  
Multiple Regression Equation ◽  
Validation Data ◽  
Data Set ◽  
Lactating Cows ◽  
Downward Bias ◽  
Protein Supply

Abstract In 1996, the NASEM beef cattle committee developed and published an equation to estimate cow feed intake using results from studies conducted or published between 1979 and 1993 (Nutrient Requirements of Beef Cattle). The same equation was recommended for use in the most recent version of this publication (2016). The equation is sensitive to cow weight, diet digestibility and milk yield. Our objective was to validate the accuracy of this equation using more recent published and unpublished data. Criteria for inclusion in the validation data set included projects conducted or published within the last ten years, direct measurement of forage intake, adequate protein supply, and pen feeding (no tie stall or metabolism crate data). The validation data set included 29 treatment means for gestating cows and 26 treatment means for lactating cows. Means for the gestating cow data set was 11.4 ± 1.9 kg DMI, 599 ± 77 kg BW, 1.24 ± 0.14 Mcal/kg NEm per kg of feed and lactating cow data set was 14.5 ± 2.0 kg DMI, 532 ± 116.3 kg BW, and 1.26 ± 0.24 Mcal NEm per kg feed, respectively. Non intercept models were used to determine equation accuracy in predicting validation data set DMI. The slope for linear bias in the NASEM gestation equation did not differ from 1 (P = 0.07) with a 3.5% positive bias. However, when the NASEM equation was used to predict DMI in lactating cows, the slope for linear bias significantly differed from 1 (P &lt; 0.001) with a downward bias of 13.7%. Therefore, a new multiple regression equation was developed from the validation data set: DMI= (-4.336 + (0.086427 (BW^.75) + 0.3 (Milk yield)+6.005785(NEm)), (R-squared=0.84). The NASEM equation for gestating beef cows was reasonably accurate while the lactation equation underestimated feed intake.

Genetic parameters for feed intake and efficiency in lactating beef cows

1996 ◽  
Vol 76 (1) ◽  
pp. 81-87 ◽  
Author(s):  
L. Q. Fan ◽  
J. W. Wilton ◽  
P. E. Colucci
Keyword(s):  
Milk Yield ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
National Research Council ◽  
Beef Cows ◽  
Feed Consumption ◽  
Research Centre ◽  
Total Data

Genetic parameters of feed intake and efficiency and production traits for lactating beef cows were estimated from data collected from 1980 to 1988 at the Elora Beef Research Centre, Guelph, Ontario. Estimates were obtained using restricted maximum likelihood (REML) with an individual animal model with year–season–treatment, sex of calf, parity, breeding system, covariate daily change of backfat depth and direct genetic and permanent environmental effects. The data included 1174 observations, 511 cows, 369 dam–maternal grand dam pairs and 245 sires of cows. Feed efficiency for milk was calculated as milk yield relative to energy consumed for milk and maintenance and residual feed consumption as estimated energy intake minus energy requirements as estimated by the National Research Council. Heritabilities for Herefords alone and total data, respectively, were estimated to be 0.02 and 0.11 for cow's daily ME intake (MEI), 0.26 and 0.26 for daily milk yield (DMY), 0.45 and 0.33 for milk fat percentage (MFP), 0.29 and 0.40 for metabolic body weight (MBW), 0.21 and 0.10 for calf weaning weight as a proportion of cow weight at weaning (PPW), 0.18 and 0.11 for feed efficiency for milk (FE), and 0.23 and 0.03 for residual feed consumption (RFC). Genetic correlations of output (DMY) and input (MEI) were 0.31 for Hereford and 0.75 for the total data. Genetic correlations of RFC with both output (DMY) and input (MEI) were low. Genetically, PPW was positively associated with FE and DMY and negatively associated with MBW. Key words: Genetic parameters, feed efficiency, lactation, beef cow

scholarly journals The use of n-alkanes for estimating feed intake in beef cows

1995 ◽  
Vol 44 (Suppl. 1) ◽  
pp. 239-239 ◽  
Author(s):  
M. Oliván ◽  
K. Osoro
Keyword(s):  
Feed Intake ◽  
Beef Cows

Methane emissions from grazing Angus beef cows selected for divergent residual feed intake

2011 ◽  
Vol 166-167 ◽  
pp. 302-307 ◽  
Author(s):  
F.M. Jones ◽  
F.A. Phillips ◽  
T. Naylor ◽  
N.B. Mercer
Keyword(s):  
Feed Intake ◽  
Residual Feed Intake ◽  
Beef Cows ◽  
Methane Emissions

PSXIII-29 Late-Breaking: Relationships between feed efficiency traits, gas emissions, and calculated heat production and respiratory quotients in mature beef cows

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 378-379
Author(s):  
Lauren Finlay ◽  
Katharine M Wood
Keyword(s):  
Gas Exchange ◽  
Heat Production ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Beef Cows ◽  
Gas Production ◽  
Feed Ratio ◽  
Metabolic Efficiency ◽  
O2 Consumption ◽  
Pearson Correlations

Abstract This research evaluated relationships between feed efficiency measurements including residual feed intake (RFI), gain to feed ratio (G:F) and enteric gas production of methane (CH4), carbon dioxide (CO2), oxygen, (O2) along with calculated respiratory quotient (RQ) and heat production (HP) of mature beef cows. Sixty pregnant multiparous Angus beef cows were measured for individual intake for 10 weeks leading up to parturition. Cows were individually fed using the Insentec feeding system to measure individual feed intake. Pens of cows were rotated weekly to the C-Lock Greenfeed trailer (C-Lock Inc.) to measure gas production for a minimum 2 periods per group. Cows were weighed, body condition scored, and ultrasound performed for rib and rump fat depth every 28 days and calf birth weight was recorded. Pearson correlations were conducted to determine relationships between gas exchange measurements and feed efficiency measures. The model for RFI included ADG, pregnancy corrected BW, and ultrasound measures of rib and rump fat (R2= 0.32). Methane emissions were 263±40.3 g CH4/d in dry lot, and daily enteric CH4 emissions per kg of pregnancy corrected body weight ranging from 0.26 to 0.53 g CH4/kg pcBW. Pearson correlations found positive correlations between DMI and CH4 and CO2 (P ≤ 0.001). Pregnancy corrected BW was also positively correlated with total O2 consumption and calculated HP (P ≤ 0.001) and negatively correlated with RQ (P = 0.04). However, RFI and feed conversion ratio were not significantly correlated with gas measurements, or calculated HP or RQ (P ≥ 0.1), although DMI/kg of BW tended (P = 0.098) to be negatively correlated with O2 consumption. In conclusion, accurately identifying feed efficiency in mature beef cows continues to be a challenge. However, the inclusion of gas exchange measures and calorimetry measurements may be able to better assess metabolic efficiency in mature beef cattle.

Supplementation of Apple Pomace with Nonprotein Nitrogen for Gestating Beef Cows. I. Feed Intake and Performance

1977 ◽  
Vol 45 (3) ◽  
pp. 513-522 ◽  
Author(s):  
J. P. Fontenot ◽  
K. P. Bovard ◽  
R. R. Oltjen ◽  
T. S. Rumsey ◽  
B. M. Priode
Keyword(s):  
Feed Intake ◽  
Beef Cows ◽  
Apple Pomace ◽  
Nonprotein Nitrogen ◽  
And Performance
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