Potential nutritive value and tannin bioassay of selected Acacia species from Kenya

Six Acacia forage species–A. brevispica, A. elatior, A. mellifera, A. nilotica, A. senegal and A. seyal—were analysed for their chemical composition, including phenolics and rumen fermentation characteristics. In vitro gas production technique was used to study the rumen fermentation characteristics and the effect of tannins present in the browse forages on in vitro fermentation by including polyethylene glycol (PEG‐6000) in the incubation. The forages had high crude protein content (145.7–270.1 g kg^?1 DM) and low to moderate content of neutral detergent fibre (220.2–442.8 g kg^?1 DM). The forages had variable content of total extractable phenolics ranging from 18.4 to 384.2 g kg^?1 DM and total extractable tannins ranging from 7.1 to 364.8 g kg^?1 DM (tannic acid equivalent). Fractionation of the condensed tannin flavonoids showed that the delphinidin/cyanidin ratio ranged from not detected:100 to 71:29. The gas production potential ranged from 28.4 to 40.8 mL gas 0.2 g^?1 DM. The rate of gas production was highest in A. elatior and lowest in A. nilotica. Addition of PEG‐6000 increased gas production significantly (P < 0.05) in all species except A. mellifera. PEG‐6000 addition did not have any significant effect on in vitro true dry matter and organic matter degradability but decreased the partitioning factor in all the species. Gas production and degradability parameters correlated positively with the CP content and negatively with the fibre and phenolics contents. Based on chemical composition, gas production and degradability, the forages have high potential nutritive value, especially as supplements to low‐quality feeds in the tropics and particularly during the dry season. However, the presence of tannins in terms of high levels and biological antinutritive activity may limit the nutritive potential of some of the forages, such as A. seyal and A. nilotica. Copyright © 2007 Society of Chemical Industry     

The effects of sorbates on the ensilage of chopped whole-plant maize and lucerne

The incorporation of (a) sorbic acid (0.18 and 0.90 g kg^?1, fresh weight basis) and potassium sorbate (0.90 g kg^?1) with chopped lucerne, and (b) sorbic acid (0.90 g kg^?1) and potassium sorbate (0.90 g kg^?1) with chopped maize (whole-plant) at the time of ensiling, led to a reduction in the surface spoilage associated with the ensilage of these two forages. Use of sorbic acid (0.90 g kg^?1) and potassium sorbate (0.90 g kg^?1) led to (a) a reduction of volatile nitrogen (VN), higher levels of residual water-soluble carbohydrates (WSC) in lucerne silage and more aerobically stable lucerne silage and (b) a reduction in weight loss, population of yeasts and moulds, and VN, higher levels of WSC in maize silage and more aerobically stable maize silage when compared to the untreated forages or forages treated with sorbic acid and potssium sorbate at 0.045 and 0.18 g kg^?1 (fresh weight basis), respectively.     

Effects of harvest date, wilting and inoculation on yield and forage quality of ensiling safflower (Carthamus tinctorius L.) biomass

BACKGROUND: Safflower (Carthamus tinctorius L.), usually grown as a source of oil crop, can be used as fodder either for hay or ensiling purposes, particularly in semi‐arid regions. RESULTS: A 2‐year trial was conducted in southern Italy to evaluate the production and forage quality of safflower biomass cv. Centennial, harvested at three different stages: 1, at complete appearance of primary buds (PB); 2, at complete appearance of secondary and tertiary buds (STB); and 3, at 25% of flowering stage (FS). For each stage of growth, 50% of the biomass was ensiled in 4 L glass jars without and with inoculation (Lactobacillus plantarum, LAB), and the other 50% was field wilted for 24 h before ensiling. Dry matter (DM) content and yield (DMY), pH, buffering capacity (BC) and water soluble carbohydrates (WSC) were determined on fresh forage. On safflower silages were also evaluated ammonia‐N, crude protein (CP), fibre fractions, fat, lactic and acetic acids, Ca and P, and gas losses. DMY ranged from 4.5 t ha^?1 (PB harvesting) to 11.6 t ha^?1 (FS harvesting). DM content varied from 129 g kg^?1 (PB not wilted) to 630 g kg^?1 (FS wilted). The WSC in forage before ensiling with not wilting ranged from 128 (PB stage) to 105 and 100 g kg^?1 DM at STB and FS stages, respectively. The wilted safflower forage showed a lower WSC compared to wilted forage. The high sugar substrate allowed lactic acid fermentation and a good conservation quality in all the harvesting stages. Silages quality was strongly influenced by the treatment performed. Wilting practice increased DM, pH and NDF contents but reduced lactic acid, acetic acid and NH₃‐N values. Inoculation reduced DM, pH and NDF contents, but increased lactic and acetic acids, CP and ash. CONCLUSION: As result, wilting the forage for 1 day was very effective in the early harvesting stage because this practice significantly increased DM, reducing on the same time the intensive fermentation and proteolysis processes of silage. When harvesting is performed at the beginning of the flowering stage wilting is not necessary. Copyright © 2011 Society of Chemical Industry     

Assessment of nutritional compounds and antinutritional factors in pea (Pisum sativum) seeds

The nutrient and antinutritional factor content of 18 pea lines was studied. The following levels were found: non‐protein nitrogen 5.2–10.2 g kg^?1 DM, protein nitrogen 35.3–42.4 g kg^?1 DM, lysine 50.7–76.3 g kg^?1 protein DM, histidine 17.8–24.8 g kg^?1 protein DM, tyrosine 22.6–30.0 g kg^?1 protein DM, protein 25.9–31.9% DM, in vitro protein digestibility 89.3–95.6%, vitamin B₁ 5.9–10.3 mg kg^?1 DM, vitamin B₂ 1.1–3.7 mg kg^?1 DM, sucrose 11.6–25.4 g kg^?1 DM, raffinose 4.1–10.3 g kg^?1 DM, stachyose 10.7–26.7 g kg^?1 DM, verbascose 0.0–26.7 g kg^?1 DM, total α‐galactosides 22.6–63.4 g kg^?1 DM, trypsin inhibitor activity 0.8–8.4 TIU mg^?1 DM, inositol hexaphosphate 2.3–6.5 g kg^?1 DM, inositol pentaphosphate 0.1–1.8 g kg^?1 DM and total inositol phosphates 2.8–7.1 g kg^?1 DM. Peas with yellow cotyledons had the highest trypsin inhibitor activities, those with light green cotyledons had the highest lysine contents, and those with dark green cotyledons were the richest in vitamins B₁ and B₂. Peas with brown testae had the lowest verbascose and sucrose contents, while they were the richest in inositol hexaphosphate. Smaller peas were characterised by the highest protein nitrogen contents as well as the highest contents of vitamins B₁ and B₂, verbascose and inositol pentaphosphate. Peas of medium size showed the lowest verbascose, α‐galactoside and vitamin B₂ contents. Bigger peas showed the lowest inositol pentaphosphate contents. © 2003 Society of Chemical Industry     

Short communication: salivary secretion during meals in lactating dairy cattle

Four multiparous Holstein cows in midlactation were used in a 4 × 4 Latin square to evaluate whether source of forage influenced salivary secretion during eating in lactating dairy cows. The forages were allocated separately from the pelleted concentrates. Cows were offered 1 of 4 forages each period: barley silage, alfalfa silage, long-stemmed alfalfa hay, or chopped barley straw. Saliva secretion was measured during the morning meal by collecting masticates through the rumen cannula at the cardia of each cow. Rate of salivation (213 g/min) was not affected by forage source. However, the forage sources differed in eating rate (g of DM/min), which led to differences in ensalivation of forages (g of saliva/g of DM and g of saliva/g of NDF). On the basis of DM, ensalivation (g of saliva/g of DM) was greatest for straw (7.23) and similar for barley silage, alfalfa silage, and alfalfa hay (4.15, 3.40, and 4.34 g/g of DM, respectively). Higher ensalivation of straw could be accounted for by its higher neutral detergent fiber (NDF) content; ensalivation of NDF (g of saliva/g of NDF) was actually greatest for long-stemmed alfalfa hay (12.4) and similar for the other chopped forages (8.9). Cows consumed concentrate about 3 to 12 times faster than the various forages (DM basis), and ensalivation of concentrate was much lower (1.12 g of saliva/g of DM) than for forages. Feed characteristics such as particle size, DM, and NDF content affect salivary output during eating by affecting the eating rate. Slower eating rate and greater time spent eating may help prevent ruminal acidosis by increasing the total daily salivary secretion in dairy cows.     

The effects of the rate of addition of formic acid and sulphuric acid on the ensilage of perennial ryegrass in laboratory silos

Perennial ryegrass was ensiled in laboratory silos after addition of formic acid (850 g kg^?1) or sulphuric acid (906 g kg^?1) at rates of 0, 2, 4 and 6 litres t^?1 fresh grass. Silos were opened after 6, 18 and 90 days and the silage subjected to chemical and microbiological analysis. The untreated control was poorly fermented with a final pH of 4.7, a butyric acid concentration of 19 g kg^?1 dry matter (DM) and an NH₃-N content of 275 g kg^?1 total nitrogen (TN). For the formic acid treatments the 2 litre t^?1 and 6 litre t^?1 levels both produced well-preserved silages but they were of different types. The silage treated with 2 litre t^?1 had a pH of 4.0, a lactic acid concentration of 92 g kg^?1 DM and 161 g NH₃-N kg^?1 TN, whereas with the 6 litre t^?1 treatment, fermentation had been severely restricted. The pH was 4.2, the lactic acid concentration was only 8 g kg^?1 DM and the NH₃-N content was 80 g kg^?1 TN. However, formic acid at 4 litre t^?1 produced a badly fermented silage of final pH 5.0 with lactic acid and butyric acid concentrations of 16 and 15 g kg^?1 DM, respectively, and an NH₃-N content of 149 g kg^?1 TN. Sulphuric acid at 2 and 4 litres t^?1 produced silages of low lactic acid contents, 36 and 24 g kg^?1 DM, and they also contained butyric acid in concentrations of 13 and 11 g kg^?1 DM; respective NH₃-N contents were 206 and 114 g kg^?1 DM. When sulphuric acid was added at 6 litres t^?1, despite a reduction in the pH of the grass to 3.5, fermentation was not restricted as it was with the equivalent level of formic acid. Lactic acid was present at 27 g kg^?1 DM and the ethanol concentration was very high at 66 g kg^?1 DM; the sulphuric acid-treated silages were characterised by high yeast counts. At the higher rates of addition, formic acid reduced the.     

Chemical composition and nutritive value of peach palm (Bactris gasipaes Kunth) in rats

The peach palm (Bactris gasipaes Kunth) is the starchy fruit of a palm tree widely cultivated in Central and South America. The present study aimed at determining its chemical composition and its nutritive value in rats. The average chemical composition of 17 samples was as follows: 410 g kg^?1 water and, in g kg^?1 of dry matter (DM), 54 g crude protein, 114 g oil, 39 g neutral detergent fibre, 716 g starch, 21 g sugars and 18 g ash. The main variability was observed for the oil (60–180 g kg^?1 DM) and starch (590–780 g DM) contents. The proteins contained, on average, in g kg^?1 of proteins, 49 g lysine, 13 g methionine, 19 g cysteine, 39 g threonine and 7 g tryptophan. The mineral fraction contained, per kg DM: 1.0 g Ca, 0.8 g P, 0.6 g Mg, 0.3 g Na, 44 mg Fe, 4 mg Cu and 10 mg Zn. The digestibility of four peach palm genotypes was determined in rats fed a diet composed of 350 g kg^?1 of peach palm and 650 g of a control diet based on maize and soybean meal. The digestibility of DM, energy, starch and protein of peach palm alone reached, on average 91, 87, 96 and 95%, respectively. No difference was observed between varieties, except for starch (p < 0.05). On average, peach palm contained 51 g of truly digestible protein kg^?1 DM and 3.691 kcal digestible energy kg^?1 DM. A growth trial was also carried out for 1 month on rats (initial weight: 78 g) fed a diet containing 0, 200, 400, 600 or 800 g peach palm kg^?1, at the expense of a diet composed of maize starch and casein. The growth rate of the rats decreased (p < 0.05) as the peach palm concentration increased. The growth decrease was due to a decrease (p < 0.05) in DM intake and to the lower quality of the peach palm protein. It is concluded that peach palm is mainly an energy source for humans and animals. It is poor in protein and minerals but can be consumed in large amounts. Copyright © 2005 Society of Chemical Industry     

Stability of fatty acids during wilting of perennial ryegrass (Lolium perenne L.): effect of bruising and environmental conditions

BACKGROUND: Oxidation of fatty acids (FA) during field wilting of herbage could cause extensive losses of polyunsaturated FA. Recent studies showed a variable effect of wilting on the losses of FA. This suggests that environment and management conditions influence the loss of FA during wilting. The present study investigated the stability of FA in untreated and mechanically bruised perennial ryegrass, wilted under field conditions for 0, 12, 24, 36 and 48 h, or wilted under controlled climate conditions at three temperatures (15, 25 or 35 °C) and two light (dark or light) regimes to dry matter (DM) contents of 425, 525 or 625 g kg^?1. RESULTS: During 48 h of field wilting, the total FA content declined (15.2 to 11.9 g kg^?1 DM) consistently, despite an increase in herbage DM content (197 to 676 g kg^?1). Under controlled climate conditions, the herbage total FA content declined (15.1 to 11.7 g kg^?1 DM) mainly during the prolonged (56 to 62 h) initial drying to a DM content of 425 g kg^?1 and did not decline with further drying to DM contents of 525 and 625 g kg^?1. The decline in total FA was associated with a parallel decline in C18:3 content under field (9.15 to 6.36 g kg^?1 DM) and controlled (9.12 to 6.15 g kg^?1 DM) conditions. Concomitantly, the proportion of C18:3 in total FA decreased, whilst the proportion of C16:0 and C18:0 increased. Lower losses of FA (P < 0.05) were observed at 15 °C compared to 25 and 35 °C. Light did not affect the losses of FA during wilting. CONCLUSIONS: The duration of the wilting period mainly affected the changes in FA content and composition. Stability of FA in herbage could be increased by minimising the duration of wilting. Copyright © 2011 Society of Chemical Industry     

Responses of intake,digestibility and nitrogen utilisation in goats fed low‐quality roughages supplemented with tree foliages

BACKGROUND: A meta‐analysis of data containing 127 different dietary treatments with 593 goats from 30 published studies was performed to explain the effects of foliage supplementation to low‐quality roughages on intake, digestibility and N utilisation in goats. RESULTS: Basal dry matter (DM) intake decreased linearly with increasing foliage level (FL) in diets and foliage crude protein (CP) intake, whereas total DM intake increased linearly with increasing FL and CP intake from foliages and quadratically with increasing concentration of neutral detergent fibre (NDF) in foliages. The digestibility of DM and CP increased linearly with increasing FL and CP concentration in basal roughages and foliage CP intake. The greater concentration of NDF in foliages and roughages decreased CP digestibility linearly. Intakes of digestible DM and CP increased quadratically with increasing FL, with plateau levels of 36.4 and 5.52 g kg^?1 (body weight)^0.75 in response to 490 and 740 g kg^?1 FL respectively. Faecal N, urinary N and N retention increased linearly with increasing FL and foliage CP intake. CONCLUSION: Responses of goats fed basal roughages supplemented with foliages are influenced by the quality and quantity of foliages and quality of roughages. Up to 490 g kg^?1 FL can be incorporated in diets for better feed utilisation and animal performance, beyond which nutrient utilisation may be adversely affected. Copyright © 2009 Society of Chemical Industry     

Quality of cassava foods in Sierra Leone

Gari and foofoo (fermented cassava foods) were purchased in the Freetown markets of Sierra Leone and analysed for factors associated with quality. Sellers were generally knowledgable about the source of the products which all originated from the country areas outside Freetown. The mean cyanide contents were higher (8.6 mg kg^?1 DM for gari and 28.2 mg kg^?1 DM for foofoo) than the amounts suggested by the Codex specification and, because of the distribution of the values around the mean, some samples necessarily contained unacceptable amounts of cyanide. Cyanogens were present as the cyanohydrin or as free cyanide; no glucoside was detected. Microbiological analysis of the samples showed high counts for total organisms, fungi and Enterobacteriaceae (10⁶–10⁷ g^?1). The mean water content of gari was 119 g kg^?1 which falls within the recommended limit of 120 g kg^?1 but again, due to the distribution of values around the mean, some samples had considerably higher water contents than that limit. Titratable acidity and pH were measured and the mean pH values were 4.18 for foofoo and 4.55 for gari. The particle size and swelling power of gari samples were also measured as these relate to consumer acceptance. The data show the quality of current cassava foods marketed in a major urban centre in Sierra Leone. As centralised processing develops, improvements can be made to those quality parameters which have been identified as important.     

Characterisation of the leaf meals,protein concentrates and residues from some tropical leguminous plants

Leaf meals (LMs) from freshly harvested leaves of butterfly pea (Centrosema pubescens), devil bean (Mucuna pruriens), flamboyant flower (Delonix regia), Bauhinia tomentosa, coast wattle (Acacia auriculiformis), quick stick (Glyricidia sepium) and ipil‐ipil (Leucaena leucocephala) were analysed for their nutrient and anti‐nutritional content. Then, leaf protein concentrates (LPCs) were produced from the leaves by fractionation and characterised along with the fibrous residues. On average, the LM contained 181 g kg^?1 dry matter (DM) CP (range: 100–280 g kg^?1 DM), 139 g kg^?1 DM crude fibre (range: 77–230 g kg^?1 DM) and 133 g kg^?1 DM ether extract (range: 86–165 g kg^?1 DM) while the gross energy averaged 17.0 MJ kg^?1. On average, leaf protein fractionation enhanced the CP, ether extract and the gross energy in the LPC by 39.5%, 33.5% and 22.0%, respectively, while the crude fibre of the LMs was reduced by 41%, on average, in the LPCs. Fractionation reduced the mineral content of the leaves generally. The mean phytin content varied from 0.36 g kg^?1 in LPCs to 0.86 g kg^?1 in leaf meal, while the mean phytin‐P content varied from 0.10 g kg^?1 in LPCs to 0.24 g kg^?1 in leaf meal. The total phenol levels in the LMs were reduced by 33.7% in the LPCs, on average. These results suggest that, while the LPCs from these plants could be used as protein supplements in non‐ruminant feeds in regions where there is an acute shortage of plant protein, the LMs or LPC fibrous residues could be fed to ruminant animals. Copyright © 2006 Society of Chemical Industry     

Influence of drying mode on iridoid bitter constituent levels in gentian root

Root samples of wild gentian (Gentiana lutea L) were harvested from six localities (altitude 970 m to 1350 m) from May to November 2000. Each batch of roots was split into three: fresh roots, naturally dried roots (ambient air) and artificially dried roots (40 °C). In all the samples, levels of iridoid bitter constituents and of xanthone coloured compounds were determined by HPLC. The mean total iridoid content in the fresh roots was 102.4 g kg^?1 in dry matter (DM). The mean level of the principal bitter compound gentiopicroside was particularly high at 81 g kg^?1 DM. Loganic acid, not previously reported in G lutea, was the second most abundant bitter compound at a mean level of 14.3 g kg^?1 DM. Swertiamarin was present at 5.4 g kg^?1, with another minor unidentified iridoid. Levels of iridoid compounds were strongly dependent of the drying mode. These amounts were 88.5 g kg^?1 DM in artificially dried roots and 62.5 g kg^?1 DM in naturally dried roots, mostly owing to a marked decrease in gentiopicroside. The temperature of 40 °C preserved the bitter compounds and the bitterness of fresh gentian roots. The amount of coloured xanthones was relatively low at 3.3 g kg^?1 and did not change with the drying mode. Copyright © 2004 Society of Chemical Industry     

The ratios of degradation characteristics of forages in the rumen of dairy cows: effect of variety and stage of maturity

In situ digestive characteristics of neutral detergent fibre (NDF), non‐fibre carbohydrates (NFC) and crude protein (CP) in alfalfa and timothy were determined in the rumen of dairy cows. Two varieties of alfalfa (Pioneer and Beaver) and timothy (Climax and Joliotte) were grown in western Canada and cut at three maturity stages (alfalfa: 1 = early bud, 2 = late bud, 3 = early bloom; timothy: 1 = joint, 2 = pre – bloom head, 3 = full head). Measured ruminal degradation characteristics were soluble fraction (NFC, CP), undegradable fraction (NDF, CP), lag time (NDF) and rate of degradation of the insoluble but degradable fraction (NDF, NFC, CP). All measured characteristics showed large differences between the two forage species (alfalfa vs timothy) and to a lesser extent between the maturity stages and varieties. Mean total rumen available NDF (248.6 vs 282.5 g kg^?1 dry matter (DM)), NFC (200.5 vs 106.1 g kg^?1 DM) and CP (139.7 vs 44.5 g kg^?1 DM) differed (p < 0.01) between alfalfa and timothy. Based on the measured characteristics, degradation ratios were calculated between total rumen available N and carbohydrates (FN/FCHO), soluble N and carbohydrates (SN/SCHO) and rumen available insoluble N and carbohydrates (EN/ECHO). The ratios showed large differences between the two forages species and to a lesser extent between the varieties and stages of maturity. Alfalfa species had significantly higher (p < 0.01) ratios of FN/FCHO (49.8 vs 18.3 g kg^?1), SN/SCHO (115.0 vs 36.1 g kg^?1) and EN/ECHO (28.3 vs 12.0 g kg^?1) than timothy. These results indicate that alfalfa varieties exhibited a superior rumen fermentation ratio (optimum FN/FCHO = 25–33 g N kg^?1 carbohydrates). The results also suggest a potential N loss in alfalfa and N shortage in timothy. Comparing the two varieties of alfalfa, no differences (p > 0.05) were found in the ratios of FN/FCHO and EN/ECHO, but a significant difference (p < 0.05) was found in SN/SCHO (132.3 vs 97.6 g kg^?1). However, comparing the two varieties of timothy, there were significant differences (p < 0.01) in FN/FCHO (23.8 vs 12.8 g kg^?1) and EN/ECHO (15.3 vs 8.7 g kg^?1) ratios but not in SN/SCHO ratio (p > 0.05), indicating large differences between legume and grass. As plant maturity advanced from stage 1 to stage 3, there were no significant changes in all ratios in alfalfa and timothy except the EN/ECHO ratio in timothy (14.3, 13.4 and 8.3 g kg^?1 at stages 1, 2 and 3 respectively). It was concluded that the degradation characteristic ratios were dependent on species, variety and/or stage of maturity. Such ratios could be used to optimise a dairy diet composition with regard to rumen fermentation. Copyright © 2004 Society of Chemical Industry     

Germination alters the chemical composition and protein quality of lupin seeds

The chemical composition and protein quality of the kernels from Lupinus angustifolius seeds were compared with that for sprouts after 6 days germination. Germination resulted in an apparent increase in protein content from 395 g kg^?1 to 435 g kg^?1 DM. Fat and carbohydrate contents decreased. The oligosaccharide content of the sprouted lupin fell to a negligible level, while the phytate and alkaloid concentrations fell from 4.7 g kg^?1 to 1.6 g kg^?1 and from 0.72 g kg^?1 to 0.16 g kg^?1, respectively. The quality of lupin kernel protein was poor with a protein efficiency ratio (PER) of 1.45±0.15. Supplementation of kernel with DL-methionine (2.0 g kg^?1) increased the protein quality (PER = 2.87±0.17) to that of casein (PER = 2.86±0.18). Germination reduced protein quality (PER = 0.44±0.16), and did not improve apparent protein digestibility (APD kernel = 80.4%; APD sprout = 77.5%). Supplementation of sprout protein with DL-methionine (2.0 g kg^?1) increased the protein quality (PER = 2.57±0.20). The total sulphur-containing amino acid concentration of lupin kernel protein, 1.9 g per 16 g N was low, and decreased further to 1.3 g per 16 g N in the sprout, a drop of 32%. The results showed that germination of lupin seeds reduced the concentration of the anti-nutritive factors; however, it also reduced protein quality.     

Fermentation characteristics,aerobic stability and ruminal degradation of ensiled pea/wheat bi‐crop forages treated with two microbial inoculants,formic acid or quebracho tannins

This study evaluated the effects of two commonly used microbial inoculants (Lactobacillus buchneri (LB) and Lactobacillus plantarum (LP)), formic acid (FA) and quebracho tannins (QT) on the fermentation quality, aerobic stability and in situ rumen degradation of pea/wheat bi‐crop forages. Precision‐chopped spring pea (Pisum sativum, var Magnus) and wheat (Triticum aestivum, var Axona) bi‐crops (3:1 pea/wheat ratio) harvested at a combined dry matter (DM) content of 301 g kg^?1 were used for the study. The bi‐crops were conserved without (Control) or with inoculants based on lactic acid bacteria (LB (10⁵ CFU g^?1 fresh weight (FW)) or LP (10⁶ CFU g^?1 FW)), QT (16 g kg^?1 FW) or FA (2.5 g kg^?1 FW) in laboratory silos of 1.5 kg capacity, with each treatment being replicated six times. The pH, chemical composition, aerobic stability and in situ rumen degradation of DM, nitrogen (N) and neutral detergent fibre (NDF) after 112 days of ensilage were measured. The average pH at silo opening was 4.0, suggesting that the silages were well fermented. There were no significant effects of additive treatment on water‐soluble carbohydrate, total N, soluble N, ammonia N and NDF. Lactic acid and acetic acid were the main fermentation products. High concentrations of acetic acid were found in all the treatments, indicating a heterofermentative pathway. Although FA treatment gave the most aerobically stable silage, the Control and QT‐treated silages did not heat up by more than 1 °C until after 6 days of exposure to air. There were no effects of additives on DM degradation characteristics. However, the inoculants increased the rate of N and NDF degradation in the rumen, and both FA and QT reduced the effective and potential degradation of N. © 2001 Society of Chemical Industry     

Distribution of aflatoxins and fumonisins in dry-milled maize fractions

The aim was to evaluate the distribution of aflatoxins and fumonisins in fractions derived from the dry-milling of contaminated maize. Two maize lots with different contamination levels were processed and sampled: the first (maize 1) had aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁) levels of 3.6 and 5379 µg kg^?1, respectively; the second (maize 2) had corresponding levels of 91.1 and 8841 µg kg^?1, respectively. The cleaning step reduced AFB₁ and FB₁ levels by 8 and 11% in maize 1 and by 57 and 34% in maize 2. The subsequent removal of bran and germ led to a further decrease in contamination levels in the products destined for human consumption. In the latter, AFB₁ was uniformly distributed, while FB₁ was concentrated in the finer size fractions. Contamination of raw maize 1 (3.6 µg kg^?1) was below the European Union AFB₁ limit of 5 µg kg^?1 for unprocessed maize, but among the final products only coarse flour (1.7 µg kg^?1) was within the European Union limit of 2 µg kg^?1, while grits and fine flour showed higher levels (2.7 and 2.5 µg kg^?1, respectively). As regards cleaned maize, a different distribution of the two toxins was observed in the kernels: AFB₁ contamination was more superficial and concentrated in germ, while FB₁ contamination affected the inner layers of the kernels.     

Comparison of a colorimetric and a high-performance liquid chromatography method for the determination of fructan in pasture grasses for horses

BACKGROUND: Pasture (fresh or conserved as hay/haylage) forms the basis of most equid diets and contains varying amounts (0 to ≥ 200 g kg^?1 dry matter (DM) or more) of fructans. Over‐consumption of fructan is associated with the onset of laminitis in equids, an agonizing condition that may necessitate euthanasia. To enable appropriate dietary management of animals susceptible to laminitis, it is essential that fructans can be properly quantified in fresh and conserved pasture. For research purposes, fructans are frequently quantified by high‐performance liquid chromatography (HPLC), but these methods are costly for routine screening. However, an inexpensive colorimetric method for measuring fructans in human foods is commercially available. The aim here was to determine the suitability of the commercially available colorimetric method for determining the fructan content of pasture grasses for horses. RESULTS: Pasture grasses (Phleum pretense, Festuca rubra, Dactylis glomerata, Lolium perenne) managed for grazing (sampled from April to November) and a further set managed for conservation (sampled in July) were analysed for fructan content by HPLC and the colorimetric technique. HPLC values ranged from 83 to 299 g fructan kg^?1 DM (mean 154); corresponding colorimetric values were 5‐238 g fructan kg^?1 DM (mean 82). Discrepancies in values between the two methods varied with time of sampling and plant species. Comparison of selected samples before and after incubation with the fructan hydrolases used in the colorimetric method revealed incomplete fructan hydrolysis from the pasture grasses, resulting in underestimates of their fructan content. CONCLUSION: The colorimetric technique was not a reliable substitute for HPLC to quantify the fructan content of pasture grasses. Copyright © 2012 Society of Chemical Industry     

Evaluation of total aflatoxin,nitrate and nitrite levels in layer feed samples of companies producing their own feed in Edincik and Bandırma province of Turkey

Feed contamination by fungi can lead to nutrient losses and detrimental effects on animal health and production. The presence of nitrates and nitrites in food can be harmful to both people and animals. The aim of this study was to determine total aflatoxin, nitrate and nitrite levels in layer feed samples from companies producing their own feed in Edincik and Band?rma provinces in Turkey and to discuss the potential risk to animal health. The results of the analyses indicated that mean total aflatoxin (AFT) ranged from 0.4 to 36.8?µg?kg^?1 and from 0.45 to 47.0?µg?kg^?1 in the year 2007 and the year 2008 samples, respectively. It was determined that nitrate levels were 2.4–10 and 1.7–13?µg?kg^?1 and that nitrite levels were 0–2.4?µg?kg^?1 and 0–2.6?µg?kg^?1 in these years, respectively. The levels of total aflatoxin, nitrate and nitrite in the layer samples could not be considered a risk to poultry health and productivity.     

Aspergillus Section Flavi and aflatoxins in dusts generated by agricultural processing facilities in the Philippines

Relatively few data exist regarding concentrations of aflatoxins and their causative organisms in dusts within occupational environments. Here, we examined Aspergillus Section Flavi populations and aflatoxin levels in 54 samples of dusts generated by agricultural processing facilities as possible indicators of aflatoxin exposure in the Philippines. The average incidence of Aspergillus Section Flavi expressed as a percentage of total mould populations in rice dust, corn dust, feed dust and copra dust were 8, 4, 31 and 10%, respectively. Predominant aflatoxigenic fungi isolated were Aspergillus flavus and A. parasiticus with ratios of 31:1, 40:5, 16:4 and 1:1 in rice dust, corn dust, feed dust and copra dust, respectively. Aflatoxins produced by selected isolates in in vitro rice culture ranged from 100 µg kg^?1 to 100.5 mg kg^?1. Toxigenicity of isolates based on the average aflatoxin concentrations produced by positive isolates were in the order of copra dust > corn dust > rice dust > feed dust. Average natural concentrations of aflatoxins in rice dust, corn dust, feed dust, and copra dust were 25, 6, 15 and 10 µg kg^?1, respectively. Estimates of the amount of inhaled aflatoxins by workers in an 8‐h work shift ranged from 0.06 to 114 ng, the average of which is higher than the amount of aflatoxins ingested by Filipinos due to the consumption of polished rice. The presence of highly toxigenic Aspergillus Section Flavi and aflatoxins in agricultural dust is a critical health risk for workers, considering the frequency of exposure and the possibility of inhalation and subsequent absorption of aflatoxins in the respiratory tract. Copyright © 2006 Society of Chemical Industry     

Iodine content of cooked and processed fish in Turkey

This study evaluates the effects of different cooking (grilling, frying and steaming) and processing (smoking, salting, marinating and drying) methods on iodine contents of valuable marine and freshwater fish species commonly consumed in Turkey. The highest mean iodine content of cooked fish was determined to be 3.760 mg kg^?1, 2.788 mg kg^?1, 5.831 mg kg^?1 and 6.161 mg kg^?1 in grilled anchovy, horse mackerel, Atlantic Bonito and whiting, 0.914 mg kg^?1, 1.452 mg kg^?1, 3.106 mg kg^?1 in steamed bluefish, red mullet. The highest mean iodine content of processed fish was determined to be 2.149 mg kg^?1 in smoked mackerel, 0.701 mg kg^?1 in salted Bonito, 1.128 mg kg^?1 in dried horse mackerel and 7.283 mg kg^?1 in marinated anchovy. This iodine values are also above the Upper Tolerable Nutrient Level of 100–150 μg day^?1 iodine.