Influence of dietary linseed, fish and coconut oil on growth performance of growing pigs kept on small holdings in central Vietnam

The aim of the study was to investigate the effect on growth performance of the addition of 5% of either linseed, fish or coconut oil to the diet of growing pigs kept on small holdings in central Vietnam. The diets were fed on six different farms; there were three animals per treatment per farm. The farmers fed a base diet according to personal choice, but were instructed to use linseed, fish and coconut oil. The diets were fed to the pigs from 70 to 130 days of age. The diets with 5% linseed oil on average contained 2.4 g alpha-linolenic acid/MJ of metabolizable energy (ME) and the diets with 5% fish oil on average contained 0.06 and 0.75 g eicosapentaenoic and docosahexaenoic acid/MJ ME, respectively. The relative percentages of docosahexaenoic, eicosapentaenoic, alpha-linolenic and linoleic acid in adipose tissue were determined by the intake of the corresponding fatty acids. Dietary linseed oil vs. coconut oil significantly enhanced daily weight gain and vs. fish oil it also stimulated growth, but this effect just failed to reach statistical significance. It is concluded that extra intake of alpha-linolenic acid may stimulate growth in growing-finishing pigs, this effect being independent of the conversion of alpha-linolenic acid into eicosapentaenoic and docosahexaenoic acid.

Unrestricted Feed Intake During the Dry Period Impairs the Postpartum Oxidation and Synthesis of Fatty Acids in the Liver of Dairy Cows

The purpose of this study was to determine the activities of key hepatic enzymes of fatty acid synthesis and oxidation in cows that had excessive body fat at parturition. Dairy cows were allocated to either an experimental group or a control group. All cows were offered a total mixed ration with an energy content of 6.6 MJ of net energy for lactation per kilogram of dry matter and consisting of corn silage, beet pulp, rapeseed meal, and soybean meal. Control cows were restricted to 6.8 kg/dry matter of the mixed ration in the dry period. Experimental cows had unrestricted access to the mixed ration during the dry period to increase body fat and induce fatty liver postpartum. Blood and liver samples were collected 1 wk before and 1, 2, and 4 wk after parturition. Before parturition, neither the serum nonesterifled fatty acids nor the hepatic triacylglycerol concentrations differed between experimental and control cows. After parturition, the values for these variables were greater in experimental cows than in control cows. Plasma 3-hydroxybutyrate increased sharply after parturition in the experimental group. In liver, the activity of acetyl-CoA carboxylase was already significantly lower in the experimental group before parturition. After parturition, the activities of acetyl-CoA carboxylase and fatty acid synthase dropped in the experimental group. The activity of 3-hydroxy-acyl-CoA dehydrogenase in liver was less in experimental cows following parturition. Hepatic citrate synthase activity increased only in the control group after parturition. Unrestricted feed intake before parturition reduces de novo fatty acid synthesis as well as fatty acid oxidation after parturition. The reduction in fatty acid oxidation following parturition may contribute to postpartum accumulation of triacylglycerol in the livers of cows with unrestricted access to feed during the dry period.

Fat Digestion in Veal Calves Fed Milk Replacers Low or High in Calcium and Containing Either Casein or Soy Protein Isolate

The hypothesis tested was that the inhibitory effect of dietary soy protein versus casein on fat digestion in veal calves would be smaller when diets were fed with high instead of low calcium content. Male calves, 1 wk of age, were fed 1 of 4 experimental milk replacers in a 2 x 2 factorial design. There were 19 animals per dietary group. The milk replacers contained either casein or soy protein isolate as variable protein source and were either low or high in calcium. Body weight gain was not significantly affected by the experimental diets. Soy protein isolate versus casein significantly reduced apparent fat digestibility. High versus low calcium intake also depressed fat digestion. The protein effect was smaller (2.9% units) for the high than the low calcium diets (3.6% units), but the interaction did not reach statistical significance. Soy protein isolate versus casein raised fecal bile acid excretion and so did high versus low calcium intake. The difference in bile acid excretion between the soy and casein containing diets was significantly greater for the high than low calcium diets. The absorption of phosphorus, calcium, and magnesium was higher for the casein diets than for the soy-containing diets. This study shows for the first time that soy protein isolate versus casein depressed fat digestion and raised fecal bile acid excretion in veal calves.

Apparent Magnesium Absorption in Dry Cows Fed at 3 Levels of Potassium and 2 Levels of Magnesium Intake

In vitro experiments with isolated rumen epithelium have shown that the relationship between the ruminal K concentration and either the apical membrane potential difference or the mucosal-to-serosal Mg flux reach plateau values at high ruminal K concentrations. Hence, it may be hypothesized that the inhibitory effect of supplemental K on Mg absorption becomes smaller at high initial K intakes. To test our hypothesis, 6 ruminally fistulated, nonpregnant dry cows were fed 6 experimental diets in a 6 x 6 Latin square design with a 2 x 3 factorial arrangement of treatments. Four cows were of a Friesian-Holstein x Holstein-Friesian cross, and the 2 remaining cows were of a Meuse-Rhine-IJssel x Holstein-Friesian cross. The diets provided either 40.6 or 69.1 g of Mg per day and contained 20.7, 48.0, or 75.5 g of K per kilogram of dry matter. The dietary variables were obtained by mixing KHCO(3) and MgO into the basal concentrate. Absorption of Mg and the urinary Mg excretion was significantly decreased by supplemental K and significantly increased after the intake of supplemental Mg. In contrast to apparent Mg absorption, the urinary excretion of Mg was not affected by the dietary K x Mg interaction. Postfeeding ruminal K and Mg concentrations were increased with increasing K and Mg intakes. Postfeeding ruminal K concentrations and the urinary excretion of Mg showed a linear negative correlation; the slope was not significantly affected by Mg intake. Therefore, our hypothesis was rejected. Furthermore, these data indicate that supplemental Mg can effectively counteract the suppressant effect of K on Mg absorption in cows.

Effect of a Dietary n-6 Polyunsaturated Fatty Acid Supplement on Distinct Immune Functions of Goats

The aim of this study was to investigate whether dietary n-6 polyunsaturated fatty acids (PUFA) alter immune functions as lymphocyte blastogenesis, expression of lymphocyte and monocyte markers, and cell adhesion molecules of the integrin family in goats. Dutch White castrated male goats received a diet either rich in olive oil (control group, n = 4) or rich in corn oil (test group, n = 4) over a period of 3 weeks. The animals in the test group had significantly higher linoleic acid (LA, 18:2n-6) levels in plasma on days 7, 14 and 21 of the diet than control animals. This was also true for washed erythrocyte membranes at day 21. A significant reduction in the percentage of alpha-4 integrin (CD49d) expressing lymphocytes was observed in goats fed LA rich corn oil at day 21. However, no changes were observed in either lymphocyte proliferative responses to ConA and PHA or the expression of other lymphocyte/monocyte markers. In conclusion, feeding corn oil rich in LA caused significant increases in the proportion of LA in the fatty acid composition of plasma and erythrocyte membranes and was accompanied by a significant decrease of the adhesion molecule alpha-4 integrin (CD49d) on lymphocytes but not on monocytes.

Relationship between the amount of linoleic acid in the diet and that in the adipose tissue of adult cats living freely in households

The present study was carried out to ascertain whether linoleic acid intake and the content of this fatty acid in adipose tissue are correlated in cats. The linoleic acid intake, as estimated from a food intake questionnaire, was indeed correlated with the linoleic acid content of the abdominal body fat in 165 adult, female cats. A statistically significant linear correlation coefficient of 0.43 was found between the percentage of linoleic acid in the adipose tissue and that in the diet. It is plausible that the observed acid content of adipose tissue of free-living cats may be considered to be a valid biomarker of linoleic acid intake that might be used in studies on diet and chronic disease.

[Health claims in dog and cat feed]

The number and diversity of health claims for dog and cat foods have increased markedly over the past few years. There is no explicit legislation as to these claims. Many claims are insufficiently supported by research and are vague and suggestive. In order to inform pet owners and veterinarians properly and to enhance honest competition among pet food producers, rules for the application of claims should be developed. For the time being, the veterinarian will have to take a stand by critical assessment.

Dietary conjugated linoleic acids as free fatty acids and triacylglycerols similarly affect body composition and energy balance in mice

The objective of this study was to compare the effects of conjugated linoleic acid (CLA) as triacylglycerols (TAG) or free fatty acids (FFA) on body composition and energy balance in mice. We fed four groups of 5-wk-old Balb-C mice (n = 9) semipurified diets containing either CLA (0.5 g CLA/100 g of diet) or high oleic sunflower oil (HOSF) in the form of FFA or TAG for 42 d. Body composition was determined and the energy in the carcasses, excreta and food was measured in a bomb calorimeter. The amount of body fat was 4.72 +/- 0.95 g (17.9 +/- 2.8%) in the HOSF-FFA group, 2.36 +/- 0.29 g (9.4 +/- 1.0%) in the CLA-FFA mice (mean +/- SD, P < 0.05), 4.76 +/- 0.74 g (18.2 +/- 2.2%) in the HOSF-TAG group and 2.32 +/- 0.38 g (9.3 +/- 1.1%) in the CLA-TAG mice (P < 0.05). The percentage of energy intake that was stored in the body was 3.5 +/- 1.2% in the HOSF-FFA group, 0.6 +/- 0.3% in the CLA-FFA group (P < 0.05), 3.5 +/- 1.1% in the HOSF-TAG group and 0.5 +/- 0.4 in the CLA-TAG mice (P < 0.05). Conversely, the percentage of energy intake that was expended as heat was 89.4 +/- 1.2% in the HOSF-FFA group, 92.4 +/- 0.8% in the CLA-FFA mice (P < 0.05), 89.47 +/- 1.23% in the HOSF-TAG group and 92.2 +/- 0.4% in the CLA-TAG group (P < 0.05). Thus, CLA in the form of FFA or TAG had similar effects on body composition and energy balance.

The influence of dietary fish oil vs. sunflower oil on the fatty acid composition of plasma cholesteryl-esters in healthy, adult cats

The question addressed was whether the fatty acid composition of plasma cholesteryl esters (CEs) in cats reflects the intake of fatty acids. Diets containing either fish oil or sunflower oil were fed to six healthy, adult cats in a cross-over trial. The dry cat foods contained approximately 18.5% crude fat, of which two-third was in the form of the variable oil. Blood samples were collected at the end of each 4-week feeding period, and the fatty acid composition of plasma CEs and plasma concentrations of lipoproteins were determined. Consumption of the diet with fish oil was associated with significantly greater proportions of eicosapentaenoic acid, arachidonic acid, alpha-linolenic acid, oleic acid, palmitic acid and myristic acid in plasma CEs. The intake of fish oil instead of sunflower oil reduced the percentage of linoleic acid in CEs. The plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, phospholipids and triglycerides were not affected by fish oil vs. sunflower oil feeding.

[Assessment of commercial feeds for parrots]

Twenty-five commercial parrot feeds were analyzed and compared with a guideline as to the nutrient requirements of parrots. There was a large variation in the composition of the different feeds. The protein content differed from 10.4 to 20.6%. A total of 18 feeds had a low protein content and thus is only suitable for adult animals during maintenance. The calcium content varied from 0.08 to 2.21 g/100 g. Seven out of the 13 seed mixtures had a calcium content lower than the requirement. Calcium deficiency can lead to rachitis, osteomalacia, secondary nutritional hyperparathyroidism and hypocalcaemia syndrome in African Grey parrots. With the help of the analyzed composition, the different feeds were judged on their quality. Apart from macronutrients, minerals and trace elements, the fatty acid composition of the feeds was also determined. Atherosclerosis is a common disease in parrots, and an important risk factor is elevated plasma cholesterol. Plasma cholesterol is strongly influenced by fat content and fatty acid composition of the diet. Based on the fatty acid composition, the effect of a diet on plasma cholesterol can be predicted. All feeds had a similar, small effect on plasma cholesterol. However, the feeds differed strongly in their alpha-linolenic acid content (0.03-0.65 g/MJ). According to literature data alpha-linolenic acid could have an anti-atherosclerotic effects.

[Evaluation of a number of commercial diets for iguana (Iguana iguana), bearded dragons (Pogona vitticeps), and land and marsh tortoises]

Fifteen commercially available, complete diets for iguanas, bearded dragons, and chelonians were analysed and compared with the ideal composition of a diet formulated by the authors. The clinical risks of feeding with a too high or a too low content of specific nutrients are described. Nutrient deficiencies are not expected if these diets are the sole source of nutrients. However, one diet had only a marginally adequate protein content, five diets for herbivorous reptiles contained a too low percentage of crude fibre, three diets contained an undesirably high percentage of calcium, and three diets had an extremely high iron content. As a rule, the calcium and iron contents of diets are not declared on the food label, which complicates evaluation of the diets.

Magnesium balance in adult cats fed a dry food rich in lactose

The question addressed was whether lactose consumption would stimulate apparent magnesium absorption in adult cats. In a cross-over study, eight cats were fed dry diets without or with 10% lactose, which was added at the expense of the glucose component. Urine and faeces were quantitatively collected and the balance of magnesium, calcium and phosphorus was determined. Lactose feeding did not affect mineral absorption. The dry matter content of faeces was unchanged after lactose consumption. Urinary excretion of galactose represented 0.2% of the intake. It is concluded that lactose ingestion at a level of 1.2 g/kg body weight has no effect on mineral absorption and on the consistency of faeces in adult cats.

Severity of Atherosclerosis in Parrots in Relation to the Intake of α-Linolenic Acid

Atherosclerosis is a common disease among parrots, but little is known about possible risk factors. Important risk factors in humans are an elevated plasma cholesterol concentration and increased platelet aggregation; high intakes of polyunsaturated fatty acids have beneficial effects. In this study, we tried to establish a relationship, if any, between dietary fatty acids and the severity of atherosclerosis in parrots. We collected dead parrots and scored the degree of atherosclerosis in the beginning of the aorta and the brachiocephalic arteries. It was not possible to assess the intake of fatty acids with food questionnaires so fatty acid composition of adipose tissue and breast muscle had to be used as an index of the dietary fatty acid composition. In all, 202 birds were collected. Gender was not related with atherosclerosis, but the degree of atherosclerosis increased with age and among the various species; African grey parrots appeared to be the most susceptible. The contents of linoleic acid in breast muscle or adipose tissue were not associated with the severity of atherosclerosis. For the relative percentage of alpha-linolenic acid in either breast muscle (P = 0.09; n = 175) or adipose tissue (P = 0.056; n = 21), a borderline significant relation with the degree of atherosclerosis was found. Parrots without atherosclerosis had significantly higher levels of alpha-linolenic acid than did the other animals. On the basis of these data, we suggest tentatively that a high dietary intake of alpha-linolenic acid protects against the development of atherosclerosis in parrots.

Effects of dietary essential oil components on growth performance, digestive enzymes and lipid metabolism in female broiler chickens

1. The present experiment was conducted to describe the effects of thymol, cinnamaldehyde and a commercial preparation of essential oil components (CRINA Poultry), in female broilers. Feed and water were provided for ad libitum consumption. 2. Feed intake, weight gain and feed:gain ratio were not different among the treatments. Water intake was significantly lowered by cinnamaldehyde. Relative liver weight (g/100 g of body weight) was highest in birds given thymol, but this was seen only at the age of 21 d and not at 40 d. Patterns of digestive enzymes in pancreatic tissue were similar for the 4 treatments. 3. Amylase activity in intestinal digesta was highest in chickens given CRINA Poultry for 21 d, but the effect had disappeared after 40 d. Ileal digestibility coefficients for starch and protein were high and identical for all treatments. 4. Fatty acid composition of diet was reflected in that of adipose tissue. Plasma lipid concentrations were not changed by any dietary treatment. 5. Thus, the present results show no effect of essential oil constituents on growth performance in female broiler chickens, but it cannot be excluded that positive effects would have been observed under less hygienic environmental conditions or when using a less digestible diet.

Influence of dietary beetpulp on the plasma level of triacylglycerols in horses

In a cross-over study with six adult horses, the effect of isoenergetic replacement of dietary glucose by beetpulp on the concentration of plasma triacylglycerols was studied. The test ration contained 25% beetpulp in the dietary dry matter. The feeding of beet pulp lowered plasma triacylglycerol concentrations (p = 0.058) in the fasting state and raised the activity of heparin-released lipoprotein lipase (LPL) (p = 0.059) and the concentration of HDL2 cholesterol (p = 0.058). In the fasting state, the plasma concentrations of free fatty acids (p = 0.073) and those of beta-hydroxybutyrate (p = 0.043) were increased after feeding beetpulp. At 3 h after feed intake, consumption of beetpulp instead of glucose had produced higher plasma concentrations of both glucose (p = 0.014) and insulin (p = 0.040). It is suggested that beetpulp ingestion activates LPL followed by a drop in plasma triacylglycerols.

Assessment of the minimum protein requirement of adult ponies

The aim of the present study was to determine the minimum protein requirement in adult ponies. Literature data from nitrogen-balance trials in adult ponies were used. In addition, nitrogen balance was measured in three mature ponies that were fed a low- and a high-protein diet according to a cross-over design. On the low-protein ration, which provided 1.1 g digestible crude protein (DCP)/kg(0.75) day, plasma albumin and total protein concentrations were non-significantly decreased by about 6% and group-mean nitrogen balance was negative. Using data from the present experiment and from six other studies, the sum of endogenous faecal and urinary nitrogen losses was calculated to be 166 +/- 37 mg/kg(0.75) day (mean +/- SE, n = 13). Subsequently, a minimum protein requirement of 1.7 g DCP/kg(0.75) day was calculated. The value for minimum protein requirement has low precision, which should be taken into account when setting the protein allowance of adult ponies.

Production and clearance of plasma triacylglycerols in ponies fed diets containing either medium-chain triacylglycerols or soya bean oil

The hypothesis was tested that feeding ponies a diet containing medium-chain triacylglcyerols (MCT) instead of soya bean oil causes an increase in the production of plasma triacylglycerols, which, under steady-state conditions, is associated with an increased clearance of triacylglycerols. Six ponies were fed rations containing either MCT or an isoenergetic amount of soya bean oil according to a cross-over design. The concentration of MCT in the total dietary dry matter was about 13%. When the ponies were fed the diets for 3 weeks, plasma triacylglycerol concentrations were 0.42 +/- 0.09 and 0.17 +/- 0.03 mmol/l (mean +/- SE, n = 6; p < 0.05) for the MCT and soya bean-oil treatment, respectively. Plasma triacylglycerol production was assessed using the Triton method and clearance with the use of Intralipid(R) infusion. Plasma triacylglycerol production was 2.91 +/- 0.88 and 0.50 +/- 0.14 micromol/l.min (means +/- SE, n = 4; p < 0.05) for the diets containing MCT and soya bean oil, respectively. It is suggested that the calculated rates of triacylglycerol production are underestimated, the deviation being greatest when the ponies were fed the ration of soya bean oil. Triacylglycerol clearance rates were calculated on the basis of group mean values for both the fractional clearance rate and the baseline levels of plasma triacylglycerols; the values were 4.28 and 3.52 micromol/l.min for MCT and soya bean oil feeding, respectively. The mean, absolute clearance rates as based on those found in individual ponies did not show an increase when the diet with MCT was fed. Nevertheless, it is concluded that the data obtained support our hypothesis.

Cholate feeding counteracts calcium-induced depression of apparent fat digestibility in rats

This study tested the hypothesis that cholate feeding would counteract the earlier described calcium-induced inhibition of fat digestion. Rats were fed semipurified diets; either low (0.25%, w/w) or high (1.0%) in calcium, the latter diets being without or with 0.5% added sodium cholate. Apparent fat digestibility was 95.6% of intake in the rats fed the low-calcium diet. Calcium feeding significantly lowered apparent fat digestibility to 82.6%, but in the presence of cholate it was 91.2%. It is concluded that the inhibitory effect of calcium on fat digestion is mediated by diminishing the availability of bile acids.

Ascorbic acid content of blood plasma, erythrocytes, leukocytes and liver in camels (Camelus dromedarius) without or with parasite infections

Healthy camels (Camelus dromedaris) and those naturally infected with trypanosomiasis, sarcoptic mange, and helminthiasis were compared as to ascorbic acid (vitamin C) contents of red blood cells, white blood cells, whole blood, plasma, and liver. The camels were kept under natural grazing conditions in Sudan. Reduced levels of vitamin C were found in camels with parasite infections, especially in animals with trypanosomiasis. It is suggested that the low vitamin C status in infected camels is caused by increased utilization and/or decreased synthesis of vitamin C.

Position of the abomasum in dairy cows during the first six weeks after calving

The position of the abomasum in six cows was examined by ultrasonography at regular intervals for six weeks after they had calved. Its position was established by determining the distance between the margin of the left side of the abomasum and the ventral midline at two sites. During the last weeks of pregnancy, the abomasum was positioned in a small region of the left ventral side of the abdominal cavity. At parturition it was positioned high on the left side and then descended. The abomasum was furthest from the midline immediately after parturition. Its position was related to the interval after calving, the cow's feed intake, and the pH and osmotic pressure of the rumen fluid. There was considerable variation between the cows in the position of the abomasum, which was in part due to analytical variation, and in individual cows it had a circadian rhythm.

Faecal bacterial profile, nitrogen excretion and mineral absorption in healthy dogs fed supplemental oligofructose

In a cross-over trial, five healthy dogs were fed a dry food without or with 1% (w/w) oligofructose to assess any oligofructose-induced effects on the faecal bacterial profile, nitrogen excretion and mineral absorption. The diets were given for a period of 3 weeks. Oligofructose feeding significantly raised the number of Bifidobacteria, Streptococci and Clostridia in faeces. The numbers of faecal anaerobic and aerobic bacteria were raised after ingestion of oligofructose. The faecal pH was unchanged. There was no effect of oligofructose feeding on the route of nitrogen excretion which was associated with a lack of effect on faecal ammonium and urinary urea excretion. It is suggested that the absence or presence of an effect of oligofructose on urinary and faecal nitrogen excretion depends on the background composition of the diet, in particular the content of non-digestible, fermentable carbohydrates. In the diets used, the content of non-digestible, fermentable carbohydrates was not measured. Both apparent magnesium and calcium absorption were significantly raised by oligofructose feeding, but phosphorus absorption was unaffected. The data presented may contribute to the qualification of the use of oligofructose in dog foods.

Influence of phosphorus intake on excretion and blood plasma and saliva concentrations of phosphorus in dairy cows

Phosphorus (P) balance, and blood plasma P and saliva P concentrations were measured in multiparous dairy cows through two lactations and two dry periods. The cows were fed three amounts of P at either 100, 80 or 67% of the Dutch P recommendation, actually resulting in dietary P concentrations of 3.2 to 3.9, 2.6 to 2.9 and 2.2 to 2.6 g P/kg dry matter during lactation for the three treatments, respectively. On the basis of plasma P values as low as 0.9 mmol/l and saliva P values as low as 5.1 mmol/l during the second lactation period within the experiment, the 67% group was considered to be deficient in P. By decreasing milk production, and thus lowering P losses with milk, P retention in the 67% group remained near zero. The P supply with the 80% ration was considered to be just sufficient. At high milk yield and marginal dietary P concentrations, plasma P and saliva P concentrations were decreased. The higher P intake in high-compared with low-producing cows resulted in a constant absolute fecal P excretion, due to the fact that the apparent P digestibility was raised with increasing milk yield. There was a direct relationship between milk P output and the percentage of apparent P digestibility for individual animals.

Plasma lipid concentrations, macronutrient digestibility and mineral absorption in dogs fed a dry food containing medium-chain triglycerides

In a cross-over trial with feeding periods of 2 weeks, six healthy dogs were fed a dry food with a total fat content of 13.4% and containing either 5% (w/w) corn oil (11% of dietary metabolizable energy) or an isoenergetic amount of medium-chain triglycerides (MCT). The two diets were supplied on a restricted basis. There were no food refusals and no diet difference in palatability was observed. The MCT vs. Corn oil did not significantly influence plasma lipid concentrations, but group mean triacylglycerol concentrations were increased by 23% (p=0.074). The MCT consumption did not affect the apparent digestibilities of crude protein and soluble carbohydrates and had no impact on the absorption of calcium, magnesium and phosphorus. The incorporation of MCT into the diet produced a slight increase (by 0.9 percentage units) in crude fat digestibility (p=0.061). It is concluded that MCT at the present inclusion level may not have disadvantageous effects.

Vitamin C concentrations in blood plasma, tissues and urine of camels (Camelus dromedarius) in Sudanese herds

There is suggestive evidence that a low status of ascorbic acid in ruminants is related with decreased disease resistance. In a first attempt to identify conditions in camels that could affect their health, an inventory was made of ascorbic acid (vitamin C) concentrations in plasma and tissues as related to breed, gender, sexual activity and season. A total of 3429 camels were studied and sub-samples were used for selected comparisons. The highest concentrations of ascorbic acid were found in adrenals (152 mg/100 g wet tissue) and the lowest in heart (8 mg/100 g), the levels being unrelated with season. Arabi camels had higher plasma concentrations of ascorbic acid (6.42 microg/ml) than did Anafi and Bishari camels, the latter breed showing the lowest concentrations (3.24 microg/ml). Female camels of the Anafi breed had higher concentrations urinary ascorbic acid than did their male counterparts. It is suggested that in camels the main elimination route of vitamin C is with urine. Female and male Arabi camels that were sexually active had 52 and 23% lower plasma ascorbic acid concentrations than did their sexually inactive counterparts. It is suggested that especially Bishari camels during the breeding season might be sensitive to disease.

The concentration of plasma triacylglycerols in horses fed diets containing either medium chain triacylglycerols or an isoenergetic amount of starch or cellulose

In a Latin square design, six horses were fed hay and concentrates with isoenergetic amounts of either starch, cellulose or medium chain triacylglycerols (MCT). The dietary variables provided on average 22% of total dietary net energy. Plasma triacylglycerols and other variables of lipid metabolism were determined. The experimental periods lasted 21 days. Blood samples were taken just before the morning meal and three and six hours later. The diet rich in MCT significantly raised the plasma level of triacylglycerols when compared to either the starch- or cellulose-rich diet. The plasma concentrations of 3-hydroxybutyrate, total cholesterol and phospholipids were significantly higher when the horses were fed the ration with MCT instead of either cellulose or starch. Postprandial insulin concentrations were lowest for the MCT diet, and concentrations of free fatty acids were highest. Lipoprotein lipase activity was not significantly different for the three diets. Our study does not support the idea that cellulose feeding generates sufficient acetic acid in the caecum and colon, so that it would enhance the provision of cytosolic acetyl-CoA which in turn would stimulate hepatic fatty acid synthesis and then raise plasma triacylglycerols.

Exercise- and metabolism-associated blood variables in Standardbreds fed either a low- or a high-fat diet

Feeding a high-fat diet increases fat utilisation and may decrease glycogen utilisation resulting in a lower lactate production during moderate exercise. The effects of fat feeding on exercise- and lipid metabolism-associated blood variables were evaluated in 6 Standardbred horses during submaximal exercise. The horses were fed a high- (11.8% fat in total dietary dry matter) or a low-fat diet (1.5% fat) in a cross-over experiment with feeding periods of 4 weeks. At the end of each feeding period, the horses were subjected to a submaximal standardised stepwise exercise test on a treadmill. Blood samples were obtained prior to the start, during the last 10 s of each exercise step, and after recovery (40 min walking in hand). Pre-exercise test values for plasma lactate, pH, pCO2, ionised sodium, ionised potassium, ionised calcium, ionised chloride, glucose, nonesterified fatty acids and glycerol did not differ for the 2 diets. The pre-exercise concentration of triacylglycerols was significantly lower on the high- compared to the low-fat diet (mean +/- s.d. 0.17 +/- 0.06 and 0.23 +/- 0.08 mmol/l, respectively), whereas the concentrations of cholesterol (3.00 +/- 0.47 and 2.11 +/- 0.49 mmol/l, respectively), HDL cholesterol (1.80 +/- 0.18 and 1.35 +/- 0.27 mmol/l, respectively) and phospholipids (2.30 +/- 0.11 and 1.72 +/- 0.20 mmol/l, respectively) were significantly higher. There was significantly less plasma lactate accumulation during exercise when the horses were given the high-fat diet (P = 0.011). Horses on a low-fat diet had significantly different plasma lipid values when compared to being on a high-fat diet. The alterations in these values during and after moderate exercise were comparable for both diets. These results indicate that fat metabolism is significantly adapted on a high-fat diet; feeding such a diet may enhance potential performance by delaying lactate accumulation and thereby delaying the onset of fatigue.

Excessive hepatic copper accumulation in jaundiced rats fed a high-copper diet

The response of copper metabolism to dietary copper challenge was investigated in jaundiced rats with elevated plasma concentrations of conjugated bilirubin as a result of impaired canicular transport of bilirubin glucuronides. Control and jaundiced rats were fed purified diets with either normal (64 micromol Cu/kg) or high (640 micromol Cu/kg) concentration of added copper. Copper loading produced a greater increase in hepatic copper concentrations in the jaundiced than in control rats. The greater dietary-copper-induced increase in hepatic copper in the jaundiced rats can be explained by the observed smaller rise in biliary copper excretion and a greater efficiency of dietary copper absorption. In individual rats, there was a positive relationship between hepatic copper concentrations and biliary copper concentrations. It is suggested that not the transport of copper from liver cells to bile but that from plasma to bile is diminished in the jaundiced rats. The elevated plasma copper concentrations in the jaundiced rats may support this suggestion.

The apparent digestibility of fibre in trotters when dietary soybean oil is substituted for an iso-energetic amount of glucose

An attempt was made to quantify the effect of extra fat intake on fibre utilization in horses. In a 4 x 4 cross-over trial with feeding periods of 24 days each, eight mature trotting horses (age 4 to 12 years, 407 to 531 kg BW) were given four diets. The concentrates were formulated to contain either soybean oil or an iso-energetic amount of glucose or combinations of the two ingredients. The concentrates were fed in combination with the same amount of hay so that the whole diets contained 30, 50, 77 or 108 g EE/kg DM. Apart from the amounts of fat and glucose the four diets were identical. With an increase of 10 g/kg DM of soybean oil the apparent total tract digestibility of crude fibre was reduced with 0.9 percentage units. Extra fat intake also reduced apparent protein and NFE digestibility, but raised apparent fat digestibility. Although the present results may hold specifically for the conditions of this study, it is suggested that the observed interaction between fat content of the diet and macronutrient utilization might have consequences for practical horse feeding in that calculating the energy content of high-fat diets on the basis of feedstuff tables will lead to over- or underestimating the amount of energy provided by the various ingredients of the diets.

A prolonged photoperiod improves feed intake and energy metabolism of weanling pigs

In a 2-wk experiment, the effect of photoperiod on performance and energy metabolism of newly weaned pigs was studied. Forty 4-wk-old crossbred weanling barrows weighing 8.0 kg (SE = 0.13) were assigned to one of eight groups (five pigs per group) based on BW and litter. Groups were allotted to one of two lighting schedules: 8 h light:16 h darkness or 23 h light:1 h darkness. Each group was housed in a climate respiration chamber. Piglets had ad libitum access to feed and water. Energy and nitrogen balances, heat production, ADFI, and ADG were measured weekly. Heat production, energy metabolism, and performance were unaffected (P > 0.10) by photoperiod during wk 1. However, in the 2nd wk ADFI (418 vs 302 g/d) and ADG (381 vs 240 g/d) were higher (P < 0.05 and P = 0.05, respectively) for pigs on the 23:1 h lighting schedule than for those on the 8:16 h schedule. Furthermore, heat production (P < 0.10), total energy retention, and energy retained as protein and as fat were higher (P < 0.05) during wk 2 in pigs on the 23:1 h lighting schedule (8, 125, 41, and 350%, respectively) than in those on the 8:16 h schedule. Moreover, metabolizability of energy tended to be higher (P < 0.10) and energy requirements for maintenance were lower (P < 0.05) during wk 2 for pigs on the 23:1 h schedule compared with those on the 8:16 h schedule (P < 0.10). In conclusion, exposing pigs to a longer period of light after weaning stimulated ADFI and ADG. In addition to the feed intake, the high ADG is due to an improved metabolizability of energy and a reduced energy requirement for maintenance. This study suggests that lighting schedule can be used as a tool to stimulate feed intake after weaning.

Quantitative trait loci influencing hepatic copper in rats

Significant differences in liver copper content have been observed between rat inbred strains. To define loci controlling this trait, the offspring (n = 190) from an (LEW/OlaHsd x BC/CpbU) F(2)-intercross was genetically analyzed. From each F(2) animal, liver copper content was determined and genomic DNA was screened with polymorphic DNA markers. We found a major quantitative trait locus (QTL) for liver copper content in females on chromosome 2 and in males on chromosome 10. Both QTLs accounted for approximately 20% of the genetic variance. In addition, suggestive linkage for liver copper content was found on rat chromosomes 1, 8, 10, 12, 14, and 19. The regions on these chromosomes contain genes that are responsible for 9.0-15.5% of the genetic variance of liver copper content.

Effect of protein : energy ratio in milk replacers on growth performance of goat kids

Two separate experiments were carried out to establish the effects of the protein:energy ratio in milk replacers on growth performance, plasma lipid concentrations and fatty acid composition in adipose tissue of male goat kids. In the first experiment there were 211 3-day- old goat kids and in the second experiment there were 121 kids aged 3-7 days. The animals were fed ad libitum for a period of 4 weeks on milk replacers containing either 11.5 or 9.5 g crude protein/MJ metabolizable energy. In essence, protein was exchanged with fat on a weight basis. Milk concentrations were increased from 160 to 190 g/l in experiment 1, from 150 to 180 g/l in experiment 2. There were significant increases in body weight and feed intake when the milk replacer with high protein : energy ratio was fed. Group mean average daily weight gain was 168 and 203 g for the groups with low and high dietary protein:energy ratio in experiment 1; for experiment 2 the values were 139 and 160 g. Average dry matter intake was 18 and 14% higher for the diet with high protein:energy ratio in experiments 1 and 2, respectively. There was no change in either feed conversion (feed:gain ratio) or energy conversion (weight gain:energy intake ratio). There were no consistent diet effects on plasma lipid concentrations. Dietary fatty acid composition was reflected by that of adipose tissue. The milk replacer with high protein:energy ratio produced a small increase in the contents of myristic and palmitic acid in adipose tissue.

Effect of creep feed consumption on individual feed intake characteristics and performance of group-housed weanling pigs

To assess the effects of creep feed consumption on individual feed intake characteristics and performance of group-housed weaned pigs, 16 litters (149 piglets) were fed a commercial creep feed (3,040 kcal NE/kg, 15.2 g lysine/kg) supplemented with 1% chromic oxide. Another five litters (48 piglets) were not given access to creep feed (no-feed). Piglets were weaned at 28 d after birth. On d 18, 22, and 27 of age, fecal samples from all the piglets were taken using fecal loops. A green color of the feces indicated that the piglet had eaten creep feed. Piglets that had green-colored feces three times were considered as eaters. Piglets that never showed green-colored feces were considered as non-eaters. At weaning 22 piglets of each type (no-feed, non-eaters, and eaters) were selected based on BW, litter origin, and sex. These 66 pigs were assigned to six pens equipped with computerized feeding stations. Eaters, non-eaters, and no-feed pigs were equally divided over all six pens. After weaning a prestarter (d 0 to 13) and a starter diet (d 14 to 34) were offered for ad libitum consumption. The individual feed intake characteristics of latency time (interval between weaning and first feed intake) and initial feed intake (intake during the first 24 h following first feed intake) and performance traits were determined for all piglets. The pigs that were designated as eaters needed less time between weaning and first feed intake than the pigs that were designated as non-eaters and no-feed pigs (P = 0.04 and P = 0.06, respectively). Initial feed intake was not affected (P > 0.1) by feed intake prior to weaning. However, during d 0 to 8 the eaters had more visits per day during which feed was consumed than both the non-eaters and no-feed pigs. Averaged over the first 8 d after weaning, the ADFI and ADG of the eaters were higher than that of the non-eaters and no-feed pigs (P < 0.05). Averaged over the total 34-d period the effect of creep feed intake on postweaning ADFI was much less pronounced (P = 0.20), whereas ADG of the eaters was the highest (P < 0.05). Creep feed intake during the sucking period stimulates early postweaning feed intake as well as postweaning performance.

Interactions of dietary polyunsaturated fatty acids and vitamin E with regard to vitamin E status, fat composition and antibody responsiveness in layer hens

1. Effects of dietary polyunsaturated fatty acids (PUFA) and vitamin E (VE) on an immune response may interact because VE may protect PUFA from in vivo oxidation. The present study was designed to study the presence of such an interaction in growing layer chickens. 2. Three dietary concentration of linoleic acid (LA, 3.3, 6.6 and 10%), in combination with 4 concentration of dietary VE (5, 20, 40 and 80 mg/kg) were used. Effects of LA and VE on circulating VE concentration, fatty acid composition of bursal and adipose fat, and antibody kinetics against keyhole limpet hemocyanin and Mycobacterim butyricum were established. 3. At high dietary LA concentration, bursal and adipose LA were higher but bursal arachidonic acid and long chain n-3 PUFA decreased. The dietary VE level did not consistently affect the deposition of PUFA in tissue. Plasma VE concentrations were affected by the dietary VE and LA content, but not by their interaction. Antibody responses before and 7 d after immunisation were affected by the dietary treatments. Antibody concentration were not affected by tissue fatty acid content. 4. In conclusion, the interaction effects of dietary PUFA and VE on fat deposition and immune responses are of minor importance compared to separate PUFA and VE effects. This implies that, within the studied range, adding extra VE to preserve or affect the effects of dietary PUFA on antibody responsiveness is unnecessary.

Dietary soyabean oil depresses the apparent digestibility of fibre in trotters when substituted for an iso-energetic amount of corn starch or glucose

The aim of the present study was to establish whether the inhibitory effect of fat feeding on fibre digestion has been underestimated due to the substitution of fat for corn starch. A high fat intake has been shown to lower total intestinal tract apparent digestibility of crude fibre in horses but, since fat was substituted for nonstructural carbohydrates, including starch, the specific effect of fat could not be ascertained. The possibility could not be excluded that starch also inhibits fibre digestibility, so that the fat effect observed earlier would have been underestimated. In this study, the intakes of iso-energetic amounts of soyabean oil, corn starch or glucose were compared as to fibre digestibility. Unlike starch, glucose is fully absorbed by the small intestine and, therefore, is not expected to influence fibre fermentation in the caecum and colon. Six trotters were fed rations high in soyabean oil (158 g/kg dry matter), corn starch (337 g/kg dry matter) or glucose (263 g/kg dry matter) according to a 3 x 3 Latin square design. Apparent crude fibre digestibility was similar for the rations with corn starch (mean +/- s.d., 70.7 +/- 3.06% of intake, n = 6) or glucose (71.0 +/- 1.90%), but was significantly depressed by fat feeding (56.5 +/- 7.65%). Similar observations were made for apparent digestibilities of neutral and acid detergent fibre and of cellulose. It was concluded that the addition of fat to the feed ration of horses has a specific inhibitory effect on fibre utilisation and, therefore, reduces the amount of energy provided by dietary fibre.

The decrease in body fat in mice fed conjugated linoleic acid is due to increases in energy expenditure and energy loss in the excreta

We carried out energy balance studies in four groups of young, growing, 5-wk-old Balb-C mice (n = 12/group) that were either food restricted or nonrestricted and fed high fat diets (38 energy%) with or without 0.93 g/100 g conjugated linoleic acid (CLA) for 39 d. The energy in carcasses, excreta and food was measured in a bomb calorimeter. CLA lowered the percentage of the energy intake that was stored in the body from 1.9 +/- 0.8 to -2.3 +/- 0.7% (mean +/- SD, P < 0.05) in the nonrestricted mice and from 1.4 +/- 1.3 to -2.9 +/- 0.7% (P < 0.05) in the restricted mice. Thus, the CLA-treated mice had a net loss of body energy. The percentage of the energy intake eliminated in the excreta increased from 7.6 +/- 0.9% in controls to 8.7 +/- 1.0% (P < 0.05) in the CLA-treated mice that were nonrestricted and from 7.3 +/- 0.8 to 8.4 +/- 0.6 (P < 0.05) in the restricted mice. The amount of energy ingested minus the amount retained in carcasses and excreta equals the energy expenditure. The percentage of the energy intake that was expended as heat increased from 90.5 +/- 1.2 in controls to 93.6 +/- 1.5% (P < 0.05) in the CLA-treated nonrestricted mice and from 91.3 +/- 1.5 to 94.5 +/- 1.0% (P < 0.05) in the restricted mice. The lower energy storage in the CLA-fed mice was accounted for by an increase in the energy expenditure (74%) and by an increase in energy lost in the excreta (26%). Feeding CLA also increased liver weight, which may warrant further studies on the safety of CLA.

Intact pectin and its polygalacturonic acid regions have similar hypocholesterolemic properties in hybrid F1B hamsters

We fed cholesterol-enriched (0.1% w/w) semipurified diets containing 3% of lemon pectin or 3% of the polygalacturonic acid regions fraction (smooth regions fraction) of the lemon pectin to hybrid F1B hamsters for a period of 8 weeks. A control group was fed cellulose and a positive control group was fed psyllium. The feeding of the semipurified diets resulted in an increase of plasma cholesterol levels in all the dietary groups when compared with initial values. The hamsters fed the psyllium, pectin, or the polygalacturonic acid regions fraction had significantly (P < 0.05) lower plasma cholesterol levels than the cellulose fed group throughout the experimental period. Plasma cholesterol levels in the hamsters fed the psyllium, pectin, or polygalacturonic acid regions fraction were not significantly different. Liver cholesterol concentrations were also lower in the hamsters fed the psyllium, pectin, or the polygalacturonic acid regions fraction than in the hamsters fed the cellulose, but this effect reached statistical significance only in the hamsters fed the polygalacturonic acid regions fraction. The results of these studies suggest that the polygalacturonic acid regions of the pectin molecule is responsible for the cholesterol-lowering properties of the pectin.

Endocrine stress response in jugular-vein cannulated rats upon multiple exposure to either diethyl-ether, halothane/O2/N2O or sham anaesthesia

The main objective of this study was to assess the endocrine stress response to multiple anaesthesia followed by sham anaesthesia in order to detect any memory effects. For this purpose, jugular-vein cannulated rats were subjected to either sham, diethyl-ether or halothane/O2/N2O anaesthesia, and their plasma ACTH, corticosterone, glucose, adrenaline and noradrenaline levels measured. The study had three separate experiments, each consisting of a control and treatment group. In two experiments, the rats were exposed to high or low concentrations (40-15%) of diethyl ether, using either a jar containing cotton soaked in diethyl ether or a vaporizer. In the third experiment, rats were exposed to halothane/O2/N2O. Control animals underwent sham anaesthesia. Blood samples were taken 6 min before and at 5, 15 and 55 min after starting the exposure (t = 0 min). For each variable, the dt5 (level at t = 5 min minus that at t = -6 min) and the cumulative levels over the one-hour period as determined by the area under the curve (AUC) were calculated. Further, the peak levels (Cmax) were determined. The mean time needed to induce anaesthesia was 68, 121 and 55 s for exposure to high and low concentrations of diethyl ether and to halothane/O2/N2O, respectively. Increased noradrenaline and adrenaline dt5 levels were observed only after the first exposure to the high concentration of diethyl ether. Multiple anaesthesia sessions using either diethyl ether or halothane/O2/N2O did not clearly influence adrenaline and noradrenaline levels. Diethyl ether induced a sharp rise in plasma ACTH and glucose levels, irrespective of the concentration used. The response of the ACTH and glucose was similar for single and multiple exposure. An increased response of ACTH, corticosterone and glucose to sham anaesthesia following multiple induction of anaesthesia was observed for the high concentration of diethyl ether only. Halothane/O2/N2O raised plasma glucose without differences between single and multiple anaesthesia sessions. Upon sham anaesthesia following multiple exposures to halothane/O2/N2O, glucose levels were significantly increased. This study indicates that repeated anaesthesia in rats can elicit an increased stress response during subsequent handling and change of environment.

Effect of acetic acid consumption on clinical laboratory values in the dog

To investigate the influence of food enriched with acetic acid on the clinical, biochemical, electrolyte, blood gas, haematological and urinary variables in the dog, a cross-over study was carried out with periods of approximately 2 weeks involving six healthy, adult dogs. Another objective was to determine the maximum concentration of acetic acid that the dogs found to be palatable. The dogs were maintained on a commercial meat-based food with added acetic acid and/or glucose. The administered acetic acid was increased in stages. All dogs accepted the diet containing acetic acid at a level of 5% of metabolizable energy. Except for a decrease in plasma total protein, none of the variables were significantly affected by acetic acid consumption. Acetic acid feeding did not affect plasma acetate concentration and urinary acetate excretion, indicating that dogs efficiently metabolize ingested acetic acid.

The plasma level of triacylglycerols in horses fed high-fat diets containing either soybean oil or palm oil

The influence of dietary soybean oil versus palm oil on the plasma level of triacylglycerols was determined in a crossover experiment with four horses. Based on published data for humans and laboratory animals it was expected that a diet rich in unsaturated fatty acids in the form of soybean oil compared to saturated fatty acids in the form of palm oil would lower the plasma triacylglycerol level. The feeding of soybean oil versus palm oil for a period of four weeks did not change the level of plasma triacylglycerols in horses. Mean levels of triacylglycerol, free fatty acids and 3-hydroxybutyrate were 0.17 (SE, 0.04), 0.44 (SE, 0.063) and 0.16 (SE, 0.008) mmol/l, respectively. The fatty acid composition of the plasma triacylglycerols reflected the fatty acid composition of the diets. The activity of lipoprotein lipase was not different between the treatments. It is concluded that, under the present experimental conditions, the feeding of soybean oil to horses does not affect triacylglycerol secretion into plasma and thus does not influence the concentration of plasma triacylgycerols, when compared to the feeding of palm oil.

Comparison of the efficacy of two anti-uric acid diets in dalmatian dogs

Commercial anti-uric acid diets for dogs may contain insufficient protein to sustain growth and lactation. In order to investigate the efficacy of an experimental purine-free diet moderately low in protein, its effect on urinary uric acid excretion was compared with that of a commercial dog food and a commercial low-protein anti-uric acid diet. The experimental diet, commercial dog food and commercial anti-uric acid diet contained 10.0, 12.8 and 5.0 g crude protein/MJ metabolizable energy, respectively. Twelve Dalmatian dogs were subjected to a 3 x 3 Latin square study. Although the plasma uric acid concentration was significantly lower when the dogs were fed either the commercial anti-uric diet (18.7 +/- 6.0 mumol/l, mean +/- SD, n = 12) or the experimental diet (19.2 +/- 8.3 mumol/l), when compared to the commercial dog food (29.2 +/- 11.1 mumol/l), no significant decrease of uric acid concentration in urine collected before the morning meal was seen. The average concentration of urinary uric acid was 60 mumol/l. There was a significant increase in the urea:creatinine ratio in urine when the dogs were fed the experimental diet compared to the commercial anti-uric acid diet, confirming that the experimental diet contained more protein. The experimental diet lowered plasma uric acid and was relatively high in protein and thus may be suitable for use in growing and lactating dogs to prevent ammonium urate urolithiasis.

Effect of dietary medium chain triacylglycerols on plasma triacylglycerol levels in horses

The hypothesis tested was that the feeding of medium chain triacylglycerols (MCT) to horses would raise the level of plasma triacylglycerols by increasing the availability of glucose as lipogenic substrate, implying that the MCT effect would be greater with glucose in the diet instead of cellulose. A Latin square experiment was carried out with 4 horses and 4 dietary treatments. The experimental periods lasted 21 d. Blood samples were taken 16 h after feeding. The diets consisted of hay and experimental concentrates, differing in fat source (MCT or soybean oil) and carbohydrate source (corn starch plus glucose or cellulose). The dietary variables, MCT or soybean oil, provided on average 27% of total dietary net energy, while glucose plus constarch or cellulose provided 33%. The feeding of MCT versus soybean oil raised the level of plasma triacylglycerols significantly from 196.7 +/- 30.2 to 427.3 +/- 85.7 mmol/l and that of VLDL cholesterol from 0.028 +/- 0.01 to 0.069 +/- 0.01 mmol/ml. As based on analysis of variance, for the four experimental diets there was no significant effect of carbohydrate source and no fat-carbohydrate interaction. Thus, the hypothesis was rejected. When the diets contained soybean oil, cellulose versus starch plus glucose produced significantly greater increase plasma triacylglycerols. This carbohydrate effect was not seen when horses were fed the MCT diets. The experimental concentrates did not differently influence the concentrations of plasma glucose, total serum cholesterol, phospholipids, insulin, free fatty acids and the activity of post-heparin lipoprotein lipase. We suggest that the MCT-induced increase in plasma triacylglycerols is related to an increase in hepatic VLDL secretion, with the extra substrate for increased synthesis of triacylglycerols being the acetyl-CoA derived from the hepatic oxidation of medium chain fatty acids.

Small intestinal morphology and disaccharidase activities in early-weaned piglets fed a diet containing spray-dried porcine plasma

The purpose of this study was to test whether dietary spray-dried porcine plasma (SDPP) in early-weaned piglets prevents small intestinal villus atrophy by trophic or protective activity. Fifty-four weaned, 18-day-old piglets were used to determine the effect of dietary SDPP on small intestinal villus length, crypt depth, enterocyt mitotic activity and brush border enzyme activities during the first week after weaning. The piglets were offered a diet containing either 8% SDPP or 8% casein. At 2 and 7 days after weaning, piglets were anaesthetized to provide samples of the small intestinal wall and killed immediately afterwards. There were no differences in daily gain and daily feed intake between the two dietary treatments. At day 2 after weaning, all piglets showed a marked reduction in villus height when compared with baseline values. In all piglets, small intestinal enterocyte mitotic activity had decreased by day 2 and was increased again on day 7. There were no significant effects of dietary SDPP on small intestinal villus length, crypt depth and enterocyt mitotic activity. This indicates that SDPP has no trophic effect on the small intestinal mucosa and that it does not protect against the damaging effect on the small intestinal villi that is associated with the process of weaning. There was no effect of SDPP on lactase-, sucrase- or maltase-specific activities that are a measure of the digestive function of the small intestine. It can be concluded that SDPP versus casein has no effect on small intestinal morphology and disaccharidase activities in early weaned piglets kept under low infection pressure.

The hypocholesterolemic effect of lemon peels, lemon pectin, and the waste stream material of lemon peels in hybrid F1B hamsters

BACKGROUND

We found in preliminary studies with hamsters that citrus peels have a cholesterol lowering effect comparable to that of pectin extracted from these peels.

AIM OF THE STUDY

We wanted to examine whether the cholesterol lowering effect of the peels could be completely accounted for by the pectin in the peels.

METHODS

We fed cholesterol enriched (0.1 %,w/w) semipurified diets containing 3% (w/w) of cellulose, lemon peels, lemon pectin, and the waste stream material of the lemon peels to hybrid F1B hamsters for a period of 8 weeks. The waste stream of the lemon peels is the left over after extraction of the lemon pectin.

RESULTS

Feeding the semipurified diets resulted in an increase of plasma cholesterol levels in all the dietary groups after 2 and 4 weeks on the diets. Cholesterol concentrations in the cellulose fed hamsters continued to increase after 4 weeks on the diet, whereas cholesterol levels in the other groups had reached a plateau. As a consequence, the plasma cholesterol levels in the hamsters fed the peels (5.59 +/- 0.74 mmol/L, mean +/- SD, n = 14), pectin (5.19 +/- 0.48 mmol/L), or waste stream (5.53 +/- 0.94 mmol/L) were lower than those in the hamsters fed cellulose (6.71 +/- 1.52 mmol/L) after 8 weeks on the diets. Differences in total plasma cholesterol were reflected in differences in both VLDL and LDL cholesterol concentration, but this effect was more distinct for the VLDL. There was no effect of the type of fiber on HDL cholesterol levels. Liver cholesterol concentrations paralleled. the concentrations of plasma cholesterol and the liver cholesterol concentrations in the hamsters fed the peels (3.57+/- 1.01 micromol/g liver, mean +/- SD, n = 14), pectin (4.86 +/- 1.42), and the waste stream (4.96 +/- 1.89) were lower than those in the cellulose group (7.19 +/- 2.32). The hamsters fed the peels, pectin, or waste stream tended to have a higher excretion of fecal bile acids and neutral sterols then the cellulose fed hamsters.

CONCLUSION

The results of this study suggest that lemon peels and the waste stream of the lemon peels are as effective in lowering plasma and liver cholesterol in hamsters as the pectin extracted from the peels and that also compounds other than pectin are probably responsible for the cholesterol lowering effect of the citrus peels.

Growth performance and health status in weanling piglets fed spray-dried porcine plasma under typical Northern European conditions

The effect of inclusion of spray-dried porcine plasma (SDPP) in diets for weanling piglets was studied. The objectives were to determine whether SDPP would have positive effects on post-weaning piglet performance and health under typical Northern European conditions. In experiment 1, 160 weanling piglets were assigned randomly to a control diet or a diet containing 3% SDPP, which was added at the expense of both fishmeal and dried skim milk. In experiment 2, 264 weanling piglets were assigned to a control diet containing whey protein, a diet without whey protein but with SDPP or a diet containing both whey protein and SDPP. In essence, SDPP was added to the test diets at the expense of either whey protein or fishmeal. Piglets were fed the diets for 3 weeks. In experiment 1, the piglets fed the SDPP diet had a 7% higher average daily gain (ADG) and a 4% lower feed conversion ratio (FCR) (p < 0.05) during the first 3 weeks after weaning than did those fed the control diet. There were no differences in leucocyte counts or gamma-globulin. In experiment 2 there were no significant differences in ADG and FCR among the dietary treatments. It is concluded that low amounts of SDPP in weanling diets can have positive effects on growth performance under Northern European conditions.

The effect of dietary spray-dried porcine plasma on clinical response in weaned piglets challenged with a pathogenic Escherichia coli

Weaned piglets were used to determine the effect of dietary spray-dried porcine plasma (SDPP) on the clinical response to an infection with a pathogenic Escherichia coli (E. coli) O139:K82 LT(-). The piglets were divided into two groups of 10 animals each. One group was fed the control diet containing soybean(meal) plus whey powder. The test piglets were fed a diet with 8% SDPP. Piglets were orally infected with the challenge strain on days 6 and 7 after weaning. The experimental period lasted 14 days after which the piglets were euthanised and necropsied. Faecal samples were collected daily for bacteriological analysis. Segments of jejunum, caecum and rectum were removed for bacteriological analysis post mortem. Feed intake and weight gain, faecal and condition scores and body temperature were measured daily. In the control and SDPP groups, 6 and 7 piglets died from diarrhoea. The average daily feed intake (ADFI) and average daily gain (ADG) were substantially higher in the SDPP group than in the control group. SDPP-fed piglets generally had a more favourable faecal score and a healthier appearance than did the control piglets. The faecal excretion of E. coli O139:K82 was similar for control and test piglets. There were no diet effects on the E. coli O139:K82 counts at different sites of the intestine. In this experiment, the inclusion of SDPP at an economically acceptable percentage in the diet could not prevent piglet losses due to challenge with a pathogenic E. coli, but improvements of ADG, ADFI and faecal and condition scores were achieved.

Genetic and correlation analysis of hepatic copper content in the rat

Thirty recombinant inbred (RI) strains derived from the spontaneous hypertensive rat (SHR/OlaIpcv) and the Brown Norway (BN-Lx/Cub) progenitors were used to search for quantitative trait loci (QTLs) that are responsible for differences in liver copper between these two strains. The heritability of liver copper concentration (expressed as microg/g liver wet wt and microg/g liver dry wt) and liver copper store (microg/whole liver) was estimated to be 57, 57, and 46%, respectively. In a total genome scan of the RI strains, involving over 600 genetic markers, suggestive association was found between liver copper store (microg/whole liver) and the D16Wox9 marker on chromosome 16 (lod score = 2.8), and between liver copper concentration (microg/g dry wt) and the D10Cebrp1016s2 marker on chromosome 10 (lod score = 3.0). These putative QTLs are responsible for nearly 34 and 40% of the additive genetic variability for liver copper store and concentration, respectively.

An approach to assessment of the efficiency of dietary energy utilization by horses and ponies kept at riding schools

The ratio of calculated net energy intake (NEi) to calculate net energy requirement (NEr) might serve as an indicator of the efficiency of dietary energy utilization. The ratio was determined for 93 horses and ponies from 10 riding schools. For each animal with an assumed constant body weight, energy intake and energy requirements were assessed. On average, the estimated NEi was 14% greater than NEr. There was a significant, negative association between crude fibre intake and the NEi: NEr ratio. Earlier work indicated that extra fat intake may lead to over estimation of the calculated energy value of the ration due to changes in macronutrient digestibility. Dietary fat concentration was found to range from 32 to 52 g/kg dry matter (5 to 6 g/MJ net energy), but on the basis of digestibility trials this range in fat concentration is too small to significantly influence the NEi: NEr ratio. This study shows that assessment of the efficiency of dietary energy utilization under normal conditions, on the basis of the NEi: NEr ratio is fraught with uncertainty.