• Nutritional Sciences
• /
• v.1 no.1
• /
• pp.3-7
• /
• 1998

The aim of the present investigation was to see whether an anabolic steroid, nandrolone phenylpropionate (NPP), exerts protienanabolic effects under such adverse nutritional conditions as protein deficiency and protein-energy malnutrition in male rats. feeding on a low-protein (8% casein) diet resulted in a marked reduction in body weight gain that was associated with reductions in body protein and protein content of gastrocnemius muscle. Administration of NPP (4 mg/kg body weight) did not alter muscle and body protein depletion induced by a low-protein diet. 50% food restriction caused reductions in body protein and in protein content of gastrocnemius muscle. These reductions were partially prevented by NPP (4 mg/kg body weight). Food restriction did not affect plasma concentration of corticosterone, insulin, or tetosterone plus dihydrotestosterone. On the other hand, neither plasma concentration of corticosterone nor insulin were affected by NPP. The present results show that anabolic steroids do not express anabolic effects under conditions of protein deficiency, but in protein-energy malnutrition, anabolic steroids exert their anabolic effects even in male rats.

• Journal of Nutrition and Health
• /
• v.16 no.4
• /
• pp.263-272
• /
• 1983

Effects of dietary protein qualify, energy restriction, and subsequent rehabilitation were studied in the weanling rats. Rats were devided into the six experimental diet groups. Rats in AC (casein- containing diet ), AS (soyprotein-containing diet), and AG(gluten-containing diet) group consumed their diets ad libitum, and rats in PC, PS, PG groups were pair-fed in 60% of the of amounts eaten by corresponding rats in the AC, AS, AG groups, respectively. After 3 weeks of nutritional restriction, all rats were switched to the AC diet for 14 days. At the end of restriction period, body weight, weight gain, food intake, and FER were higher in casein- fed rats than other groups of rats. The differences were, however, disappeared with rehabilitation diet, except body weights which were not fully recovered until the end of experiment. The weights of liver, gastrocnemius muscle, kidney, small intestine, spleen, and lung were the highest in the casein group, and the lowest in gluten group at the end of restriction period. The recovery with rehabilitation diet were differ in different organs. The muscle and liver seemed to be the most affected organs by dietary protein quality and energy restriction. There were no differences in brain weights among the experimental groups during the restriction period, however, after 2 weeks of rehabilitation, rats in AC group showed lower brain weight compared to AC and AS groups, and the brain weight of PC group was lower than AC group. Protein contents in liver and muscle showed the same trends as their weights. Gluten-fed rats showed low serum protein concentration, but recovered fully with rehabilitation diet for 3 days.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.7
• /
• pp.1038-1047
• /
• 2008

This study aimed at targeting fixed increases in body weight (100 g/wk) by quantitatively regulating energy allowances (ME) in broiler breeders from 5 to 20 wks of age. Four energy regimes were tested: 1. The energy required for maintenance, activity and growth was calculated for 100 g increases in body weight/wk and a measured quantity of grower diet (160 g protein and 2,600 kcal ME/kg) was offered to the control group (ME-100) to achieve the anticipated weight gain. The energy allowances increased with age from 132 to 294 kcal/d. 2. Additionally, three energy regimes were considered, quantitatively reducing ME by 10% (ME-90) or 20% (ME-80) and increasing by10% (ME-110) over the control group. Each test group had 23 replicates5 female chicks housed in cages. The influence of energy regimes and age on growth, nutrient digestibility, carcass attributes, bone parameters and stress was evaluated at 4 wk intervals. Quantitative ME restriction by 10% (119-265 kcal/d) produced an average weight gain of 98.1 g/wk, which was closer to the targeted increase of 100 g/wk, whereas the control group attained it nine days earlier. Restriction of energy by 10 or 20% produced better conversion efficiency of feed, energy and protein and apparent digestibility of protein, Ca and P than 10% excess ME. Energy regimes did not influence eviscerated meat yield, but higher energy allowances (ME-110) significantly increased abdominal fat pad and liver weights and decreased giblet weight, percent muscle protein and tibia ash. Relatively higher stress was recorded in ME-restricted groups, as reflected by wider heterophil and lymphocyte ratios and increased bursa weight. Early age (5-12 wk) significantly influenced bone mineralization, conversion efficiency of feed, energy and protein and apparent digestibility of protein, Ca and P, while later ages (13-20 wk) increased eviscerated meat yield, abdominal fat, tibia weight and muscle protein and reduced stress. Energy regime x age interactions were significant and are discussed. In conclusion, the synthetic broiler line used in our study responded positively to controlled energy feeding during the rearing period. Breeders offered 119-265 kcal/d, a reduction of 10% energy over the control group, were more effective in regulating grower performance than the latter. In addition to energy regimes, age intervals also exhibited significant influence on specific parameters during the grower phase.

• Asian-Australasian Journal of Animal Sciences
• /
• v.3 no.2
• /
• pp.125-133
• /
• 1990

The effect of dietary protein-energy restriction (PER) on the growth of long bone were examined in sheep during growing period and then following a cycle of reproduction. Three months-old female sheep were offered protein-energy restricted feed for 6 months (growing period), thereafter changed to normal nutritional conditions for 8 months (reproduction period). A half of animals in each group took pregnancy, parturition and lactation. The nutritional restriction reduced the growth in bone diameter more than that in bone length. Compensatory growth resulting from the removal of the nutritional restraint strongly occurred in bone diameter, especially the bone cortical width, as compared to bone longitudinal growth. A cycle of reproduction severely decreased the growth in the bone cortical width relative to that in the bone width, and little effect was found on the growth in bone length and bone mass. The depression of bone development by pregnancy and lactation tended to exhibit severer in animals having received normal nutrition than in those having received PER. Bone mineral density was not affected by the nutritional restriction. A cycle of reproduction had an adverse effect on the mineral density between in animals having received normal nutrition and in those having received PER.

• Journal of Nutrition and Health
• /
• v.6 no.3
• /
• pp.1-8
• /
• 1973

Metabolic responses to the protein-free, high-carbohydrate diet and subsequent food restriction on the same diet at the level of 50% and 75% has been studied on the adult albino rats. The energy source was either corn starch or sugar. In experiment I, adult male rats weighing $509{\pm}8g$ were divided into two groups 10 rats each. Rats fed on the stock diet served as a control. Rats of restriction group received a protein free diet until they reduced their weight down to 400g and continue on a protein-calorie restriction diet until they reduced their weight down to 300g. In experiment II, 28 adult male rats and the same numbers of female rats weighing $329{\pm}5g$ and $223{\pm}4g$ respectively were divided into four groups, 7 males and females in each. Rats fed on a stock diet were sacrificed at the point when others started a protein free diet. These were served as the control. The protein free group received a protein free diet ad libitum for 4 weeks. The 50% restriction group and 75% restriction group were fed on a protein free diet coupled with food restriction at levels of 50% and 75% respectively for 3 weeks. In the result of this study: 1. The rate of body weight changes was similar between the males and the females. Feeding protein free diet ad lib. initiated a rapid weight lost of approximately 25% and protein free diet coupled with food restriction showed 37-43% reduction of their initial weight. 2. There was no significant differences in the value of the N concentration in liver, spleen, brain and muscle between controls and experimental groups. 3. Rats fed on protein free diet showed 1/10 value of the control in the nitrogen excretion in urine. However female showed less N excretion than male. 4. Observing blood picture, the effects of protein depletion and calorie restriction were not appeared any remarkable changes. 5. There was no sign of fatty liver which might result from protein depletion and calorie restriction. 6. Following semi-starvation, FAO and HMP-DH total enzyme activity was reduced, but activity per unit weight was relatively stable.

• Journal of Animal Science and Technology
• /
• v.64 no.2
• /
• pp.330-342
• /
• 2022

We aimed to investigate candidate proteins related to long-term caloric restriction and feed efficiency in bovine longissimus dorsi muscle (LM). A total of 31 Korean native steers were randomly distributed to ad libitum (n = 16) or caloric restriction group (n = 15) to conduct two feeding trials for 13 mon. In the first trial (10-18 mon of age), steers were fed with 100% ad libitum (NE_g = 0.63 Mcal/kg) or caloric restriction (80% of the previous day's feed intake of ad libitum group). In the second trial (18-23 mon of age), the energy value of 100% ad libitum diet was 1.13 Mcal/kg NE_g and those in caloric restriction group diet was 0.72 Mcal/kg NE_g. At the endpoint of this experiment, in each group, 6 animals were selected with high (n = 3) or low feed efficiency (n = 3) to collect muscle tissue samples (6 animals/group). From muscle tissues of 23 mo of age, we excavated 9 and 12 differentially expressed (two-fold or more) proteins in a nutritional group and feed efficiency group using two-dimensional electrophoresis, respectively. Of these proteins, heat shock protein beta-6 was up-regulated in both the caloric restriction and the low feed efficiency group. In bovine embryonic fibroblasts, the mRNA expression of heat shock protein beta-6 increased after adipogenic differentiation, however, decreased after myogenic differentiation. Our data provide that heat shock protein beta-6 may be an adipogenic protein involved in the mechanism of caloric restriction and feed efficiency in the LM of the steer.

• Journal of Nutrition and Health
• /
• v.33 no.7
• /
• pp.697-702
• /
• 2000

The objective of this study was to determine the extent to which the compensatory nutrition regimen modulates lactation performance and milk protein gene expression in the first and second lactation cycles. Female rats(28 days of age) were assigned to 1)control ad libitum ; 2) stari-step compensatory nutrition(SSCN) regimen an alternating 3-2-3-4-week schedule beginning with an energy restriction diet(40% restriction) for 3 weeks followed by the control diet(ad libitum) for 2 weeks and then alternating another 3-4 week feeding regimen. The SSCN rats were received an overall 20% energy restriction(average from all stair-step periods) compared with the conventionally fed control group. Rats were bred during the first week of the second realimentation. All pups were weaned on day 21 of lactation. About 1 week after weaning all dams were mated for the second pregnancy. Mammary tissues were obtained from pregnant and lactating rats during the first and second lactation cycles. During these lactation cycles the SSCN group had a 11% increase in average lactation performance over that of control. The SSCN group had significantly increased levels of milk protein gene($\alpha$- and $\beta$-casein) expression in mammary tissues during the first lactation cycle compared with those of the control group. During the second lactation period the levels of milk protein gene expression in lactating mammary tissues of the SSCN group were also higher than those of the control group. These results suggest that the effects of compensatory growth imposed at an early age extend to the second lactation cycle with regard to increased lactation performance and milk protein gene expression.

• Asian-Australasian Journal of Animal Sciences
• /
• v.6 no.3
• /
• pp.401-410
• /
• 1993

Day-old male and female broilers obtained from commercial strain (Hubbard) were used in this study. At 7 days of age, all chicks were weighed individually (female 0.11 kg and male 0.12 kg in average) and divided into 5 group of 45 birds each group with no replicate in each treatment group as follows: 1. fed ad libitum; 2. fed 75% ad libitum; 3. fed 65% ad libitum; 4. fed 55% ad libitum; 5. fed 45% ad libitum. Chicks were restricted for 10 days (d 7 through 17) of a 56-day trial. Chicks were fed a commercial starter diet (crude protein (CP) 23.8% and metabolizable energy (ME) 3,070 kcal/kg) for 21 days, and commercial finisher diet (CP 20% and ME 3,160 kcal/kg) from 22 to 56 days of age. When chicks were feed-restricted at an early age, compensatory growth did not immediately occur following refeeding. Body weights of restricted chicks were not equal to the ad libitum chicks before 49 days of age. At 56 dyas of age, body weights of restricted chicks were heavier (p<0.01). Abdominal fat values of female chicks fed ad libitum was not significantly different from those fed 45% to 75% ad libitum. Carcass fat values of restricted female chicks were lower than those of control chicks when female chicks were fed either 55% or 45% ad libitum. Furthermore, feed efficiencies of restricted chicks were better. The response of chicks to early feed restriction might depend on the degree of feed restriction, and sex. Factors contributing carcass fat included energy loss, fat protein ratio of carcass, fatty acid synthesis in the liver and triglyceride content of the liver. The heavier body weights in the restricted chicks might be correlated with the lower growth rate during period of feed restriction.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.8
• /
• pp.1258-1265
• /
• 2007

Metabolizable energy (ME) required for basal metabolism, activity and growth was considered as the criterion for targeting specific increases in body weight (100 g/week) of broiler chicks during the grower phase (5-20 weeks) and its impact was evaluated on breeder performance. Broiler female chicks (460) from a synthetic dam line were randomly distributed to 4 test groups with 23 replicates of 5 birds each and housed in cages. The first group (ME-100) was offered a calculated amount of ME by providing a measured quantity of grower diet (160 g protein and 2,600 kcal ME/kg) which increased with age and weight gain (133-294 kcal/bird/day). The other three groups were offered 10 or 20% less ME (ME-90 and ME-80, respectively) and 10% excess ME (ME-110) over the control group (ME-100). From 21 weeks of age, a single breeder diet (170 g protein and 2,600 kcal ME/kg) was uniformly fed to all groups and the impact of grower ME restriction on breeder performance evaluated up to 58 weeks. The targeted body weight gain of 1,600 g in a 16-week period was achieved by pullets of the ME-100 group almost one week earlier by gaining 8.7 g more weight per week. However, pullets in the ME-90 group gained 1,571 g during the same period, which was closer to the targeted weight. At 20 weeks of age, the conversion efficiency of feed (5.21-5.37), ME (13.9-14.1 kcal/g weight gain) and protein (0.847-0.871 g/g weight gain), eviscerated meat yield, giblet and tibia weights were not influenced by ME restriction, but the weights of abdominal fat and liver were higher with increased ME intake. Reduction of ME by 10% in the grower period significantly delayed sexual maturity (169.3 d), but increased egg production (152.5 /bird) with better persistency. Improved conversion efficiency of feed, ME and protein per g egg content were also observed in this group up to 56 weeks. The fertility and hatchability at 58 weeks of age were higher in the ME-90 group compared to the control and 10% excess ME feeding. In conclusion, the present study revealed the possibility of achieving targeted weight gain in broiler growers by feeding measured quantities of ME during the rearing period with consequential benefits in breeder performance.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.9
• /
• pp.1213-1220
• /
• 2010

This experiment evaluated the effects of dietary lysine restriction and energy density on growth performance, nutrient digestibility and meat quality of finishing pigs. A $2{\times}2$ factorial arrangement of treatments was utilized in a randomized complete block (RCB) design, and factor 1 was lysine restriction and factor 2 was energy density. The control diet was formulated to contain 3.265 Mcal of ME/kg, 0.75% lysine in the early-finishing phase and 3.265 Mcal of ME/kg, 0.60% lysine in the late-finishing phase and other nutrients met or exceeded NRC (1998) standards. Compared to the control diet (CON), lysine levels of experimental diets were restricted to 15% (treatment EL, EEL) or 30% (treatment ELL, EELL), whereas energy level of experimental diets was increased by 0.100 or 0.200 Mcal of ME/kg. A total of 100 crossbred pigs ([Yorkshire${\times}$Landrace]${\times}$Duroc), with average initial body weight of $58.47{\pm}1.42\;kg$, were allotted to 5 dietary treatments based on sex and body weight. Each treatment had 5 replicates with 4 pigs (two barrows and two gilts) per pen. ADG, ADFI and feed efficiency were calculated in an 8-week growth trial. In the late finishing period (5-8 weeks), pigs fed ELL or EELL diets had decreased ADG and feed efficiency (p<0.01), however, when the EEL diet was provided, a similar growth performance was observed compared to those fed the CON diet during the whole experimental period (p>0.05). In a metabolic trial, 15 pigs were used to evaluate the effect of dietary lysine restriction and energy density on nutrient digestibility. The digestibility of dry matter, crude fat and crude ash was not improved by restricting dietary lysine or energy density. However, crude protein digestibility was decreased (p<0.05) as dietary lysine was restricted. When dietary lysine was restricted, fecal nitrogen was increased whereas nitrogen retention was decreased. BUN concentration was affected by dietary lysine restriction; treatments ELL and EELL had higher BUN values than other treatments (p<0.01). Carcass characteristics and meat quality were measured when average body weight of pigs reached $107.83{\pm}1.50\;kg$. Treatment ELL had higher last rib backfat depth (p<0.05) than treatment CON, but ELL and EEL did not differ significantly. The ELL and EEL treatments had higher (p<0.05) subjective marbling score than treatment CON. Treatment EEL showed higher longissimus fat content than treatment EL and CON (p<0.01). The results indicated that finishing pigs fed a diet with 15% lysine restriction and 3.465 Mcal of ME/kg energy density had no detrimental effects on growth performance and N utilization, and could achieve substantial increases in marbling and longissimus fat content of pork.