Voluntary Energy Research Articles

Effect of Immunization against Somatostatin on Antibody Binding Capacity and Affinity, Hormone Concentrations, Performance and Carcass and Meat Quality in Young Friesian Bulls

Abstract Eight bull calves were immunized against somatostatin (SS) conjugated to human serum α-globulin (anti-SS), while another 8 were immunized against human serum α-globulin alone (placebo). All calves were tethered, individually fed concentrates ad libitum and slaughtered at an average live weight of 400 kg within each block. Only 5 of the 8 anti-SS calves formed significant amounts of antibodies, with an average binding capacity of 24–34 picomole SS per litre plasma and an antibody affinity (K D) of 0.20 ± 0.04 nM. No difference was found in daily gain (1454 vs. 1378 g, SEM = 71) although voluntary daily energy intake of concentrates was slightly higher (P = 0.17) in anti-SS calves (6.09 vs. 5.54 Scandinavian Feed Units, SEM = 0.27). Feed conversion was also higher (P = 0.08) in. anti-SS calves (4.20 vs. 4.01 SFU/kg gain, SEM = 0.7) and fat content (6.8 vs. 5.4 kg, SEM = 0.3) and amount of perirenal and mesenterial fat (8.45 vs. 6.26 kg, SEM = 0.44) was significantly increased (P < 0.01). Plasma lev...

Broiler chick responses to anorectic agents: dietary acetic and propionic acids and the blood metabolites.

The effects of dietary supplementation with acetic or propionic acid, given at a level of 3% of diets containing 2,500 or 2,750 kcal of metabolizable energy per kg, on levels of blood glucose, and on lipid, protein, and energy metabolisms were studied in female broiler chicks. Voluntary feed and energy intakes, as well as body weight gain, decreased significantly with the inclusion of the acids in either diet, in decreasing order of effect: propionate > acetate > nonsupplemented controls. The relative weight of the abdominal adipose tissue decreased significantly with the inclusion of either acid, but was unaffected by dietary energy level. In contrast, the weight of the liver was higher in birds fed the low-energy diet, but was unaffected by the anorectic agents. Inclusion of the acids increased the concentration of volatile fatty acids in the cecum and blood plasma. The rate of clearance of plasma propionate was greater than that of acetate. Anorectic agents and dietary energy density exhibited a synergistic effect on feed intake. These agents altered blood metabolites involved in lipid and energy metabolisms, but not in that of protein. Plasma metabolites and enzymes, particularly beta-hydroxybutyrate and alkaline phosphatase, reflected the degree of feed restriction, supporting the hypothesis that the hypophagic effect of these acids is due to metabolic intervention.

Weighting Nonrandom Samples in Voluntary Energy Conservation Program Evaluation*

In this paper we examine the endogenous stratification problem in the evaluation of DSM programs and determine the appropriate weighting necessary for consistent estimation. Both the complexity and number of alternative DSM programs create the need for a cartful statement of the problems and solutions. We examine two commonly occurring evaluation situations: pure participation models and models of net conservation. A hypothetical numerical example is presented to help elucidate the concepts, and data from a DSM program sponsored by a large U.S. utility is used to examine the effect of weighting. In both hypothetical and actual DSM programs, severe biases resulted when unweighted data was used.

Underfeeding and body weight regulation in normal-weight young men.

The mechanisms of energy regulation invoked by moderate dietary restriction were investigated in seven healthy young men of normal body weight leading unrestricted lives. Following a baseline period of weight maintenance, subjects were underfed by 806 +/- 162 (mean +/- SE) kcal/day for 21 days. Changes in total energy expenditure (TEE) and resting energy expenditure (REE) and subsequent voluntary nutrient intakes were measured. The REE, averaged for fasting and fed states, decreased during underfeeding by 100 +/- 29 kcal/day (P less than 0.01). TEE decreased nonsignificantly by 296 +/- 170 kcal/day, equivalent to an average of 37% of the decrease in energy intake. Body energy stores were estimated to decrease by 510 +/- 172 kcal/day (P less than 0.03), thus compensating for 63% of the dietary energy deficit on average. Voluntary energy intake following dietary restriction increased above the initial amount required for body weight maintenance, was proportional to the weight loss during underfeeding (P less than 0.03), and was associated with a rapid regain of weight lost during underfeeding. These results indicate that energy balance is regulated by adaptive variations in both energy intake and energy expenditure in normal-weight young men leading unrestricted lives but do not support the hypothesis that energy-wasting mechanisms contribute substantially to body energy regulation.

Energy expenditure and subsequent nutrient intakes in overfed young men

We investigated the mechanisms of body weight regulation in young men of normal body weight leading unrestricted lives. Changes in total and resting energy expenditure, body composition, and subsequent voluntary nutrient intakes in response to overeating by 4,230 +/- 115 (SE) kJ/day (1,011 +/- 27 kcal/day) for 21 days were measured in seven subjects consuming a typical diet. On average, 85-90% of the excess energy intake was deposited (with 87% of this amount in fat and 13% in protein on average). There was no detectable difference between individuals in susceptibility to energy deposition. The resting metabolic rate, averaged for fasting and fed states, increased during overfeeding (mean +/- SE, 628 +/- 197 kJ/day, P less than 0.01), but at least some of this amount was obligatory expenditure associated with nutrient assimilation. No significant increase in energy expenditure for physical activity or thermoregulation resulted from overfeeding. Thus energy expenditure did not substantially adapt to increased energy intake. However, significant decreases in voluntary energy intake (1,991 +/- 824 kJ/day, P less than 0.05) and fat intake (48 +/- 11 g/day, P less than 0.01) followed overeating, indicating that adaptive changes in nutrient intakes can contribute significantly to body weight regulation after overeating.

Response of modern hybrid pigs to dietary energy concentration

In a recent experiment using the same improved genotype, pigs over the liveweight range 25 to 120 kg were found to have modest voluntary energy intakes (Chadd and Cole, 1988) particularly when compared with former intake prediction equations. It follows that the response of such pigs in terms of voluntary feed intake behaviour when provided with diets differing in energy concentration may have also changed. Diets that are formulated to be low in energy density and therefore bulky in nature are likely to represent more of a limitation to voluntary feed intake than previously. Former experiments designed to examine the pig's ability to adjust feed intake in order to maintain a constant energy intake have produced results varying from complete to incomplete compensation.A study was undertaken to examine the response of a modern genotype in terms of voluntary feed intake, digestible energy (DE) intake, growth performance and associated carcass characteristics, when offered a range of dietary energy concentrations ad libitum and taken to a heavy slaughter weight.

Menstrual cycle and voluntary food intake

The relationship of food intake and the human menstrual cycle has not been well quantified. In this study, voluntary energy and sucrose intake of seven women, aged 24-43 y, were evaluated by the weighed-intake method over one entire menstrual cycle. Portable tape recorders facilitated the recording of food intake. Although daily fluctuations of energy intake were large, analysis of variance showed intake during the luteal phase to be significantly greater than during the periovulatory and follicular phases (p less than 0.05). From 95% simultaneous (Bonferoni) confidence intervals, the estimate of difference was 283 kcal greater during the luteal phase than the periovulatory phase; the estimate of difference was 214 kcal greater during the luteal phase than during the follicular phase. No significant differences in energy intake were found among the menstrual, follicular, and periovulatory phases. No significant relationship was found between sucrose intake and the menstrual cycle.

Self-Selection Bias in the Evolution of Voluntary Energy Conservation Programs

While voluntary energy conservation programs have been extensively promoted by electric utilities and public utility commissions, their effectiveness has been insufficiently critiqued. This paper contributes to the growing evaluation of such programs by measuring the net energy savings directly attributable to an actual set of programs. The analysis explicitly corrects for the self-selection bias that can arise in program evaluation. The correction is found to be important; traditional evaluation methods are subject to considerable bias. Correcting for this bias, the amount of program-induced energy savings is found to be considerably less than traditionally believed. Copyright 1988 by MIT Press.

Voluntary Energy Assistance Programs: Community Self-Help in Action

In recent years, the ever-widening gap belocality development, which presupposes tween income and the cost of gas and electhat community change may be pursued op tric services has become a major problem for timally through broad participation of a wide lowand marginal-income individuals and spectrum of people at the local community families. Heating costs for the individual conlevel in goal determination and action.4 Pro sumer have soared,1 resulting in an increasject HELP engages the cooperation and ser ing number of people who are unable to pay vices of several people and organizations their utility bills. Energy experts reports that from both the private and public sectors of unpaid electric and gas bills nationwide the community. It operates as a partnership amount to an estimated $500 million annualbetween social service agencies, two utility ly.2 Although the consumers and stockcompanies, and the companies' consumers, holders of the utility companies assume this The program serves elderly and disabled debt, the more disturbing consequence is the persons in the metropolitan Nashville area thousands of people who face the threat, or who need assistance in paying their heating for many the reality, of their gas or electric bills. It is funded primarily through small service or both being disconnected during donations by individual customers of the two the winter because they are unable to pay utility companies, who are given the oppor their utility bills. tunity to add $1.00 to their monthly pay In most communities, traditional social ments. In the first five years of operation, the service programs, including government amount of money contributed and dis sponsored ones, fall short of meeting this tributed to recipients has more than tripled; mounting need. In general, the trend toward however, the number of individuals and less governmental funding of social service families assisted has increased more than programs has forced communities either to ig200 percent (Table l).5 nore pressing needs or to find alternate fundNo administrative costs are taken from the ing sources. In an effort to find new ways to donations, assuring donors that every dollar fund programs, numerous suggestions and given results in direct assistance to recipients analyses have emerged. Some of these sugin need. The local American Red Cross chap gestions include expanding the use of volunter administers the program, using volunteers teers, improving managerial practices and who are trained by, and work with, members setting priorities on needs and services, buildof the Red Cross social work staff in filter ing coalitions, increasing the solicitation of viewing applicants to determine eligibility, private philanthropy and, in general, creating Collection of donations and most promotional custom-made paths to needed funds.3 efforts are conducted by the two utility com In response to the inability of certain panies. An advisory committee (comprising populations to pay their utility bills, the representatives from the utility companies, Nashville community created such a path by Red Cross, and other social service agencies developing and implementing an innovative in the city who serve the elderly and handi community self-help program, staffed pricapped) provides direction regarding policy marily with volunteers and funded exclusivedevelopment and day-to-day operation of the ly through contributions. The purpose of this program, article is to report on that program's first five years of operation and to provide a review _ . ,^ of similar voluntary energ? assistance proReview of Voluntary Energy grams around the com4 Assistance Programs The concept of voluntary energy ^ ... , . TT„T „„ assistance programs is a fairly recent one. Description of Project HELP Baltimore Fuel Fund, which began operation This voluntary energy assistance program in 1979, generally is credited with being the most closely resembles the kind of communifirst. Since that time, numerous other pro ty intervention referred to by Rothman as grams have begun operation. Through sep arate surveys to member companies, the American Gas Association and Edison Elec tric Institute report more than 100 energy assistance programs across the country.6 In reviewing these programs, a comparison will be drawn between Project HELP and other voluntary energy assistance programs using the following five criteria: (1) target group served, (2) eligibility guidelines, (3) assis tance provided applicants, (4) geographic size of programs, and (5) program funding.

The effects of dietary fibre, source of fat and dietary energy concentration on the voluntary food intake and performance of growing pigs

ABSTRACTNinety entire male pigs were used in two experiments to investigate the effects of energy concentration on the performance of growing pigs given diets containing relatively high or low levels of fibre. A blended fat product was also compared with tallow as a source of dietary energy for pigs in the first experiment.In experiment 1, 60 pigs growing between 20 and 45 kg live weight were given 10 diets containing approximately 120 g acid-detergent fibre per kg (80 g crude fibre per kg), and 10, 30, 50, 75 or 100 g/kg of either tallow or the blended fat product.Although the source of fat had no significant effect on food intake or growth performance, voluntary energy intake and growth rate increased with increase in the level of fat added to the diet and with concomitant increase in dietary digestible energy (DE) concentration up to 50 g/kg and 13·2 MJ/kg respectively. Further increase in the level of fat added to the diet and in DE concentration resulted in a decline in voluntary food intake, whilst energy intake and growth rate remained relatively constant at 27 MJ/day and 720 g/day respectively.In experiment 2, 30 pigs were used to investigate the animals' response to five levels of dietary DE concentration (11·8 to 15·1 MJ DE per kg) between 20 and 50 kg live weight. The highest level of acid-detergent fibre in the diets was 62 g/kg (50 g crude fibre per kg) and this declined with increase in energy concentration to 30 g/kg (25 g crude fibre per kg) in the diet of highest energy concentration.Voluntary food intake was not significantly affected by dietary energy concentration, and voluntary energy intake and growth rate increased linearly with increase in dietary energy concentration up to 14·5 MJ DE per kg. Maximum energy intake (31 MJ DE per day) and growth rate (905 g/day) in experiment 2 was proportionately 0·15 and 0·26 higher than that achieved by pigs given the higher fibre diets in experiment 1.The results for voluntary food intake and growth rate suggested that the pig's demand for energy and consequently its response to dietary energy concentration was affected by dietary fibre concentration.

Seasonal changes in energy economy of farmed polecat as evaluated by body weight, food intake and behavioural strategy

An analysis of seasonal changes in energy budget of the farmed polecat ( Mustela putorius) was performed in subarctic climate. Cyclical variations were found in the body weight of male polecats from maximum values in February (2.1 kg) to minimum values in June–July (1.5 kg). There were only minor seasonal changes in the body weight of females. There was a direct relationship between body weight and voluntary energy intake on one hand (r=0.89) and an inverse relationship between body weight and locomotor activity (r=−0.88) on the other hand. Energy intake was significantly ( p<0.05) higher during winter (224 kcal/animal/day) than during summer (142 kcal/animal/day). Total time spent outside the nest was at its maximum during the winter months (60 min/day). The results suggest that in male polecats, changes in absolute food intake induce seasonal changes in body weight. Seasonal changes in locomotor activity seem to be less important in energy balance regulation. The fact that the body weight of females showed only minor seasonal variation supports the role of sexual hormones in the control of the body weight.

A model of energy systems and its macro-properties

This paper proposes a new mathematical model of energy systems rooted in Odum and Odum's (1976) concepts of energy flows. Models of two types of energy systems have been studied: a composite system with energy supply and consumption sectors, and a competition system with two energy consumption sectors drawing in parallel on the same energy source. Interesting results were obtained as follows : feedback of high quality energy to pump in more energy, and voluntary energy supply are generally effective in stability and growth of the supply-consumption energy system ; saving energy plays an important role in coexistence in the competition system

Preferred Solutions to the Energy Crisis as a Function of Causal Attributions

Results of two studies support the hypotheses that those accepting personal responsibility for the energy crisis favor and report adopting the personal “solution” of voluntary energy conservation, and those making attributions to nonpersonal causes (OPEC, oil companies, U.S. government) are most likely to favor nonpersonal solutions. Implications are discussed.

Influence of the level of dietary phosphorus on the voluntary intake of energy and metabolic utilization of nutrients in the growing rat

1. An experiment was carried out on growing male rats to study the effects of a phosphorus deficiency on voluntary energy intake, estimated by the separate-feeding technique, as well as the consequences on growth and metabolic utilization of energy, protein and minerals. After a preliminary period of P deprivation, three groups of twelve animals were fed separately and simultaneously two dietary rations. A protein ration provided 1.2 g protein/d to which was added one of three levels of P in the form of monosodium phosphate: a normal level of 35.4 mg/d (treatment A), half the normal level (19.1 mg/d, treatment B) or one-quarter the normal level (9.6 mg/d, treatment C). Another protein-free ration was fedad lib.2. It was only when the level of P represented one quarter the normal level that a significant decrease in growth rate was noticed, accompanied by a definite decrease in daily energy consumption. The food conversion ratio (g dry matter intake/g body-weight gain) increased whereas the protein efficiency ratio (g body-weight gain/g protein intake) was lower. The nitrogen and energy retentions changed in the same way: both dectreased with treatment C compared to treatment A and B. Independently of the protein supply, the voluntary energy intake was closely related to the intensity of protein retention, which depended on the dietary level of P. The daily retention of P only slightly decreased at the lowest ingestion level (9.6 mg/d in treatment C), compared to that of the higher levels. On the other hand, the amount of calcium retained regularly decreased with the decreasing supply of P. The result of this was a progressive reduction in retained Ca:P as the level of P decreased.3. From these results it appeared that the primary effect of a P deficiency in the growing rat was a decrease in bone mineralization. At a more advanced stage, the tissue P levels were affected and the resulting metabolic alterations reduced protein deposition and consequently the voluntary energy intake. The level of energy consumption, in separate-feeding, is more generally dependent on the level of protein deposition allowed by the limiting factor for growth, either protein, minerals or vitamins.

Dietary protein content and the subsequent body composition and food intake of pigs

SUMMARYForty Large White × Wessex pigs were fed from 7 to 27 kg live weight, on diets containing either 28 or 14% crude protein. From 27 to 113 kg live weight the pigs were fed a common diet ad libitum. Pigs from each treatment were killed at 27, 54, 82 and 113 kg live weight and the chemical composition was determined. From 7 to 27 kg and from 27 to 113 kg live weight, daily gain, food intake and food conversion efficiency were similar for the two treatments.At 27 kg, pigs on the lower protein diet were fatter and contained less lean tissue. Between 27 and 54 kg live weight the pigs previously on the higher protein diet deposited a much greater amount of fat than the pigs on the lower protein diet, so that by 54 kg the pigs initially on the lower protein contained less fat. At 82 and 113 kg live weight the pigs given the lower protein diet initially also tended to contain less fat. These findings are discussed with particular reference to the voluntary energy intake of growing pigs.

Feeding Value of Protected Animal Tallow for High Yielding Dairy Cows

Supplement containing animal tallow protected with formaldehyde-treated soybean meal was introduced into concentrates at 0, 21, and 32% and fed ad libitum to Holstein cows in a changeover design during early lactation. Primary objective was to determine whether feeding protected tallow in concentrates would increase voluntary energy intake, milk yield, and fat test without adversely affecting other milk components or flavor. Intakes of total dry matter and from concentrates were decreased, dry matter from forage increased, and energy intake was unchanged by feeding protected tallow at each percent. Treatments did not affect milk yield significantly but did increase output of 4% fat-corrected milk. Solids-corrected milk yield and gross energetic efficiency were not improved consistently by feeding protected tallow. Supplement increased fat tests by .43 and .76 percentage units over control when fed at 21 and 32% but lowered protein and lactose content of milk. Cholesterol, formaldehyde, and flavor of milk were unaffected by treatment whereas cholesterol and triglycerides in blood plasma rose dramatically during short-term feeding of protected tallow. Blood glucose remained unchanged.

Energy Requirement of Roosters as Influenced by Environmental Temperature, Dietary Energy and Age

Little information is available on the energy requirement of roosters. The voluntary energy intake is reported for roosters exposed to environmental temperatures of 23, 30 or 37° C. while fed one of three diets differing in energy level. There was a reduction in the energy intake as the environmental temperature increased. The data indicated that the energy requirement was reduced somewhat as the birds get older than 9–10 months of age.

FEED INTAKE AND NUTRIENT DIGESTIBILITY OF GROWING LAMBS SUPPLEMENTED INTRAGASTRICALLY WITH FULL-FAT RAPESEED (CV. TOWER)

Seventeen lambs were used to study the effects of ruminal and/or abomasal infusions of rapeseed on voluntary feed intake, nutrient digestibility and nitrogen retention. The basal diet (65% barley, 30% ground hay) contained 92% dry matter, 12% protein and 3.9 kcal/g of gross energy as fed. In experiment 1, full-fat rapeseed (FFRS, 25% protein, 50% fat) was either heated in boiling water or non-heated and infused into the abomasum of lambs as a 20% solids suspension to provide 25% of the daily energy requirement for maintenance. The intake, nutrient digestion and nitrogen retention of lambs were not affected by the heat treatment. In experiment 2, abomasal infusions of 0, 100, 200 and 400 ml of saline did not affect the "hunger drive" or daily feed intake of lambs. In experiment 3, FFRS (20% solids) was infused into the abomasum at levels of 12.5 and 25% of the energy requirements for maintenance with no infusion as control. Within 30 min post-infusion, voluntary energy intake decreased with increasing levels of FFRS infused (r = − 0.68, P &lt; 0.01), but the total of the energy consumed during this time period plus that infused was not different. Nutrient digestibility, nitrogen retention and average daily gains were not affected by the infusion level. In experiment 4, 15% of maintenance energy requirements were infused as FFRS into the rumen or abomasum. Voluntary energy intake at 30 min post-infusion was lower following infusions into the rumen or abomasum as compared to no infusion (P &lt; 0.01). Daily energy intake, weight gain and nutrient digestibility were not affected by the site of infusion. Nitrogen retention was lower when FFRS was infused into the rumen. In experiment 5, partially extracted rapeseed (31% protein, 15% fat) was infused into the abomasum to supply either 0.1 or 0.2 g of nitrogen per kg0.75 body weight and compared to non-infused controls. Voluntary intake at 30 min post-infusion was lower for lambs that received the infusions (P &lt; 0.02). Daily energy intake and nitrogen retention were not affected by the level of infusion. Nutrient digestibility increased gradually with each level of infusion (P &lt; 0.01). These experiments indicate that intra-abomasal supplementation with Tower FFRS does not improve the performance of growing lambs fed a pelleted diet containing about 12% crude protein. The FFRS protein had low solubility in rumen fluid, in vitro, and therefore may be only partially degraded in the rumen in vivo.

Commitment and Voluntary Energy Conservation

Homeowners were interviewed and expected to be either personally identified (public commitment) or not identified (private commitment) as having agreed to attempt energy conservation. The response measure of energy usage was provided by utility-meter readings for the month following the interview. Homeowners under public commitment showed a lower rate of increase in the use levels for both natural gas (Experiment I) and electricity (Experiment II) than under private commitment or in the control (no interview condition). Results from a set of self-monitoring conditions suggested that conservation may be related to increased attention to energy use levels.

Methods of Delaying Sexual Maturity of Pullets: 2. Restricting Energy Consumption

In three experiments, delay of sexual maturity of broiler breeder pullets has consistently resulted in increased production of total eggs, increased percentage of settable eggs, and increased average egg weight. When the delay was accomplished by restricting energy intake to about two thirds of voluntary consumption the pullets were considerably leaner at time of maturity. Birds delayed in reaching maturity by the use of declining daylength were fatter at time of maturity, but this did not appear to be detrimental in terms of egg production or percent settable eggs. In periods of extremely hot weather, however, greater mortality occurred in those groups which were more obese at time of maturity. When restricted energy and declining daylength were both imposed the beneficial effects on productivity were additive.Energy restriction was accomplished equally well by diets of relatively high or low energy density when feed intake was restricted to permit two-thirds of voluntary energy intake of a control group.The skip-a-day program, in which the entire ration was restricted to approximately two-thirds of the control group, proved to be an equally satisfactory method of delaying maturity. The low-lysine or low-protein programs did not delay maturity appreciably or improve egg production over full-fed controls when all groups received constant daylength.