0017 Performance and net energy in high and low RFI beef cattle

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 8-8 ◽  
Author(s):  
K. C. Dykier ◽  
R. D. Sainz
Keyword(s):  
Beef Cattle ◽  
Net Energy

Evaluation of the National Research Council (NRC) nutrient requirements for beef cattle: Predicting feedlot performance

2003 ◽  
Vol 83 (4) ◽  
pp. 787-792
Author(s):  
E. K. Okine ◽  
D. H. McCartney ◽  
J. B. Basarab
Keyword(s):  
Beef Cattle ◽  
Dry Matter ◽  
Research Council ◽  
Average Daily Gain ◽  
National Research Council ◽  
Metabolizable Energy ◽  
Dry Matter Intake ◽  
Net Energy ◽  
Feeder Cattle

The accuracy of predicted CowBytes® versus actual dry matter intake (DMI) and average daily gain (ADG) of 407 Hereford × Angus and Charolais × Maine Anjou (445.6 ± 36 kg) feeder cattle using digestable enery acid detergent fiber (DE) estimated from the (ADF) content [Laboratory analysis method (LAB)] and from values determined in vivo (INVIVO method) was examined. The diet consisted of a 73.3% concentrate diet, 22.0% barley silage, 1.6% molasses, and 3.1% feedlot supplement fed ad libitum (as-fed basis). The calculated DE values of the feed were used to predict the metabolizable energy (ME), net energy of maintenance (NEm), and net energy of gain (NEg) of the diet. These energy values were then used in CowBytes® to predict dry matter intake (DMI), ADG, and days on feed (DOF) necessary to meet targeted quality grade of AA and weights of 522 and 568 kg for the heifers and steers, respectively. There was no effect of gender and prediction method interaction (P > 0.10) on any of the variables measured. There were no (P > 0.05) differences in predicted DMI by either the INVIVO or LAB method but both methods underestimated DMI actually consumed by the cattle by 6.8 and 4.9% (P = 0.007), respectively. Indeed, regression values from these predictive methods and actual DMI were (P < 0.05) different from the one-to-one relationship expected by definition. In spite of the higher actual DMI, the actual ADG of the cattle was 14 and 11% (P = 0.0004) lower than was predicted by either the INVIVO or LAB methods. A possible reason for the lower ADG could be an overestimation of DE of the diet. Thus, if available, users of CowBytes® should use actual DMI from their experience in ration formulation. In addition, the effects of environmental temperature on digestibility of diets should be taken into consideration when using the DE of the diet as determined from in vivo digestibility trials or calculated from chemical analyses in determining the DMI of feedlot cattle. Key words: Beef cattle, performance, CowBytes®, National Research Council

Net energy value of timothy and bromegrass silages for beef cattle

1998 ◽  
Vol 78 (1) ◽  
pp. 107-114 ◽  
Author(s):  
D. R. Ouellet ◽  
J. R. Seoane ◽  
H. Lapierre ◽  
P. Flipot ◽  
J. F. Bernier
Keyword(s):  
Beef Cattle ◽  
Heat Production ◽  
Stem Elongation ◽  
Prediction Equation ◽  
Metabolizable Energy ◽  
Net Energy ◽  
Beef Steers ◽  
Boot Stage ◽  
Ad Libitum ◽  
Net Energy Value

Metabolizable energy (ME), net energy for maintenance and net energy for growth of grass silages were evaluated by the comparative slaughter technique using a 2 × 2 × 3 factorial design. Sixty medium frame beef steers (259 ± 29 kg BW) were divided in groups of five and fed during 3 months either Timothy (T) or Bromegrass (B) harvested at stem elongation (S) of the first cut or at boot stage of the aftermath (A). Forages were fed at one of three levels of intake: ad libitum (FF), 80% of FF, or 65% of FF. Silages averaged 26.9% DM, 16.0% CP and 37.7% ADF. Regression of logarithm of heat production (HE) against ME intake were similar for all silages (log HE = 0.00046*ME + 2.4923; r2 = 0.89). From this equation, fasting HE of 311 kJ kg−0.75 d−1, ME for maintenance of 559 kJ kg−0.75 d−1 and efficiency of utilization of energy for maintenance of 56% were determined. Regression of ME intake against retained energy (RE) were similar for all silages. Efficiency of ME utilization for growth was 33% using the regression of ME over RE with a ME requirement for maintenance fixed at 559 kJ kg−0.75 d−1. Net energy for maintenance and growth were similar for all silages, averaging 6.17 and 3.70 MJ kg−1, respectively. The use of a prediction equation based on ADF of forages underestimated ME values of silages by approximately 25%. Moreover, NRC (1984) equations that estimate NE from experimentally estimated ME values tended to overestimate the net energy of our grass silages. Key words: Net energy, grass silages, timothy, bromegrass, beef cattle

Incorporation of environment and feed quality into a net energy model for beef cattle

1983 ◽  
Vol 11 (2) ◽  
pp. 67-94 ◽  
Author(s):  
Otto J. Loewer ◽  
Edward M. Smith ◽  
Nelson Gay ◽  
Robert Fehr
Keyword(s):  
Beef Cattle ◽  
Energy Model ◽  
Net Energy ◽  
Feed Quality

scholarly journals California net energy system for Bos taurus indicus

2019 ◽  
Vol 3 (3) ◽  
pp. 991-998
Author(s):  
Mario Luiz Chizzotti ◽  
Sebastião de Campos Valadares Filho ◽  
Pedro Del Bianco Benedeti ◽  
Flávia Adriane de Sales Silva
Keyword(s):  
Body Weight ◽  
Beef Cattle ◽  
Bos Taurus ◽  
Energy Requirement ◽  
Energy System ◽  
Energy Requirements ◽  
Net Energy ◽  
Nutrient Requirements ◽  
Crossbred Cattle ◽  
Bos Taurus Indicus

Abstract The California net energy system (CNES) was the reference for the development of most energy requirement systems worldwide, such as Nutrient Requirements of Beef Cattle (NASEM, Nutrient requirements of beef cattle, 8th Revised ed, 2016) and Brazilian Nutrient Requirements of Zebu and Crossbred Cattle (Valadares Filho, S. C., L. F. C. Silva, M. P. Gionbelli, P. P. Rotta, M. I. Marcondes, M. L. Chizzotti, and L. F. Prados, BR-CORTE: nutrient requirements of zebu and crossbred cattle, 3rd ed, 2016). This review aimed to compare methods used by NASEM and BR-CORTE to estimate the energy requirements for beef cattle. The net energy requirements for maintenance (NEm) of BR-CORTE is based on empty body weight (EBW), whereas NASEM uses shrunk body weight (SBW), but the Bos taurus indicus presents 10% to 8% lower NEm than Bos taurus taurus. We have compared animals with different EBW and SBW but with same equivalent empty body weight/standard reference weight ratio (0.75), as both systems have suggested different mature weights. Both systems predicted similar net energy requirements for gain (NEg) for animals with 1.8 kg of daily gain. However, estimated empty body gain was lower for NASEM estimations when the same metabolizable energy for gain is available. For pregnancy and lactation of beef cows, the NEm and net energy requirements for pregnancy (NEp) of a Zebu cow estimated by BR-CORTE were lower than the values estimated by NASEM. Furthermore, the magnitude of differences between these systems regarding NEp increased as pregnancy days increase. The NASEM and BR-CORTE systems have presented similar values for energy requirement for lactation (0.72 and 0.75 Mcal/kg milk, respectively).

AN EVALUATION OF TOTAL DIGESTIBLE NUTRIENTS, METABOLIZABLE ENERGY, AND NET ENERGY FOR THE PREDICTION OF ENERGY REQUIREMENTS FOR BEEF CATTLE IN ONTARIO

1973 ◽  
Vol 53 (3) ◽  
pp. 471-477
Author(s):  
D. I. DICKIE ◽  
J. W. WILTON ◽  
T. D. BURGESS
Keyword(s):  
Beef Cattle ◽  
Research Council ◽  
National Research Council ◽  
Domestic Animals ◽  
Metabolizable Energy ◽  
Energy Requirements ◽  
Net Energy ◽  
Nutrient Requirements ◽  
National Academy Of Sciences ◽  
Academy Of Sciences

Four studies and populations of beef animals were used to evaluate different methods of expressing energy requirements by comparing actual to predicted gains of bulls and steers fed in Ontario. Large differences between predicted and actual gains occurred. Based on a total of 503 animals, gains predicted by the net energy method (National Academy of Sciences–National Research Council. 1970. Nutrient requirements of domestic animals. 4. Nutrient requirements of beef cattle. (4th rev.). Nat. Acad. Sci., Publ. ISBN 0-309-01754-8; Washington, D.C.) were approximately 20% below the actual gains but exceptions within treatment groups were evident. Three hundred and twenty-five individually fed bulls were used to compare the accuracy with which gains were predicted from equations using total digestible nutrients (National Academy of Sciences–National Research Council. 1963. Nutrient requirements of domestic animals. 4. Nutrient requirements of beef cattle. Nat. Acad. Sci., Publ. 1137, Washington, D.C.) net energy (National Academy of Sciences–National Research Council. 1970. Nutrient requirements of domestic animals. 4. Nutrient requirements of beef cattle. (4th rev.). Nat. Acad. Sci., Publ. ISBN 0-309-01754-8, Washington, D.C), and metabolizable energy (Agricultural Research Council. 1965. The nutrient requirements of farm animals. No. 2. Ruminants. London, England). The metabolizable energy method predicted gains most accurately.

scholarly journals Supplementing an immunomodulatory feed ingredient to improve thermoregulation and performance of finishing beef cattle under heat stress conditions

2019 ◽  
Vol 97 (10) ◽  
pp. 4085-4092 ◽  
Author(s):  
Eduardo A Colombo ◽  
Reinaldo F Cooke ◽  
Allison A Millican ◽  
Kelsey M Schubach ◽  
Giovanna N Scatolin ◽  
...  
Keyword(s):  
Heat Stress ◽  
Beef Cattle ◽  
Animal Health ◽  
Plasma Concentrations ◽  
Stress Conditions ◽  
Net Energy ◽  
Hair Cortisol ◽  
Feed Ingredient ◽  
Hair Samples ◽  
Finishing Beef Cattle

Abstract This experiment compared physiological and productive responses in finishing beef cattle managed under heat stress conditions, and supplemented (SUPP) or not (CON) with an immunomodulatory feed ingredient (Omnigen-AF; Phibro Animal Health, Teaneck, NJ). Crossbred yearling cattle (¾ Bos taurus × ¼ Bos indicus; 64 heifers and 64 steers) were ranked by initial body weight (BW) (440 ± 3 kg) and sex, and allocated to 1 of 16 unshaded drylot pens (8 heifers or steers/pen). Pens within sex were randomly assigned to receive SUPP or CON (n = 8/treatment). Cattle received a total-mixed ration (91% concentrate inclusion and 1.21 Mcal/kg of net energy for gain; dry matter [DM basis]) during the experiment (day 0 to 106). The immunomodulatory feed was offered as a top-dress to SUPP pens (56 g/d per animal; as-fed basis) beginning on day 7. Cattle BW were recorded on day 0, 14, 28, 42, 56, 70, 84, 98, and 106. Feed intake was evaluated from each pen by recording feed offer daily and refusals biweekly. Intravaginal temperature of heifers was recorded hourly from day 1 to 6, 29 to 41, and 85 to 97. Environmental temperature humidity index (THI) was also recorded hourly throughout the experiment, and averaged 79.8 ± 0.6. Concurrently with BW assessment, hair samples from the tail-switch were collected (3 animals/pen) for analysis of hair cortisol concentrations. Blood samples were collected on day 0, 28, 56, 84, and 106 from all animals for plasma extraction. Whole blood was collected on day 0, 56, and 106 (3 animals/pen) for analysis of heat shock protein (HSP) 70 and HSP72 mRNA expression. Cattle were slaughtered on day 107 at a commercial packing facility. Results obtained prior to day 7 served as independent covariate for each respective analysis. Heifers receiving SUPP had less (P ≤ 0.05) vaginal temperature from 1500 to 1900 h across sampling days (treatment × hour, P < 0.01; 39.05 vs. 39.19 °C, respectively; SEM = 0.04), when THI ranged from 85.3 to 90.1. Expression of HSP70 and HSP72 was less (P ≥ 0.03) for SUPP cattle on day 106 (22.6- vs. 51.5-fold effect for HSP70, SEM = 9.7, and 11.0- vs. 32.8-fold effect for HSP72; treatment × day, P ≤ 0.04). No treatment effects were detected (P ≥ 0.22) for performance, carcass traits, plasma concentrations of cortisol and haptoglobin, or hair cortisol concentrations. Results from this study suggest that SUPP ameliorated hyperthermia in finishing cattle exposed to heat stress conditions, but such benefit was not sufficient to improve productive responses.

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