High-energy Feeding Research Articles

Teat perimeters for South African Boer and Nguni goats: Use of these measurements to predict milk production potential and kids growth

The aim of this trial was to assess the possibility of using teat perimeter in estimating milk production potential and kids’ growth rate in Nguni and Boer goats of South Africa. Traditionally, the productive capacity of goats doe, are judged to a large extent by the physical phenotypic characteristics. In this trial a 2 × 2 factorial design (two goat breeds and two nutritional management systems) were used. Thirty six (36) recently kidded does (18 Boer goats and 18 Nguni goats) were also used in this experiment. The investigation was conducted between seven (7) and hundred (100) days post-partum. Half (n = 9) the Boer goat does and half (n = 9) the Nguni does were allocated randomly within breed to an extensive (veld) feeding treatment, and the other half per breed to an intensive (high energy) feeding treatment (this is traditionally practiced by profit driven intensive farmers). The results revealed that teat perimeter measurement could be used in both breeds under an intensive feeding regime. The results further revealed that in the extensive feeding regime, the prediction of milk potential through teat perimeter can only be carried out in the Nguni goat breed. These results indicate that the teat perimeter measurement can be used to measure milk production of the Nguni goats based on the two feeding systems. These results appear to suggest that teat perimeters in the Nguni goat could be the best tool for the resource poor farmers. Key words: Milk production, teat, perimeter, Boer goat, Nguni goat.

Fish oil combined with SCFA synergistically prevent tissue accumulation of NEFA during weight loss in obese mice

Based on their proposed metabolic effects, we examined whether fish oil (FO) and SCFA, alone or in combination, accelerate weight loss and the resultant metabolic improvements. Obesity was induced in male C57BL/6J mice by high-energy feeding for 10 weeks. The mice were transferred to a low-fat diet (2·5w%) for 4 weeks, the source of fat being either FO, a lard-safflower oil mix (control), or both types combined with SCFA. Weight, fasting insulin, tissue and serum lipid concentrations, as well as mRNA amount of genes related to adipose inflammation and hepatic fat oxidation were determined. All groups lost weight and showed reduced fasting insulin concentrations and reduced liver TAG. However, weight loss on the control-fat diet caused significant increase in hepatic and cardiac NEFA. Substituting 20% of the fat with SCFA increased weight loss by 48% and reduced fasting insulin 1·5-fold more than the no-SCFA diets. It furthermore significantly increased the amount of mRNA for PPAR-α, and decreased the mRNA amount for NF-κB in the liver and white adipose tissue. The FO diets enhanced improvement of tissue lipid levels. Thus, FO improved liver TAG and NEFA levels compared with weight loss on the control diet. Combining FO and SCFA further reduced tissue NEFA accumulation. In conclusion, we found that dietary SCFA had a significant impact on gene expression in the liver and adipose tissue, and that the effect of FO on tissue NEFA content was modified by SCFA. Thus, interactions between fatty acids should be considered when studying the effects of specific fatty acids.

Cellular conditions for intramuscular fat deposition in Japanese Black and Holstein steers

The experiment was conducted to study the development of intramuscular fat in Japanese Black (JB) compared to Holstein (HS) steers and to find breed differences for fat depot development and distribution in the carcass under equal feeding conditions. Additional to slaughter samples, biopsy samples of longissimus muscle (LM) and subcutaneous fat, taken at 10, 14, 18, and 22 months of age, were used for histological and molecular investigations. Japanese Black steers stored about 14% more fat in the LM (P = 0.001), resulting in larger marbling flecks (P < 0.001). Muscle fibers and intramuscular adipocytes in both breeds responded to the high energy feeding with significant enlargement, which was faster in JB. Histograms of intramuscular adipocytes size showed a shift toward larger cells during growth, but also the abundance of small, developing adipocytes. This development was accompanied by a correlated up-regulation of adipogenic genes until 22 months of age.

Dietary energy source and feeding levels during the rearing period affect ovarian follicular development and oocyte maturation in gilts

Fifty-four Landrace × Yorkshire gilts (59.0 ± 4.2 kg and 147 ± 3 d old) were used to examine the effects of dietary energy source (starch or mixed fat) at high [112.5% of energy requirements recommended by NRC (1998)], normal (100%), and low (87.5%) energy feeding levels on ovarian follicular development and oocyte maturation. Forty-seven estrus gilts were slaughtered at Day 19 after the second estrus; oocytes were recovered from follicles >4 mm in diameter, and matured in vitro for 44 h. Gilts fed high-energy diets had more follicles >4 mm (mean, 25.8 vs. 19.1, P < 0.05) and more oocytes that reached metaphase II (80.3 vs. 64.0%, P < 0.05) than those fed the low-energy diet. Furthermore, gilts fed starch-rich diets had enhanced oocyte nuclear maturation relative to those fed fat-rich diets (75.4 vs. 68.0%, P < 0.05). Compared to the lower-energy feeding groups, high-energy feeding groups had higher ( P < 0.05) blood concentrations of postprandial insulin (1562.4 vs. 990.0 ng/4 h), IGF-I (321.2 vs. 256.9 ng/mL), and LH pulses (2.7 vs. 1.4 pulses/6 h). Follicular fluid concentrations of IGF-I (198.5 vs. 143.1 ng/mL) and estradiol (152.6 vs. 124.8 ng/mL) were higher ( P < 0.05) in the high-energy group than in the normal group. Compared with gilts fed the high-energy diet supplemented with fat, gilts fed the high-energy diet supplemented with starch had a tendency ( P < 0.10) towards increased IGF-I concentration in both blood and follicular fluid, and improved oocyte nuclear maturation during culture in vitro. We inferred that starch-rich, high-energy diets during rearing may improve ovarian follicular development and oocyte maturation in replacement gilts.

Characterization of β‐Cell Mass and Insulin Resistance in Diet‐induced Obese and Diet‐resistant Rats

The selectively bred diet-induced obese (DIO) and diet-resistant (DR) rats represent a polygenetic animal model mimicking most clinical variables characterizing the human metabolic syndrome. When fed a high-energy (HE) diet DIO rats develop visceral obesity, dyslipidemia, hyperinsulinemia, and insulin resistance but never frank diabetes. To improve our understanding of the underlying cause for the deteriorating glucose and insulin parameters, we have investigated possible adaptive responses in DIO and DR rats at the level of the insulin-producing beta-cells. At the time of weaning, DR rats were found to have a higher body weight and beta-cell mass compared to DIO rats, and elevated insulin and glucose responses to an oral glucose load. However, at 2.5 months of age, and for the remaining study period, the effect of genotype became evident: the chow-fed DIO rats steadily increased their body weight and beta-cell mass, as well as insulin and glucose levels compared to the DR rats. HE feeding affected both DIO and DR rats leading to an increased body weight and an increased beta-cell mass. Interestingly, although the beta-cell mass in DR rats and chow-fed DIO rats appeared to constantly increase with age, the beta-cell mass in the HE-fed DIO rats did not continue to do so. This might constitute part of an explanation for their reduced glucose tolerance. Collectively, the data support the use of HE-fed DIO rats as a model of human obesity and insulin resistance, and accentuate its relevance for studies examining the benefit of pharmaceutical compounds targeting this disease complex.

Effects of Feeding Prepubertal Heifers a High-Energy Diet for Three, Six, or Twelve Weeks on Mammary Growth and Composition

The experimental objective was to determine the effects of feeding prepubertal dairy heifers a high-energy diet for 3, 6, or 12wk on mammary growth and composition. Holstein heifers (age = 11wk; body weight = 107±1kg) were assigned to 1 of 4 treatments (n=16/ treatment). The treatment period lasted 12wk and treatments were H0 (low-energy diet fed for 12 wk, with no weeks on the high-energy diet); H3 (low-energy diet fed for 9wk, followed by the high-energy diet for 3 wk); H6 (low-energy diet fed for 6wk, followed by the high-energy diet for 6wk); and H12 (high-energy diet for all 12wk). The low- and high-energy diets were formulated to achieve 0.6 and 1.2kg of average daily gain, respectively. Heifers were slaughtered at 23wk of age and mammary tissue was collected. A longer duration of feeding the high-energy diet increased total mass of the mammary gland, extraparenchymal fat, and intraparenchymal fat, but did not alter the mass of fat-free parenchymal tissue. When adjusted for carcass weight to reflect differences in physical maturity, the mass of fat-free parenchymal tissue decreased in a linear fashion with a longer duration on the high-energy diet. Total masses of mammary parenchymal DNA and RNA were not different. However, after adjustment for carcass weight, the masses of DNA and RNA decreased as heifers were fed the high-energy diet for a longer duration. The percentages of epithelium, stroma, and lumen, the number of epithelial structures, and the developmental scores of mammary parenchymal tissue were not different among treatments. However, the percentage of proliferating epithelial cells in the terminal ductal units, as indicated by Ki-67 labeling, decreased as heifers were fed the high-energy diet for a longer duration. We concluded that feeding prepubertal heifers a high-energy diet for a longer duration resulted in a linear decrease in both the percentage of mammary epithelial cells that were proliferating and in the mass of fat-free mammary parenchyma per unit of carcass. High-energy feeding hastens puberty and, in this study, decreased mammary epithelial cell proliferation in areas of active ductal expansion. These data are consistent with the idea that feeding heifers a high-energy diet will reduce mammary parenchymal mass at puberty.

Effects of two protein sources and energy level of diet on the performance of young Marchigiana bulls. 1. Infra vitam performance and carcass quality

The aim of this trial was to evaluate the influence of two protein sources and the energy levels of the diet on growth performance and carcass quality of young Marchigiana bulls. Eighteen weaned young bulls (129 d of age) were equally divided into three groups. Until the slaughter weight (620 kg) was achieved two groups were fed diets with the same protein and energy concentrations, but differing in protein sources (faba bean-FB vs soya bean meal s.e.-SB), and the last group was fed high-energy diets (HE) with both protein sources in the concentrates. Body weight, daily weight gain and biological efficiency of growth at different ages and periods, and feed conversion indexes, were calculated from individual growth curves. Beginning at 180 d of age Group HE showed always significantly (P<0.01) higher body weight and daily weight gain than groups FB and SB. Moreover, group HE reached the slaughter weight and conformation earlier than the other two groups (500 vs 540 d, respectively). The protein sources affected the growth only in the first phase after weaning (body weight at 180 d: 173 vs 186 kg for groups FB and SB, respectively; P<0.01). The highest energy diets appreciably improved growing rate, but worsened feed conversion indexes. Animal and carcass measurements were not influenced either by energy intake or by dietary protein source. Group HE showed the lowest incidence of long bones (6.2 vs 6.7 vs 5.8% of cold carcass for FB, SB and HE groups respectively; P<0.01) and the highest percentage of fat (5.1 vs 4.7 vs 7.1% of cold carcass, for FB, SB and HE groups respectively; P<0.01). As respects the protein sources, only the incidence of long bones resulted significantly different between FB and SB groups (6.2 vs 6.7% of cold carcass, respectively; P<0.05). These data demonstrate that faba beans could be used as alternative sources to soya bean meal s.e., as it did not influence growth rate and feed conversion indexes in the entire experimental period. Nevertheless, immediately after weaning, the association of faba beans with another protein source richer in rumen undegradable protein would be preferable. Moreover the utilisation of high energy feeding planes could improve the growth dynamics of young Marchigiana bulls, although in the final phase it may be suitable to reduce the energy intake in order to decrease fat deposition.

Association between aggressive behaviour and high-energy feeding level in beef cattle

The aim of this study was to investigate an association between aggressiveness and high level of feeding in a half-open feedlot production system. An experiment was conducted on 72 head of beef cattle of different breeds. The animals were at about 10 months of age. Medium quality silage was offered ad libitum and supplemented with high (HE) and low level (LE) of barley (2.5 and 1.5 kg/day/head, respectively) and supplemented without (nil) or with (+) extracted soybean meal (0.45 kg/day/head). Several types of animal behaviour were observed such as those parameters that are categorized to be main aggressive behaviours, butting, being butted, mounting and being mounted. Significant differences (P &amp;lt; 0.05) were found in butting, being butted behaviours between HE and LE treatment groups. Mounting and being mounted behaviours were significantly different (P &amp;lt; 0.05) in steers and heifers and between the seasons as well. Steers performed more incidents of mounting behaviour than heifers and it was the same for spring, during which animals had more mounting behaviours. It was concluded that there was a close relationship between high-energy diets and aggressive behaviour, which necessitates some management measures to be taken in order to ensure better animal welfare and beef production. &amp;nbsp;

The effects of overfeeding on myofibre characteristics and metabolical traits of the breast muscle in Muscovy ducks (Caïrina moschata).

The aim of this experiment was to study the consequences of precise feeding on the myofibre characteristics and metabolic traits of the breast muscle (Pectoralis major, Pm) of Muscovy ducks. Twenty-four samples of breast muscle, without skin or subcutaneous fat, from two groups of ducks, control and overfed respectively, were collected at 14 weeks of age. We assayed different chemical (water content, crude proteins, total lipid ashes, total and thermosoluble collagen), biochemical (activities of the CS, LDH and beta-HAD enzymes), histological (muscle fibre typing and intramuscular adipocyte measurements) and technological (drip and cooking losses, texture) determinations. At the force-feeding period, the overfed ducks weighed 6366 g and the control ducks 4606 g of body weight. In the PM muscle, some modifications of the biochemichal parameters and enzyme activities were observed but neither the shear force nor the histological characteristics of the breast muscle were affected by the fattening treatment. The overfed birds had an increased total lipids content (correlated to an increase in the intramuscular area occupied by the adipocyte) and a different fatty acid profile as the result of a higher energy feed intake. The lipids of the Pm muscle of the overfed ducks contained more C16:0, C16:1n-7 and C18:1n-9, but less C18:0, C18:2n-6 and C20:4n-6 than the control birds. These results show that in response to high energy feeding, the muscle is able to respond quickly on a metabolic basis (by increasing the activities of the oxydative enzymes) without changing its typology or morphology. Additionally, fattening was correlated to a degradation in the technological qualities of the breast muscle, especially an increase in the cooking losses.

The influence of dry period feeding on liver fat and postpartum performance of dairy cows

Animal performances were monitored in 30 Friesean dry cows (18 multiparous, MP-cows and 12 primiparous, PP-cows) starting six weeks before calving to eight weeks after calving. The cows were kept indoors and fed individually with a prepartum diet containing either low, moderate or high energy (0.75, 1.00 or 1.25 of the calculated ME requirement) and supplemented with low (0.3 kg day −1) or high (1.5 kg day −1) rapeseed meal (RSM). The diets were consisted of 1.5 kg hay, 20–25 kg wilted grass silage and grain (barley and oat, 1 : 1 DM basis) with RSM. The average ME intake during six weeks of prepartum was 75, 97 and 123 MJ day −1 on three different energy levels. After calving the cows were fed grass silage ad lib, 6.5 kg (primiparous) or 8.5 kg (multiparous) grain and 1.5 kg RSM. Liver biopsy and blood samples were taken to determine differences in metabolites due to diet and parity. Reduction of prepartum energy allowance to 0.75 of the moderate level did not affect the calf's birth weight and colostrum composition. Cows fed prepartum low energy–high rapeseed meal diet (LEHR) showed a faster increase in feed intake and milk production after parturition. Continuous low feed intake and milk production were observed in cows fed a prepartum high energy–low rapeseed meal diet (HELR). Milk yield was constantly lower for cows fed prepartum high energy diet, the difference being significant ( p<0.01 and p<0.05) at six and seven weeks of lactation. Overall milk yield also showed a linear decrease with energy feeding level and an increase ( p<0.10) with RSM feeding levels. Prepartum high energy feeding increased ( p<0.01) milk protein content. Neither energy nor RSM feeding level affected the liver fat infiltration of the experimental cows. Cow parity however showed a significant influence on liver fat content, β-hydroxybutyrate (BHBA) and plasma glucose. A week before calving, the plasma concentration of essential amino acids (EAA) was lower for cows fed prepartum low energy diet. During the first four weeks of lactation, the concentrations of plasma non-esterified fatty acids (NEFA) and insulin were similar for all the treatment group.

Studies on growth cartilage in the horse and their application to aetiopathogenesis of dyschondroplasia (osteochondrosis)

The importance of osteochondrosis (dyschondroplasia) to the horse industry has been well documented since it was first recorded 50 years ago. The condition is known to be multifactorial in origin, arising from focal failure of endochondral ossification at predilection sites in articular/epiphyseal growth cartilage, but specific information on its aetiopathogenesis is sparse. This paper reviews the current knowledge of growth cartilage metabolism and the process of normal endochondral ossification in the horse. It highlights the localization of various protein products of chondrocytes and the differences in the zones of articular cartilage. In the early focal lesions (referred to as dyschondroplasia) there are alterations in the chondrocytes, extracellular matrix and some of the local protein products. The most obvious feature is an alteration in matrix metabolism which may be responsible for triggering a range of other factors leading to the development of a retained core of cartilage and a primary lesion of dyschondroplasia. Based on available evidence, a preliminary hypothesis for pathogenesis is presented. This suggests that there are a number of factors capable of initiating the condition. One of these involves high circulating insulin levels from high energy feeding which may affect chondrocyte maturation leading to altered matrix metabolism and faulty mineralization resulting in the formation of cartilage cores which characterize the condition. Further research to test this hypothesis is needed before there can be a rational basis for prophylaxis.

RESPIRATORY STATUS, TOTAL ENERGY EXPENDITURE, AND GROWTH IN INFANTS WITH BRONCHOPULMONARY DYSPLASIA 1967

Growth failure was studied in infants with BPD by relating their nutritional balance and growth to past and current clinical status. Total daily energy expenditure (TEE) was measured with doubly labeled water in 9 preterm infants with BPD receiving supplemental oxygen (all male, age 61±13 days) and 9 matched controls (5 male, age 36 ±21 days) during a 6 day period. Energy and protein balance, and growth were assessed as well. TEE was higher in the BPD infants compared to controls (73 ±9 vs. 63 ±8 kcal/kg/day, P < 0.05), but faecal energy loss in BPD infants was lower (P < 0.01). Weight gain, energy intake, energy cost of growth, protein retention, and physical activity were not different. The respiratory frequency (RR) in the BPD infants was elevated in comparison with controls (P< 0.01); within the BPD group RR was significantly associated with energy expenditure (r2 = 0.82, P < 0.001). The fitted equation was TEE[kcal/kg/day] = 26.3 + 0.71*RR [min-1]. We conclude that total energy expenditure in BPD infants is elevated, and is strongly associated with their respiratory status. These findings support the use of high-energy feeding for the nutritional management in infants with severe BPD.

Early Supplementary Feeding, Child Development, and Health Policy

We carried out a meta-analysis of six field studies that assessed the effects of supplementary feeding on infants’ performance on mental and motor development scales— conducted in nutritionally at-risk populations in Colombia, Guatemala, Indonesia, Jamaica, Taiwan, and the United States—which showed that early high energy and protein supplementary feeding has a beneficial effect on motor development in young infants (8–15 months old) and on both motor and mental development in older infants (1824 months old) who are nutritionally at risk. These findings provide justification for food assistance programmes targeted to young at-risk children. However, positive findings in field studies do not guarantee that similar results will be achieved by large-scale programmes, as complex bureaucracies and inadequate infrastructure are often obstacles to success.

Crude protein requirements of large frame cattle fed two levels of energy as weaned calves or as backgrounded yearlings

Two trials were conducted to determine the crude protein (CP) requirements of large-frame (LF) cattle managed under two regimes and fed one of two energy levels. Trial 1 involved 216 recently weaned LF calves, while trial 2 involved 192 LF backgrounded yearling steers. In each trial, the cattle were fed diets formulated to one of two energy levels (11.17 and 11.88 MJ ME kg−1 DM) and one of six CP levels (11, 13, 15, 16, 17 and 19% DM basis). High-energy feeding increased (P &lt; 0.05), average daily gain (ADG), average daily carcass gain (ADCG) and average daily fat gain (ADFG) of weaned calves but did not influence the performance of the backgrounded yearlings. Weaned calves fed 16, 17 or 19% CP had higher (P &lt; 0.05) ADG than those fed 11%, while those fed 16% CP exhibited increased (P &lt; 0.05) ADFG. ADG and ADCG of weaned calves and backgrounded yearlings and ADFG of weaned calves fed low-energy diets increased (P &lt; 0.05) linearly with increasing dietary CP concentration. Daily carcass lean gain of weaned calves fed low-energy diets decreased in a quadratic manner (P &lt; 0.05) as dietary CP level increased. No influence of dietary CP concentration was observed on carcass tissue gain of the backgrounded yearlings. It was concluded that energy balance of animals fed low-energy diets improved with CP supplementation and that current NAS-NRC (1984) CP requirements accurately predict performance of LF cattle. Key words: Steers, growth, carcass composition, energy, crude protein

Palatability of beef from bulls administered exogenous hormones

One-hundred and forty four weanling bulls of Angus (A, n = 48), Simmental x Hereford (SH, n = 48) and Simmental (S, n = 48) breeding were either castrated, left intact, left intact and implanted with Ralgro or left intact and implanted with Synovex S. Cattle were slaughtered after either 190, 246 or 315 days of high-energy feeding, and the right side of each carcass was electrically stimulated. Sensory analysis was conducted on longissimus dorsi steaks after 5 days aging and Warner-Bratzler shear force (WBS) was measured after 5, 10 and 15 days aging. Steers had lower ( P < 0·05) WBS and more desirable sensory panel scores for juiciness, ease of fragmentation, amount of connective tissue and overall tenderness than all intact treatments. The implanting of weanling bulls with synthetic steroid hormone compounds did not make a practical improvement in beef tenderness.

Performance and carcass characteristics of bulls as influenced by exogenous hormones

One-hundred and forty-four weanling bulls of Angus (A, n = 48), Simmental x Hereford (SH, n = 8) and Simmental (S, n = 48) breeding were either castrated, left intact, left intact and implanted with Ralgro or left intact and implanted with Synovex S. Cattle were slaughtered after 190, 246 or 315 days of high-energy feeding. The right side of each carcass was electrically stimulated. Steers were inferior to intact treatments for most performance and carcass cutability traits, but steers were superior in marbling and lean quality ( P < 0·05). There were no differences ( P>0·05) in dressing percentage or ribeye area per 100 kg of carcass weight among treatments. Relative to intact bulls, Ralgro and Synovex S increased carcass masculinity. Implanted intact treatments did not differ from nonimplanted intacts for feed conversion, average daily gain, yield grade characteristics, percent longissimus dorsi chemical fat and 9–10dash11th rib composition ( P >0·05).

The effect of postweaning level of dietary energy on sex drive and semen quality of young beef bulls

Two postweaning feeding trials were conducted on 112 bull calves from a beef synthetic breed group to examine the effects of postweaning level of dietary energy and change in the level of energy on sex drive and semen quality of young bulls in 1988 and 1989. Within each year, the test period was 168 d, which was divided in two periods of 77 d and separated by a 14-d adjustment period. Within each year the bulls were randomly assigned to eight pens. The pen population was balanced with respect to age and weight of bulls. Bulls in four of the pens were fed a high concentrate diet while those in the remaining four pens were fed a low concentrate diet consisting of one half of the high diet plus hay ad libitum in the first period. After the adjustment period, the diets of four pens of bulls were reversed from high to low or from low to high resulting in high-high, high-low, low-high and low-low dietary treatments. The year was a significant (P<0.05) source of variation for all the components of libido score except for number of services achieved. The effect of energy on components of libido and libido score was not significant (P>0.05). Bulls on high-high had significantly larger scrotal circumference but exhibited poorer semen characteristics than their contemporaries on high-low, low-high and low-low diets. Even though feeding of high energy diet throughout the feedlot test period showed a positive effect on scrotal circumference, its effect on semen quality was negative. It was found that feeding a low energy diet in either half of the feedlot test period may prevent the detrimental effects of prolonged high energy feeding on semen characteristics of young beef bulls.

The effects of high-energy feeding on energy balance and growth in infants with congenital heart disease and failure to thrive

Failure to thrive (FTT) in infants with congenital heart disease (CHD) can be attributed to their low energy intakes and high resting energy expenditures. Energy intake, energy expenditure and growth were studied in infants with CHD on normal formula feeds and then on feeds supplemented with glucose polymer to see whether supplementation improved energy retention and growth. Mean gross energy intakes increased by 31.7% on high-energy feeding and mean weight gain improved from 1.3 g/kg per d on control to 5.8 g/kg per d on high-energy feeding. Resting oxygen consumption (VO2 ml/kg per min) was not significantly different on the two feeding regimens, although respiratory quotient rose on high-energy feeding reflecting the increased carbohydrate intake. Estimated energy costs of growth on high-energy feeding fell within the previously described range for normal infants. It is recommended that infants with CHD known to be associated with FTT are fed on high-energy diets from the time of diagnosis in order to optimize growth.

High-energy feeding for protein-calorie malnutrition. Results in a rural hospital in Zambia.

The efficacy of high-energy feeding regimens in the nutritional resuscitation of severely malnourished children is established, but most reports come from specialist units, We devised a high-energy feeding mixture using locally available ingredients and applied it in service conditions on 275 unse1ected children. After an initial stabilization period, children were fed 150 kcal/kg/day and protein 4 g/kg/day. The weight gain achieved for the whole series was 8.93 g/kg/day. For the different diagnostic categories the weight gains were: 12.11 g/kg/day for children with marasmic kwashiorkor; 10.01 g/kg/day for children with kwashiorkor; 7.49 g/kg/day for children with marasmus; and 6.39 g/kg/day for children who were underweight. The hospital case fatality was 4.4%. These figures show that rural hospitals can devise and apply high-energy feeding regimens and obtain results as good as those obtained in specialist units

Dietary obesity and exercise in young rats

Food intake, body weight, body composition, resting metabolic rate (RMR) and the thermic effect of food (TEF) were measured in young rats, some of which were fed a high energy (HE) diet and some of which were forced to swim daily. In general, high energy feeding as compared to chow feeding, resulted in higher food intake, higher body weight, higher body fat, and a slightly lower TEF. In many cases, however, the specific effects varied with the age and sex of the animals. Animals forced to swim weighed less; were leaner; and had higher RMR and TEF than sedentary animals. The effects of exercise on energy balance were greatest in males, while the effects of the high energy diet on energy balance were greatest in females. All HE-fed rats were switched to lab chow at 104 days of age. Body weights of sedentary HE-fed rats returned to control levels but those of exercised HE-fed rats did not. Both HE-fed groups remained fatter than chow-fed controls, even two months after the diet switch.