A preliminary report on a fat-free diet formula for nasogastric enteral administration as treatment for hyperlipaemia in ponies

A fat-free liquid diet was formulated to be administered by nasogastric tube as therapy for hyperlipaemia in ponies. The liquid diet provided energy, protein, minerals, trace elements, and vitamins in accordance with the requirements of ponies. As sole source of nutrition, the liquid diet fully counteracted fasting-induced hyperlipaemia in two healthy ponies. The liquid diet was also used in hyperlipaemic patients, but only in combination with conventional therapy, consisting of intravenous administration of glucose, insulin, and heparin. Although no patients were treated with the liquid diet alone, the liquid diet has potential in the treatment of hyperlipaemia - it is easy to prepare and to administer by nasogastric tube and it provides energy and nutrients to counteract the negative energy balance and low nutritional status of patients. Experience is needed with hyperlipaemic patients that are treated with the liquid diet only.

[Composition of commercial feeds for mynah birds with particular attention to the iron content]

The composition of 12 commercial feeds for mynah birds was analysed, with special attention being paid to the iron content. To prevent iron overload, the iron content of such diets should be maximally 5 mg/MJ, which is equivalent to 100 mg iron/kg if the commercial diet is the sole food source. Only three of the 12 feeds met this requirement. In all feeds the iron content was minimally three times higher than the recently suggested iron requirement of 25 mg/kg. In general, the total iron intake is not reduced sufficiently by providing cooked rice or fruit together with commercial feeds.

Fat feeding increases equine heparin-released lipoprotein lipase activity

The aim of this study was to establish the dose-response relationship between fat intake and heparin-released plasma lipoprotein lipase (LPL) activity in horses. Eight mature trotters were fed 4 rations with different fat levels (3.0, 5.0, 7.7, or 10.8% fat in the dry matter) according to a 4 X 4 Latin square design. The experimental rations consisted of hay and different concentrates; the concentrates and hay were given in a 3:1 ratio on an energy basis. Soybean oil was added to the concentrates at the expense of isoenergetic amounts of glucose. Blood samples were taken at the end of each dietary period, which lasted 3 weeks. Fat feeding was found to increase heparin-released plasma LPL activity in a dose-dependent fashion. When the data from this study and previous studies were combined it was calculated that an increase in fat intake by 1 g/kg dry matter is associated with an increase in LPL activity by 0.98 micromol fatty acid released-mL(-1) x h(-1). Fat feeding raised the plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, and phospholipids. Diet did not have a statistically significant effect on plasma triacylglycerol concentrations. The results are discussed in the light of the possible enhancing effect of fat feeding on the oxidative capacity of skeletal muscle.

High density lipoprotein cholesteryl ester metabolism in the pony, an animal species without plasma cholesteryl ester transfer protein activity: transfer of high density lipoprotein cholesteryl esters to lower density lipoproteins and the effect of the amount of fat in the diet

The metabolism of high density lipoprotein cholesteryl esters (HDL CE) was studied in the pony, an animal species without plasma cholesteryl ester transfer protein (CETP) activity. Studies were done in ponies fed a low- (1.5% fat, w/w) and a high-fat diet (11.5%, w/w fat). The ponies fed the high-fat diet had higher plasma HDL CE concentrations (1.08+/-0.15 vs. 0.84+/-0.11 mmol/l, mean+/-S.D., n=6, P<0.01) and plasma lipoprotein lipase (LPL) activities (14.3+/-4.0 vs. 5.7+/-3.4 micromol free fatty acids (FFA)/ml per h, P<0.05) than those on the low-fat diet. Plasma triacylglycerol (TAG) concentrations were lower on the high-fat diets (0.129+/-0.043 vs. 0.180+/-0.050 mmol/l), but these differences were not statistically significant. There was a negative correlation between the levels of plasma TAG (r=0.598, P<0.05) and VLDL CE (r=0.658, P<0.05) on the one hand and the HDL CE concentrations on the other hand. The transport rates of HDL CE were not significantly different between ponies fed high-fat (0.029+/-0.008 mmol HDL CE/h per l plasma) and those fed low-fat diets (0.024+/-0.004). HDL CE were transferred to low density lipoproteins (LDL) and we calculated that the percentage of LDL CE derived from HDL was 0.69+/-0.13 in the ponies fed the low-fat diet and 0.53+/-0.05 in the ponies fed the high-fat diet (P<0.05). The results of these in vivo studies suggest that in ponies, similarly as reported in rats and pigs, HDL CE can be transferred to LDL despite the absence of plasma CETP activity, and that the magnitude of this transfer is related to the levels of HDL CE as induced by the amount of fat in the diet.

Hypocholesterolemic effect of dietary psyllium in female rats

We fed cholesterol-enriched (1% cholesterol and 0.2% cholic acid) semipurified diets containing either 3% cellulose or psyllium to 2 groups of female Wistar rats for a period of 8 weeks. The feeding of the cholesterol-enriched semipurified diets resulted in a progressive increase in plasma cholesterol levels in both groups during the 8 weeks of the experiment. The rats fed psyllium, however, had significantly lower plasma cholesterol concentrations than the animals fed cellulose throughout the experimental period (at 8 weeks, 8.92 +/- 4.42 and 16.47 +/- 8 mmol/l, respectively, means +/- SD, n = 14, p < 0.01). Most of the plasma cholesterol in both groups at the end of the study was located in the very low-density lipoprotein (VLDL) fraction (91%) and differences in total plasma cholesterol concentrations were predominantly reflected in differences in VLDL cholesterol. Plasma triglyceride concentrations were not significantly different between the 2 groups. Liver cholesterol concentrations paralleled the concentrations of plasma cholesterol and were significantly lower (p < 0.001) in the psyllium-fed rats (90.31 +/- 13.81 micromol/g liver) than in the cellulose-fed rats (60.49 +/- 15.25 micromol/g liver). Substitution of psyllium for cellulose resulted in an increase in the excretion of fecal bile acids by 26%, and this increase was predominantly caused by an increased excretion of beta-muricholic acid and the bile acids derived from beta-muricholic acid (omega-muricholic acid and hyodeoxycholic acid).

Apparent digestibility of crude fibre in ponies fed either a low or high-protein diet

The question addressed was whether apparent crude fibre digestibility in ponies would change after lowering protein intake from adequate to borderline deficient. Four adult ponies were fed a low- and high-protein diet according to a cross-over design. The diets consisted of grass hay and concentrates and provided either 1.5 or 3.6 g digestible crude protein/kg(0.75) per day. The two whole rations provided 2.4 g crude fibre/kg body weight per day. Apparent crude fibre digestibility was not affected by protein intake (low-protein diet: 42.9 +/- 4.03%; high-protein diet: 38.1 +/- 1.14%, means +/- SE, n=4). The low-protein diet caused a significant increase in the ratio of faecal: urinary nitrogen. It is suggested that, when the low-protein diet was fed, sufficient urea flew from the blood into the intestine and ammonia released in the hindgut was conserved so that microbial growth, and thus fibre fermentation, was maintained.

Small intestinal morphology in weaned piglets fed a diet containing spray-dried porcine plasma

The hypothesis tested in this study was that the reported beneficial effects of spray-dried porcine plasma (SDPP) on piglet post-weaning performance and health are associated with a trophic effect on small intestinal mucosa. At 24 days of age, the piglets of seven sows were assigned to one of three treatment groups. One group continued to be suckled. The other two groups were weaned and offered a diet containing either 15 per cent SDPP or casein. From each treatment group, one piglet was anaesthetised and samples were taken from the small intestinal wall at 26, 28 and 31 days of age. There were no significant effects of SDPP versus casein on villus length. On average, there was less mitotic activity in the SDPP -fed piglets than in those fed casein on days 4 and 7 after weaning. As less mitotic activity leads to less immature enterocytes, this may provide a mechanism for the reported beneficial effects of SDPP on performance and health.

Consumption of fructooligosaccharides and nitrogen excretion in cats

In a cross-over study with adult cats the effect on nitrogen (N) excretion of a diet supplemented with fructooligosaccharides (FOS) was compared with a diet supplemented with an equal amount of fructose and glucose. FOS raised N excretion with faeces by 26% (P < 0.05) and non-significantly lowered N excretion with urine by 5%. Thus, there was a shift in N excretion from urine to faeces. The amount of faecal dry matter was significantly higher (by 23.3%) when FOS was consumed.

Is pseudocholinesterase activity related to markers of triacylglycerol synthesis in Type II diabetes mellitus?

Hypertriglyceridaemia is a risk factor for cardiovascular disease in patients suffering from Type II diabetes mellitus, and is due to enhanced synthesis and/or impaired clearance of triacylglycerol-rich lipoproteins. In the present study we investigated whether pseudocholinesterase (PChE) activity could serve as a marker for the rate of triacylglycerol synthesis in these patients. Patients were stratified according to their apolipoprotein E (apoE) phenotype, i.e. E3E2, E3E3 or E3E4. In study I, the relationship between PChE activity and serum triacylglycerols was investigated in 224 insulin-treated patients with Type II diabetes. In study II, which had a cross-over design, PChE activity was measured in 45 dyslipidaemic, insulin-treated patients with Type II diabetes that were treated with bezafibrate or pravastatin. In study I, PChE activity was correlated positively with serum triacylglycerol concentrations, but did not differ significantly between apoE phenotypes. The strongest relationship was found in the E3E4 group (r=0.50; P=0.001), the phenotype for which hypertriglyceridaemia is expected to be the result of increased triacylglycerol synthesis. In a stepwise multiple regression analysis, serum triacylglycerol concentrations were found to be the strongest predictor of PChE activity in the E3E4 group. In study II, PChE activity decreased as a result of bezafibrate treatment in all three apoE groups. The decrease in PChE activity with bezafibrate treatment paralleled the decrease in serum triacylglycerol concentrations in the apoE subgroups. Pravastatin treatment did not significantly affect PChE activity. Thus the present study suggests an association between PChE activity and the rate of triacylglycerol synthesis. Measurement of PChE activity may therefore be a useful tool in the choice of drug for treatment of hypertriglyceridaemia in patients with Type II diabetes.

High arsenic intake raises kidney copper and lowers plasma copper concentrations in rats

The effect of high arsenic intake on copper metabolism was investigated. Male rats aged 6 wk had free access to purified diets containing either 0 or 100 mg As/kg diet and demineralized water for a period of 2 wk. Arsenic was added to the diet in the form of NaAsO2. The high-arsenic diet decreased feed and water intake and body weight gain, but significantly increased liver weight. Kidney weight was not affected. Arsenic feeding drastically elevated kidney copper concentration, but significantly reduced copper concentration in plasma. Both true absorption and biliary excretion of copper were decreased significantly in rats fed the high-arsenic diet. True copper absorption was lowered essentially through the lower copper intake in the rats fed arsenic. It is speculated that arsenic feeding primarily leads to copper accumulation in the kidney, followed by a decrease in feed intake and thus in true, absolute copper absorption, a decrease in plasma copper concentration, and a decrease in biliary copper excretion.

High fat intake lowers hepatic fatty acid synthesis and raises fatty acid oxidation in aerobic muscle in Shetland ponies

The metabolic effects of feeding soyabean oil instead of an isoenergetic amount of maize starch plus glucose were studied in ponies. Twelve adult Shetland ponies were given a control diet (15 g fat/kg DM) or a high-fat diet (118 g fat/kg DM) according to a parallel design. The diets were fed for 45 d. Plasma triacylglycerol (TAG) concentrations decreased by 55 % following fat supplementation. Fat feeding also reduced glycogen concentrations significantly by up to 65 % in masseter, gluteus and semitendinosus muscles (P < 0.05 and P < 0.01 and P < 0.01 respectively). The high-fat diet significantly increased the TAG content of semitendinosus muscle by 80 % (P < 0.05). Hepatic acetyl-CoA carboxylase and fatty acid synthase activities were 53 % (P < 0.01) and 56 % (P < 0.01) lower respectively in the high-fat group, but diacylglycerol acyltransferase activity was unaffected. Although carnitine palmitoyltransferase-I (CPT-I) activity in liver mitochondria was not influenced, fat supplementation did render CPT-I less sensitive to inhibition by malonyl-CoA. There was no significant effect of diet on the activity of phosphofructokinase in the different muscles. The activity of citrate synthase was raised significantly (by 25 %; P < 0.05) in the masseter muscle of fat-fed ponies, as was CPT-I activity (by 46 %; P < 0.01). We conclude that fat feeding enhances both the transport of fatty acids through the mitochondrial inner membrane and the oxidative capacity of highly-aerobic muscles. The higher oxidative ability together with the depressed rate of de novo fatty acid synthesis in liver may contribute to the dietary fat-induced decrease in plasma TAG concentrations in equines.

Apparent fat digestibility in rats fed different diets is negatively correlated with faecal bile acid excretion

Seventy-two rats were fed one out of 9 diets differing as to protein source and calcium concentration. For the individual rats apparent fat digestibility and faecal bile acid excretion were negatively correlated. It is suggested that a high solubility of bile acids in the small intestinal digesta, which is associated with little loss of bile acids with faeces, stimulates the process of fat digestion.

[Supplemental fat in the diet of horses...is it advantageous?]

Feeding fat-supplemented diets to horses has drawn considerable interest. One of the advantages of such diets is that the energy density is increased, so that less feed is needed to meet energy requirements. In addition, adding fat to the diet enhances the contribution of fat oxidation to energy production, thus sparing muscle glycogen. The 'spared' glycogen is available for energy metabolism when the acutely exercising horse reaches a point of oxygen deficit and must rely on anaerobic metabolism. This appears to be beneficial for both aerobic and anaerobic performance. Fats are readily digested by the horse. Vegetable oils are more palatable to horses than animal fats, but the palatability of fat-rich diets may decrease in the long term.

Dietary lactulose decreases apparent nitrogen absorption and increases apparent calcium and magnesium absorption in healthy dogs

To study the effect of lactulose on the route of nitrogen excretion, we fed six healthy, adult dogs on diets containing either 0, 1 or 3 g lactulose/MJ metabolizable energy according to a 3 x 3 Latin square design. The results were analysed to identify statistically significant linear trend effects of lactulose. Faecal pH was significantly lowered by lactulose. Faecal ammonium and nitrogen excretion tended to be raised by lactulose feeding whereas urinary urea excretion was significantly reduced. Lactulose feeding significantly lowered apparent nitrogen digestibility. It is concluded that lactulose feeding shifts nitrogen excretion from urine to faeces in dogs which may be beneficial for liver patients. The data are in line with the concept that lactulose stimulates bacterial growth in the colon which in turn enhances faecal nitrogen excretion and lowers the entry of colonic ammonia into the bloodstream, leading to a lesser workload for the liver and less urinary nitrogen excretion. Lactulose consumption was also found to produce a dose-dependent increase in the apparent absorption of calcium and magnesium, but not phosphorus.

Blood sampling from the retro-orbital plexus, the saphenous vein and the tail vein in rats: comparative effects on selected behavioural and blood variables

We compared the behaviours of rats, and measured various blood parameters, after three blood sampling techniques: orbital puncture while they were under diethyl-ether anaesthesia, blood collection by tail vein puncture under O2-N2O-halothane anaesthesia and puncture of the saphenous vein without anaesthesia. Twelve rats were subjected to the three treatments according to a Latin square design. After each treatment, the behaviour of the rats was automatically monitored using the so-called LABORAS method, which discriminates between grooming, locomotion and inactivity in rats. Based on excitation scores and urine production, it was found that induction of diethyl-ether anaesthesia combined with orbital puncture caused more distress than did the other two blood sampling techniques. The three techniques had no differential effects on the behaviours of grooming, locomotion and inactivity. Collecting 0.5 ml of blood by orbital puncture was +/-7 times faster than doing so by saphenous vein puncture and +/- 15 times faster than collecting blood by tail vein puncture while the rats were under O2-N2O-halothane anaesthesia. The levels of some haematological and plasma variables differed significantly between the three blood collection techniques. These observations may help to select the most appropriate technique of blood sampling with respect to anticipated discomfort in the animals.

The IVOG feeding station: a tool for monitoring the individual feed intake of group-housed weanling pigs

Three batches of weanling pigs (total n=310 pigs) were used in a 34-day experiment to validate the use of an IVOG feeding station as a tool for monitoring individual feed intake of group-housed weanling pigs. An IVOG feeding station for weanling pigs consists of a single-space dry feeder placed on a load cell in combination with electronic identification. Data of 192 weanling pigs (18 pens) fed by IVOG feeding stations were used to develop a protocol for the screening of IVOG data. To assess the quality of the IVOG data, the feed intake per pen computed from the screened IVOG data was compared with the feed intake calculated from feed weighing. To assess the suitability of the use of IVOG feeding stations under practical pig husbandry conditions, performance of 96 weanling pigs fed by the IVOG feeding stations was compared with that of 118 weanling pigs that were fed using commercial single-space dry feeders (11 pens). Feed intake per pen computed from the IVOG data was similar to the feed intake calculated from feed weighing (average recovery 101.1%) for all test periods (p > 0.1). Furthermore, feed recovery did not differ among feeding stations (p > 0.1). During the first 13 days after weaning, the average daily feed intake (ADFI) of weanling pigs fed by the single-space dry feeders was higher (p < 0.05) than that of weanling pigs fed by the feeding stations. Average daily gain and gain to feed ratios did not differ (p > 0.1) between both feeding systems. During the remaining 21 days and averaged over the entire experimental period, performance did not differ between the feeding systems (p > 0.1). It can be concluded that IVOG feeding stations for weanling pigs are a suitable tool to monitor individual feed intake of group-housed weanling pigs.

Nutrition: Chemical analysis and consistency of faeces produced by captive monkeys (françois langurs,trachypithecus françoisi) fed supplemental fibre

The effect of additional dietary fibre on the consistency of faeces was studied in a group of four François langurs (Trachypithecus francoisi) kept in Rotterdam Zoo. To increase fibre intake, a diet pellet rich in fibre was offered instead of the usual, commercial primate pellet. This dietary change raised the amounts of hemicellulose and cellulose that were consumed at the expense of non-structural carbohydrates. The experiment had an A1-B-A2 design. Stool quality improved when the high-fibre pellet was fed. The monkeys produced somewhat more faecal dry matter and the faeces contained markedly more non-structural carbohydrates and less crude fibre when the high-fibre pellet was fed. The percentage of water in the faeces was slightly lower when the high-fibre diet was offered. We speculate that the extra fibre was partly fermented and that the breakdown products were recovered in the carbohydrate fraction of faeces. These breakdown products might have a superior water-binding capacity, leading to well-shaped faeces. This study showed that François langurs have the capacity to digest dietary fibre, as has been demonstrated earlier for other species of leaf-eating monkeys.

The lowering effect of high copper intake on selenium retention in weanling rats depends on the selenium concentration of the diet

The question addressed was whether the influence of dietary copper concentration on selenium metabolism depends on the amount of selenium in the diet. Weanling, male rats were fed purified diets containing either 1 (low), 4 (normal) or 42 (high) mg Cu/kg diet and either 0.03 (low), 0.05 (normal) or 1.0 (high) mg Se/kg diet in a 3(2) factorial design. Extra copper was added to the diets in the form of CuSO(4) x 5H(2)O and selenium as Na(2)SeO(3) x 5H(2)O. In rats fed either the low or normal amounts of selenium, higher intakes of copper decreased the apparent intestinal selenium absorption and increased urinary selenium excretion. The effects of copper on selenium absorption, excretion and retention were not seen in rats fed the high-selenium diets. An increase in dietary copper concentrations elevated selenium concentrations in the liver and kidneys, but slightly lowered those in the spleen of rats that were fed the diets with the normal level of selenium. In rats that were fed the diets with either low or high selenium concentration, copper intake had no effect on organ selenium concentrations. Glutathione peroxidase activity in erythrocytes was raised by feeding the diets which contained either normal or high copper content instead of those that were low in copper. It is concluded that the amount of selenium in the diet determines whether or not an increase in dietary copper concentration affects selenium metabolism.

Individually measured feed intake characteristics and growth performance of group-housed weanling pigs: effects of sex, initial body weight, and body weight distribution within groups

Feed intake characteristics of 192, 27-d-old weanling pigs housed in groups and given ad libitum access to feed and water were measured individually with the use of computerized feeding stations. The groups were either homogeneous or heterogeneous as to BW distribution; pigs of three defined initial BW classes were used (mean BW of 6.7, 7.9, or 9.3 kg). The effects of BW distribution, BW class, and sex were studied with regard to average performance traits, latency time (interval between weaning and first feed intake), initial feed intake (intake during the first 24 h following first feed intake), and daily increase in feed intake during the interval between first feed intake and the day on which energy intake met or exceeded 1.5 times the maintenance requirement. Homogeneous and heterogeneous groups had similar latency times, initial feed intakes, and daily increases in feed intake. For the period 0 to 34 d after weaning, ADFI and ADG were also similar for homogeneous and heterogeneous groups, but gain:feed ratio was greater (P < 0.05) in the homogeneous groups. Gilts had higher (P < 0.05) initial feed intakes than barrows and also had greater (P < 0.05) ADFI and ADG during the period 0 to 13 d after weaning. Pigs with average BW of 6.7 kg had higher (P < 0.05) initial feed intakes than their counterparts with average BW of 7.9 kg and 9.3 kg, but the daily increase in feed intake was similar for the three groups. The lighter pigs had more daily visits and a lower feed intake per visit and tended to have a shorter postweaning latency to the onset of feeding than the heavier pigs. This study indicates that the high variability in early feeding behavior among group-housed weanling pigs may be related to BW and sex.

Apparent digestibility of macronutrients in captive babirusa (Babyrousa babyrussa)

The apparent digestibilities of macronutrients by babirusa (Babyrousa babyrussa) were measured. Three group-housed captive babirusa were fed a diet of pelleted feed, boiled potatoes, grains, vegetables, and fruits. To determine reproducibility of the results, two digestibility trials were conducted 5 wk apart. The apparent digestibilities for crude protein, crude fat, and nonstructural carbohydrates (nitrogen-free extract) were 71, 76, and 78% of intake, respectively. Average apparent digestibilities of neutral detergent fiber and acid detergent fiber were 62 and 19% of intake, respectively. Hemicellulose (neutral detergent fiber minus acid detergent fiber) digestibility was 75%. Cellulose digestibility on average was 19% of intake, i.e., identical to acid detergent fiber digestibility because the diet did not contain a detectable amount of acid detergent lignin.

[Energy and protein supply for event horses during training: comparison between intake and requirements]

In horses that exercise intensively (for example, event horses in training) the intake and energy requirements were compared on the basis of a diet record and estimates of energy required for exercise. Daily net energy intake over a 7 days period was on average 30% (n = 15) higher than the net energy requirement. Since the horses had a constant body weight, and thus were in energy balance, the energy intake was overestimated and/or the energy requirement was underestimated. The intake of digestible protein was 92% higher than the protein requirement. This study illustrates the problems concerning ration assessment and evaluation in practice.

Time courses of plasma magnesium concentrations and urinary magnesium excretion in cows subjected to acute changes in potassium intake

Hypomagnesaemic tetany in cows develops occasionally after an acute increase in K intake such as can occur when cows are transferred to spring grass. There is evidence that under these conditions plasma Mg concentrations are only transiently decreased. In this study the questions addressed were whether the plasma Mg concentration, indeed adapts to a high K intake as only dietary variable, and whether urinary Mg excretion is associated with this adaptation. Dry cows were fed rations containing either 26 or 50 g K/kg dm, the extra K being in the form of KHCO3. When the cows were acutely transferred from the low to the high K ration, plasma Mg concentrations fell slightly, but significantly from 0.86 to 0.76 mmol/l within five days, but rose again to 0.80 mmol/l after another 23 days, this rise being also statistically significant. None of the animals developed tetany. The decrease in plasma Mg concentration in individual animals after five days on the high-K ration ranged from 6 to 21%. The time course of urinary Mg excretion resembled that of plasma Mg concentration; minimum Mg excretion was seen after four to six days on the high-K ration with a subsequent increase thereafter. To explain the transient lowering of plasma Mg concentration, it is suggested that the K-induced decrease in Mg status caused a delayed increase in the carrier-mediated component of Mg absorption, which in turn caused an increase in urinary Mg excretion. When the cows were acutely switched from the high to the low K ration, plasma Mg concentration and urinary Mg excretion rose, but no transient changes were seen.

The lowering effect of dietary glucose versus starch on fat digestibility in rats is dependent on the type of fat in the diet

The aim of the study was to determine whether the type of dietary fat influences the effect of dietary glucose on lipid digestibility. Earlier work had shown that glucose, when compared with starch, reduced fat digestibility in rats fed rations containing animal fat as fat source. Male rats (n = 6/group) were fed for two weeks on purified diets containing either 62% (w/w) starch or glucose and either 8% (w/w) palm oil, coconut fat, soybean oil or medium-chain triglycerides (MCT) as the main source of fat. The diets had no differential effect on growth. Glucose significantly depressed apparent lipid digestibility in rats fed the diets containing either palm oil or coconut fat, but not in rats given the diets containing either soybean oil or MCT. Thus, the inhibitory effect of glucose on lipid digestibility in rats is dependent on the dietary lipid source. This observation may contribute to understanding the mechanism by which dietary glucose inhibits fat digestion.

The hypercholesterolemic effect of cafestol in coffee oil in gerbils and rats

Coffee beans contain the diterpene cafestol, which raises plasma cholesterol concentrations in humans. Daily consumption of 2 g coffee oil, which provides approximately 60 mg cafestol (equivalent to 5.7 mg cafestol/MJ), increases plasma cholesterol concentrations by 28%. We studied the effect of cafestol in coffee oil on gerbils and rats to determine whether the pathways that lead to cafestol-induced hypercholesterolemia in humans are also present in other species. We fed coffee oil from the same batch used in humans to female gerbils and rats. Gerbils were fed a semipurified diet containing 0.5% or 5% (w/w) coffee oil (equivalent to 8.7 and 86.8 mg cafestol/MJ, respectively) in the presence or absence of 0.05% (w/w) cholesterol for a period of 10 weeks. When compared with the gerbils fed no coffee oil, the addition of 0.5% coffee oil to the diets did not affect plasma cholesterol. Plasma cholesterol was significantly higher only when 5% coffee oil was fed, both in the absence (1.01 mmol/L, 33% higher) and presence (1.87 mmol/L, 70% higher) of dietary cholesterol. Liver weight was also significantly higher when 5% coffee oil was fed. Rats were also fed diets containing 0.5% or 5% coffee oil (equivalent to 8.7 and 86.8 mg cafestol/MJ) with and without 0.05% cholesterol for 8 weeks. Feeding 0.5% coffee oil compared with no coffee oil resulted in significantly higher plasma cholesterol levels throughout the study both in the absence (0.46 mmol/L, 27% higher) and presence (0.28 mmol/L, 15% higher) of dietary cholesterol. Diets containing 5% coffee oil appeared to be toxic. Thus, coffee oil diterpenes can result in higher plasma cholesterol in gerbils and rats. The failure to observe these effects in previous studies may be due to doses that were too low.

Lipid metabolism in equines fed a fat-rich diet

The hypothesis tested was that dietary fat, when compared with an isoenergetic amount of non-structural carbohydrates, stimulates lipolysis in adipose tissue and also stimulates the fatty-acid oxidative capacity in skeletal muscle from horses. Six adult horses were fed a high-fat, glucose or starch containing diet according to a 3 x 3 Latin square design with feeding periods of three weeks. The diets were formulated so that the intake of soybean oil versus either glucose or corn starch were the only variables. In accordance with previous work, whole plasma triacylglycerol (TAG) concentration decreased significantly by 58% following fat supplementation. This fat effect was accompanied by a 247% increase in lipoprotein lipase (LPL) activity in post-heparin plasma. The dietary variables did neither significantly affect the basal in vitro lipolytic rate nor the lipolytic rate after adding noradrenaline. There was no significant diet effect on the activities of hexokinase and phosphofructokinase as indicators of glycolytic flux and citrate synthase and 3-hydroxy-acyl-CoA dehydrogenase as indicators of fatty-acid oxidative capacity. The concentrations of muscle glycogen and TAG were not affected by fat supplementation. It is concluded that our hypothesis is not supported by the present results.

Consumption of olive oil has opposite effects on plasma total cholesterol and sphingomyelin concentrations in rats

The hypothesis that olive-oil consumption alters plasma sphingomyelin concentrations and hepatic sphingomyelin metabolism was tested. Rats were fed on purified, high-cholesterol diets with either coconut fat or olive-oil (180 g/kg). In accordance with previous work, olive-oil v. coconut-fat consumption significantly elevated hepatic and total plasma cholesterol concentrations. During the course of the experiment, the concentration of plasma sphingomyelin rose in the coconut-fat group and remained constant in the olive-oil group. When compared with the coconut-fat-fed group, the plasma sphingomyelin levels were significantly lower in the olive-oil-fed group after 14 and 21 d of treatment. Dietary olive oil raised the amounts of cholesterol and sphingomyelin in the VLDL density region, and this change was associated with a reduction in the cholesterol and sphingomyelin contents of the LDL and HDL density ranges. Olive-oil consumption reduced the activity of serine palmitoyltransferase, while the activities of phosphatidylcholine:ceramide cholinephosphotransferase and phosphatidylethanolamine:ceramide ethanolaminephosphotransferase were left unchanged. Dietary olive oil also enhanced the activity of acidic sphingomyelinase, but not that of neutral sphingomyelinase. The present data indicate that dietary olive oil v. coconut fat has opposite effects on total plasma cholesterol and sphingomyelin concentrations. The lower plasma sphingomyelin levels observed in olive-oil-fed, as compared with coconut-fat-fed rats, may be explained by a simultaneous elevation and reduction in sphingomyelin catabolism and synthesis respectively, as based on the measured enzyme activities.

Indicators of erythrocyte formation and degradation in rats with either vitamin A or iron deficiency

Vitamin A deficiency produces anemia and altered iron status. In this study with rats we tested two hypotheses regarding vitamin A deficiency: (1) that it impairs erythropoiesis, leading to an increased red cell turnover, and (2) that it inhibits the glycosylation of transferrin. Erythropoietic activity was assessed indirectly by determining the myeloid:erythroid ratio in bone marrow smears, the number of erythroid colonies in the red pulp of spleen, the blood reticulocyte index, and zinc protoporphyrin and plasma transferrin receptor concentrations. Transferrin glycosylation was assessed by measuring the sialic acid content of transferrin. The effects of vitamin A deficiency were compared with those of iron deficiency. Iron deficiency produced anemia and low iron levels in organs. Vitamin A deficiency produced low levels of plasma and hepatic retinol, and it induced decreased plasma total iron-binding capacity and raised iron levels in tibia and spleen. Short- but not long-term iron deficiency reduced the number of erythroid colonies in spleen; vitamin A deficiency had no influence. Neither iron nor vitamin A deficiency influenced the myeloid:erythroid ratio in bone marrow smears and the blood reticulocyte production. Plasma transferrin receptor and erythrocyte zinc protoporphyrin concentrations were not affected by vitamin A deficiency but increased with iron deficiency. Vitamin A deficiency did not stimulate erythrocyte breakdown, as indicated by unaltered plasma lactate dehydrogenase activity and reduced plasma total bilirubin levels. Both vitamin A and iron deficiencies raised the proportion of multiple sialylated transferrins in plasma. Thus, we have not found evidence that vitamin A deficiency affects erythropoiesis and erythrocyte turnover. The iron accumulation in spleen and bone marrow may be related to reduced iron transport due to inhibition of transferrin synthesis rather than inhibition of transferrin sialylation.

Decreasing dietary fat saturation lowers HDL-cholesterol and increases hepatic HDL binding in hamsters

In order to study the mechanism by which increasing unsaturation of dietary fat lowers HDL-cholesterol levels, we studied various measures of HDL metabolism in hamsters fed with fats with different degrees of saturation. Hamsters were fed on a cholesterol-enriched (1 g/kg) semipurified diet containing 200 g/kg of maize oil, olive oil, or palm oil for 9 weeks. Increasing saturation of dietary fat resulted in increasing concentrations of total plasma cholesterol (4.29 (SD 0.51), 5.30 (SD 0.67) and 5.58 (SD 0.76) mmol/l respectively, n 12) and HDL-cholesterol (3.31 (SD 0.50), 3.91 (SD 0.12) and 3.97 (SD 0.43) mmol/l) and these concentrations were significantly higher (P < 0.05) in the palm-oil and olive-oil-fed hamsters compared with the maize-oil group. Total plasma triacylglycerol levels also increased with increasing fat saturation (1.01 (SD 0.59), 1.56 (SD 0.65) and 2.75 (SD 1.03) mmol/l) and were significantly higher (P < 0.05) in the palm-oil group compared with the olive-oil and maize-oil-fed hamsters. The three diets did not have differential effects on plasma activity levels of lecithin: cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP). Levels of phospholipid transfer protein (PLTP) tended to be higher with increasing fat saturation but this effect was not significant. The capacity of liver membranes to bind human HDL3 was significantly higher (P < 0.05) in the hamsters fed with maize oil (810 (SD 100) ng HDL3 protein/mg membrane protein, n 4) compared with those fed on palm oil (655 (SD 56) ng/mg), whereas the olive-oil group had intermediate values (674 (SD 26) ng/mg). The affinity of HDL3 for the binding sites was not affected by the type of dietary fat. Hepatic lipase (EC 3.1.1.3) activity, measured in liver homogenates, increased with increasing fat saturation. We conclude that dietary maize oil, when compared with either olive oil or palm-oil, may lower HDL-cholesterol concentrations by enhancing HDL binding to liver membranes.

Dietary polyunsaturated fatty acids and plasma butyrylcholinesterase activity in piglets

Diets containing different ratios of n-3:n-6 polyunsaturated fatty acids, were fed to piglets for a period of 10 days. Diets with n-3:n-6 ratios of 0.2 and 0.3 decreased the group mean activity of plasma butyrylcholinesterase when compared with a diet with a ratio of 0.1.

The effect of replacing nonstructural carbohydrates with soybean oil on the digestibility of fibre in trotting horses

The hypothesis tested was that the intake of extra fat at the expense of an isoenergetic amount of nonstructural carbohydrates reduces fibre utilisation in horses. In a crossover trial with feeding periods of 42 days each, 6 mature trotting horses (age 4-12 years, bodyweight 340-476 kg) were given either a control or test diet. The test concentrate was formulated to contain 37% of net energy in the form of soybean oil. The control concentrate contained an isoenergetic amount of corn starch plus glucose. The concentrates were fed in combination with the same amount of hay so that the control and test diet contained 25.13 and 86.66 g crude fat/kg dry matter, respectively. Apart from the amounts of fat and nonstructural carbohydrates, the 2 diets were identical. The test diet reduced the apparent total tract digestibilities of crude fibre, neutral and acid detergent fibre by 8.0 (P = 0.007), 6.2 (P = 0.022) and 8.3 (P = 0.0005) percentage units, respectively. It is suggested that a high fat intake by horses may increase the amount of fat entering the large intestine to levels that depress fermentation by cellulolytic bacteria. The observed interaction between fat content of the diet and fibre utilisation may have consequences for practical horse feeding in that calculating the energy content of test diets on the basis of feedstuff tables leads to overestimating the amount of energy provided by the high-fibre ingredients of the diets.

Orbital sinus blood sampling in rats: effects upon selected behavioural variables

The question addressed was whether the behaviour of rats is changed after orbital sinus blood sampling while they are under diethyl-ether anaesthesia. Twelve rats were subjected to sham anaesthesia, diethyl-ether anaesthesia and anaesthesia plus orbital puncture according to a Latin square. After each treatment, the behaviour of the rats was automatically monitored using the so-called LABORAS method, which discriminates between grooming, locomotion and inactivity. Treatment ended, and behaviour monitoring began, when the light period changed over to the dark period. The various behaviours were quantified as relative duration and frequency. Anaesthesia versus sham anaesthesia reduced the relative duration of grooming during the first 5 h after treatment. Anaesthesia plus orbital puncture versus anaesthesia alone did not significantly influence grooming, but orbital puncture did reduce the relative duration and the frequency of locomotion during the entire 20 h period, which was mainly due to a decrease in the dark period. After orbital puncture, the animals were also less frequently inactive. It is concluded that orbital puncture has an effect on behaviour superimposed on that of diethyl-ether anaesthesia. This observation may contribute new arguments to the debate on the acceptability of the orbital puncture technique.

Influence of excessive fluoride consumption on the severity of dystrophic cardiac calcification in DBA/2 mice

Soft tissue calcifications in inbred laboratory mice are frequently observed and are often associated with dystrophic cardiac calcinosis (DCC). We tested the hypothesis that an excessive intake of fluoride would inhibit pathological calcifications in DCC-susceptible mice. A diet containing either a high (200 mg F/kg added to the diet) or low fluoride content (no F added) was fed to both weanling and retired breeder DBA/2 mice. The high-fluoride diet reduced feed intake and body weight gain when given after weaning. It was found that a high fluoride intake effectively reduces soft tissue calcifications in young mice, but not in retired breeders. Because DCC in mice is a pathological finding that could interfere with certain experimental procedures, it is suggested that the optimum fluoride concentration in the diet for mice of susceptible strains should be established.

Consumption of casein instead of soybean protein produces a transient rise in the concentration of sphingomyelin in VLDL in rats

In rats fed cholesterol-rich diets, dietary casein vs. soybean protein raises VLDL cholesterol concentrations. Because sphingomyelin may be an essential, structural component of VLDL, we tested whether casein feeding would raise VLDL-sphingomyelin. Rats were fed cholesterol-rich semipurified diets containing either soybean protein (35 g/100 g) or casein for up to 21 d. Consistent with previous work, casein consumption increased hepatic and VLDL cholesterol concentrations. Dietary casein also significantly raised the amount of sphingomyelin in the VLDL fraction, but this effect was transient. Casein feeding transiently lowered LDL- and HDL-2-sphingomyelin concentrations. We suggest that an increase in hepatic VLDL secretion after casein consumption imposed an increased demand for sphingomyelin in the liver. The activity of key enzymes of sphingomyelin synthesis, i.e., serine palmitoyltransferase, phosphatidylcholine:ceramide phosphocholinetransferase and phosphatidylethanolamine:ceramide phosphoethanolaminetransferase and sphingomyelin degradation, i.e., acid sphingomyelinase, were enhanced and depressed, respectively, by casein consumption. Again these effects were transient. Thus, these data indicate that the extra sphingomyelin needed after short-term casein feeding came about through enhanced rates of biosynthesis and reduced rates of degradation in the liver. In addition, plasma transfer of sphingomyelin from HDL-2 to VLDL might have contributed to the increase in VLDL sphingomyelin in the casein-fed rats. This study shows that dietary casein vs. soybean protein transiently influences sphingomyelin metabolism in rats.

Quantification of inositol phosphates using (31)P nuclear magnetic resonance spectroscopy in animal nutrition

A (31)P NMR method for quantitative determination of inositol phosphates in simple incubation samples of sodium phytate and Aspergillus niger phytase and in different types of complex samples, such as diets, digesta, and feces, is described. The inositol phosphates in complex samples were extracted with HCl, concentrated, and purified using freeze-drying and filtration and subsequently determined at pH 12.6 in aqueous solution using a (31)P NMR method. The (31)P NMR technique has as its main advantages over the HPLC techniques that it does not necessitate standards that may cause background matrix effects and that the spectra of inositol phosphates and orthophosphate appear in the same run without further sampling errors. The results of inositol hexaphosphate analysis with HPLC can be confirmed by this (31)P NMR method. Contents of inositol tetra-, tri-, di-, and monophosphate in the biological samples appear to be quantitatively not important. The (31)P NMR method can be applied for use in animal nutrition in general and studies of using phytase in diets for farm animals in particular, by measuring the content of inositol phosphates in feed ingredients, complete feeds, ileal contents, and feces of pigs and poultry.

[The feeding of Dutch sled dogs in training]

To evaluate the diet of Dutch sled dogs, we investigated the dietary history of the dogs of 5 mushers. The animals were offered a commercial dry diet supplemented with a protein-rich product, a fat-rich product, and/or vitamins. At our request, the mushers prepared for 'their average dog' (a 20-kg Siberian husky) a daily ration of which the composition was calculated and chemically analysed. The calculated energy content of the rations was up to 50% higher than the requirement of the 'average dog' for maintenance. The composition of the rations was adequate from a nutritional viewpoint. However, the distribution of energy between macronutrients was not optimal in terms of the physiology of extreme endurance running: the rations had a relatively low fat content and a high content of carbohydrates.

Calcium balance in Drakensberg crag lizards (Pseudocordylus melanotus melanotus; Cordylidae)

Eight nonreproductive female Drakensberg crag lizards (Pseudocordylus melanotus melanotus) were each fed diets of mealworms and calcium capsules with various calcium levels. Excreta were collected and analyzed for calcium and uric acid content. The amount of calcium in the feces was calculated. The lizards appeared to be able to maintain calcium balance at calcium intakes equivalent to 1.4-5.6% calcium in the dry matter of feed. Calcium balance was maintained by adapting intestinal calcium absorption.

High calcium intake lowers apparent digestibility of energy in veal calves

Veal calves aged 8 weeks were fed iso-energetic amounts of milk replacers with either a low (7.1 g of calcium/kg of air-dry diet) or a high concentration of calcium (11.6 g of calcium/kg of air-dry diet) for a period of 10 weeks. The extra calcium was added in the form of calcium formiate. Final body weight of the two dietary groups was similar. Faeces were collected during the final week of the trial. The high calcium diet raised faecal dry matter output by 87% and faecal energy by 70%. The extra output of faecal dry matter was composed of 36% and 37% of crude fat and ash, respectively. The extra faecal energy output was for 75% in the form of crude fat. The high versus low calcium intake not only depressed apparent digestibility of total lipids but also that of crude protein, carbohydrates and ash. It is concluded that a high calcium intake by veal calves reduced energy availability without affecting body weight gain.

Dietary corn oil versus olive oil enhances HDL protein turnover and lowers HDL cholesterol levels in hamsters

We studied the effect of dietary olive and corn oil on high-density lipoprotein (HDL) metabolism in golden Syrian hamsters. The animals were fed a semipurified diet containing 0.1% cholesterol and 40 energy % in the form of either olive or corn oil for a period of nine weeks. Hamsters fed corn oil had significantly lower very-low density and low-density lipoprotein (VLDL+LDL) cholesterol concentrations than those fed olive oil (0.98+/-0.24 vs. 1.40+/-0.34 mmol/l, means+/-S.D., n = 12), as well as significantly lower HDL cholesterol concentrations (3.31+/-0.50 vs. 3.91+/-0.12 mmol/l). The binding capacity of 125I-labelled HDL to liver membranes was 33% higher in the hamsters fed corn oil instead of olive oil (571+/-29 vs. 429+/-24 ng HDL protein/mg membrane protein, P<0.05, n = 4). HDL protein kinetics were studied with 125I-HDL using a constant infusion technique. Both HDL fractional catabolic rate (0.255+/-0. 058 vs. 0.121+/-0.023 /h, P<0.01, n = 5) and transport rate (2.386+/-0. 753 vs. 1.218+/-0.101 mg/h, P<0.01, n = 5) were about 2-fold higher in the hamsters fed corn oil. The rate of plasma cholesterol esterification by lecithin: cholesterol acyltransferase (LCAT) was essentially the same for the two diets. It is concluded that the low HDL level in the hamsters fed corn oil diets is linked with increased HDL binding and degradation in the liver and possibly other tissues. Due to increased HDL protein turnover, the capacity for reverse cholesterol transport is increased in hamsters fed corn oil despite the relative low HDL concentrations

Dietary potassium bicarbonate and potassium citrate have a greater inhibitory effect than does potassium chloride on magnesium absorption in wethers

We addressed the question whether the type of anion in potassium salts affects magnesium absorption and the transmural potential difference by using wethers (n = 8) fed a control diet and diets supplemented with equimolar amounts of KHCO(3), KCl or K-citrate according to a Latin-square design. The control diet contained 10.9 g K/kg dry matter and the high K diets contained 41.3 g K/kg dry matter. Compared with the control diet, KHCO(3) and K-citrate significantly reduced apparent Mg absorption by 9.5 and 6.5%, respectively. Supplemental KCl tended to reduce (P = 0.070) group mean magnesium absorption by 5.5%. Consumption of supplemental KHCO(3) and K-citrate produced a significant increase in the transmural potential difference (serosal side = positive) by 17.1 and 20.7 mV, respectively, whereas the addition of KCl to the diet did not. The individual values for the four diets tended to show a negative correlation (r = -0.336, n = 32, P = 0.060) between the transmural potential difference and apparent magnesium absorption. We conclude that different potassium salts have different effects on magnesium absorption in ruminants as caused by different effects on the transmural potential difference.

[Enteral, nutritional support for critically ill patients]

Critically ill patients are characterized by acute changes in their metabolism, which are described by the term 'hypermetabolism'. In combination with anorexia, hypermetabolism leads to a negative energy and nitrogen balance. Consequently, wound healing can be inhibited, resistance is reduced, and (multiple) organ failure can occur. With the aid of nutritional support these consequences can be counteracted. During hypermetabolism protein breakdown is increased, and it is necessary to supply extra protein in the diet of critically ill patients. The amino acid glutamine is an important source of energy for enterocytes, and extra glutamine can improve the protective function of the intestinal mucosa. Branched amino acids serve as energy source during the acute phase. Arginine can reduce symptoms of encephalopathy by improving the conversion of ammonia to urea. Extra arginine in the diet also improves resistance. Because of the increased energy demand, diets for critically ill patients should be rich in fat. Moreover, extra n-3 fatty acids can improve immune function. A diet supplemented with extra zinc seems warranted because of its beneficial effect on wound healing and its inhibitory effect on protein breakdown. The enteral route is preferred because it protects the mucosal barrier of the gut, and it is less expensive and easier than the parenteral route. An enteral diet for critically ill patients is presented. Various factors that determine the choice of technique for enteral feeding are discussed.

Effects of intrinsic potassium in artificially dried grass and supplemental potassium bicarbonate on apparent magnesium absorption in dry cows

Literature data indicate that the form of K in the ration can affect its inhibitory influence on Mg absorption in ruminants. We tested whether identical amounts of K either intrinsically present in artificially dried grass or present in added KHCO3 have different effects on Mg absorption in dry cows. In a 3 x 3 Latin square design, six cows were fed rations consisting of low-K grass and concentrate with or without KHCO3 or a ration consisting of high-K grass with concentrate without added KHCO3. Each ration was given for a period of 4 wk. The ration low in intrinsic K contained 26 g of K/kg of dry matter, the ration low in intrinsic K plus KHCO3 contained 43 g of K/kg of dry matter, and the ration high in intrinsic K also contained 43 g of K/kg of dry matter. The three rations were balanced for crude protein, crude fat, crude fiber, Mg (2.2 g/kg of dry matter), Ca, P, and Na. Apparent Mg absorption was 10.8 +/- 1.54% of intake (mean +/- SE, n = 6) when the cows were fed the low-K ration, but dropped to 1.9 +/- 3.4 and 2.1 +/- 1.9% of intake, respectively, when the rations high in KHCO3 and high in intrinsic K were fed. The two high-K rations induced similar increases in ruminal K concentrations both before and after feed consumption. The feeding of KHCO3 did not influence ruminal pH. The intake of extra K may raise ruminal K concentrations, which increases the transmural potential difference so that Mg transport across the rumen epithelium becomes depressed. Thus, intrinsic and added K had identical effects on ruminal K concentrations and on Mg absorption. Feeding trials with ruminants in which K intakes are manipulated with the use of KHCO3 may reflect those cases when concentrations of K intrinsically present in feedstuffs may vary.

[Nutrition of horses: ration calculation and assessment]

In various situations it is desirable to evaluate the diet of horses. Such situations occur when nutrition is considered as the cause of disease or symptoms or and when a diet or diet change raises concern about whether the animal is receiving sufficient nutrients. Ration evaluation consists of translating feed ingredients into nutrients supplied and comparing this with nutrient requirements. The basics of ration evaluation are illustrated by means of four examples of horse diets.

[Nutrition of horses: digestion, energy and protein evaluation and nutritional standards]

The diet of horses should cover the energy and nutrient requirements of these animals. The desired composition of the ration depends on its digestion in the equine gastrointestinal tract. Nutritional problems or diseases caused by incorrect composition of the ration or by incorrect feeding should be prevented. The digestion of carbohydrates, fats, and proteins in the different parts of the gastrointestinal tract is described. In addition, the recently introduced net energy and digestible protein evaluation systems for feeds, and the energy and protein requirements of horses are presented.

Transient lowering of plasma vitamin B12 concentrations in Ouessant sheep fed on a potassium-rich ration

The hypothesis tested was that a high intake of potassium (K) interferes with cobalt (Co)-vitamin B12 metabolism in ruminants. Ouessant sheep were fed either a low- (8 g K/kg dry matter) or high-K diet (43 g K/kg dry matter) with an adequate amount of Co (124 micrograms Co/kg dry matter). Plasma vitamin B12 concentrations were measured. Sheep fed a low-K diet, but containing only 70 micrograms Co/kg dry matter, served as positive controls. Feeding the low-Co ration produced a significant decrease in plasma vitamin B12 concentrations. The high- versus low-K ration induced a significant decrease in plasma vitamin B12 during the first 6 weeks, but thereafter the values in the high-K group rose to those seen in the low-K group. The mechanism by which dietary K may interact with Co-vitamin B12 metabolism in sheep is unknown.