scholarly journals Description and evaluation of a net energy intake model as a function of dietary chewing index

2016 ◽  
Vol 99 (11) ◽  
pp. 8699-8715 ◽  
Author(s):  
L.M. Jensen ◽  
B. Markussen ◽  
N.I. Nielsen ◽  
E. Nadeau ◽  
M.R. Weisbjerg ◽  
...  
Keyword(s):  
Energy Intake ◽  
Net Energy ◽  
Net Energy Intake

EFFECTS OF CORRECTING FOR FEEDING LEVELS ON ESTIMATES OF GENETIC PARAMETERS OF MILK YIELD AND COMPOSITION

1976 ◽  
Vol 56 (3) ◽  
pp. 523-529 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY
Keyword(s):  
Energy Intake ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Relationships ◽  
Protein Yield ◽  
Net Energy ◽  
Yield Traits ◽  
Genetic And Phenotypic Correlations ◽  
Net Energy Intake ◽  
Quadratic Effects

A total of 13,561 Holstein 305-day lactation records were studied to examine the effects of correcting records for linear and quadratic effects of 305-day net energy intake from silage, hay, pasture and meal feeding on estimates of genetic parameters of milk, fat and protein yield and fat and protein percent. Correcting records for net energy intake reduced variances of yield traits, but had little effect on composition trait variances. When expressed as a percentage of the total variance, the relative importance of sire and sire–herd components were unchanged using corrected records, and heritabilities, except for that of protein yield, were unaltered. Cow components of yield traits were reduced relative to other components after records were corrected for feeding levels. Consequently, repeatabilities were reduced as well, suggesting that a large portion of the permanent environmental effects on yield traits may be of nutritional origin. Genetic and phenotypic correlations between yield traits were also reduced appreciably after records were corrected for feed intake. Genetic relationships between milk, fat and protein yield may not be as great as commonly believed.

Position Choice by Drift-Feeding Salmonids: Model and Test for Arctic Grayling (Thymallus arcticus) in Subarctic Mountain Streams, Interior Alaska

1990 ◽  
Vol 47 (10) ◽  
pp. 2039-2048 ◽  
Author(s):  
Nicholas F. Hughes ◽  
Lawrence M. Dill
Keyword(s):  
Energy Intake ◽  
Water Depth ◽  
Focal Point ◽  
Water Velocity ◽  
Net Energy ◽  
Intake Rate ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Net Energy Intake ◽  
Energy Intake Rate

We develop a model to predict position choice of drift-feeding stream salmonids, assuming a fish chooses the position that maximizes its net energy intake rate. The fish's habitat is represented as a series of stream cross-profiles, each divided into vertical strips characterized by water depth and velocity. The fish may select a focal point in any of these strips, and include several neighbouring strips in its foraging area. The number of prey the fish encounters depends on its reaction distance to prey, water depth, and water velocity; the proportion of detected prey the fish is able to capture declines with water velocity. The fish's net energy intake rate is its gross energy intake rate from feeding minus the swimming cost calculated by using water velocity at the fish's focal point. There was a close match between the positions predicted by this model and those chosen by solitary Arctic grayling (Thymallus arcticus) in the pools of a mountain stream in Alaska.

Microhabitat variables explain patch switching by wintering Bewick’s swans through giving-up net energy intake rates

2020 ◽  
Vol 27 (15) ◽  
pp. 18843-18852
Author(s):  
Chao Yu ◽  
Lizhi Zhou ◽  
Nazia Mahtab ◽  
Shaojun Fan ◽  
Yunwei Song
Keyword(s):  
Energy Intake ◽  
Net Energy ◽  
Net Energy Intake

Responses of rufous hummingbirds to midday fasts

1985 ◽  
Vol 63 (10) ◽  
pp. 2249-2253 ◽  
Author(s):  
Zena J. Tooze ◽  
Clifton Lee Gass
Keyword(s):  
Body Weight ◽  
Energy Balance ◽  
Food Intake ◽  
Energy Intake ◽  
Laboratory Tests ◽  
Net Energy ◽  
Energy Reserves ◽  
Metabolic Costs ◽  
Net Energy Intake ◽  
Highly Correlated

This study investigates how rufous hummingbirds regain energy balance after experimentally imposed midday fasts reduce their energy reserves. Net energy balance calculated from food intake, activity budgets, and allometric equations for the costs of flying and perching was highly correlated with change in body weight in laboratory tests of 3 h or more. Individuals accumulated energy and body weight at the same rate after fasts as before, resulting in energy deficits at the end of the day compared with control conditions. Energy balance relative to control values was regained by the following morning, primarily by reducing metabolic costs in the dark through torpor. Net energy intake increased the following day, but this increase was relatively unimportant to reestablishing equilibrium.

Statistical properties of proportional residual energy intake as a new measure of energetic efficiency

2017 ◽  
Vol 84 (3) ◽  
pp. 248-253
Author(s):  
Pouya Zamani
Keyword(s):  
Energy Efficiency ◽  
Energy Intake ◽  
Residual Energy ◽  
Energetic Efficiency ◽  
Net Energy ◽  
Production Traits ◽  
Feed Conversion ◽  
Gross Energy ◽  
Net Energy Intake ◽  
Residual Energy Intake

Traditional ratio measures of efficiency, including feed conversion ratio (FCR), gross milk efficiency (GME), gross energy efficiency (GEE) and net energy efficiency (NEE) may have some statistical problems including high correlations with milk yield. Residual energy intake (REI) or residual feed intake (RFI) is another criterion, proposed to overcome the problems attributed to the traditional ratio criteria, but it does not account for production or intake levels. For example, the same REI value could be considerable for low producing and negligible for high producing cows. The aim of this study was to propose a new measure of efficiency to overcome the problems attributed to the previous criteria. A total of 1478 monthly records of 268 lactating Holstein cows were used for this study. In addition to FCR, GME, GEE, NEE and REI, a new criterion called proportional residual energy intake (PREI) was calculated as REI to net energy intake ratio and defined as proportion of net energy intake lost as REI. The PREI had an average of −0·02 and range of −0·36 to 0·27, meaning that the least efficient cow lost 0·27 of her net energy intake as REI, while the most efficient animal saved 0·36 of her net energy intake as less REI. Traditional ratio criteria (FCR, GME, GEE and NEE) had high correlations with milk and fat corrected milk yields (absolute values from 0·469 to 0·816), while the REI and PREI had low correlations (0·000 to 0·069) with milk production. The results showed that the traditional ratio criteria (FCR, GME, GEE and NEE) are highly influenced by production traits, while the REI and PREI are independent of production level. Moreover, the PREI adjusts the REI magnitude for intake level. It seems that the PREI could be considered as a worthwhile measure of efficiency for future studies.

Development of net energy intake models for drift-feeding juvenile coho salmon and steelhead

2008 ◽  
Vol 83 (3) ◽  
pp. 259-267 ◽  
Author(s):  
John J. Piccolo ◽  
Nicholas F. Hughes ◽  
Mason D. Bryant
Keyword(s):  
Energy Intake ◽  
Coho Salmon ◽  
Net Energy ◽  
Drift Feeding ◽  
Net Energy Intake

Altitude and temperature effects on the energetic cost of hover-feeding in migratory rufous hummingbirds, Selasphorus rufus

2008 ◽  
Vol 86 (3) ◽  
pp. 161-169 ◽  
Author(s):  
Kenneth C. Welch, ◽  
Raul K. Suarez
Keyword(s):  
Oxygen Consumption ◽  
Energy Intake ◽  
Foraging Strategies ◽  
Net Energy ◽  
Hovering Flight ◽  
Energetic Costs ◽  
Ambient Temperatures ◽  
Selasphorus Rufus ◽  
Consumption Rates ◽  
Net Energy Intake

During migratory stopovers, rufous hummingbirds ( Selasphorus rufus (Gmelin, 1788)) can achieve high daily rates of net energy intake and mass gain while foraging at a range of elevations and ambient temperatures, despite the high energetic costs of hovering flight and thermoregulation. To gain insights into the factors affecting the energetic costs incurred during foraging, we captured migratory hummingbirds and measured their oxygen consumption rates during hover-feeding. Measurements were performed in situ where rufous hummingbirds forage as they migrate at several locations along a gradient in elevation and over the range of ambient temperatures normally experienced. Oxygen consumption rates during hover-feeding varied between the sexes and between juveniles and adults. These differences appeared to reflect differences in the power requirements for hovering flight in relation to variation in wing morphology. Decreasing ambient temperature and increasing elevation both significantly increased oxygen consumption rate during hover-feeding. The effects of these two environmental variables were additive, suggesting that hummingbird thermoregulatory requirements were not met by the additional heat produced by the higher metabolic rate necessary to support hovering flight at higher elevation. These results provide insight into the ways different foraging strategies may allow hummingbirds to maximize net energy intake.

scholarly journals Effects of lipid and starch supplementation as water intake mitigation techniques on performance and efficiency of Nursing Holstein Calves

2021 ◽  
Author(s):  
A Macias-Franco ◽  
A E M da Silva ◽  
F H de Moura ◽  
A B Norris ◽  
K Van Den Broek ◽  
...  
Keyword(s):  
Energy Intake ◽  
Water Intake ◽  
Corn Starch ◽  
Metabolizable Energy ◽  
Milk Replacer ◽  
Net Energy ◽  
Total Water ◽  
Holstein Calves ◽  
Ad Libitum ◽  
Net Energy Intake

Abstract Exploring alternative supplementation sources capable of maximizing feed and water efficiency in nursing Holstein calves is often ignored. The goals herein involve investigating the effects of two isoenergetic supplements on a non-medicated milk replacer diet on total water intake, milk water intake, fresh water intake, feed intake parameters, and performance of Holstein nursing bull calves. Twenty-three animals (body weight [BW] = 94.67 ± 12.07 kg, age = 67 days old) were randomly assigned to one of three treatments for 68 days: control (CON; ad libitum milk replacer, n = 7), carbohydrate supplement (CHO; corn starch on top of ad libitum milk replacer-based diet, n = 8), or lipid supplement (FAT; menhaden fish oil on top of ad libitum milk replacer-based diet, n = 8). The isoenergetic supplementation consisted of 3% menhaden fish oil addition on DM basis for FAT. This was matched energetically with corn starch for the CHO group resulting in a 7% composition in DM basis. All animals were provided free access to mineral mix and 120 g daily dried microbrewer’s spent grains (BG). Data were analyzed with the GLMMIX procedure of SAS in a completely randomized design with the diets as a fixed effect. Dry matter intake (DMI) adjusted by average daily gain (ADG; DMI/ADG) resulted in significantly lower values for supplemented groups with CON = 2.48, CHO = 2.38, and FAT = 2.27 kg/kg(ADG) (P = 0.033). Energy intake values were lower for CON when analyzing metabolizable energy intake (P < 0.0001), net energy intake for maintenance (P < 0.0001), and net energy intake for gain (P < 0.0001), followed by CHO, and then FAT. Total water intake (P < 0.0001), milk water intake (P < 0.0001), and fresh water intake (P < 0.0001) all resulted in CHO consuming 0.5 L or less water than the other two treatments. Energy requirements as digestible energy (P < 0.0001), metabolizable energy (P < 0.0001), net energy for maintenance (P < 0.0001), and net energy for gain (P < 0.0001) were lower for CHO, followed by CON, and then FAT having the highest requirements. Similar results were observed for residual feed (RFI; P = 0.006) and residual water intakes (RTWI; P = 0.902). Ultimately, no performance differences were detected with regards to BW, (CON = 146.71, CHO = 146.25, and FAT = 150.48 kg; P > 0.1). These results indicate that lipid-based and starch-based supplementation can potentially increase feed efficiency and decrease voluntary water intake without adversely affecting performance.

Quantification of changes in body weight and body condition scores during lactation by modelling individual energy balance and total net energy intake

2001 ◽  
Vol 72 (2) ◽  
pp. 325-334 ◽  
Author(s):  
R. Schwager-Suter ◽  
C. Stricker ◽  
D. Erdin ◽  
N. Künzi
Keyword(s):  
Body Weight ◽  
Energy Balance ◽  
Energy Intake ◽  
Body Condition ◽  
Dairy Cow ◽  
Fixed Effects ◽  
Net Energy ◽  
Net Energy Intake ◽  
Gut Fill ◽  
Body Condition Scores

AbstractIndividual energy balances (EB) and total net energy intake (NEI) were modelled to quantify the energy content of the explanatory variables body-weight change corrected for gut fill (BWC) and body condition-score change (BCSC). A total of 6147 records from 213 lactating dairy cows, 71 Holstein-Friesians, 71 Jerseys and 71 HolsteinJersey F1-crosses was analysed (1st, 2nd and >2nd lactation). Data were collected during 210 days of lactation, from calving to week 30. Individual EB were calculated as total energy for lactation (MJ NEL) minus estimated energy necessary for maintenance and production. Body-weight changes were calculated as differences between weekly means of body weight corrected for gut fill (BWCw) as well as from polynomial regression (BWCp). BCSC were differences between assessed body condition scores. The study included analyses of 1- and of 4-week periods for BWCw and BWCp, of differences between measuring periods for BCSC as well as separate analyses of data from cows in either negative or positive energy balance.Analysis of repeated measurements were performed applying mixed model theory. Models for EB contained type of dairy cow, lactation and type of roughage as fixed effects, week of lactation and either BWCw, BWCp or BCSC. Models for NEI contained type of dairy cow, lactation and quality of roughage as fixed effects, week of lactation as well as energy corrected milk, metabolic body weight and either BWCw, BWCp or BCSC as covariates.Most plausible energy contents per unit body tissue change were estimated for BWCp from weekly data with either EB (with energy partitioned into milk production and maintenance fixed) or NEI (no restrictions concerning partitioning) as the response variable. The estimated energy contents for BWCp were 15·40 and 10·47 MJ NEL, respectively.

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