Influence of N doses and form on ¹⁵N natural abundance of pepper plants: considerations for using δ¹⁵N values as indicator of N source

BACKGROUND: The aim of this study was to ascertain the effect of the N form (NO₃^?, NH₄⁺ and organic N) and N concentration on plant isotopic fractionation and on the contribution of the different N sources to the plant N budget, in order to evaluate the feasibility of using plant δ¹⁵N values for discriminating between conventional and organic crops. To this end, different N concentrations (applied as NO₃^?), N forms (NO₃^? versus NH₄⁺), and increasing NO₃^? applications to an organic N‐based fertilization regime were studied. RESULTS: When using NO₃^? as N source, intra‐plant fractionation was significant and tended to increase when NO₃^? concentration increased in the root medium. However, negligible net isotopic fractionation was observed when comparing theoretical and measured plant δ¹⁵N values. On the other hand, when plants are fertilized with a mixture of NO₃^? and NH₄⁺, differences in uptake patterns for both salts could result in variation in plant δ¹⁵N regarding to the expected value. Finally, the application of NO₃^? to plants was detected when it was combined with high levels of organic N sources, from 99:1 organic:inorganic N ratio. CONCLUSION: Under certain conditions and following some considerations concerning sampling, δ¹⁵N values can be considered to be a potential tool to guarantee the authenticity of organic products. Copyright © 2011 Society of Chemical Industry     

Influence of nitrogen form on yield and nitrate content of subirrigated early potato

Potato is classified among the vegetables with low nitrate content but, in diet, it contributes most to the daily intake of nitrate, because of its high per capita consumption. Two trials were carried out in winter–spring and autumn–winter cycles using a trough bench subirrigation system. Potato seedlings were transplanted into pots containing peat, pumice and vermiculite in a 3:1:1 volume ratio. Both trials were carried out to compare three nutrient solutions having the same nitrogen concentration (6.4 mM ), but different ammonium:nitrate (NH₄‐N:NO₃‐N) percentage ratios (100:0, 50:50 and 0:100). In the winter–spring cycle, tubers were lower in weight and were more numerous than in the autumn–winter cycle. The tuber yield of ammonium‐fed plants was lower than with the mixed form and 100% NO₃‐N, but only in the trial carried out in the winter–spring period. Nitrate‐fed plants yielded a number of tubers almost 3‐fold higher than ammonium‐fed plants. The NO₃ content of tubers harvested in spring in the presence of 100% NH₄‐N in the nutrient solution was a 25% of that in nitrate‐fed plants (44 vs 169 mg kg^?1 of fresh mass); in tubers harvested in winter, with worse light conditions, nitrate content increased with increasing NO₃‐N in the nutrient solution (26, 109, and 225 mg kg^?1 of fresh mass with NH₄‐N:NO₃‐N 100:0, 50:50 and 0:100, respectively). The substrate electrical conductivity increased with increasing ammonium concentration in the nutrient solution, and was higher in the upper layer of the substrate. Copyright © 2004 Society of Chemical Industry     

Effect of Poultry Manure on the Leaching of Carbon from a Sandy Soil as a Potential Substrate for Denitrification in the Subsoil

There is evidence from laboratory incubations that denitrifying bacteria occur in the deep subsoils of UK soils and that lack of available carbon (C) generally limits their activity. Animal manures can be a source of substantial carbon input to farming systems. This experiment measured the effect of broiler litter application on the movement of C in soil solution to depths below 1 m, which might be sufficient to allow denitrification of nitrate moving from the rooting zone towards ground water aquifers. Six broiler litter rates were applied each autumn from 1992–1994 to field plots on a loamy medium sand in Nottinghamshire, UK. Total loadings over the 3 years ranged from 0 to 125 t ha^-1 broiler litter, supplying 0–32 t ha^-1 total C. Teflon and ceramic water samplers, placed at 1·0 and 1·5 m, and monolith lysimeters (0·5 m² area, 1·5 m deep) were used to measure total organic carbon (TOC) concentrations in the drainage. Ceramic samplers indicated significantly (P<0·05) larger concentrations than Teflon samplers; there were no differences between concentrations measured by Teflon samplers and the lysimeters. Water samples analysed for both dissolved and total C showed that nearly all was in a dissolved form. TOC concentrations on plots which received no manure were less than 20 mg litre^-1 at 1 m for the duration of the experiment; concentrations peaked at 65 mg litre^-1 with the largest manure loading. There was a linear relationship between C leached and C applied, with about 5% leached below 1 m by the end of the experiment. There was some evidence of movement of C to 1·5 m depth, but there were no large peaks corresponding to those at 1 m, because of either adsorption or microbial utilisation. The results provide evidence of movement of substantial C to depth in some circumstances, particularly on fields which regularly receive large dressings of organic manure. The availability of this as a substrate for denitrification needs further examination. © 1997 SCI     

Effect of different sources of dietary omega‐3 fatty acids on general performance and fatty acid profiles of thigh,breast, liver and portal blood of broilers

One hundred and sixty‐eight 1‐day‐old Cobb broiler chickens were randomly assigned to 12 broiler cages to determine the dietary effect of different sources of oils rich in long‐chain omega‐3 polyunsaturated fatty acids (LCω3PUFA). The following oils were added to the feed at a concentration of 12.5 g kg^?1: a highly refined seal blubber oil (SBO) containing 225 g kg^?1 LCω3PUFA; a fish oil (FO) concentrate containing >800 g kg^?1 LCω3PUFA in the form of triglycerides; and an FO concentrate containing >600 g kg^?1 LCω3PUFA in the form of ethyl esters. Fatty acid profiles of the breast and thigh meat were measured in order to determine the deposition of LCω3PUFA into the body tissues, whilst fatty acid profiles of the liver and the portal blood were taken in order to deduce consequences of the different ester forms on the absorption process. A triangular sensory evaluation was performed on the breast meat. The levels of LCω3PUFA in all tissues and the portal blood reflected the concentrations of LCω3PUFA in the diets. The sensory properties of the breast meat were negatively influenced by ethyl ester supplementation only. Copyright © 2004 Society of Chemical Industry     

Interaction between nitrogen and sulfur by foliar application and its effects on flour bread‐making quality

BACKGROUND: Optimization of nitrogen (N) and sulfur (S) nutrition of wheat influences the bread‐making quality of grain. This study was conducted to determine whether the application of N and S in winter wheat at anthesis stage during two field trials could influence the absorption and distribution of N and S in grain and flour bread‐making quality RESULTS: The incorporation of ¹⁵N and ³⁴S tracers in various plant parts (leaves, stems, spikes) was determined by isotopic ratio mass spectrometry coupled with an elemental analyser (EA‐IRMS). The effects of foliar fertilization on percentage of ¹⁵N and ³⁴S recovery in various plant parts, grain yield, flour protein content, and dough properties were investigated after a combination of treatments: N (urea), S (micronized elemental S) and NS (both urea and micronized elemental S). Nitrogen (70–80%) and S (35–55%) were quickly assimilated during the days following application. Sixty days after application, 42–68% N and 6–12% S were recovered in the grain. When N and S fertilizers were applied simultaneously, N and S recoveries (68% and 12%), N/S ratios (11–14), flour protein content (115 g kg^?1) and dough strength (310 × 10^?4 J), swelling (21.8 mmH₂O) and extensibility (96.4 mm) were increased. CONCLUSION: A synergistic effect between the foliar applied N and S fertilizers appears to increase N and S assimilation in grain and may improve bread‐making qualities. Copyright © 2007 Society of Chemical Industry     

Absorption and tissue distribution of dietary quercetin and quercetin glycosides of apple skin in broiler chickens

BACKGROUND: Apple skins are a rich source of flavonols, in particular quercetin (Q) glycosides. The objective of the present study was to investigate the presence of Q metabolites in plasma, various tissues, and excreta when the commercial broiler chicken's diet was supplemented with Q (0, 50, 150, 300, or 600 mg kg^?1 body weight per day), an apple skin extract (ASE; 50, 150 mg total phenolics kg^?1 body weight per day), or a dried apple skin powder (ASP; 50 mg total phenolics kg^?1 body weight per day). RESULTS: When Q was supplemented for 3 days, Q sulfate, Q glucuronide, Q glucoside glucuronide, Q glucoside sulfate, and isorhamnetin glucoside were detected by liquid chromatography–tandem mass spectrometry in the liver and duodenum. Deconjugated Q was also detected in the breast and thigh tissues of ASE‐ and ASP‐supplemented broilers. Regardless of the source or concentration of Q, the antioxidant capacity measured by ferric reducing ability of plasma (FRAP) assay in the plasma and tissues of the broilers did not change significantly. CONCLUSIONS: As far as is known, this is the first report to demonstrate that Q and its glycosides can be absorbed and metabolized by broiler chickens. Copyright © 2010 Society of Chemical Industry     

Estimation of metabolisable energy content of date pit and its effect on lipid and protein oxidation in broiler chicks

BACKGROUND: Two experiments were conducted to evaluate date pit as a feed ingredient in broiler chick diets. In the first experiment, apparent metabolisable energy (AME) of date pit was determined using 72 Ross (308) broiler chicks. Broiler chicks received experimental diets from 25 to 30 days of age. Two diets were fed: diet 1, basal diet and diet 2, 60% basal diet + 40% date pit. Date pit ileal AME_n was estimated to be 704 kcal kg^?1. The second study was conducted to evaluate the AME_n value obtained and also the effectiveness of using a commercial multi‐enzyme in diets containing date pit. Diets with three levels of date pit (10, 20 and 30% date pit) with or without enzyme supplementation were fed to broiler chicks from day old to 42 days of age. RESULTS: Chicks receiving different levels of dietary date pit had comparable body weight to those fed on corn–soybean meal diet. Both date pit levels and enzyme supplementation had a significant effect on feed conversion ratio. Plasma total antioxidant levels of positive control were significantly lower than the experimental diets. CONCLUSION: Results obtained in our study suggested that date pit could be used as a feed ingredient in the diet of broiler chicks without any negative effect on performance. Furthermore, date pit may have beneficial effects on plasma antioxidant status in broiler chicks. Copyright © 2009 Society of Chemical Industry     

In vitro inhibitory effects of cranberry bean (Phaseolus vulgaris L.) extracts on aldose reductase, α‐glucosidase and α‐amylase

The in vitro inhibitory activities of different seed extracts prepared from cranberry bean mutant SA‐05 and its wild‐type variety Hwachia against aldose reductase, α‐glucosidase and α‐amylase were examined. The results indicated that the polyphenolics‐rich extracts obtained using 800 g kg^?1 methanol and 500 g kg^?1 ethanol demonstrated inhibitory activities against aldose reductase (IC₅₀ of 0.36–0.46 mg mL^?1) and α‐glucosidase (IC₅₀ of 1.32–1.94 mg mL^?1). The 500 g kg^?1 ethanol extracts also showed α‐amylase inhibitory activities (IC₅₀ of 70.11–80.22 μg mL^?1). Subsequent extracts, prepared further with NaCl and H₂O from precipitates of 800 g kg^?1 methanol or 500 g kg^?1 ethanol extracts, exhibited potent α‐amylase inhibitory activities (IC₅₀ of 17.68–38.68 μg mL^?1). A combination of 500 g kg^?1 ethanol extraction plus a subsequent H₂O extraction produced highest polyphenolics and α‐amylase inhibitors. The SA‐05 α‐amylase inhibitor extracts showed greater inhibitory activities than that of Hwachia. Thus, cranberry bean mutant SA‐05 is an advantageous choice for producing anti‐hyperglycaemic compounds.     

Immunomodulatory and hepatoprotective role of feed-added Berberis lycium in broiler chicks

BACKGROUND: A large number of plants and their isolates have been shown to potentiate immunity. Some plants exert anti‐inflammatory and anti‐stress effects, others hepatoprotective activity. In this study, 320 1‐day‐old broiler chicks were randomly divided into four major groups A, B, C and D and fed rations supplemented with 0, 15, 20 and 22.5 g Berberis lycium kg^?1 ration respectively. Each group was further divided into two subgroups, one vaccinated against Newcastle disease (ND) and infectious bursal disease (IBD), the other non‐vaccinated. Antibody titre against IBD and ND, relative weight of lymphoid organs, post‐challenge morbidity and mortality, serum hepatic enzymes and total serum protein were observed. RESULTS: Group C had higher anti‐IBD and anti‐ND antibody titres. Relative bursa weight in groups C and D was higher until day 28, but birds in group C performed better at later stages of examination. Relative spleen weight was highest in group C. During initial stages there was no effect on relative thymus weight, but at later stages the effect was significant. Groups C and D performed similarly in terms of relative thymus weight. The birds were challenged to field IBD through intramuscular injection at a dose rate of 0.5 mL per bird. Post‐challenge morbidity was lowest in groups C and D, while treatment significantly (P < 0.001) affected mortality amongst affected (morbid) birds. Levels of serum alanine aminotransferase and alkaline phosphatase were lowest in group C. Serum protein was similar in all groups and in both vaccinated and non‐vaccinated broiler chicks. CONCLUSION: Berberis lycium added to feed at 20 g kg^?1 is effective in improving immunity against ND and IBD as well as liver function in broiler chicks. Copyright © 2011 Society of Chemical Industry     

Quality of fresh‐cut baby spinach grown under a floating trays system as affected by nitrogen fertilisation and innovative packaging treatments

BACKGROUND: Alternative techniques for cultivation of leafy vegetables such as a floating tray system and unconventional gas mixtures for post‐harvest active modified atmosphere packaging (MAP) could be of interest in the minimally processed vegetable industry. RESULTS: The combined effect of three pre‐harvest fertilisation doses (8, 12 or 16 mmol N L^?1) and three post‐harvest MAP conditions (passive, super‐atmospheric or N₂O‐enriched) on the main quality attributes of fresh‐cut baby spinach leaves throughout 10 days at 5 °C was studied. After 8 days of shelf life, spinach leaves fertilised with 8 and 16 mmol N L^?1 and stored under N₂O‐enriched MAP showed the lowest microbial growth, with good sensory quality. Such combined treatments also preserved the total antioxidant capacity sampled at harvest (8 g ascorbic acid equivalent antioxidant capacity kg^?1 f.w.). A decrease of 10–20% in total vitamin C content regardless of N fertilisation and packaging treatment was found during shelf life. Total phenolics content at harvest was 2 g gallic acid equivalents kg^?1 f.w., which was slightly decreased or preserved during shelf life while total chlorophylls were preserved for all treatments assayed around 550 mg kg^?1 f.w. CONCLUSION: No clear effect of fertilisation doses was observed during post‐harvest storage on overall quality of fresh‐cut baby spinach leaves, while N₂O‐enriched atmospheres seems to be a promising alternative to passive MAP for extending shelf life. Copyright © 2010 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     

Integrated processing of fresh Indian sea buckthorn (Hippophae rhamnoides) berries and chemical evaluation of products

An efficient pilot‐scale process was developed to produce nutraceutical products from fresh sea buckthorn (Hippophae rhamnoides) berries. Fresh berries were subjected to high‐pressure dewatering using a continuous screw press. The separated liquid phase containing 80–90% of pulp oil was clarified at 80 °C and centrifuged to obtain pulp oil, clear juice and sludge. The pulp oil yield was 2.7–2.8% of fresh berry weight with 66–70% extraction efficiency. The pulp oil was remarkably rich in carotenoids (2450–2810 mg kg^?1), tocopherols (1409–1599 mg kg^?1) and sterols (4096–4403 mg kg^?1), with a characteristic fresh berry flavour and 16:1 as the major fatty acid (45.6–49.1%). The clear juice obtained was free from oil and contained high amounts of vitamin C (1683–1840 mg kg^?1) and phytochemicals such as polyphenols (2392–2821 mg kg^?1) and flavonoids (340–401 mg kg^?1). Isorhamnetin (251–310 mg kg^?1) was the major flavonoid in the juice, along with quercetin (77–81 mg kg^?1) and kaempherol (12–16 mg kg^?1). The juice was very acidic (pH 3), with high concentrations of organic acids (30.8–36.0 g kg^?1). High‐performance liquid chromatography profiling of organic acids revealed quinic acid (18.1–19.9 g kg^?1) as the major acid in the juice. The seeds in the pressed cake were separated and extracted for oil using supercritical CO₂. Copyright © 2006 Society of Chemical Industry     

Unexploited Acacia cyanophylla seeds: potential food sources of ω6 fatty acids and antioxidants?

BACKGROUND: In order to investigate new sources of dietary phytochemicals, recent studies have focused on underexploited seeds. In this study the total lipid contents, fatty acid profiles and levels of soluble proteins, minerals and antioxidants in seeds from 12 Acacia cyanophylla ecotypes commonly grown in Tunisia were determined. RESULTS: Total lipids averaged 101.7 g kg^?1 on a dry weight basis. Linoleic (61.11–65.45% of total fatty acid content), oleic (19.67–22.85%) and palmitic (9.18–9.98%) acids were the principal fatty acids. Smaller proportions of stearic (1.49–1.82%), vaccenic (1.13–2.05%) and palmitoleic (0.34–0.58%) acids were also quantified. Proteins (by Kjeldahl assay) averaged 107.2 g kg^?1 on a dry weight basis. Total phenolics averaged 1.91 g gallic acid equivalent kg^?1 dry weight (DW) and total flavonoids averaged 0.40 g rutin equivalent kg^?1 DW. The free radical‐scavenging activity determined by 2,2‐diphenyl‐1‐picrylhydrazyl assay averaged 0.59 mmol L^?1 Trolox equivalent antioxidant capacity (TEAC), while that determined by 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) assay averaged 0.28 mmol L^?1 TEAC. CONCLUSION: The findings of this study confirm the presence of ω6 fatty acids at high levels in A. cyanophylla seeds. These metabolites could be used as such and/or extracted for the formulation of supplements and/or ingredients to provide a ratio close to the ideal for the ω3/ω6 balance. Copyright © 2012 Society of Chemical Industry     

Functional properties and retrogradation behaviour of native and chemically modified starch of mucuna bean (Mucuna pruriens)

Mucuna bean (Mucuna pruriens) starch was isolated and subjected to chemical modification by oxidation and acetylation. The proximate analysis of the non‐starch components of the native starch on a dry weight basis was 92 g kg^?1 moisture, 5 g kg^?1 ash, 2 g kg^?1 fat, 7 g kg^?1 crude fibre and 19 g kg^?1 protein. Chemical modification reduced the values for all the non‐starch components except the moisture level. For all the samples, swelling power and solubility increased as the temperature increased in the range 50–90 °C. The swelling power of mucuna native starch (MNS) and mucuna acetylated starch (MAS) increased with increasing acidity and alkalinity, while that of mucuna oxidised starch (MOS) only increased with increasing pH in the acidic range. The maximal solubility of all the starches was observed at pH 12. All the starch samples absorbed more oil than water. The lowest gelation concentration followed the trend MAS < MNS < MOS. Chemical modification reduced the gelatinisation temperature (Tp), while peak viscosity (Pv), hot paste viscosity (Hv) and cold paste viscosity (Cv) decreased after oxidation but increased following acetylation. The setback tendency of the native starch was reduced significantly after chemical modification. However, the breakdown value of MNS, 65 BU (Brabender units), was lower than that of MOS (78 BU) but higher than that of MAS (40 BU). Differential scanning calorimetry studies of gelatinisation and retrogradation revealed that chemical modification reduced the onset temperature (T_o), peak temperature (T_p) and conclusion temperature (T_c). Oxidation and acetylation reduced the gelatinisation and retrogradation enthalpies of the native starch. The enthalpy of retrogradation of the starches increased as the length of storage increased. Copyright © 2003 Society of Chemical Industry     

Nutrient utilisation and performance of broilers in response to processed flaxseed dietary levels and vitamin B6 supplementation

The objective of this study was to determine the effects of processing and dietary inclusion level of flaxseed on broiler performance and nutrient utilisation. Flaxseed was included in the diet fed to day‐old broilers for the first 3 weeks as whole seed, ground seed, autoclaved whole seed, ground autoclaved whole seed or whole seed pelleted with the other ingredients, at levels of 0, 100, 120 and 140 g kg^?1. Chicks fed the pelleted flaxseed‐containing diets had heavier body weights, consumed more feed and had better feed/gain ratios than those fed the other flaxseed‐containing diets during the 3 weeks period (P < 0.01). The flaxseed level in the diet also had very significant (P < 0.01) effects on body weight and feed/gain ratio at the end of weeks 1 and 3, with the diets containing 100 g kg^?1 flaxseed resulting in better performance than the other flaxseed‐containing diets. Among the flaxseed containing diets, the pelleted diets led to higher apparent ether extract digestibilities, with values of 778 and 770 g kg^?1 for the diets containing 100 and 140 g kg^?1 flaxseed respectively. This better utilisation of ether extract by young broilers may explain the significantly (P < 0.05) higher AME_n (apparent metabolisable energy) value of 2924 kcal kg^?1 for the pelleted 140 g kg^?1 flaxseed‐containing diet. This was 15.4–17.5% higher than for the diets with the same level of flaxseed but provided as raw or autoclaved whole seed. The pelleting of flaxseed allowed an inclusion rate of 100 g kg^?1 without any reduction in the performance and nutrient utilisation of broilers. Copyright © 2003 Society of Chemical Industry     

Nutritional evaluation of transgenic high‐methionine lupins (Lupinus angustifolius L) with broiler chickens

The nutritive value of transgenic lupin seeds (Lupinus angustifolius L) with higher contents of methionine was evaluated with broiler chickens. The crude protein, methionine and cysteine contents in the conventional and transgenic lupins were 322 and 324, 2.0 and 4.5, and 3.6 and 3.7 g kg^?1 dry matter respectively. In the feeding trial, conventional and transgenic lupins with hulls were incorporated into a maize–soyabean meal diet at 250 g kg^?1 level and the diets were fed to female broiler chicks from 6 to 20 days of age. All diets were balanced to contain similar levels of apparent metabolisable energy (AME), lysine and sulphur‐containing amino acids. The levels of free methionine added to the maize–soyabean meal control, conventional lupin and transgenic lupin diets were 2.2, 2.8 and 2.2 g kg^?1 respectively. Weight gain and feed intake were not influenced by dietary treatments, but feed/gain tended to be higher (P = 0.09) in birds fed lupin diets compared with those fed the control diet. Feed/gain of birds fed the conventional lupin diet was higher (1.82 vs 1.74) than for those fed the transgenic lupin diet. These results showed that the supplemental methionine required in poultry diets containing 250 g kg^?1 lupin can be lowered by 0.6 g kg^?1 diet by the use of high‐methionine lupins. The AME values of conventional and transgenic lupins were determined to be 9.42 and 10.18 MJ kg^?1 dry matter respectively. The higher AME value in transgenic lupins may be related to the lower content of soluble non‐starch polysaccharides (45.6 vs 60.7 g kg^?1 air‐dry basis). Data on ileal amino acid digestibility indicate that the amino acids in transgenic lupins are as digestible as those in conventional lupins. © 2002 Society of Chemical Industry     

Influence of foliar urea on the antioxidant response and fruit color of sweet pepper under limited N supply

BACKGROUND: Foliar fertilizer methods could provide a rapid and efficient response when uptake by plant roots is limited. This work studies the effect of foliar urea sprays (15 g L^?1) at different frequencies on the antioxidant metabolism and fruit quality of sweet pepper fruits under N‐limited nutrient solution (3.5 mmol L^?1 NO₃^?) and fully N‐supplied (12.5 mmol L^?1 NO₃^?) plants. RESULTS: Foliar applications of urea in root N‐limited plants increased the total N concentration in the fruits and no significant differences were found with respect to control fruits (plants fully supplied with N by the roots). Fruit color was significantly affected by the urea sprays, and at the highest frequency (twice a week) the largest overall color difference (ΔE) with respect the non‐sprayed fruits was obtained. Foliar urea increased anthocyanin concentration to control values but flavonoids were only affected at the highest application frequency. N deficiency induced oxidative stress but foliar application of urea altered this response, significantly diminishing catalase and ascorbate peroxidase activity. CONCLUSION: Sweet pepper fruits showed a significant and positive response to foliar fertilization on the studied parameters, compensating to a major extent the reduction of N by the roots. In addition to the environmental issues in reducing N contamination, fully monitored automatically sprayed foliar fertilizer could utilize N more efficiently and at lower cost than applying the full recommended rate of other N fertilizers to the nutrient solution, providing flexibility in correcting N nutrition in the plant, and especially the control of nutrient supply independent of the water supply. Copyright © 2008 Society of Chemical Industry     

The nutritional quality of two types of fish silage for broiler chickens

Fish waste was ensiled either by acidification with formic acid or by fermentation with a bacterial starter culture and molasses. The resulting liquids were mixed with wheat bran (85:15 w/w liquid: bran) and dried (70°C) to produce acid silage meal (ASM) and fermented silage meal (FSM). ASM and FSM were incorporated into wheat-based diets at 25, 50 and 100 g kg^?1 at the expense of soya bean meal. There were two control diets, one which contained soya bean meal as the predominant protein supplement and a second in which fish meal (50 g kg^?1) was added at the expense of some of the soya bean meal. Starter diets (13.25 MJ ME kg^?1, 12 g kg^?1 lysine) were fed from 1-day-old to 21-days-old and finisher diets (13.25 MJ ME kg^?1, 9.5 g kg^?1 lysine) were fed from 22 to 42-days-old to six replicates each of five birds. Birds were reared in raised-wire cages, and feed intake, liveweight and mortality were recorded. There were no significant effects of dietary inclusion of either ASM and FSM on the performance of broiler chickens relative to those fed on control diets. FSM contained less crude protein and amino acids than ASM. The recovery of amino acids relative to the total crude protein content from FSM was only 78.7%, presumably as a result of formation of Maillard reaction products during drying.     

Evaluation of triticale for use in diets for meat-type chickens

Cultivar variation in the nutritional quality of triticale grain was examined with respect to apparent metabolisable energy (AME), ileal digestibility of dry matter (DM), nitrogen (N) and amino acids, and growth, in male broiler chickens. Eight triticale cultivars and two wheat cultivars were grown in an agronomic trial at a single experimental site to collect grain samples. Mean (±SD) AME was 13.54 (±0.64) MJ kg^?1 DM, with a range of 12.57 to 14.25 MJ kg^?1 DM. There were significant (P<0.05) differences between the grain cultivars in their DM, N and amino acid digestibility at the terminal ileum. Apparent lysine digestibility coefficients varied between 0.85 and 0.97. There was a significant (P<0.01) relationship between nutrient digestibility at the terminal ileum and acid-detergent fibre (ADF) in the cereal grains. Three triticale cultivars (Towan, Grow-quick and Ningadhu) had a lower N and lysine digestibility than the other triticales or wheat cultivars, but this was related to their higher ADF content. Trypsin inhibitor level in the cereal grain did not influence either nutrient digestibility or growth rate. Growth rate of broiler chickens from 1 to 21 days of age fed balanced diets which contained 50% cereal grain was significantly affected by cultivar. Birds fed one of the wheat cultivars (Warigal) had a higher (P<0.05) feed conversion ratio (g feed g^?1 liveweight gain) than those birds fed diets containing triticale. Feeding birds diets which contained the triticale cultivar Ningadhu and the maize resulted in greater (P<0.05) liveweight gain than did the other cereal grains tested.     

Efficacy of trivalent chromium on growth performance,carcass characteristics and tissue chromium in heat‐stressed broiler chicks

BACKGROUND: Trivalent chromium (Cr) is usually claimed to have a positive effect on growth and carcass traits in livestock. The objective of this study was to comparatively assess the effects of 6 weeks of treatment with different forms of Cr (500 µg kg^?1), namely Cr nanocomposite (CrNano), Cr picolinate (CrPic) and Cr chloride (CrCl₃), on growth performance, carcass characteristics and tissue Cr in heat‐stressed broiler chicks. RESULTS: Supplementation of CrNano and CrPic significantly increased average daily gain, feed efficiency, carcass yields and lean muscles and decreased abdominal fat. In addition, CrNano significantly increased protein contents in breast and thigh muscles and lowered fat and cholesterol levels in thigh muscles. CrPic significantly increased thigh muscle protein content and decreased thigh muscle fat and cholesterol levels. Dietary addition of CrNano, CrPic and CrCl₃ resulted in significant increases of Cr content in serum, liver and kidney. Moreover, supplemental CrNano produced significant increments of Cr deposit in breast and thigh muscles. CONCLUSION: The results indicate that supplementation of Cr in the form of CrNano and CrPic might be an effective tool for enhancing the growth performance and carcass traits of broiler chicks in heat‐stressed condition. CrNano seemed to have greater beneficial effects in comparison with CrPic. Copyright © 2009 Society of Chemical Industry