Detoxifying deoxynivalenol (DON)-contaminated feedstuff: consequences of sodium sulphite (SoS) treatment on performance and blood parameters in fattening pigs

A 10-week feeding experiment was carried out examining the effects of deoxynivalenol (DON)-contaminated maize treated with different sodium sulphite (SoS) concentrations on performance, health and DON-plasma concentrations in fattening pigs. Two maize batches were used: background-contaminated (CON, 0.73 mg/kg maize) and Fusarium-toxin contaminated (DON, 44.45 mg/kg maize) maize. Both were wet preserved at 20% moisture content, with one of three (0.0, 2.5, 5.0 g/kg maize) sodium sulphite concentrations and propionic acid (15%). Each maize batch was then mixed into a barley-wheat-based diet at a proportion of 10%, resulting in the following 6 feeding groups: CON− (CON + 0.0 g SoS/kg maize), CON2.5 (CON + 2.5 g SoS/kg maize), CON5.0 (CON + 5.0 g SoS/kg maize), DON- (DON + 0.0 g SoS/kg maize), DON2.5 (DON + 2.5 g SoS/kg maize) and DON5.0 (DON + 5.0 g SoS/kg maize). Dietary DON concentration was reduced by ~ 36% in group DON2.5 and ~ 63% in group DON5.0. There was no impact on ZEN concentration in the diets due to SoS treatment. Pigs receiving diet DON- showed markedly lower feed intake (FI) compared to those fed the control diets. With SoS-treatment of maize, FI of pigs fed the DON diet (DON5.0: 3.35 kg/d) were comparable to that control (CON−: 3.30 kg/day), and these effects were also reflected in live weight gain. There were some effects of SoS, DON or their interaction on serum urea, cholesterol and albumin, but always within the physiological range and thus likely negligible. SoS wet preservation of Fusarium-toxin contaminated maize successfully detoxified DON to its innocuous sulfonates, thus restoring impaired performance in fatteners.

Modification of the equine gastrointestinal microbiota by Jerusalem artichoke meal supplementation

The objective of this study was to investigate the impact of natural prebiotic active compounds on the microbial composition in different regions of the equine gastrointestinal tract. Twelve adult horses (body weight [bwt] 534 ± 64.5 kg; age 14 ± 7.5 years) were randomly divided into two feeding groups. Six horses received a basal diet consisting of 1.5 kg hay/100 kg bwt x d^-1 and oat grains equal to 1.19 g starch/kg bwt x d^-1, supplemented with Jerusalem artichoke meal providing prebiotic fructooligosaccharides + inulin in a quantity of 0.15 g/kg bwt x d^-1. The remaining horses received a placebo added to the basal diet. The horses were fed for 21 d and euthanized at the end of the feeding period. Digesta samples from different parts of the gastrointestinal tract were taken, DNA extracted and the V1-V2 region of the 16S rRNA gene amplified. Supplementation with the prebiotic increased the relative abundance of Lactobacillus (P < 0.05), with a concurrent reduction of the relative abundance of Streptococcus mainly in the stomach (P < 0.05). In the hindgut, the supplemental prebiotic also increased the relative abundance of Lactobacillus but further reduced the relative abundance of fibrolytic bacteria, specifically the unclassified members of the families Lachnospiraceae (P < 0.05) and Ruminococcaceae. The relative abundance of the genus Ruminococcus increased solely in the caecum and colon transversum. Overall, the addition of the prebiotic significantly increased the diversity in nearly all parts of the gastrointestinal tract (P < 0.05). The feeding of this natural prebiotic compound to horses had an impact on the microbial community in the entire gastrointestinal tract. Furthermore, the effect on the bacterial community in the foregut (especially the stomach) was more pronounced in comparison to the effect in the hindgut. Therefore, the impact on stomach health should be carefully considered.

Renal energy excretion of horses depends on renal hippuric acid and nitrogen excretion

The prediction of renal energy excretion is crucial in a metabolizable energy system for horses. Phenolic acids from forage cell walls may affect renal energy losses by increasing hippuric acid excretion. Therefore, the relationships were investigated between renal energy, nitrogen (N) and hippuric acid excretion of four adult ponies (230-384 kg body weight (BW)) consuming diets based on fresh grass, grass silage, grass cobs (heat-dried, finely chopped, pressed grass), alfalfa hay, straw, extruded straw and soybean meal. Feed intake was measured; urine and faeces were quantitatively collected for three days. Feed was analysed for crude nutrients, gross energy, amino acids and neutral-detergent-insoluble crude protein (CP); faeces were analysed for crude nutrients and cross energy; urine was analysed for N, hippuric acid, creatinine and gross energy. Renal energy excretion (y; kJ/kg BW0.75 ) correlated with renal N excretion (x1 ; g/kg BW0.75 ) and renal hippuric acid excretion (x2 ; g/kg BW0.75 ): y = 14.4 + 30.2x1 +20.7x2 (r = .95; n = 30; p < .05). Renal hippuric acid excretion was highest after intake of fresh grass and lowest after intake of soybean meal. The ratio of hippuric acid to creatinine in urine and the excretion of hippuric acid per gram of dry matter intake was significantly higher for fresh grass than for all other rations. There was no relationship between aromatic amino acid intake and renal hippuric acid excretion. The results of the present study and literature data suggest that feed can be categorized into four groups with regard to the energy losses per gram CP intake: (i) protein supplements (e.g., soybean meal): 4.2-4.9 kJ/g CP intake (ii) alfalfa hay, grains, dried sugar beet pulp: 6.4 kJ/g CP intake, (iii) hay, preserved grass products, straw: 5.2-12.3 kJ/g CP intake (mean 8) and (iv) fresh grass. For group (iii) a negative relationship was observed between renal energy losses per gram of CP and the content of CP or neutral-detergent-insoluble CP in dry matter.

Hyperketonämie mit und ohne Hyperbilirubinämie bei Kühen in Mecklenburg-Vorpommern

Gegenstand und Ziel: Hyperketonämien treten in Milchviehbeständen scheinbar vermehrt im Frühsommer auf. Ziel der Untersuchung war, unter den Bedingungen des Landes Mecklenburg-Vorpommern (MV) festzustellen, ob diese Häufung statistisch nachweisbar ist und zu welchem Anteil es sich bei den beschriebenen Fällen um alimentär oder energiemangelbedingte Hyperketonämien handelt. Material und Methoden: Anhand der in 5 Jahren gewonnenen Blutproben von 7081 Kühen aus MV wurde der jahreszeitliche Verlauf der Hyperketonämie-Prävalenz untersucht. Konzentrationen von ≥ 1,0 mmol/l β-Hydroxybuttersäure (BHB) bzw. ≥ 5,0 μmol/l Bilirubin wurden als Hyperketonämie (Ket) bzw. Hyperbilirubinämie (Bili) gewertet. Der Anstieg beider Parameter wurde als energiemangelbedingte Hyperketonämie (h-Ket) interpretiert. Ergebnisse: Die Ket- und h-Ket-Prävalenzen der laktierenden Milchkühe in 5 Jahren betrugen 19,3% und 10,0%. Ein jahreszeitlicher Effekt ließ sich nur für die Bili-Prävalenz bei laktierenden Milchkühen nachweisen, die im Herbst sank (p < 0,05). Bei Mutterkühen betrug die Ket- und h-Ket-Prävalenz im Beobachtungszeitraum 11,0% bzw. 9,1%. Schlussfolgerungen: Unter den Bedingungen der vorliegenden Studie lag kein fester jahreszeitlicher Effekt auf die Ketoserate von Kühen vor. Etwa die Hälfte der bei laktierenden Milchkühen auftretenden Hyperketonämien war durch Energiemangel bedingt, wobei die energetische Versorgung der Tiere im Herbst offenbar vergleichsweise gut war. In der Mutterkuhhaltung hat Ketose eine geringere Bedeutung, bei deut - lichem Überwiegen energiemangelbedingter Ereignisse. Klinische Relevanz: In der tierärztlichen Praxis sollten bei Verdacht auf subklinische Ketose bzw. bei Stichprobenuntersuchung zur Bestandsbetreuung neben BHB auch Parameter mit Bezug zum Energiehaushalt, zumindest auch Bilirubin im Blutserum, untersucht werden.

Porcine intestinal yeast species, Kazachstania slooffiae, a new potential protein source with favourable amino acid composition for animals

There is little information about Kazachstania slooffiae which dominates among other yeasts in the pigs' intestine. Therefore, the aims of this study were to characterise the yeast cell contents and to investigate which nitrogen sources, organic acids and alcohols may be utilised or produced by this species. The results showed that, K. slooffiae could use urea, ammonium sulphate, peptides and single amino acids and produce thereby ethanol and formic acid. However, this yeast did not metabolise amino acids, lactic, butyric, propionic and acetic acids as sole carbon source. Using a global metabolite profiling approach employing gas chromatography and high-resolution liquid chromatography mass spectrometry, was found that the amount of peptides and dehydroascorbic acid considerably increased in the fermentation residues after yeast cultivation. It is noteworthy that the cells of K. slooffiae had higher contents of nitrogen and total amino acids (especially lysine) than the cells of nutritional yeast (Saccharomyces cerevisiae). This study indicates that due to potential production of peptides and formic acid in the intestinal tract, K. slooffiae might have an impact on the gut health. Moreover, from a nutritional standpoint, the cells of this yeast can be a good source of protein with useful amino acid composition for animal.

Influence of conjugated linoleic acids and vitamin E on milk fatty acid composition and concentrations of vitamin A and α-tocopherol in blood and milk of dairy cows

The objective of this trial was to investigate the influences of conjugated linoleic acid (CLA) and vitamin E (Vit. E) and their interactions on fatty acid composition and vitamins in milk (α-tocopherol, retinol and β-carotene) as well as on α-tocopherol in blood of pluriparous cows from week 6 ante partum until week 10 post-partum (p.p.). We assigned 59 pluriparous German Holstein cows to four treatment groups with the treatment factors CLA and Vit. E at two levels in a 2 × 2 factorial design. Milk fatty acid composition and milk vitamins were analysed on lactation days 7 and 28. α-tocopherol in blood serum was analysed on days -42, -7, 1, 7, 14, 28 and 70 relative to parturition. Milk concentration of α-tocopherol was influenced by Vit. E (p < .001) and CLA (p = .034). Percentage of cis-9, trans-11 CLA in total milk fat was influenced by treatment with CLA (p < .001), while for percentage of trans-10, cis-12 CLA an interaction between treatment and day (p = .019), driven by an increase in both CLA groups from day 7 to day 28, was found. Serum ratios of α-tocopherol to cholesterol were influenced by Vit. E (p < .001). Results suggest that treatment with CLA during late pregnancy and early lactation is suitable to enhance the proportion of trans-10, cis-12 CLA in milk and thereby influencing nutritional properties. As treatment with Vit. E did not have an impact on milk fatty acid composition, it might be possible to increase the antioxidative capacity of the dairy cow without affecting milk properties. Consequently, combined treatment with CLA and Vit. E might elicit synergistic effects on the cow and milk quality by increasing the proportion of CLA in milk fat as well as the excretion of Vit. E and the Vit. E levels in serum.

Effects of isoenergetic quantities of a low-starch muesli feed high in fat and fibre vs. oat grains on the glycemic and insulinemic responses and feed intake patterns in sport ponies

Aim of this study was to compare glycemic and insulinemic responses and feed intake patterns in sport ponies after feeding isoenergetic quantities of low-starch muesli feed high in fat and fibre (FF) or oat grains (OG). Six sport ponies were randomly assigned to one of these two treatment groups for 2 × 3 weeks according to a crossover-design. Ponies received two equal meals/day of either semi-crushed OG (1 g starch/kg bwt*meal^-1 ) or an isoenergetic quantity of FF. Hay was also given in two equal meals/day and provided the remaining metabolisable energy up to 1.3-fold maintenance level. On day 21, blood was sampled 1 h after each pony received 0.5 kg hay (0 min). Then, the concentrate was provided and blood sampled 30, 60, 90, 120, 180, 240 and 300 min thereafter. Plasma glucose and serum insulin were analysed, and the areas under the curve (AUC) was calculated 120 and 300 min postprandial (PP). Feed intake patterns were measured in 4 ponies/group via a modified halter. OG was ingested faster than FF (feed intake time; FIT_DM in min/kg DM: 8.8 ± 1.6 vs. 15.9 ± 1.62, p < 0.05) combined with a higher chewing frequency (p < 0.05). The AUCs_{gluc120/300, ins120/300} were statistically higher with OG than FF (mmol/L*min^-1 : AUC_gluc120 : 776 ± 128 vs. 676 ± 80.4; AUC_gluc300 : 1811 ± 295.3 vs. 1569 ± 126.3; nmol/L*min^-1 : AUC_ins120 : 38 ± 18 vs. 22 ± 8.1; AUC_ins300 : 83 ± 39 vs. 35 ± 12; p < 0.05). Plasma glucose tended to decline following the intake of FF, which might be beneficial for equines with reduced glucose tolerance. This, however, requires further investigation. In this study, the ponies consumed OG unexpectedly rapidly. The rate of feed intake was similar to the results previously reported in the literature for warmblood horses.

Body composition and plasma lipid and stress hormone levels during 3 weeks of feed restriction and refeeding in low birth weight female pigs

Compensatory growth in response to feed restriction (FR) affects deposition rates of lean and adipose tissues. It is, however, unclear whether pigs with low birth weight differ from their counterparts with normal birth weight with regard to compensatory growth. Female littermate pigs with low (UW; 1.1 kg) and normal (NW; 1.5 kg) birth weight were fed to appetite (control, CON) or feed restricted (RES) at 60% of DMI of the CON group between 78 and 98 d of age and subsequently refed at the level of the CON group until 131 d of age. Subgroups of pigs were slaughtered at 75, 98, 104, and 131 d of age to compare BW and body composition. Blood samples were taken at 98 and 119 d of age to analyze plasma metabolites and hormones. At birth UW pigs were shorter and had lower BW until 131 d of age than NW pigs ( < 0.05). Feed intake per kilogram of BW was greater in UW than in NW pigs ( < 0.01). The UW and NW pigs differed in carcass composition as indicated by greater relative subcutaneous fat at 75 d ( < 0.1), greater shoulder back fat ( < 0.05) at 98 d, and lower carcass weight at 131 d with greater abdominal and subcutaneous neck back fat in UW compared with NW pigs ( < 0.05). During FR, BW gain of RES pigs was lower than in NW pigs. The RES pigs showed greater feed intake after termination of FR until 131 d than CON pigs ( < 0.01). At 98 d RES pigs were leaner than CON pigs ( < 0.05). After 6 d of refeeding (104 d) relative fat depot weights were still smaller ( < 0.03) in RES pigs than in CON pigs. After 5 wk of refeeding, RES pigs had lower abdominal fat weights and greater plasma cortisol levels than CON pigs ( < 0.05). Regarding the plasma metabolite and hormone response, at 98-d fasting levels of plasma NEFA and glycerol were greater in RES than in CON pigs ( < 0.05), and after the drop in their levels after morning feeding ( < 0.001), plasma NEFA and glycerol and also triacylglycerol increased until the next meal in RES vs. CON pigs ( < 0.01). Plasma cortisol was greater in RES pigs after 3-wk FR ( < 0.05), whereas only a trend for increased plasma adrenalin concentrations in RES pigs at the end of the FR period and after 5 wk of refeeding was found ( < 0.1). In conclusion, UW pigs at 75 d of age (20 to 23 kg BW) had greater subcutaneous fat, whereas at 131 d (61 to 68 kg BW) they showed greater abdominal fat than NW pigs, suggesting that subcutaneous fat is deposited earlier than abdominal fat. The FR caused similar changes in body composition, plasma lipids, and stress hormones in UW and NW pigs.

Methylating micronutrient supplementation during pregnancy influences foetal hepatic gene expression and IGF signalling and increases foetal weight

PURPOSE

Maternal diet during pregnancy impacts foetal growth and development. In particular, dietary levels of methylating micronutrients (methionine, folate, choline, vitamins B6, and B12) interfere with the availability and allocation of methyl groups for methylation reactions, thereby influencing normal transcription. However, the currently recommended methylating micronutrient supplementation regimen is haphazard and arbitrary at best.

METHODS

To investigate the effects of a methylating micronutrient-rich maternal diet, pregnant Pietrain sows were fed either a standard diet (CON) or a diet supplemented with methionine, folate, choline, B6, B12, and zinc (MET). Foetal liver and muscle (M. longissimus dorsi) tissues were collected at 35, 63, and 91 days post-conception. Transcriptional responses to diet were assessed in foetal liver. Altered insulin-like growth factor (IGF) signalling in transcriptome analyses prompted investigation of IGF-2 and insulin-like growth factor binding proteins (IGFBPs) levels in muscle and liver.

RESULTS

Maternal diet enriched with methylating micronutrients was associated with increased foetal weight in late gestation. Hepatic transcriptional patterns also revealed differences in vitamin B6 and folate metabolism between the two diets, suggesting that supplementation was effective. Additionally, shifts in growth-supporting metabolic routes of the lipid and energy metabolism, including IGF signalling, and of cell cycle-related pathways were found to occur in liver tissue in supplemented individuals. Weight differences and modulated IGF pathways were also reflected in the muscle content of IGF-2 (increased in MET) and IGFBP-2 (decreased in MET).

CONCLUSIONS

Maternal dietary challenges provoke stage-dependent and tissue-specific transcriptomic modulations in the liver pointing to molecular routes contributing to the organismal adaptation. Subtle effects on late foetal growth are associated with changes in the IGF signalling mainly in skeletal muscle tissue that is less resilient to dietary stimuli than liver.

Effects of oral Enterococcus faecium strain DSM 10663 NCIMB 10415 on diarrhoea patterns and performance of sucking piglets

Effects of probiotic Enterococcus faecium DMS 10663 NCIMB 10415 on diarrhoea and performance of sucking piglets were evaluated in a double-blind, placebo-controlled study. Piglets from treatment group (TG, n=56) and placebo group (PG, n=53) sows were included in the study. Immediately after birth and at day 2 and 3 post natum, each of the TG piglets received 2.8×109 colony forming units (cfu) per os. From day 4 until weaning (day 26), 1.26×109 cfu E. faecium/piglet were given twice a day via a liquid additive. Piglets already suffering from diarrhoea additionally got a glucose-electrolyte solution enriched with 2.9×108 (week 1) and 5.8×108 (week 2) cfu E. faecium/day. PG piglets received corresponding placebo preparations. A score was defined to characterise the severity of diarrhoea, including accompanying symptoms. The counts of viable born, stillborn and weaned piglets were similar in TG and PG litters (P≯0.05). The probiotic treatment mitigated incidence and severity of diarrhoea (P<0.05) with no impact on diarrhoea length (P≯0.05). Probiotic treatment improved daily weight gain (P<0.05) yet with no provable effect on body weight at weaning (P≯0.05). The additional supply of E. faecium in piglets suffering from diarrhoea had no further beneficial effect.

Effect of ensiling moist field bean (Vicia faba), pea (Pisum sativum) and lupine (Lupinus spp.) grains on the contents of alkaloids, oligosaccharides and tannins

Ensiling legume grain may be an inexpensive and ecologically interesting method to produce a high-protein feed of local origin. The typically patchy maturation recommends harvesting and ensiling the seeds in moist condition. Developing a method for preserving legume grains harvested before maturation by lactic acid fermentation would have several advantages. Under laboratory conditions, crushed legume seeds of beans, peas and lupines with high moisture content of 35 % were ensiled with different additives (molasses and lactic acid bacteria). To characterize the final silages, contents of proximate nutrients and antinutritional factors (alkaloids, oligosaccharides, tannins) were analysed. The addition of lactic acid bacteria ensured a fast and pronounced lactic acid production and decreased contents of undesired fermentation products like ethanol. An additional use of molasses for ensilage did not provide a remarkable additional benefit. Excluding sugar and starch, the contents of proximate nutrients were not remarkably altered after ensiling. As an overall effect, lactic acid fermentation reduced tannins and oligosaccharides. It can be supposed that the oligosaccharides after breakdown of the complex molecules acted as a source of fermentable carbohydrates. A relevant reduction of alkaloids did not occur. The lactic acid fermentation of legume grains can be recommended as an appropriate method for conservation. With respect to the economic advantages and compared with methods of chemical preservation, the lactic acid fermentation of legume grains under anaerobic conditions is an environmentally compliant procedure and therefore also an option for organic farming.

Scoring of sweat losses in exercised horses--a pilot study

Based on a series of exercise tests which included the estimation of sweat losses, this article proposes a novel sweat scoring system for exercising horses. This provides a practical estimate of individual animal exercise-induced sweat losses, based on visible appearance of sweat on the coat after work, which takes into account the effect of various influencing factors. In terms of accuracy and flexibility, the score seems to provide advantages over estimates based on current general recommendations from reference books. Additional studies are needed to validate this scoring system and its use under more diverse situations.

Fermentation of six different forages in the semi-continuous fermentation technique Caesitec

The aim of the present study was to compare carbohydrate degradation of forages which store carbohydrates either predominantly as fructan or starch, in horses' hindgut. The effects of an abrupt change from hay-based feeding to green fodder-based feeding on the caecal flora were tested with the in vitro hindgut simulation technique 'Caesitec'. Six trials with different forages (English ryegrass, tall fescue, grass mixture-horses, grass mixture-cows, lucerne, white clover) were conducted. During a 4-day stabilisation period, samples were taken once a day before loading the fermenters with hay. After diet-change to forage-based feeding, samples were taken four times a day. Ammonia and pH-value were measured before and 1, 2 and 6 h after loading the 'Caesitec'. Gas formation was measured daily. Bacterial numbers, lactate and short chain fatty acids were detected at four time-points of each trial. The grass mixtures contained the highest amounts of fructan. The pH-values were in the physiological range from pH 6 up to 7 (6.58-6.83) by feeding all forages. Gas formation, anaerobic and aerobic bacterial numbers increased after diet change from hay to any forage. The maximum amount of fructan (3.75 g/kg) in swiss pasture did not cause a permanent pathological change in the hindgut-flora.

Microscopic evidence for the uptake of orally given humic acids by the intestinal mucosa in piglets

In veterinary medicine, humic acids are sometimes used as oral supplements to protect and treat young animals from diarrhoea. With regard to their mode of action, it was generally believed that humic acids are unable to penetrate the intestinal mucosal surface and rather act from the intestinal lumen. In the past, some reports indicated, however, that prophylactic and therapeutic effects of orally administered humic acids might not be confined to the lumen of the digestive tract. The present study used piglets to examine whether orally administered humic acids would be able to cross the intestinal barrier and if so, whether the humic acids would also be transported from the intestine to other regions of the body. The study was carried out with three 64-day-old piglets, two of which were bottle fed daily with 1 g humic acids/kg bodyweight and day for 2 weeks. The third piglet served as an unsupplemented control. At the end of the study, the piglets were slaughtered and 10 tissue specimens were collected from each piglet. Examination by light microscopy of unstained sections revealed the presence of humic acid particles in each tissue sample from both humic acid-treated piglets whereby no such deposits were found in any tissue of the control piglet. This demonstrated that the humic acids had indeed passed the epithelial barrier of the intestinal mucosa and had been transported to other body tissues. In most tissue samples the humic acid particles showed a distinct clustered distribution pattern.

Glycaemic and insulinaemic response of Quarter Horses to concentrates high in fat and low in soluble carbohydrates

REASONS FOR PERFORMING STUDY

Quarter Horses are particularly susceptible to polysaccharide storage myopathy (PSSM). Nutritional therapy and possibly prophylaxis includes fat-supplemented diets whilst starch supply should be kept to a minimum.

OBJECTIVES

To investigate the glycaemic and insulinaemic response of clinically normal Quarter Horses to concentrates high in fat and low in starch.

METHODS

Twelve Quarter Horses were studied. The precondition for inclusion in the study population was that the horses had not shown clinical signs of myopathy. The Quarter Horses were fed according to a 4 x 4 Latin square design haylage plus isocaloric concentrates based on barley and oats as control (CO), sugar beet pulp, grass meal and soybean oil (SB), rice bran and grass meal (RB) and rice bran, grass meal, sugar beet pulp and soybean oil (CP), each over 2 weeks after 1 week of adaptation. At the end of each period, 1 kg of concentrate was fed and blood sampled 0, 30, 60, 90, 120, 180, 240, and 300 min post prandial (ppr.). Creatine kinase (CK; 0 min ppr. only), glucose and insulin were analysed. Glycaemic and insulinaemic index was calculated from each concentrates area under the curve (AUC) relative to CO.

RESULTS

Rice bran containing concentrates were partially refused at the beginning of the trial periods. CK activity, and glucose and insulin patterns (ppr. mean, peak, AUC, index) were highest with CO (P<0.05). The correlation between glucose and insulin (P<0.001) ranged from r = 0.570 (CO) to r = 0.364 (RB). Basal CK was highly correlated (P<0.001) to the mean ppr. plasma glucose.

CONCLUSION

Rice bran, sugar beet pulp, grass meal and soybean oil are suitable to include in concentrates that induce low glycaemic and insulinaemic response. Its acceptance seems to be a question of habituation. Although the mechanism is not completely understood, glucose patterns and basal CK activity are highly positively correlated. Both were affected by the type of concentrate used.

POTENTIAL RELEVANCE

Results support the suggestion that low-starch and high-fat feeding may be helpful not only in the nutrition of affected horses, but also to prevent future PSSM associated discomfort in particularly susceptible horses.

Effects of a probiotic Enterococcus faecium strain supplemented from birth to weaning on diarrhoea patterns and performance of piglets*

This placebo-controlled double-blind study was conducted to evaluate effects of Enterococcus faecium DSM 10663 NCIMB 10415 (EcF) orally given from birth to weaning on diarrhoea and performance of piglets. At the first 3 days postnatum (p.n.), piglets from 54 [verum group (VG)] and 60 [placebo group (PG)] sows got 1 g of a gel directly per mouth by a dosing device. Gel for the VG contained 2.8 x 10(9) colony forming units (CFU) EcF/g. From day 4 p.n. until weaning (24 +/- 3.2 days p.n.) a liquid additive was given that administered twice a day 1.26 x 10(9) CFU EcF to each VG piglet. In case of diarrhoea, an electrolyte solution was used which provided daily 2.9 and 5.8 (week 1 and >or= 2, respectively) x 10(8) CFU EcF per VG piglet. Diarrhoea scores were defined as follows: (i) no diarrhoea; (ii) piglets developed diarrhoea, but were vital and (iii) piglets suffered from diarrhoea and additionally looked pale, developed rough coat, showed slackening of the flank and lethargy. Counts of viable born, stillborn and weaned piglets were normal and not different between groups (p > 0.05). Placebo group vs. VG piglets suffered more frequently from diarrhoea (40.0 vs. 14.8%, p < 0.05). Duration of diarrhoea was not affected by feeding EcF (2.2 +/- 0.81 days, p > 0.05). Diarrhoea score was lower in VG vs. PG (1.2 vs. 1.5 +/- 0.54, p < 0.05) and the daily weight gain (DWG) was higher by 17 g/day (p < 0.05). Results suggest that the daily oral supplementation of EcF from birth to weaning reduces the portion of piglets suffering from diarrhoea. This may improve performance, as the higher DWG indicates. In contrast, no obvious benefit seems to result from an additional supply of EcF via electrolyte solution when diarrhoea is always present.

Effect of feeding exercised horses on high-starch or high-fat diets for 390 days

Our hypothesis was that, because horses have not evolved as fat eaters, there may be negative metabolic long-term effects of feeding a high fat diet. The objective of the present study was to identify these long-term effects and compare them with the effects of isoenergetic long-term high starch feeding. This randomised block study with 20 exercised horses looked at the effect of feeding either a high starch (HS) or a high fat (HF) diet type in 3 periods during stabling (Stable 1), pasture, and stabling (Stable 2) over 390 days. The horses received a HS or HF concentrate, straw, hay and 6 h pasture/day in the pasture period. HF horses gained weight (2% of initial bwt) and, therefore, fat intake was reduced (from 1.43 to 0.88 g/kg bwt/day). Blood plasma glucose, total protein, albumins, gamma-globulins, free fatty acids, phospholipids and cholesterol concentrations were higher but urea concentration was lower with HF compared to HS feeding (P<0.05). Plasma concentrations of triglycerides, bilirubin and pre-beta lipoproteins were unaffected by the diet type. There were period effects (P<0.05) for all variables except triglycerides and pre-beta lipoproteins. In contrast to HS, in HF the quotient alpha/beta lipoproteins rose (P<0.05) throughout the stable periods and decreased (P<0.05) during 'pasture'. Glutamic acid dehydrogenase, gamma-glutamyl transferase, alkaline phosphatase, aspartate aminotransferase, creatine kinase and lactate dehydrogenase activity in sera were within the normal range. In conclusion, on the precondition that substantial bodyweight changes were prevented, no apparent adverse effects of long-term high fat feeding were identified and there were no apparent disadvantages of feeding on high fat compared with high starch diets.

Effects of substituting starch with fat on the acid-base and mineral status of female horses

Feeding a high-fat diet may have potential advantages by maintaining pH homeostasis during intense exercise; conversely, effects including elevated PCV and increased plasma concentration of total protein may indicate effects detrimental to performance by reducing perfusion of tissues and organs. Six horses were used to determine the effects of an replacement of starch (diet '0.00') with 0.33, 0.67, 1.00 and 1.33 g soybean oil/kg bwt/day (diets '033', '0.67', '1.00' and '1.33') on venous and renal acid-base status and fractional clearance (FC) of electrolytes in a postprandial state but prior to exercise. Venous blood and urine were sampled for 3 days at the end of the 28 day periods, in each case 3 h postprandially. Throughout the study, the horses put on weight by 35 kg (P<0.05). From diet '0.00' to '0.67', blood pH decreased (P<0.05) and carbon dioxide tension increased (P<0.05). Simultaneously, the base and net acid-base concentration in the urine rose (P<0.05) but diuresis decreased (P<0.05) and, therefore, the daily excretion of bases and net acid-bases was only unsystematically affected. From diet '0.00' to '1.33', the FC of magnesium and chloride fell (P<0.05). These results suggested that the exchange of starch with up to moderate amounts of fat affects the venous and renal acid-base status of resting horses. The decrease in urine volume is most striking. Further research is needed to investigate the importance of these effects for sporting performance.

Metabolic functions of L-carnitine and its effects as feed additive in horses. A review

L-carnitine, a betaine derivative of beta-hydroxybutyrate, is found in virtually all cells of higher animals and also in some microorganisms and plants. In animals it is synthesized almost exclusively in the liver. Two essential amino acids, i.e., lysine and methionine serve as primary substrates for its biosynthesis. Also required for its synthesis are sufficient amounts of vitamin B6, nicotinic acids, vitamin C and folate. The first discovered ergogenic function of L-carnitine is the transfer of activated long-chain fatty acids across the inner mitochondrial membrane into the mitochondrial matrix. For this transfer acyl-CoA esters are transesterified to form acylcarnitine esters. Thus, in carnitine deficiency fat oxidation and energy production from fatty acids are markedly impaired. Skeletal muscles constitute the main reservoir of carnitine in the body and have a carnitine concentration at least 200 times higher than blood plasma. Uptake of carnitine by skeletal muscles takes place by an active transport mechanism which transports L-carnitine into muscles probably in the form of an exchange process with gamma-butyrobetain. In young animals including foals, the capacity for biosynthesis of carnitine is not yet fully developed and apparently cannot meet the requirements of sucking animals. Sucking animals depend therefore on an extra supply of carnitine which is usually provided with milk. Additionally, young animals including foals possess a lower concentration of carnitine in blood plasma than adult animals. Besides its role as carrier of activated acyl groups, L-carnitine functions as a buffer for acetyl groups which may be present in excess in different tissues during ketosis and hypoxic muscular activity. Other functions of L-carnitine are protection of membrane structures, stabilizing of a physiologic CoA-SH/acetyl-CoA ratio and reduction of lactate production. Animal's derived feeds are rich in L-carnitine whereas plants contain usually very little or no carnitine. Carnitine is absorbed from the small intestine by active and passive transport mechanisms. From the increase in renal excretion of L-carnitine after oral supplementations of 10 g/d to horses it has been concluded that the efficiency of absorption of L-carnitine is rather low (about 5 to 10% of the supplied dose). A further decrease in fractional carnitine absorption was observed when the oral dose of carnitine was increased. L-carnitine is virtually not degraded in the body and renal excretion of carnitine is comparatively small under normal conditions. The concentration of L-carnitine in blood plasma of horses varies markedly between animals and between different days. In addition, circadian changes in carnitine concentration in plasma have been reported. Peak concentrations were found during late afternoon, being up to 30% higher than those in the morning. In breeding mares the carnitine concentration in blood plasma declines with onset of lactation. In resting skeletal muscles about 90% of the total carnitine content is present as free carnitine with the remaining part being available as carnitine esters. With increasing exercise intensity a continuing greater proportion of free carnitine (up to 80%) is converted into carnitine esters, mainly into acetylcarnitine. This shift from free to acetylcarnitine is readily reversed within about 30 min after termination of exercise. It appears that acute exercise does not have a marked effect on the content of total carnitine in skeletal muscle whereas training seems to elevate its total concentration in the middle gluteal muscle of 3 to 6 year old horses and to reduce variation of its concentration compared to age-matched untrained horses. Oral supplementations of 5 to 50 g of L-carnitine per day to horses elevated the carnitine concentration in blood plasma to about twice its basal concentration. No clear relationship existed, however, between the orally administered dose of carnitine and the increase of L-carni