Weight increase following administration of insulin to rats with reduced feed intake]

Young male Wistar rats, adapted to single daily administration of feed (from 8.00 to 10.00 a.m.) were studied for the intake of feed, weight gains, and feed consumption per weight gain unit after administration of Superdep insulin in the dose of 10 u kg-1 of body weight. The time limitation of access to food reduced the over-all intake of feed and weight gains and adversely affected the utilization of feed, expressed as consumption per 1 g of weight gain. The administration of insulin partly compensated the adverse effect of the reduced feed intake; this was manifested by better utilization of feeds by the experimental group, in comparison with the control animals.     

Relationship between food consumption and energy and nitrogen utilisation by chicks given varying amounts of standard and leucine-, isoleucine- and valine-deficient diets

The effect of different amounts of food, varying from below to above the rate of voluntary intake, was studied in chicks using a standard diet and diets containing only half the recommendation concentrations of leucine, isoleucine or valine. Irrespective of diet the body weight gain of the chicks increased with increasing food consumption. The body weight gain of chicks given the leucine-deficient diet was similar to that of chicks given the same amount of the standard diet. In contrast, the body weight gains of chicks given either the valine- or isoleucine-deficient diet were significantly less than that of chicks given the same amount of the standard diet. When the food intakes of the birds were similar the differences in body protein and water contents of the birds fed the different diets reflected differences in body weight gains, whereas body fat content was affected in the reverse manner. Retention and retention rate of dietary energy increased as food consumption increased. This was particularly evident in chicks given the isoleucine-deficient diet, followed by those given the valine-, leucine-deficient and standard diets. For all diets, the amounts of nitrogen retained and nitrogen retention rate (N retained/N consumed) increased in line with body weight gain. The metabolisable energy values of the diets were similar, except for the isoleucine-deficient diet which had a significantly higher metabolisable energy value than the standard valine-deficient diets.     

Residual feed intake: a nutritional tool for genetic improvement

The goal of this bibliographical study was to provide information about residual feed intake (RFI), a new criterion used in the selection of beef cattle for growth rate, food ingestion, and feed efficiency. RFI is calculated as the difference between real consumption and the quantity of food an animal is expected to eat based on its mean live weight and rate of weight gain. In studies of RFI, many speculations are made among researchers about the reliability of this criterion. However, there is a high genetic correlation with characteristics related to post-weaning consumption and maturity, indicating that the biological processes that regulate consumption and efficiency in young animals are similar to the processes that regulate consumption and efficiency in animals of greater age. In contrast to feed conversion, selection based on RFI seems to select for lower rates of consumption and lower animal maintenance requirements without changing adult weight or weight gain. Therefore, we conclude that the data indicate that there are extraordinary benefits to be gained from changing the goals of selection from increased weight gain to improved nutritional efficiency. Given the importance of animal production for economic development in Brazil choosing the best selection goals for livestock improvement is essential. To include an index of feed efficiency in future goals would be desirable, and RFI may play a part in this if economic methods of implementation can be developed.     

Fiber but not conjugated linoleic acid influences adiposity in dogs

Feeding obese dogs a high-fiber food with or without added conjugated linoleic acid (CLA) resulted in reduced caloric consumption, reduced body weight, and a 3.3% reduction in body fat, whereas feeding a low-fiber food resulted in a comparable increase in caloric consumption and a 2.4% gain in body fat. The addition of CLA did not significantly affect food intake, energy intake, final lean body percent, change in lean body percent, or final fat percent. These results suggest that the addition of dietary fiber but not CLA to foods may be helpful in the treatment of canine obesity.     

Differences in triglyceride and cholesterol metabolism and resistance to obesity in male and female vitamin D receptor knockout mice

A lean phenotype has been detected in vitamin D receptor (VDR) knockout mice; however, the gender differences in fat metabolism between male and female mice both with age and in response to a high‐fat diet have not been studied before. The objective of our study was to assess changes in body and fat tissue weight, food intake and serum cholesterol and triglyceride in VDR knockout mice from weaning to adulthood and after a challenge of adult animals with a high‐fat diet. Although VDR knockout mice of both sexes consumed more food than wild‐type and heterozygous littermates, their body weight and the weight of fat depots was lower after 6 months on a diet with 5% crude fat content. When adult animals were challenged with a high‐fat diet containing 21% crude fat content for 8 weeks, VDR knockout mice of both sexes had a significantly higher food intake but gained less weight than their wild‐type littermates. Cholesterol levels were higher after 2 days on the high‐fat diet in both sexes, but in the VDR knockout mice, less cholesterol was detected in the serum after 8 weeks. Wild‐type male mice showed signs of fatty liver disease at the end of the experiment, which was not detected in the other groups. In conclusion, lack of the VDR receptor results in reduced fat accumulation with age and when adult mice are fed a high‐fat diet, despite a higher food intake of VDR knockout mice relative to their wild‐type littermates. These effects can be detected in both sexes. Wild‐type male mice react with the highest weight gain and cholesterol levels of all groups and develop fatty liver disease after 8 weeks on a high‐fat diet, while male VDR knockout mice appear to be protected.     

Energy balance and growth rate of outbred and inbred male guinea pigs

Water intake, food consumption, growth rate, and rectal temperature were measured daily for 14 days and oxygen uptake was determined weekly for 3 weeks in healthy outbred (Hartley stock) and inbred (strains 2 and 13) male guinea pigs. Body weights ranged from 300 to 465 g, and ages were approximately 6 to 10 weeks. Strain-13 guinea pigs had the lowest daily body weight gain (3.27 +/- 0.33 g), when compared with strain-2 (4.04 +/- 1.21 g) and Hartley guinea pigs (5.72 +/- 1.08 g). Outbred guinea pigs also had highest values of water intake and water/food intake ratio(s), and had significantly (P less than 0.05 and 0.01) lower oxygen uptake values than did inbred guinea pigs. The ratio of daily average body weight gain to the corresponding daily retained calories, with or without corrections of body surface area (0.05 m2), was higher in Hartley stock than in the strain-13 guinea pigs. Rectal temperatures and food consumption were similar in all guinea pigs. Data indicated that the outbred Hartley guinea pig had a faster growth rate and appeared stronger physiologically, compared with inbred strains.     

羊、鸡抗鼠脂肪细胞膜抗血清对大鼠体脂与生长性能的影响

应用提取的鼠脂肪细胞膜分别免疫羊和鸡 ,所产生的抗血清用于 Wistar大鼠被动免疫。实验 1: 组腹腔注射羊正常血清 , 组腹腔注射羊抗鼠脂肪细胞膜抗血清 ,剂量均为 1m L /只 ,连续注射 4 d。结果表明 ,羊抗鼠脂肪细胞膜抗血清免疫促进了大鼠体增重 ,降低了体脂沉积 ,与对照组相比 ,7周末体重增加 6 .35 % (P<0 .0 5 ) ,饲料摄入增加6 .85 % (P<0 .0 1) ,料重比 (F/G)提高 4 5 .0 0 % (P<0 .0 5 ) ;肾周、附睾、网膜脂肪垫重量分别降低 2 3.92 % (P<0 .0 5 )、34.4 5 % (P<0 .0 5 )、0 .98% ,脂肪总量降低 2 0 .92 %。实验 2 :1组腹腔注射鸡正常血清 ,2组腹腔注射鸡抗鼠脂肪细胞膜抗血清 ,剂量均为 1m L/只 ,连续注射 4 d。结果表明 ,鸡抗鼠脂肪细胞膜抗血清免疫对大鼠的生长发育产生了不利影响 ,7周末 ,免疫大鼠平均体重较对照组减少 4 0 g(P<0 .0 5 ) ,饲料摄入显著降低 (P<0 .0 1) ;对体脂的沉积和血液中 TG和 FFA的影响没有规律 ,且无统计学意义     

Central effects of rat versus mouse leptin: ingestive behavior and adipose apoptosis

Leptin decreases food intake, body weight and fat mass while sparing lean mass. Although mouse leptin (ML) and rat leptin (RL) are 95.9% identical, our impression from previous studies was that they were not equally potent in rats. Thus, in the present study, 0 microg (vehicle) or 10 microg of ML or RL was injected into the lateral ventricle of rats (eight per treatment) once a day for four consecutive days. Body temperature, body weight, food intake and water intake were measured daily. Intrascapular and perirenal brown fat pads, white fat tissues (retroperitoneal, epididymal and inguinal fat pads) and the gastrocnemius muscle were collected and weighed 24h after the last treatments. Body temperature was not affected by either ML or RL. Both ML and RL caused significant reductions in food intake (P<0.05), and there was no difference between them. ML and RL also similarly inhibited water intake on days 2 and 3 (P<0.05). By day 5 both ML- and RL-treated rats had lost weight (11.6 and 15.4 g, respectively), while vehicle-treated rats gained weight (6.8 g). Weights of retroperitoneal and epididymal fat pads, but not other tissues, were reduced similarly by both leptin treatments (P<0.05). However, an increased apoptotic response was detected in the retroperitoneal fat tissue of RL- but not ML-treated rats (P<0.05). These results suggest that RL is more effective than ML in inducing apoptosis in retroperitoneal fat tissue after i.c.v. injection in rats.     

Subacute toxicity of dietary 3-acetyldeoxynivalenol in mice.

3-Acetyldeoxynivalenol was incorporated into a semisynthetic diet at levels of 2.5, 5, 10 or 20 ppm and fed to mice for up to 48 days. Body weights and feed consumption were determined, and blood samples for hematological evaluation were taken. Selected tissues were examined microscopically and the humoral immune response was assessed using the Jerne plaque assay. 3-Acetyldeoxynivalenol caused a dose-related depressed feed consumption within the first seven days and reduced body weight until day 14 when fed at levels up to 10 ppm. When fed at a level of 20 ppm, an initial depression in body weight gain and a general malaise were followed by a return to normal. At necropsy, no macroscopic or microscopic lesions could be found. The immune response was not significantly affected after seven or 14 days, but at 21 days, a dose-dependent enhanced response was observed. The findings indicate that, after an initial period of reduced feed intake, animals are apparently able to overcome the toxic effects of 3-acetyldeoxynivalenol.     

Genetic variation and phenotypic correlations of food consumption of laying hens corrected for body weight and production

1. On samples from two brown‐egg strains between 1967 and 1979, “ residual” food consumption (i.e. food consumption corrected for body weight, weight change and egg mass) of laying hens was investigated with respect to variation between sire families and phenotypic correlations with production traits, egg traits, morphological and physiological variables. A similar residual food intake (corrected for body weight and body‐weight gain) was obtained for samples of males in some years.

2. Highly significant differences between sire families were observed for residual food consumption in both strains for females and in one strain for males.

3. In females, highly significant positive phenotypic correlations were found in both populations for residual food intake with wattle length and shank temperature, and in one population with shank length and width. On the whole, a negative correlation was observed with egg‐shell thickness. For two variables recorded only in one strain, proportion of broken eggs and yolk : albumen ratio, there were highly significant positive correlations.

4. For males also, wattle length and shank temperature were positively correlated with residual food intake.

5. The physiological meaning and possible use of correlated variables as criteria for indirect selection for food efficiency of layers are discussed.     

Study on Subchronic Toxicity Test of Different Polarity Section Extracts from Aster tataricus L.f.on SD rats

The aim of the experiment was to observe the liver toxicity of different polarity section extracts from Aster tataricus L.f.on SD rats.The subchronic test was performed via the daily oral administration of Aster tataricus L.f.at dose of 0.34 g/kg body weight in SD rats which were divided into six groups(control group, petroleum ether group, ethyl acetate group, N-butyl alcohol group, mother liquid group and 75% ethanol group), observing the effects on food consumption, body weight gain, viscera coefficient, urine examination, blood routine examination, serum biochemistry indices, liver antioxidant function analysis and histopathological observation.There was no significant changes of body weight gain, viscera coefficient, urine examination and liver antioxidant function among six groups(P>0.05), but WBC significantly and extremely significantly decreased in male rats of ethyl acetate group, mother liquid group and N-butyl alcohol group(P<0.05; P<0.01), and significantly and extremely significantly decreased in female rats of N-butyl alcohol group and petroleum ether group, ethyl acetate group(P<0.05; P<0.01);The LDH significantly increased in female rats of ethyl acetate group(P<0.05);Slight congestion and necrosis were showed in liver in petroleum ether group and ethyl acetate group, there was no differences observed in other groups.The extracts of Aster tataricus L.f., especially petroleum ether extract and ethyl acetate extract could cause slight liver toxicity under the dose of 0.34 g/kg body weight.     

紫菀不同极性段提取物对SD大鼠亚慢性毒性试验研究

本试验旨在观察紫菀不同极性段提取物对SD大鼠的肝脏毒性损伤。SD大鼠随机分为空白组、石油醚组、乙酸乙酯组、正丁醇组、母液组、75%乙醇组,每组10只,灌胃给药0.34g生药/kg体重,连续28 d,观察对大鼠摄食量、体增重、脏器系数、尿液指标、血常规、血清生化指标、肝脏组织抗氧化酶、病理切片等的影响。试验结果显示各组大鼠体增重、肝脏组织抗氧化酶、尿液指标、脏器系数均无显著变化(P>0.05);雄鼠乙酸乙酯组、母液组白细胞计数(WBC)显著降低(P<0.05),正丁醇组极显著降低(P<0.01),雌鼠石油醚组、乙酸乙酯组WBC极显著降低(P<0.01),正丁醇组显著降低(P<0.05);雌鼠乙酸乙酯组乳酸脱氢酶(LDH)显著升高(P<0.05);病理组织学检查可见石油醚组和乙酸乙酯组大鼠肝脏出现轻微的肝索紊乱、颗粒变性,其余组与空白组相比无明显差异。结果表明在0.34g生药/kg体重给药条件下,紫菀的石油醚和乙酸乙酯提取物对大鼠产生轻微的肝脏毒性。     

Effect of avoparcin interaction with anticoccidial compounds on the growth and carcase composition of broilers

The anticoccidial drugs narasin, lasalocid, monensin and salinomycin, with and without avoparcin, were fed to 1280 broiler chickens from 1 to 49 d old. At day 49 significant interactions were detected between avoparcin and the anticoccidial compounds for body weight and food consumption. This indicated that the increases in body weight and food consumption obtained with avoparcin were greater with some anticoccidial compounds (lasalocid and salinomycin for body weights and lasalocid for food consumption) than with others (monensin and narasin for body weights and monensin, narasin and salinomycin for food consumption). Overall there was evidence that avoparcin increased body weight (5.8%), food consumption (2.5%) and efficiency of food utilisation (2.9%). In addition avoparcin produced significant increases in plucked weight and the proportion of visceral fat together with and decreases in the proportions of edible giblets and waste offal.     

Direct and correlated responses to selection for efficiency of lean gain in mice

Improvement in feed efficiency when selection is based on gain:feed ratio has often been accompanied by a reduction in feed intake. The following four criteria were used in mass selection for improved lean gain efficiency in mice with an objective of evaluating changes in lean gain and intake: 1) gain deviation, animals selected had the greatest gain in fat-free mass (FFM) after adjustment to a constant intake; 2) intake deviation, mice selected had the least feed intake after adjustment to a constant gain in FFM; 3) intrinsic efficiency, similar to the second criterion except that adjustment was also made for average weight maintained during the period; and 4) a positive control that used the ratio of gain in FFM: feed intake as the selection criterion. A fifth line, in which a male and a female were selected at random from each litter, served as a negative control. Experimental animals were outbred mice of the CF1 strain. Two replicates of the five lines were included in the study. Twelve males and females were pair-mated within each line-replicate combination each generation. Feed disappearance was measured from 25 to 42 d. Mice were scanned to obtain an electrical conductivity measurement for prediction of FFM. After six generations of selection, realized heritabilities for gain:feed, gain deviation, intake deviation, and intrinsic efficiency were .00 +/- .04, .04 +/- .29, .35 +/- .08, and .28 +/- .06, respectively. There were no differences among lines for gain:feed ratio. The correlated response in feed intake reduction was significant in the intake deviation and intrinsic efficiency lines (-.17 +/- .05 and -.21 +/- .04 g x d(-1) x generation(-1), respectively). The realized genetic correlations between the ratio and gain deviation, intake deviation, and intrinsic efficiency were .83 +/- .15, .01 +/- .04, and .21 +/- .12, respectively. Litter size was depressed in all selected lines.     

Influence of a high-protein diet on energy balance in obese cats allowed ad libitum access to food

The influence of a high-protein [HP, 47% of metabolizable energy (ME)] diet on energy balance was evaluated in obese cats allowed ad libitum access to food. Energy intake, body weight, body composition, energy expenditure, and concentrations of hormones and metabolites associated with carbohydrate and lipid metabolism (glucose, insulin, free fatty acids, triglycerides and leptin) were measured in cats after consuming either a moderate protein (MP, 27% of ME) or HP diet for 4 months. Indirect respiration calorimetry showed that resting and total energy expenditure (kJ/day) adjusted for either body weight or lean body mass was increased in cats consuming the HP in relation to MP diets. However, voluntary energy intake also was increased in the HP treatment and, thus, there was no difference in body weight between animals consuming the two diets. Body composition measurements using deuterium oxide dilution showed that dietary protein content did not alter amounts of either lean body mass or fat mass. No significant differences (p > 0.05) were observed between the two treatment groups for blood glucose, free fatty acid or leptin concentrations, although there was a trend (p = 0.054) towards an increase of serum insulin concentrations in the cats eating the HP diet. This study showed that short-term ad libitum feeding of an HP diet did not reduce food intake or promote weight loss in obese cats. However, energy expenditure was increased in the HP diet group and it is possible that this effect of HP might help promote weight loss when energy intake is restricted.     

An intrauterine catch‐up growth regimen increases food intake and post‐natal growth in rats

Nutritional conditions during the intrauterine stage are an important developmental programming factor that can affect the growth and metabolic status during foetal development and permanently alter the phenotypes of newborn offspring and adults. This study was performed to examine the effects of intrauterine catch‐up growth (IUCG) on food intake, post‐natal body growth and the metabolic status of offspring and growing rats. Control pregnant rats were fed ad libitum during the entire gestation period. For the IUCG regimen, pregnant rats were fed 50% of the food of the controls from pregnancy days 4 through 11 (8 days), followed by ad libitum feeding from pregnancy days 12 through parturition. The birth weight of offspring was not affected by the IUCG regimen. At weaning, offspring from each treatment group were assigned to two groups and given either a normal diet or high‐fat diet (HFD) for 12 weeks until 103 days of age. In the normal diet group, the IUCG offspring showed a 9.0% increase (P < 0.05) in total food intake, were 11.2% heavier (p < 0.05) at 103 days of age and had an 11.0% greater (p < 0.05) daily weight gain compared with control offspring. The IUCG regimen did not affect body glucose and lipid metabolism. After exposure to the HFD, the IUCG regimen has not exacerbated metabolic disorders. In conclusion, our findings suggest that the IUCG nutritional regimen during pregnancy can increase the food intake and post‐natal body growth of offspring without inducing metabolic disorders such as obesity and insulin resistance. The IUCG nutritional regimen might be used to improve the food intake and post‐natal body growth of domestic animals.     

The effect of daily energy intake on growth rate and composition of weight gain in pigs

An experiment with 29 crossbred female growing pigs (Dutch Landrace × Dutch Yorkshire) was carried out to measure the effect of daily energy intake on growth rate, N retention (according to the balance method) and composition of the weight gain. The weight gain composition was analysed by slaughtering pigs at regular intervals between 25 and 110 kg live weight. Two levels of daily energy intake, at an adequate protein intake, were used, and pigs on both treatments were slaughtered at the same age.Differences in daily energy intake affected growth rate and composition of the weight gain. Restriction of the daily energy intake by 20% caused a 15% lower live weight gain and a 12% lower N retention. Carcass muscle growth was 8% lower and fatty tissue growth was lower by 28%. Growth of bone was unaffected. Chemical analysis of different parts of the body revealed that reducing the daily energy intake by 20% caused an 8% lower protein deposition and a 28% lower fat deposition in the total body. However, there were differences between different anatomical parts of the body.Efficiency of pig meat production is discussed in relation to the effects of energy supply on weight gain composition.     

Effect of hexoestrol implantation and body size on the chemical composition and body components of chickens

Two groups of meat‐type cockerels, 56 d of age, from the same hatch but of different mean live‐weights (1135 g ± SD 96.2 and 544 g ± 72.0) due to differences in earlier nutritional treatments were implanted with hexoestrol to determine the effects on food consumption, live‐weight gain, carcass gain, chemical composition of carcass and offal, and weight of some body components. Replicate groups were slaughtered prior to implantation and at the end of the 28‐d experimental period.

Implantation with a single 15 mg hexoestrol pellet resulted in the following significant differences compared with untreated controls: increases in food consumption, live‐weight gain, carcass weight and weight of offal of 21.5, 14.2, 8.2 and 16.6 per cent respectively; poorer food conversion, higher total fat in the carcass, offal and total body and, relative to body weight, heavier livers and lighter hearts, gizzards, legs and necks. The increased fat in treated chickens accounted for all the increased body weight and carcass weight.

In comparisons of small and large chickens there was no significant difference in live‐weight gain during the 28‐d experimental period. At both 56 and 84 d of age the dressing percentages were lower and the weights relative to body weight of offal, liver, shanks and gizzards were higher in small than in large chickens. Percentage moisture was significantly higher in the total bodies and carcasses of small chickens, while percentage fat was significantly lower in the carcasses of small chickens at both 56 and 84 d and in the total bodies and offals at 56 d.     

Effects of chronic mild food restriction on behavior and the hypothalamic malonyl‐CoA signaling pathway

Depression induces anorexia, leading to suppressed feeding behaviors and energy intake. Previously, we revealed that chronic social defeat induced a mild suppression of feeding in rats with elevated levels of hypothalamic malonyl‐CoA which regulates feeding. Therefore, we attempted to elucidate the effects of chronic mild food restriction on behavior and on hypothalamic malonyl‐CoA. The chronic mild food restricted rats were fed a restricted diet approximately 80% to 90% amount of diet compared to the control for 5 weeks. Ratios of restriction were adjusted with feed consumption in the chronic social defeat stressed rats. Chronic mild food restricted rats exhibited a suppression of body weight gain similar to that of the chronic social defeat stressed rats. Also these rats showed increased time spent in the center area of an open field (OF), prolonged immobility time in forced swim, increased phosphorylation of hypothalamic adenosine monophosphate‐activated protein kinase (AMPK) and acetyl‐CoA carboxylase and a decreased concentration of hypothalamic malonyl‐CoA. Weight of the adrenal glands, locomotion in an OF, mitogen‐activated protein kinase cascade and calcium/calmodulin‐dependent protein kinases II in the hippocampus were not affected by chronic mild food restriction. Our findings suggest that chronic mild food restriction activates AMPK following a decreased hypothalamic malonyl‐CoA.     

Phenotypic and genetic variation in body weight,food intake and energy utilisation in Hereford cattle I. Performance test results

From body weight, food intake and carcass composition data on 542 Hereford bull calves, measuredfrom 200 to 400 days, several traits relating to the efficiency of beef cattle production were derived and analysed. Traits included body weight at various ages, weight gain, predicted carcass lean content, lean growth rate, food intake, food conversion ratio, lean food conversion ratio, food intake in relation to metabolic body weight, energy required for protein and fat deposition, and predicted maintenance expenditure.Maintenance expenditure and the costs of fat and protein deposition were calculated by two means,firstly from allometric equations describing fat and protein accretion, and secondly from a multiple regression of food intake on weight gain and predicted carcass lean content. The two methods gave different mean values, but the correlations between traits calculated by the two methods were almost all 1.00. Exponents for metabolic body weight derived from the two methods were 0.738 and 0.758, respectively.Genetic parameters were calculated using multivariate Restricted Maximum Likelihood techniques.Body weight, carcass composition and traits combining these measurements were moderately to strongly inherited whereas traits related to food intake and efficiency were weakly to moderately inherited. Energy used to deposit fat and lean was more strongly inherited than predicted maintenance expenditure, and these traits were genetically almost uncorrelated. Maintenance energy expenditure showed no genetic relationship with predicted carcass lean content. Efficiency and predicted maintenance expenditure were favourably correlated.