Effects Of Dietary Energy Levels Research Articles

Survival, Growth, Feed Efficiency and Carcass Composition of Rabbitfish, Siganus Rivulatus, Fed Different Dietary Energy and Feeding Levels

A feeding trial was conducted to study the effects of dietary energy level and feeding level or daily energy density (DED) on growth, feed conversion, nutrient retention efficiencies, carcass composition, apparent nutrient digestibility and cost benefit analysis for fingerling of rabbitfish, Siganous rivulatus. Twelve net cages, each with dimensions of 1x1x0.4m were stocked with 10 fingerlings (10g/fish initial weight). The fish were fed three isonutrogenous diets (25% CP), with varying three oil supplement (0,5 and 10%), and digestible energy levels (3882, 4056 and 4360 kcal/kg diet), at of 2 and 4% body weight/day (BW/d), corresponding six daily energy densities based on calorie per 1g BW of fish per day. Fish were fed the experimental diets three times daily, six days a week for 98 days. Fish were weighed every two week intervals and feed amounts were adjusted on the basis of the new fish weight. Final body weight, gain and specific growth level (SGR) were increased with an increase in dietary energy level at 2% feeding level but no trends were evident at 4% feeding level. Feed conversion (FCR), protein efficiency ratio (PER), productive protein value (PPV%) and energy retention (ER%) were higher when fish were fed at 2% than 4% feeding level. Furthermore, increasing daily energy density resulted in an increase in SGR until level of 162.4cal/g BW of fish. However the differences in SGR above 155.2cal/g BW were not significant (P >0.05). There are a positive effect between energy density and SGR (y= 0.099x+0.5, r 2 = 0.88). Fat content of carcass increased by increasing both energy and feeding levels while protein content did not affected.

EFFECT OF DIETARY ENERGY AND CORN GLUTEN FEED ON THE PERFORMANCE OF GROWING WHITE PEKIN DUCKS.

A factorial design experiment (3x3) was performed to study the effect of three levels of energy (2800, 3000 and 3200 Kcal ME/Kg) and three levels of corn gluten feed, CGF (0, 8 and 16%) on growth performance and economical efficiency of White Pekin ducklings. A total number of 270 unsexed two-weeks-old White Pekin ducklings were randomly distributed among 9 treatment groups (30 ducklings each) nearly equal in average live body weight. Each group was subdivided into three replicates each of 10 ducklings. Growth performance, some carcass traits, blood constituents and economical efficiency were studied. The results obtained could be summarized as follows: Live body weight and daily weight gain were significantly (P<0.05) higher with the 3000 Kcal ME/Kg diet energy level at most experimental period. During the starter (2 to 7 weeks age) and the whole experimental (2 to 12 weeks age) periods, improved (P<0.05) feed conversion values were noticed with the 3000 Kcal ME/Kg diet energy level. Ducklings fed the level of 8% corn gluten feed possessed significantly (P<0.05) higher live body weight at 7 and 12 weeks of age than those fed 0 or 16% corn gluten feed. The best feed conversion value was found with ducklings fed 8% CGF. Liver, heart, total giblets and abdominal fat percentages were significantly (P<0.05) affected by dietary energy level. The previous carcass traits increased with increasing dietary energy level in Pekin duckling diets. However, no significant effects of dietary energy level on gizzard, carcass and dressing weight percentages of Pekin ducklings were observed. It is worth to note that, liver, heart, carcass and dressing percentages were increased significantly (P<0.05) with the increasing the dietary corn gluten feed from 0 to 16%.Increasing the dietary energy level from 2800 to either 3000 or 3200 Kcal ME/Kg diet caused a significant (P<0.05) increase in cholesterol blood values. Ducklings fed the diet contained 3000 Kcal ME/Kg diet and 8% CGF recorded the best EEf as compared with other treatment or control. From the previous results, it can be concluded that a dietary level of 3000 Kcal ME/Kg diet with 8% CGF is recommended for feeding growing Pekin ducks from 2 to 12 weeks of age.

Effect of Dietary Energy Level on Nutrient Utilization, Insulin-like Growth Factor-I and Insulin-like Growth Factor Binding Protein-3 in Plasma, Liver and Longissimus dorsi Muscle in Growing-finishing Pigs Using Soybean Oil as an Energy Source

Two experiments were carried out to study the effects of dietary energy level on nutrient digestion, nitrogen (N) utilization, growth performance, insulin-like growth factor-I (IGF-I), and insulin-like growth factor binding protein-3 (IGFBP-3) in plasma, liver and longissimus dorsi muscle in growing-finishing pigs. In experiment 1 (Exp 1), 15 castrated male pigs (Duroc×Landrace ×Large White) (Body weight, BW, 55.6±1.8 kg) were divided into three groups and fed rations containing 13.33, 14.87 and 17.35 MJ digestible energy (DE)/kg as treatments I, II and III, respectively, using soybean oil as an energy source. The experiment lasted 8 days and faecal and urinary samples were collected during the last 3 days. The results showed that the digestibility of dry matter (DM), energy and N was increased from treatments I to III (p 0.05). In experiment 2 (Exp 2), 36 female pigs (Duroc×Landrace×Large White) (BW 41.5±3.8 kg) were divided into three groups. The pigs were fed with the same three rations used in Exp 1 for 60 days. At the end of Exp 2, eight pigs were selected from each group for blood sampling and 4 pigs for slaughter trial. The results indicated that average daily feed intake (ADFI) and N-intake were significantly decreased (p<0.01), and DE intake (p<0.01) and average daily gain (ADG) (p<0.05) were increased. IGF-I and IGFBP-3 in plasma were increased (p<0.05). No significant differences in IGF-I and IGFBP-3 in liver and longissimus dorsi muscle were found between different treatments. It was concluded that higher dietary DE level improved nutrient digestibility, ADG and feed/gain ratio when soybean oil was used as an energy source in the ration of growing-finishing pigs. No significant differences were found in N- retention and IGF-I and IGFBP-3 in liver and longissimus dorsi muscle between different treatments. (Key Words : Dietary Energy, IGF-I, IGFBP-3, Pigs, Soybean Oil)

Effects of Dietary Energy Level and Tanniferous Acacia karroo Leaf Meal Level of Supplementation at Finisher Stage on Performance and Carcass Characteristics of Ross 308 Broiler Chickens in South Africa

The study was conducted to determine the effect of dietary energy level and tanniniferous Acacia karroo leaf meal level of supplementation at finisher stage on performance and carcass characteristics of male and female Ross 308 broiler chickens. Three hundred and sixty, 21 days old male and female broiler chickens were assigned to twelve treatments with three replications of ten birds in a 2 (sex) x 3 (dietary energy level) x 3 (tanniniferous Acacia karroo leaf meal level) factorial, complete randomized design. Supplementation with Acacia karroo leaf meal had no effect on diet intake, digestibility and live weight of broiler chickens. However, supplementation with 9 and 12 g of Acacia karroo leaf meal per kg DM feed reduced fat pad weights in male broiler chickens by 26 and 29% points, respectively. Similarly, supplementation with 9 and 12 g of Acacia karroo leaf meal per kg DM feed reduced fat pad weights in female chickens by 26% points. These reductions were achieved without any significant reduction in feed intake and digestibility. However, the physiological explanation for this effect is not clear and it, thus, merits further investigation.

Effects of dietary energy levels on ovarian and uterine expression of IGF-1R and EGFR mRNA in prepubertal gilts

AbstractNine prepubertal gilts (JunMu No. 1) were randomly allocated into three groups (n=3) and fed with a high-energy diet (Group H), a low-energy diet (Group L), or a moderate-energy diet (Group M) for 14 days. Free access to water was provided throughout the research period. Ovaries and uteri were collected after the energy treatments, and processed for determination of the absolute quantities of insulin-like growth factor receptor (IGF-1R) and epidermal growth factor receptor (EGFR) mRNA, using real-time polymerase chain reaction (PCR). The expression of IGF-1R and EGFR mRNA in ovaries and uteri was significantly ranked as: Group H&gt;Group M&gt;Group L (P&lt;0.05). This result suggests that high energy intake markedly enhanced the ovarian and uterine expression of IGF-1R and EGFR in prepubertal gilts, whereas insufficient energy intake markedly inhibited such expression. IGF-1R and EGFR may be involved in mediating the effects of energy intake on the development of the reproductive system in prepubertal gilts.

탈피대두박 급여가 흑돼지의 생산성, 도체 및 육질 특성에 미치는 영향

A total of 360 Berkshire (hog) weighing 25 kg were fed experimental diets containing either dehulled soybean meal (DSBM) or non-dehulled soybean meal (NDSBM) as a major protein source until they reach 80 kg. The pigs were then fed the finisher diets either high (3,265 kcal/kg) or low (2,940 kcal/kg) in ME to evaluate the effects of dietary energy level for finisher phase on the growth performances, carcass and meat quality parameter. In growth performance, daily weight gain (kg/day) was higher (P<0.05) in T1 than in other groups. Feed conversion (feed/gain) was lower (P<0.05) in other groups. In carcass parameter, carcass percentage was higher (P<0.05) in T2 than in T1 and T4. Backfat thickness was lower (P<0.05) in T2 than in T1 and T3. The ratio of up B grade in carcass grade tender to be higher in T2 than in other groups. In meat quality, chemical composition was similar between groups. WHC was slighter higher in T1 than in other groups. Shear force was tender to be higher in T1 than in other groups. Hunter L and a in meat color were tender to be higher in T2 than in other groups. Hunter L in backfat color was thender to be higher in T1 than in other groups. The results indicate that growth performance and carcass parameter of Berkshire were improved by the dehulled soybean meal as comparison with non-dehulled soybean meal during growing and finishing periods.

Regulation of dietary energy level and oil source on leptin and its long form receptor mRNA expression of the adipose tissues in growing pigs

Two experiments were conducted to evaluate the effects of dietary energy level and source of oil on leptin mRNA and long form leptin receptor (Ob-Rl) mRNA expression in dorsal, abdominal and visceral adipose tissues in young growing pigs. In experiment one, 15 barrows (initial body weight 15.0 kg) were used to examine the effects of dietary energy levels on leptin mRNA and Ob-Rl mRNA expression. The pigs were randomly allotted to one of three dietary treatments ( n = 5 per treatment) containing 13.4, 15.1 or 16.7 MJ DE/kg diet for 28 days. Based on the results of experiment one, experiment two was designed to examine the effects of oil sources including soybean oil (rich in n-6 polyunsaturated fatty acids) or fish oil (rich in n-3 polyunsaturated fatty acids) on leptin mRNA and Ob-Rl mRNA expression in the same adipose tissues examined in experiment one. The energy content of these diets was 15.1 MJ/kg. Fourteen barrows (initial weight 20.5 kg) were allocated to either of the two dietary treatments ( n = 7 per treatment), which was supplemented with either soybean or fish oil (both 5.73% of the diet) and fed to the pigs for 21 days. At the end of both experiments, blood samples were collected to determine plasma leptin and insulin concentrations. Adipose tissues were sampled to determine leptin and Ob-Rl mRNA expression using real-time fluorescence quantification PCR. In experiment one, plasma leptin concentrations were enhanced ( P = 0.02), and insulin concentrations were decreased ( P < 0.01) in pigs fed the high-energy diet (16.7 MJ DE/kg). Dorsal adipose tissue leptin mRNA expression was increased by feeding the diet containing 15.1 MJ/kg DE compared with the diets containing 13.4 and 16.7 MJ/kg DE. There was no difference in leptin mRNA expression in abdominal and visceral adipose tissue. In experiment two, there were no differences in plasma leptin and insulin concentrations between pigs fed with either fish oil or soybean oil diets. Nevertheless, fish oil decreased both leptin mRNA and Ob-Rl mRNA expression in dorsal adipose tissues compared with soybean oil ( P < 0.01). These experiments indicate that the source of oil plays a more potent role in regulation of leptin mRNA expression relative to dietary energy levels by an insulin-independent mechanism. Plasma leptin concentrations may also be regulated by a post-transcriptional mechanism.

Effect of dietary energy levels on the urinary excretion of purine derivatives in sheep

ABSTRACTThe effect of dietary energy levels on the urinary excretion of purine derivatives (PD) was investigated in sheep fed hay and concentrate diets. In addition, the possibility of using PD concentrations in spot samples of urine as a useful tool for determining daily PD excretion was also examined. Three female lambs (mean bodyweight (BW) ± standard error, 31.4 ± 1.0 kg) were fed three diets consisting of timothy hay (20 g dry matter/kg BW per day) and rolled barley at three different energy levels (low‐energy (LE), medium‐energy (ME) and high‐energy (HE) at 1.0‐, 1.2‐ and 1.5‐fold greater than the maintenance level of energy (450 KJ/BW0.75/day), respectively) in a 3 × 3 Latin square design. The dietary protein level was almost constant (380 mg nitrogen/BW0.75/day as digestible crude protein base) and was adjusted using soybean protein. Digestible organic matter intake (DOMI) increased (P &lt; 0.05) with an increase in the dietary energy level and there was a difference (P &lt; 0.05) in the organic matter digestibility between the LE and HE diets. For urinary PD excretion, the differences between the LE and ME diets and the HE diet were significant (P &lt; 0.05), although there was no clear difference between the LE and ME diets. There was a positive correlation (r = 0.47, P &lt; 0.05) between urinary PD excretion and DOMI. There was also a correlation (r = 0.59, P &lt; 0.05) between the urinary PD level at 7–8 h after the morning feed and the daily total PD excretion, suggesting that the PD level in spot urine samples could be useful for estimating microbial protein synthesized in the rumen and/or digested in the lower gut.

The effects of diet, feeding regime and catch-up growth on flesh quality attributes of large (1 + sea winter) Atlantic salmon, Salmo salar

A 122-day sea trial was undertaken in the summer/autumn of 2001 to evaluate the effects of diet, feeding regime and catch-up growth on the flesh quality of 1 + sea winter Atlantic salmon. Two diets, extremely high- or medium-energy (XE ∼ 39% and ME ∼ 33% oil, respectively), were fed to satiation or restrictively (80% of recommended ration) to salmon in 24 seawater pens. Feeding intensities were reversed mid-way through the trial for half the replicates, creating 8 feed/feeding combinations. The fish grew from approximately 3.8 kg to between 6.5 and 7.6 kg, with specific growth rates (SGR) ranging from 0.44 to 0.58% day − 1 . Growth depended on the combined effects of dietary energy level and feeding intensity (dietary treatment). Fish fed the XE diet grew faster than ME-fed counterparts and feeding to satiation produced higher growth rates than restrictive feeding. Catch-up, or compensatory growth was observed amongst salmon fed to satiation after initial restrictive feeding. These fish had significantly higher SGRs than all other treatment groups during the catch-up growth phase ( P < 0.0001) and grew to a size equal to that of their unrestricted conspecifics. Condition factor and carcass yield increased throughout the trial irrespective of diet type or feeding intensity. Visually assessed colour, using the Roche SalmoFan™, was unaffected by diet or feeding intensity however instrumental readings for chroma and hue° increased irrespective of diet type or feeding intensity. At harvest, fat content was influenced by the combined effects of diet and feeding intensity, but when fish size was taken into consideration these influences were lost ( P = 0.5192). No relationship between fillet fat content and texture was found irrespective of treatment ( r 2 = 0.0006, P = 0.7819) and instrumentally measured texture was unaffected by diet, feeding intensity and growth rate. The extent of free oil (flesh oiliness) increased throughout the trial, but was similar amongst fish from all treatment groups. Feed type and feeding level significantly affected growth, but had little impact on the assessed quality attributes or incidence of free oil. These same attributes were unaffected by catch-up growth.

Efeitos da energia da dieta sobre desempenho, rendimento de carcaça e gordura abdominal de frangos de corte

Um experimento foi realizado com o objetivo de avaliar o efeito do nível de energia da dieta sobre desempenho, rendimento de carcaça e porcentagem de gordura abdominal de frangos de corte. Foram utilizados 2400 pintos de um dia da linhagem Ross 308, criados em boxes até 42 dias de idade. O delineamento experimental adotado foi o inteiramente casualizado em esquema fatorial 6 x 2 (energia x sexo). Os tratamentos consistiram de combinações de seis níveis de energia (2.900, 2.960, 3.020, 3.080, 3.140 e 3.200 kcal EM/kg) e dos sexos, com quatro repetições de 50 aves cada. No período de 1 a 42 dias de idade, houve redução no consumo de ração e melhora na conversão alimentar à medida que se aumentou o nível de energia da ração. Os machos apresentaram melhores resultados de desempenho que as fêmeas, exceto para mortalidade. À medida que se acrescentou energia na dieta, houve efeito linear na porcentagem de gordura abdominal e no rendimento de asas, mas não houve efeito sobre o rendimento de carcaça e das demais partes. Os machos apresentaram maiores porcentagens de pernas e de carne de pernas e menores de carne de peito e de gordura abdominal que as fêmeas.

Effect of dietary energy level on physiological responses and reproductive performance of Malpura sheep in the hot semi-arid regions of India

Malpura ewes, approximately 2 years of age and weighing 25.8 kg ( N=16) having lambed 4 months earlier were used to study the effect of feed restriction and re-alimentation on physiological responses and reproductive efficiency. The study was conducted in two phases of 14 weeks with two groups of eight ewes. Ewes were provided a diet consisting of 50% concentrate and 50% roughage ad libitum (Group-1) or placed on a restricted diet i.e. 30% intake of Group-1 (Group-2). The first phase was in summer followed by the second phase during the start of the monsoon season when all animals have access to natural pasture of Cenchrus ciliaris for 8–10 h daily. Each day at 1600 h all animals were provided fresh water. Weekly observations on respiration rate (breath per min), pulse rate (beat per min) and rectal temperature (°C) at 0600 and 1400 h were recorded along with body weight. Estrus in ewes was detected with the aid of intact rams of proven vigor at six-hour intervals. Ewes in estrus were hand mated during phase-II following a 14-weeks of re-alimentation period. During the differential feeding (phase-I), Group-1 animals had significantly higher respiration rate and pulse rate at 0600 and 1400 h, respectively, than those of Group-2 animals, whereas rectal temperature was similar ( P>0.05). During phase-II, significantly higher values were observed only for respiration rate of ewes in Group-1 compared to Group-2. Animals fed ad libitum maintained their body weights throughout the study period. In contrast, those on a restricted feeding (Group-2) weighed less during phase-I and more during phase-II ( P<0.05). Restricted feeding significantly reduced the duration of estrus (15 h versus 26 h) and increased the estrus interval (31.5 days versus 18.6 days) in phase-I with a tendency to reach its normal value during phase-II. After 14 weeks of re-alimentation, all the animals were hand mated. Animals in Group-1 required less services per conception than those of Group-2 (1.3 mating/ewes versus 1.9 mating/ewes). Again, birth weight of lambs from ewes in Group-1 was significantly higher than those from ewes in Group-2 (3.59 kg versus 3.06 kg). Results indicate that ewes tend to compensate for reproductive losses incurred during the restricted feeding period following access to adequate feed resources but were not consistent with those fed ad libitum.

Effects of dietary energy levels on plasma leptin in sheep

This experiment investigates the changes in the plasma leptin levels of sheep fed a diet of three energy levels (low, moderate and high). Four mature wethers were used for this experiment. For the first 4 weeks, the sheep were fed diets to provide 1.2 times the maintenance metabolizable energy requirements, low energy levels (LE). During the second 4 weeks, the sheep were fed diets to provide 1.5 times the maintenance metabolizable energy requirements, moderate energy levels (ME). During third 4-week period, the sheep were fed a diet to provide 1.8 times the maintenance metabolizable energy requirements, high energy levels (HE). Body weight was determined every week. Blood samples were collected prior to the morning meal at 3 days intervals throughout the experiment, and plasma leptin, insulin and nonesterified fatty acid (NEFA) concentrations were assayed. Body weight decreased in week 1 after the start of the experiment, it continued to decrease during the LE feeding, but it gradually increased until the end of HE period. Similarly, plasma leptin concentration decreased during LE feeding, but increased during the HE feeding. Additionally, positive correlation was obtained between leptin and insulin or glucose concentrations, whereas no clear relationship with circulating NEFA was observed. In conclusion, it was suggested that plasma leptin concentrations were affected by the metabolizable energy in feed.

Effects of Dietary Energy Level and Number of Meals on Growth and Body Composition of Nile Tilapia Oreochromis niloticus (L.) During Summer and Winter Seasons

AbstractTwo feeding trials (experiments 1 and 2) were conducted to determine the combined effect of dietary energy levels (low energy, LE and high energy, HE) and number of daily meals (one meal with the entire daily amount, two meals with half of the daily amount, and three meals with one‐third of the daily amount) on the growth and body composition of Nile tilapia Oreochromis niloticus in a recirculating system at different water temperatures, representing winter and summer seasons. In experiment 1 (winter), weight gain and specific growth rate (SGR) were significantly (P &lt; 0.05) affected by dietary energy levels, but not by number of meals. Weight gain and SGR for fish fed the LE diet one daily meal were significantly (P &lt; 0.05) higher than for fish fed the HE diet in one daily meal. Feed efficiency ratio (FER) and energy efficiency ratio (EER) were significantly (P &lt; 0.05) affected by dietary energy levels, but not by number of meals. Protein efficiency ratio (PER) was not significantly (P &gt; 0.05) affected by either dietary energy levels or number of meals. However, protein retention was significantly (P &lt; 0.05) affected by both dietary energy levels and number of meals. The chemical composition (moisture, protein, lipid, and ash) of fish muscle was not significantly (P &gt; 0.05) affected by either dietary energy levels or number of meals. However, visceral fat content was significantly (P &lt; 0.05) affected by dietary energy levels, but not by number of meals. In experiment 2 (summer), weight gain and SGR were significantly (P &lt; 0.05) affected by number of meals, but not by dietary energy levels. Weight gain and SGR for fish fed the LE and HE diets in two daily meals were significantly (P &lt; 0.05) higher than those fed one daily meal. FER and PER were significantly (P &lt; 0.05) affected by number of meals, but not by dietary energy levels. The highest FER and PER were observed in fish fed two daily meals. EER was significantly (P &lt; 0.05) affected by both dietary energy levels and number of meals. Moisture and protein content of the whole fish were not significantly (P &gt; 0.05) affected by either dietary energy levels or number of meals. Lipid content was significantly (P &lt; 0.05) affected by dietary energy levels, but not by number of meals. Based on the results of these experiments, Nile tilapia should not be fed high‐energy diets to improve fish performance even under a limited feed allowance during winter or summer. Fish grew rapidly when fed two daily meals during summer, but number of meals had no effect on fish performance during winter.

Energy level in winter diets of Fallow deer: effect on plasma levels of insulin-like growth factor-I and sex ratio of their offspring

To determine the effect of dietary energy level in the first winter on subsequent puberty onset, pregnancy, growth, and secretion of progesterone and insulin-like growth factor-I (IGF-I) in Fallow deer, prepubertal deer were fed either a high (H) or a low (L) energy diet in a randomised complete block design. June-born female Fallow deer were fed ad libitum either 12.5 MJ/kg DM (H, n=29) or 10 MJ/kg DM (L, n=29) in pelleted rations once per day during the winter (approximately 4–10 months of age) preceding puberty. Blood samples were collected twice weekly during the peripubertal period. During the winter feeding period, DM intake was similar for both groups but average daily gain was greater ( P<0.05) for deer fed the H versus L diet. Onset of puberty was not affected ( P>0.10) by dietary treatment. Concentrations of progesterone in plasma did not differ ( P>0.10) between dietary treatments before or after puberty, increasing after puberty in both groups, and reaching maximal levels 8–12 days after the onset of puberty. Concentrations of plasma IGF-I increased ( P<0.05) before puberty in both groups reaching maximal levels 3–4 days before the onset of puberty but did not differ ( P>0.10) between H and L diets before or after puberty. Of the 28 does fed the H diet that calved, 75% of the calves born were male versus 46% in the L diet ( P<0.05). In conclusion, increased plasma IGF-I concentrations were associated with the onset of puberty in Fallow deer regardless of the level of dietary energy intake during the preceding winter. Increased dietary energy during winter does not alter pregnancy rates but does alter sex ratio of calves born.

Effects of feeding frequency and dietary energy level on growth and body composition of juvenile flounder, Paralichthys olivaceus (Temminck &amp; Schlegel)

A two (dietary energy levels; low energy, LE and high energy, HE) × 4 (feeding frequency; one feeding in 2 days, one feeding daily, two times daily and three times daily) factorial experiment was performed to determine the effects of dietary energy level and/or feeding frequency on the growth and body composition of juvenile flounder Paralichthys olivaceus. The survival rate was not significantly different among treatments. Weight gain of fish fed the LE and HE diets significantly increased as feeding frequency increased. The weight gain of fish fed the LE diet was higher at each level of increasing feeding frequency. The weight gain of fish fed the HE diet was higher than that of fish fed the LE diet once in 2 days and once daily, but weight gain of fish fed the HE diet was lower than the LE diet three times daily. Daily feed intake was significantly influenced by feeding frequency, but not by dietary energy level. Feed efficiency of fish fed the HE diet once daily was significantly higher than that of fish fed the LE diet once in 2 days, but no significant difference in feed efficiency was observed among other groups of fish. The protein efficiency ratio of fish fed the LE diet once in 2 days was the lowest. Feeding frequency and dietary energy level had a significant effect on the body lipid content. A feeding frequency of two times or three times daily would be effective, depending on dietary energy level for maximum growth of juvenile flounder grown from 3.5 to 15 g.

Effect of dietary energy level on efficiency of SA Mutton Merino lambs and Boer goat kids under feedlot conditions

Effect of dietary energy level on efficiency of SA Mutton Merino lambs and Boer goat kids under feedlot conditions

Efeito do nível de energia da dieta e da exposição prévia ao calor sobre a respiração mitocondrial do músculo cardíaco de frangos de corte

Este trabalho foi realizado com o objetivo de avaliar o efeito do nível de energia da dieta, da exposição prévia ao calor e do sexo de frangos de corte sobre a atividade respiratória das mitocôndrias do músculo cardíaco de fragos de corte. Foram usados frangos Hubbard, de ambos os sexos, alimentados com ração contendo 2900 ou 3200 kcal de EM/kg e criados em câmara climática. Os frangos foram estressados por calor (35ºC/4 h) no 1º, 21º e 42º dia de idade. A atividade respiratória das mitocôndrias do músculo cardíaco foi avaliada por intermédio de oxígrafo Gilson modelo 5/6, utilizando-se alfa-ceto-glutarato como substrato e ADP (adenosina-di-fosfato) para estimular a atividade respiratória. Não houve efeito do nível de energia da ração e de estresse calórico prévio sobre a atividade respiratória mitocondrial do músculo cardíaco. Contudo, as fêmeas apresentaram maior atividade respiratória que os machos. Em razão da menor capacidade oxidativa das fibras musculares do coração dos frangos machos, estes podem ser mais susceptíveis a problemas cardíacos que as fêmeas.

Effect of dietary energy level and oil source on broiler performance and response to an inflammatory challenge

Broiler chicks were fed one of five diets from 3 d of age: a low energy diet containing 7% cellulose (ME 2,714 kcal/kg), or high energy diets containing approximately 7% of either tallow, corn oil, safflower oil, or fish oil (each 3,302 kcal/kg). Half of the chicks were injected intra-abdominally with Salmonella typhimurium lipopolysaccharide (LPS) on Day 11, sephadex on Day 13, and Freund's complete adjuvant on Day 15; samples were collected on Day 16. The uninjected chicks served as controls. In a second experiment, 3-d-old chicks were fed one of eight isocaloric diets containing tallow as the sole supplemental fat source, or tallow plus either 2% corn oil, 1, 1.5, or 2% fish oil, or fish meal at an amount to provide 1, 1.5 or 2% supplemental oil. Half of the chicks were injected intra-abdominally with S. typhimurium LPS on Days 10, 12 and 14; the uninjected chicks served as controls. Samples were taken on Day 15. In Experiment 1, the cellulose diet decreased performance to 10 d of age relative to the other diets, whereas immunogen injection decreased weight gain and feed efficiency and increased indices of inflammation among all dietary groups. Fish oil at approximately 7% of the diet did not improve weight gain. Fish oil diets improved weight gain and feed efficiency in Experiment 2 relative to the other diets, in spite of minimal effects on indices of inflammation. Injection of LPS decreased performance and increased inflammation across dietary treatment, although the second LPS injection was less potent in altering performance responses and inflammation compared to the first injection, indicating that repeated injections of LPS amy cause the chicks to become refractory to that stimulus. The fish meal diets resulted in poorer performance than similar levels of lipid provided as fish oil. Lower levels of dietary fish oil were more efficacious in improving broiler performance than higher levels, and fish oil provided from fish meal was not as efficacious as oil per se, possibly due to nonlipid components of the meal.

Effects of dietary energy level and source on foetal development and energy balance in concurrently pregnant and lactating primiparous rabbit does

AbstractThe aim of this experiment was to study the effects of dietary energy level and source on foetal growth and survival and mobilization of body stores in concurrently pregnant and lactating primiparous rabbit does. Does were given a moderate-energy diet (≍9·9 MJ digestible energy (DE) per kg dry matter (DM); group M, no. = 23) or a high-energy diet (-12·2 MJ DE per kg DM). In this latter case, additional energy came from starch (group S, no. = 23) or starch and fat (group F, no. = 22). Primiparous rabbit does were mated within 12 h after parturition and were slaughtered on day 28 of gestation-lactation. During the first 21 days, the DE intake and milk production were higher in the group F than in the groups S and M (P &lt; 0·05). On day 28 of pregnancy, the weight of adipose tissues and liver, as well as the lipid content of the carcass, were higher in the groups S and F than in the group M (P &lt; 0·05). Foetal survival and weight were similar in the three groups. These results indicate that increased energy level of the diet did not improve foetal survival or growth in concurrently pregnant and lactating primiparous does. On the contrary, it could reduce the mobilization offat stores, especially if the energy source is starch.

The effects of dietary energy levels on the carcass composition of the broilers

A study was conducted to determine the arcass composition of broilers when fed with three varying levels of dietary energy(3,000, 3,200 and 3,400 kcal/kg ME) at 20% crude protein and 0.79% Total Sulphur Amino Acid. The results showed that there was a significant(p<0.05) increase in the ME intake of the chickens when the ME of the diet increased. Other factors like the protein intake, dressing percentage, weight gain and feed intake were not significantly affected. On the carcass, the increasing dietary ME levels resulted in a significant(p<0.05) decrease in the carcass protein percentage. Similarly, the dietary ME produced a significant(0.05) increase in the amount of and fat percentages of breast meat, thigh meat, and drumstick meat with a significant reduction in the protein percentage. There seemed to be an inverse relationship between the perentages of protein and fat. An increase in fat percentages always resulted in similar reduction in the protein content of the meat. These results also showed major differences between the white and red meat of the chicken.