Reduced fasting periods increase intestinal permeability in chickens.

Fasting of up to 24 hr has been shown to increase intestinal permeability (IP) in chickens. The aim of this study was to determine whether fasting duration of 4.5 and 9 hr increased IP and whether l-glutamine (a non-essential amino acid) supplementation before fasting provided some protection of barrier function as shown in other species. Ross 308 male broilers (n = 96) were fed either a control diet or the same diet supplemented with 1% glutamine from d0 to d38 post-hatch. On d37, the birds were assigned to single-bird metabolism cages and were fasted for either 0, 4.5, 9 or 19.5 hr. This study design was 2 × 4 factorial with two levels of glutamine and four levels of fasting. Birds in the 0-hr fasting group had free access to feed. All birds had ad libitum access to water. To measure IP on day 38, following their respective fasting periods, birds were administered two separate oral gavages of fluorescein isothiocyanate dextran (FITC-d) followed by lactulose, mannitol and rhamnose (LMR) sugars, 60 min apart. Whole blood was collected from the jugular vein 90 min post-LMR sugar gavage. FITC-d and L/M/R ratios were measured by spectrophotometry and high-performance ionic chromatography respectively. Lipopolysaccharide (LPS) endotoxins in plasma of the birds fed the control diet were also measured using chicken-specific LPS antibody ELISA. Serum FITC-d and plasma L/M and L/R ratios for 4.5, 9 and 19.5 hr were significantly (p < .05) higher compared to the non-fasting group. However, IP was not different in the glutamine-supplemented group (p > .05) compared to the control group. LPS concentrations measured by the ELISA were below the detectable range. We conclude that fasting periods of 4.5 and 9 hr increased IP compared to non-fasted birds and dietary glutamine supplementation did not ameliorate changes in IP.

Gene expression and morphological changes in the intestinal mucosa associated with increased permeability induced by short-term fasting in chickens.

Short-term fasting for 4.5 and 9 hr has been demonstrated to increase intestinal permeability (IP) in chickens. This study aimed to investigate the effects of 0, 4.5, 9 and 19.5 hr fasting on intestinal gene expression and villus-crypt architecture of enterocytes in jejunal and ileal samples. On day 38, Ross-308 male birds were fasted according to their group and then euthanised. Two separate intestinal sections (each 2 cm long, jejunum and ileum) were collected. One section was utilised for villus height and crypt depth measurements. The second section was snap-frozen in liquid nitrogen for quantitative polymerase chain reaction (qPCR) analysis of tight junction proteins (TJP) including claudin-1, claudin-3, occludin, zonula occludens (ZO-1, ZO-2), junctional adhesion molecules (JAM) and E-cadherin. Additionally genes involved in enterocyte protection including glucagon-like peptide (GLP-2), heat-shock protein (HSP-70), intestinal alkaline phosphatase (IAP), mammalian target of rapamycin (mTOR), toll-like receptors (TLR-4), mucin (MUC-2), cluster differentiation (CD-36) and fatty acid-binding protein (FABP-6) were also analysed. Normally distributed data were analysed using one-way analysis of variance ANOVA. Other data were analysed by non-parametric one-way ANOVA. Villus height and crypt depth were increased (p < .05) only in the ileum after fasting for 4.5 and 9 hr compared with non-fasting group. mRNA expression of claudin-3 was significantly reduced in the ileum of birds fasted for 9 and 19.5 hr, suggesting a role in IP modulation. However, all other TJP genes examined were not statistically different from control. Nevertheless, ileal FABP-6 of all fasted groups was significantly reduced, which could possibly be due to reduced bile acid production during fasting.

New biomarkers for increased intestinal permeability induced by dextran sodium sulphate and fasting in chickens.

Increased intestinal permeability (IP) can lead to compromised health in chickens. As there is limited literature on in vivo biomarkers to assess increased IP in chickens, the objective of this study was to identify a reliable biomarker of IP using DSS ingestion and fasting models. Male Ross chickens (n = 48) were reared until day 14 on the floor pen in an animal care facility, randomized into the following groups: control, DSS and fasting (each with n = 16), and then placed in metabolism cages. DSS was administered in drinking water at 0.75% from days 16 to 21, while controls and fasted groups received water. All birds had free access to feed and water except the birds in the fasting group that were denied feed for 19.5 h on day 20. On day 21, all chickens were given two separate oral gavages comprising fluorescein isothiocyanate dextran (FITC-d, 2.2 mg in 1 ml/bird) at time zero and lactulose, mannitol and rhamnose (LMR) sugars (0.25 g L, 0.05 g M and 0.05 g R in 2 ml/bird) at 60 min. Whole blood was collected from the brachial vein in a syringe 90 min post-LMR sugar gavage. Serum FITC-d and plasma LMR sugar concentrations were measured by spectrophotometry and high-performance ion chromatography respectively. Plasma concentrations of intestinal fatty acid binding protein, diamine oxidase, tight junction protein (TJP), d-lactate and faecal α-antitrypsin inhibitor concentration were also analysed by ELISA. FITC-d increased significantly (p < 0.05) after fasting compared with control. L/M and L/R ratios for fasting and L/M ratio for DSS increased compared with control chickens (p < 0.05). TJP in plasma was significantly increased due to fasting but not DSS treatment, compared with controls. Other tests did not indicate changes in IP (p > 0.05). We concluded that FITC-d and LMR sugar tests can be used in chickens to assess changes in IP.

Incidence of pulmonary embolism after the first 3 months of spinal cord injury.

BACKGROUND: Pulmonary embolism (PE) is a significant cause of morbidity and mortality in patients with spinal cord injury (SCI). Prophylactic anticoagulation is associated with a reduction in mortality rates, but there is limited evidence regarding the incidence rate of PE following cessation of anticoagulation after the first 3 months of injury. STUDY DESIGN: Single-centre retrospective study. OBJECTIVE: To estimate the incidence rate of PE after 90 days of SCI. SETTING: The National Spinal Injuries Centre at Stoke Mandeville Hospital, Aylesbury, UK. METHODS: The study includes 640 new-onset SCI patients. All computer tomography pulmonary angiograms (CTPAs) or ventilation-perfusion lung scans between 2008 and 2013 were identified. Medical notes and scans were reviewed and clinical outcomes and radiological findings were recorded. RESULTS: A total of 91 patients with a new-onset SCI had a CTPA or a perfusion lung scan. PE was detected in a total of 8 patients. The incidence of PE was 1.25%; 95% confidence interval (0.39-2.11) over a 6-year period. The duration of injury at the time of PE was 7 months. CONCLUSION: The incidence rate of PE post 3 months of SCI remains significant, though much lower than immediately post injury.

Posterior circulation infarction in patients with traumatic cervical spinal cord injury and its relationship to vertebral artery injury.

STUDY DESIGN: Prospective study. OBJECTIVE: To ascertain the prevalence of posterior circulation stroke in traumatic chronic spinal cord injured (SCI) patients and associated traumatic vertebral artery injuries (VAI). METHODS: All adult patients with cervical SCI and American Spinal Injury Association Impairment Scale (AIS) grade A or B referred for follow-up magnetic resonance imaging of their spinal cord were invited to take part in the study between January 2010 and December 2012 at the National Spinal Injury Centre. Two additional sequences were added to the existing imaging protocol to evaluate the brain and vertebral arteries. RESULTS: Ninety-eight patients were recruited. All imaging were analysed independently by three consultant radiologists. Posterior circulation infarcts were noted in seven (7%) patients. Significant VAI was noted in 13 patients (13%) with 10 occlusions and 3 with high-grade stenosis. However, only one patient had co-existent posterior circulation infarct and significant VAI. CONCLUSION: There is an increased prevalence of posterior circulation infarction in SCI patients. The relationship with associated traumatic VAI requires further investigation.

Outcomes of whole-body computed tomography in spinal cord-injured patients with sepsis.

STUDY DESIGN: Retrospective case series. OBJECTIVES: To evaluate the efficacy of body computed tomography (CT) in spinal cord injury (SCI) patients with sepsis. SETTING: Specialist acute care and rehabilitation SCI centre in United Kingdom. METHODS: Patients with SCI and suspected or known sepsis, who had CT of the chest, abdomen and pelvis, over a 4-year period, were identified. Only patients who fulfilled the definition of sepsis or severe sepsis were included. Their medical notes and CT scans were reviewed and clinical outcomes and radiological findings recorded. RESULTS: Twenty-two patients with sepsis were identified including seven categorised as having severe sepsis. A specific radiological diagnosis was found in three patients (14%) and non-specific findings were found in 15 patients (68%). CONCLUSION: Although in the majority of cases, the findings were non-specific, a small number of patients had significant pathology identified by CT, which influenced their management significantly.

Out-of-hours MRI provision in the UK and models of service delivery.

AIM: To examine current out-of-hours magnetic resonance imaging (MRI) provision through a snapshot survey of National Health Service (NHS) trusts and to assay how radiographer staffing cover was provided for out-of-hours services. MATERIALS AND METHODS: A snapshot postal survey was mailed to heads of service of all 234 trusts in England and Wales. A literature search on the models of service delivery and correlation with the authors' internal MRI rota, which has provided a full on-call service for 20 years was undertaken. RESULTS: The response rate was 45.7% (107 of 234); 14% of responders provided full access to MRI 24 h a day; 63% provided extended weekday service, typically to 20.00 h; and 81% provided a weekend daytime service. The radiographers running the service were typically from the core MRI team. Approximately one-third (29.9%) of trusts provided training in basic brain and spine MRI to non-core MRI team members, but they typically did not participate in out-of-hours provision. CONCLUSION: There is currently a paucity of information on the provision of out-of-hours MRI in the NHS. However, there is increasing pressure to provide complex imaging out of hours, and in the future, trauma centres may be required to provide MRI to assess spinal injury. The authors describe a system to provide access to MRI at no additional cost to the organization based on 20 years of experience. A minority of surveyed acute NHS trusts have full out-of-hours access to MRI. Demand for MRI provision out of core hours is likely to increase.

Long-term effect of MRI on sacral anterior root stimulator: the Stoke Mandeville experience.

STUDY DESIGN: Retrospective review study. OBJECTIVES: To identify whether it is safe to perform a magnetic resonance imaging (MRI) exam on patients who have a sacral anterior root stimulator (SARS). SETTING: Adult patients with spinal cord injury and implanted SARS attending the National Spinal Injuries Centre who have had MRI scans. METHODS: Retrospective review between 1989 and 2010. The effect of the MRI scans on the function of the SARS (Finetech-Brindley, UK) was assessed up to 6 months following MRI at 0.2 and 1.5 T. RESULTS: A total of 18 patients with SARS implants had MRI scans at 0.2 and 1.5 T of the cervical, thoracic and lumbar spine, head, shoulder and pelvis. MRI examinations were abandoned on two occasions in one patient due to radiofrequency interference. One patient's stimulator ceased to function 5 months following MRI; both of these patients showing complications had their MRI examinations at 0.2 T. There were no adverse effects at 1.5 T. In one patient the SARS was removed within 6 months after MRI due to an unrelated medical condition. A total of 17 patients showed no symptoms that required terminating the examination. In all the 11 patients with a complete and functioning implant before MRI at 1.5 T, the SARS was functioning appropriately, and no change in bladder function was reported up to 6 months following MRI. CONCLUSION: It is safe to perform an MRI scan on patients with SARS providing the examination is conducted in a 1.5 T system.

MRI in acute and subacute post-traumatic spinal cord injury: pictorial review.

STUDY DESIGN: Pictorial review. OBJECTIVES: To illustrate MRI signs of acute and subacute injury with emphasis on evidence-based links to clinical outcome and implications for treatment. METHODS: Description of important aspects of MRI techniques and illustration of critical MRI signs important in the assessment of spinal cord injury following trauma, in the acute and subacute stages. CONCLUSIONS: Familiarity with cord MRI appearances has an important impact on planning the management of the acutely spinal cord injured patient and also identifying complications in the subacute phase particularly in the presence of neurological deterioration.

Quantitative analyses of genes associated with mucin synthesis of broiler chickens with induced necrotic enteritis.

Clostridial infection of the intestine can result in necrotic enteritis (NE), compromising production and health of poultry. Mucins play a major role in protecting the intestinal epithelium from infection. The relative roles of different mucins in gut pathology following bacterial challenge are unclear. This study was designed to quantify the expression of mucin and mucin-related genes, using intestinal samples from an NE challenge trial where birds were fed diets with or without in-feed antimicrobials. A method for quantifying mucin gene expression was established using a suite of reference genes to normalize expression data. This method was then used to quantify the expression of 11 candidate genes involved in mucin, inflammatory cytokine, or growth factor biosynthesis (IL-18, KGF, TLR4, TFF2, TNF-α, MUC2, MUC4, MUC5ac, MUC5b, MUC13, and MUC16). The only genes that were differentially expressed in the intestine among treatment groups were MUC2, MUC13, and MUC5ac. Expression of MUC2 and MUC13 was depressed by co-challenge with Eimeria spp. and Clostridium perfringens. Antimicrobial treatment prevented an NE-induced decrease in MUC2 expression but did not affect MUC13. The expression of MUC5ac was elevated in birds challenged with Eimeria spp./C. perfringens compared with unchallenged controls and antimicrobial treatment. Changes to MUC gene expression in challenged birds is most likely a consequence of severe necrosis of the jejunal mucosa.

The effects of lactoferrin on the intestinal environment of broiler chickens.

The influence of in-feed lactoferrin (Lf) on bird production, intestinal microbiota, mucosal immune system and gut microarchitecture was assessed in male Cobb 500 broiler chickens. Birds were given one of four diets from day of hatch: Control (basal diet with no additives), ZnB (basal diet + 50 mg/kg zinc bacitracin), Lf 250 mg/kg (basal diet + 250 mg/kg Lf) and Lf 500 mg/kg (basal diet + 500 mg/kg Lf); n = 24 birds/treatment. An apparent metabolisable energy study was performed between d 25-32. Lf did not affect growth rate or feed conversion in the period 0-21 d of age, nor performance or energy metabolism during the 7 d metabolism experiment which commenced at 25 d of age.The profiles of caecal microbial communities were significantly different in birds given ZnB compared with birds given a diet with no additives, or supplemented with 250 mg/kg Lf. Birds given 250 mg/kg Lf also had a different microbial profile compared with birds given 500 mg/kg Lf. In comparison to control birds, Lf treated birds showed some differences in the T cell proportions in caecal tonsil and spleen. No differences in ileal villus height, crypt depth or goblet cell proportions were observed amongst dietary treatments. Whilst Lf had little effect on the measured parameters, the use of an integrated approach to study the influence of novel feed additives may facilitate a greater understanding of the relationships between nutrition, gut health and bird performance.

Effects of necrotic enteritis challenge on intestinal micro-architecture and mucin profile.

1. This study investigated the effect of Eimeria spp./Clostridium perfringens induced necrotic enteritis and traditional antibiotic preventatives on intestinal micro-architecture and mucin profile. 2. A total of 600 Cobb 500 broiler chickens were randomly assigned to the following three groups: (i) unchallenged, (ii) challenged, and (iii) zinc bacitracin/monensin (ZnB/monensin) (n = 25 chickens/pen, 8 pens/group). The challenged and ZnB/monensin chickens were individually inoculated with Eimeria acervulina, E. maxima and E. tenella and C. perfringens type A (EHE-NE18) at 9 and 15 d post-hatch respectively, to induce necrotic enteritis. 3. The challenge procedure significantly decreased villus height, increased villus width and increased crypt depth in the challenged compared to the unchallenged chickens. Zinc bacitracin and monensin maintained villus-crypt structure similar to that of the unchallenged chickens. 4. Mucin profile was not affected by Eimeria spp./C. perfringens challenge as demonstrated by periodic acid-Schiff and high iron diamine-alcian blue pH 2 x 5 staining. Zinc bacitracin and monensin decreased the number of intestinal mucin-containing goblet cells. 5. Lectin histochemistry showed a trend towards greater Arachis hypogea (PNA) reactivity in unchallenged chickens. 6. In summary, Eimeria spp./C. perfringens challenge disrupted intestinal micro-architecture; however, challenge did not appear to affect intestinal mucin profile. Traditional antibiotics, zinc bacitracin and monensin maintained micro-architecture.

Comparison of alternatives to in-feed antimicrobials for the prevention of clinical necrotic enteritis.

AIMS: The capacity for Lactobacillus johnsonii and an organic acid (OA) blend to prevent Clostridium perfringens-induced clinical necrotic enteritis (NE) in chickens was studied. METHODS AND RESULTS: Cobb 500 birds were allocated into six groups (n = 25 birds/pen, eight pens/treatment); Unchallenged, Challenged, Antimicrobial (zinc bacitracin (ZnB)/monensin), OA, probiotic Lact. johnsonii and probiotic sham (Phosphate-buffered saline). All birds were challenged with Eimeria spp. and Cl. perfringens except for unchallenged controls. Birds fed antimicrobials were protected from NE development as indicated by maintenance of body weight, low mortality and clostridium levels, and decreased intestinal macroscopic lesion scores compared to challenged controls (P < 0.05). Lactobacillus johnsonii-fed birds had reduced lesion scores, whilst OA-fed birds had decreased Cl. perfringens levels. Both Lact. johnsonii and OA-fed birds had improved feed efficiency between days 0 and 28 compared to challenged controls; however, mortality and body weights were not improved by either treatment. Microbial profiling indicated that the challenge procedure significantly altered the jejunal microbiota. The microbiota of antimicrobial-fed birds was significantly different from all other groups. CONCLUSIONS: Whilst Lact. johnsonii and OA altered specific intestinal parameters, significant protection against NE was not observed. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobacillus johnsonii and OA did not prevent NE; however, some improvements were evident. Other related treatments, or combinations of these two treatments, may provide greater protection.

Diffusive benefits of cylinders in front of a Schroeder diffuser.

A numerical investigation is performed into the diffusive effects of cylinders positioned in front of a Schroeder diffuser. A regular line of cylinders is shown to offer notable improvements to diffusion from a periodic Schroeder device, provided lateral cylinder spacing is incommensurable with the Schroeder period width. Further investigation considers angular dependence and low frequency results in greater detail, as well as the effects on narrowband and modulated Schroeder devices. An optimization procedure is subsequently performed to investigate the effects of an irregular cylinder arrangement, which provides further diffusive benefits.

Indigestible carbohydrates alter the intestinal microbiota but do not influence the performance of broiler chickens.

AIMS: Prebiotics are a potential alternative to in-feed antimicrobials to improve performance of chickens. We investigated the effects of mannanoligosaccharide (MOS) and fructooligosaccharide (FOS) on growth, performance and the intestinal microbiota. METHODS AND RESULTS: Cobb 500 birds were fed either: Control, starter diet without antimicrobials; ZnB, Control + 50 ppm zinc bacitracin; MOS, Control + 5 g kg(-1) MOS; or FOS, Control + 5 g kg(-1) FOS. An energy metabolism study was conducted and intestinal microbial communities assessed by T-RFLP and Lac PCR-DGGE. Diet did not influence performance. Ileal microbial communities were significantly different in ZnB-fed birds compared to all diets, and FOS-fed chickens compared to Control. MOS-fed chickens had a different caecal profile to ZnB and FOS-fed birds. Consensus Lac PCR-DGGE profiles indicated Lactobacillus communities clustered according to diet with Lactobacillus johnsonii characteristic of ZnB diet. Control and MOS-fed chickens displayed significantly different jejunal Lactobacillus profiles to each other whilst ileal profiles were different between MOS and FOS-fed birds. CONCLUSION: Prebiotics influenced the intestinal microbiota, but did not affect performance. SIGNIFICANCE AND IMPACT OF THE STUDY: In light of pressure for in-feed antimicrobial withdrawal, the impact of alternative compounds on the intestinal microbiota and bird performance is critical to the poultry industry.

Influence of different litter materials on cecal microbiota colonization in broiler chickens.

A chicken growth study was conducted to determine if litter type influenced gut microbiota and performance in broilers. Seven bedding materials were investigated and included soft and hardwood sawdust, softwood shavings, shredded paper, chopped straw, rice hulls, and reused softwood shavings. Microbial profiling was done to investigate changes in cecal bacterial communities associated with litter material and age. Cecal microbiota were investigated at 14 and 28 d of age (n = 12 birds/litter material). At both ages, the cecal microbiota of chickens raised on reused litter was significantly (P < 0.05) different from that of chickens raised on any of the other litter materials, except softwood shavings at d 28. Cecal microbiota was also significantly different between birds raised on shredded paper and rice hulls at both ages. Age had a significant influence on cecal microbiota composition regardless of litter material. Similarity in cecal microbial communities among birds raised on the same litter treatment was greater at 28 d of age (29 to 40%) than at 14 d of age (25 to 32%). Bird performance on the different litter materials was measured by feed conversion ratio, live weight, and feed intake. Significant (P < 0.05) differences were detected in live weight at 14 d of age and feed intake at 14 and 28 d of age among birds (n = 160/treatment) raised on some of the different litter materials. However, no significant (P > 0.05) differences were observed in feed conversion ratio among birds raised on any of the 7 different litter materials at either 14 or 28 d of age. The type of litter material can influence colonization and development of cecal microbiota in chickens. Litter-induced changes in the gut microbiota may be partially responsible for some of the significant differences observed in early rates of growth; therefore, litter choice may have an important role in poultry gut health particularly in the absence of in-feed antibiotics.

Dietary omega-3 polyunsaturated fatty acid does not influence the intestinal microbial communities of broiler chickens.

The capacity for n-3 polyunsaturated fatty acids (PUFA) to improve broiler chicken growth, influence the intestinal microbial communities, and modify the PUFA content of meat was studied. Male Cobb 500 chickens were fed 1 of 4 diets from hatch: control (standard diet with no additives), ZnB (standard diet with added antibiotics), 2% SALmate (standard diet with 2% SALmate, which is composed of 42% fish oil and 58% starch), and 5% SALmate (standard diet with 5% SALmate). A 7-d energy metabolism study was conducted between d 15 and 22 posthatch. Birds were killed at d 25 and intestinal samples were collected to assess microbial communities by terminal restriction fragment length polymorphism and Lactobacillus PCR-denaturing gradient gel electrophoresis. Diet did not affect BW, feed intake, feed conversion, or ileal digestible energy (P > 0.05). Apparent ME was greater in ZnB-fed birds compared with all other diets (P < 0.05). Breast tissue levels of eicosapentaenoic acid, docosahexaenoic acid, docosapentaenoic acid, and total n-3 PUFA were elevated significantly in 2% SALmate- and 5% SALmate-fed chickens compared with control and ZnB diets (P < 0.05). No significant differences in overall microbial communities were observed in the ileum or cecum as assessed by terminal RFLP (P > 0.05). Birds fed 2% SALmate had a significantly different cecal Lactobacillus species profile compared with birds fed the control diet (P < 0.05); however, no differences were observed in birds fed 5% SALmate compared with birds fed all other diets. In addition to the expected increase in breast tissue n-3 fatty acid levels, a low level of dietary n-3 PUFA also altered the intestinal Lactobacillus species profiles. However, n-3 PUFA supplementation did not alter the overall microbial communities or broiler performance.

Iron content of eggs from hens given diets containing organic forms of iron, serine and methyl group donors, or phytoestogens.

1. This investigation included three experiments to determine whether the iron content of egg yolks could be enriched by supplementation of the laying diet with iron bound to organic compounds (Experiment 1), serine and methyl group donors methionine and choline (Experiment 2) or phytoestrogens (Experiment 3). 2. Hens at 34, 54 and 56 weeks of age were given experimental diets for 6, 4 and 4 weeks, respectively, in Experiments 1-3. Yolks from eggs laid over three successive days in the final week of feeding were pooled for each hen for analysis of iron by inductively coupled plasma mass spectrometry. 3. Iron concentration in egg yolk averaged 68-70, 66-71 and 62-69 microg/g in the respective experiments. 4. The addition of bloodmeal (1.22 mg Fe/egg) or phytoestrogens (1.25 mg Fe/egg) increased the total iron content of yolks by over 15% compared with the control diet (1.10 mg Fe/egg), and although this increase was not statistically significant it suggests that the iron content of eggs could be sufficiently manipulated to justify a nutritional claim of iron enrichment.

A method for collecting breath samples from individual chickens for analysis of 13CO(2), H(2), and CH(4).

This study describes experiments using simple helmets to collect breath samples from individual birds for measurement of (13)CO(2), H(2), and CH(4), which form the basis for various diagnostic tests for intestinal dysfunction in humans. Peak enrichment in (13)C in breath CO(2) occurred between 5 and 30 min postingestion by 18-d-old chickens administered a gelatin capsule containing approximately 3.6 mg of (13)C-octanoic acid dissolved in vegetable oil. For 25-d-old chickens given 10 mL of homogenized cooked corn by oral gavage, peak enrichment occurred 60 to 90 min postingestion. In fully fed 25-d-old chickens, H(2) and CH(4) concentrations in breath ranged from 7 to 115 ppm and from 0 to 5.5 ppm, respectively. Following an overnight fast, H(2) and CH(4) concentrations in breath ranged from 0.5 to 7.5 ppm and 0 to 3.0 ppm, respectively, in the same chickens. Ranges in H(2) (1.0 to 56.5 ppm) and CH(4) (0 to 8.0 ppm) concentrations widened considerably 3 h after oral gavage with approximately 130 mg of lactulose (an indigestible disaccharide) dissolved in 5 mL of water. The results from these investigations indicate that collection of re-breathed air samples from chickens is plausible, which opens the way for development of noninvasive methods for evaluating gastrointestinal functions in chickens.

Relationship between digesta transit time and apparent metabolisable energy value of wheat in chickens.

1. This study tested the hypotheses that: (a) apparent metabolisable energy (AME) values and whole tract transit time (WTTT) were related, and that (b) the relationship between AME and WTTT differed between male and female Ross broiler chickens. 2. Enzyme products with xylanase activity were added to a basal diet to provide 4 dietary treatments comprising control (no enzyme), Avizyme 1300 (1 kg/tonne), Kemzyme W1 (1 kg/tonne), and Bio-Feed Wheat CT (200 g/tonne). The basal diet comprised (in g/kg), 800 wheat, 155 casein, 20 dicalcium phosphate, 11 limestone, 7 D,L-methionine, 2 vitamin and mineral premix, 3 sodium chloride and 2 choline chloride (60%). 3. AME values for diets were determined in a 7-d energy balance study commencing when chickens were 21 d of age. WTTT was the time elapsed (in min), from time of administration by oral gavage of 200 mg ferric oxide in a gelatine capsule, to time of first observation of the distinctive red colouration in droppings. 4. The mean AME value for the wheat was high (15.7 MJ/kg dry matter) and ranged from 14.4 to 16.3 MJ/kg dry matter for individual birds. Mean WTTT was 206 min and ranged from 105 to 429 min. AME and WTTT were unaffected by enzyme addition to the diet, and the interaction between diet and gender was not significant. 5. There was a significant but weak positive relationship between AME and whole tract transit time, with AME increasing by 2.2 kJ/min. This relationship was unaffected by gender of the chicken.