Effects of adding yeast cell walls and Yucca schidigera extract to diets of layer chicks

1.?This research was conducted to determine the impact of diet supplementation with yeast cell walls and Yucca schidigera extract on the growth performance, antibody titres, and intestinal tissue histology of layer chicks.

2.?White, 1-d-old, Hy-Line hybrid chicks (n?=?840) were divided into 4 main groups, each comprising 7 replicates of 30 chicks (n?=?210): (1) control; (2) 1000?mg/kg yeast cell walls (YCW) added; (3) 1000?mg/kg Yucca schidigera extract (YE) added; and (4) 500?mg/kg YE?+?500?mg/kg YCW added. The trial lasted 60?d.

3.?Daily weight gain of the chicks was positively affected between d 45-60 in the YE and YCW?+?YE groups compared with the control group.

4.?Overall, feed consumption did not differ between the control and YCW, YE, YCW?+?YE groups during the 60?d study period. Feed efficiency was better in the YE and YCW?+?YE groups than in the control group between d 1-60.

5.?During the 60?d evaluation period, live weight gain, and final live weight were higher in YE and YCW?+?YE groups than in the control group.

6.?Antibody titres against infectious bronchitis and infectious bursal disease did not differ among the 4 treatments, but those for Newcastle disease were higher in the YE?+?YCW groups than in the control, YCW and YE groups on d 45.

7.?There were differences in intestinal histomorphometry between the 4 treatments. The height of the jejunal and ileal villi was greater in the YE and YCW?+?YE groups than in the control and YCW groups

8.?It can be concluded that YCW and YE supplementation for layer chicks is beneficial for growth performance and intestinal histology during the 1-60?d growing period.     

Immune-modulatory effects of dietary Saccharomyces cerevisiae cell wall in broiler chickens inoculated with Escherichia coli lipopolysaccharide

1. An experiment was conducted to study the effect of yeast (Saccharomyces cerevisiae) cell wall (YCW) supplemented in diets of broiler chickens challenged with Escherichia coli lipopolysaccharide (LPS).

2. One-day-old broiler chicks were randomly distributed into 24 cages (6 replicate cages; 8 birds/cage) and were inoculated with 0 or 1 mg/kg body weight E. coli-LPS (d 4 and 9) and 0 or 500 mg YCW/kg feed, resulting in a 2 × 2 factorial arrangement of treatments. Experimental diets did not include coccidiostats, in-feed antibiotics or enzymes.

3. On d 21, the inoculation of E. coli-LPS reduced weight gain and feed intake and increased feed conversion ratio (FCR) of birds, an effect maintained until 28 d. In contrast, chickens given diets with YCW improved the FCR at both 21 and 28 d of age.

4. E. coli-LPS challenge reduced the relative weight of bursa of Fabricius, except when chickens were given YCW, which resulted in an interaction. Supplementation of broiler diets with YCW exacerbated the cellular immune response as measured by the delayed cutaneous hypersensitivity response test.

5. The results of this study suggested a benefit on feed efficiency when YCW was added to diets fed to broiler chickens challenged with E. coli-LPS. Part of the mode of action of YCW might be related to better maintenance of immune status in response to microbial challenge.     

Factors influencing bacterial eggshell contamination in conventional cages,furnished cages and free-range systems for laying hens under commercial conditions

1.?The aim was to assess eggshell contamination in various laying hen-housing systems and to identify factors influencing this contamination.

2.?Fifty-eight laying hen farms in France were studied, including 21 flocks housed in conventional cages, 7 in furnished cages and 30 kept on-floor.

3.?Sixty eggs per flock were analysed to obtain counts of the total mesophilic flora. Data on equipment and hen management were collected.

4.?Mean bacterial count on eggshells tended to be higher in on-floor systems (4·82 ± 0·51 log CFU/eggshell) than in cage systems (4·57 ± 0·58 log CFU/eggshell, P = 0·09).

5.?Contamination increased with age of the hens, airborne dust concentration, manual packing of the eggs, and packing in plastic rather than in recycled-pulp egg-flats.

6.?The effect of the housing system on eggshell contamination, previously described in experimental assays, was confirmed under production conditions.     

Comparison of gene expression profiles of the jejunum of broilers supplemented with a yeast cell wall-derived mannan oligosaccharide versus bacitractin methylene disalicylate

1. The addition of yeast cell wall (YCW) mannan fractions or low concentrations of antibiotics to the diet of broilers positively affects gut health by improving intestinal cell morphology and improves feed efficiency and performance; however the exact mechanisms are unclear. Based on these production responses, the objective of this study was to compare the effects of supplementing YCW and bacitracin methylene disalicylate (BMD) in the diet on mRNA levels in the jejunum of 6-week-old broilers.

2. Dietary treatments were a maize-soya control diet and the control diet with the addition of YCW or BMD. Birds (n = 7) from each dietary treatment were randomly selected and killed at d 42. Whole jejunum (with serosa) samples were collected for RNA isolation. Gene expression analysis was performed using the AffymetrixGeneChip Chicken Genome Array (Santa Clara, CA, USA).

3. Supplementation with YCW resulted in 928 genes that were significantly changed (456 down-regulated, 472 up-regulated) and supplementation with BMD resulted in 857 genes that significantly changed (408 down-regulated, 449 up-regulated). In addition, 316 genes were significantly changed by both YCW and BMD (146 down-regulated, 170 up-regulated).

4. BMD increased the expression of genes involved in lipid and carbohydrate metabolism and decreased expression of genes associated with T-helper cell pathways. Gene expression profiles from birds fed on diets containing YCW showed changes on a genomic level that correspond to slower gut cell turnover and therefore increased energy preservation for growth.

5. In conclusion, supplementation with BMD or YCW had similar influences on the number of differentially expressed genes in the jejunum. Biological functions common to both YCW and BMD with positive activation scores included antiviral response and antimicrobial response. Genes that were affected by BMD or YCW classified into both different and common biological functions and pathways related to improved metabolism and health in the jejunum.     

Bacillus subtilis and yeast cell wall improve the intestinal health of broilers challenged by Clostridium perfringens

1. The objective was to investigate the effects of Bacillus subtilis, yeast cell wall (YCW) and their combination on intestinal health of broilers challenged by Clostridium perfringens over a 21-d period.

2. Using a 5 × 2 factorial arrangement of treatments, 800 1-d-old male Cobb 500 broilers were used to study the effects of feed additives (without additive or with zinc bacitracin, B. subtilis, YCW, and the combination of B. subtilis and YCW), pathogen challenge (without or with Clostridium perfringens challenge), and their interactive effects.

3. C. perfringens infection increased intestinal lesions scores, damaged intestinal histomorphology, increased serum endotoxin concentration, cytokine mRNA expression and intestinal population of C. perfringens and Escherichia coli and decreased ileal bifidobacteria numbers. The 4 additives decreased serum endotoxin. Zinc bacitracin tended to decrease cytokine mRNA expression and the intestinal number of C. perfringens and E. coli. B. subtilis, YCW and their combination increased cytokine mRNA expression. B. subtilis and YCW decreased the number of C. perfringens and E. coli in the ileum, and their combination decreased pathogens numbers in the ileum and caecum.

4. In conclusion, B. subtilis, YCW and their combination improved the intestinal health of NE-infected broilers, and could be potential alternatives to antibiotics.     

Kaempferol improves carcase characteristics in broiler chickens by regulating ANGPTL3 gene expression

1. The objective of this study was to examine the beneficial effects of kaempferol, a naturally occurring polyphenol, on carcase characteristics in broiler chickens and the mechanisms involved in this regulation.

2. Broiler chickens were randomly divided into 7 groups: control, carrier control, kaempferol (0·3%), kaempferol (0·6%), hypercholesterolemic (HLD), HLD and kaempferol (0·3%), HLD and kaempferol (0·6%).

3. Seven weeks after treatment, carcase characteristics, lipid levels in the blood and liver, expression of hepatic Angiopoietin-like protein 3 (ANGPTL3) mRNA, and expression of adipose lipoprotein lipase (LPL) protein were determined.

4. Treatment with kaempferol (0·3 or 0·6%) significantly increased plasma high-density lipoprotein cholesterol levels, decreased percentage of abdominal fat, thickness of subcutaneous fat, plasma and hepatic total cholesterol and triglyceride concentrations, muscle malondialdehyde level and down-regulated expression of ANGPTL3 mRNA concomitantly with up-regulated expression of LPL protein in normal and hypercholesterolemic broiler chickens.

5. Kaempferol (0·3 or 0·6%) treatment had no significant effect on the values of percentage of breast muscle, percentage of leg muscle, carcase weight and eviscerated percentage.

6. The results suggest that kaempferol improves carcase characteristics by decreasing expression of ANGPTL3 in broiler chickens.     

Changes in eggshell conductance,water loss and hatchability of layer hens with flock age and moulting

1.?Changes in water loss, eggshell conductance and hatchability with flock age were monitored in layer hens in a commercial hatchery.

2.?Optimal water loss for maximal hatchability of layer eggs was found to be 12 to 13% of initial egg mass at d 18 of incubation.

3.?Mass specific water vapour conductance (GH₂Osp) increased linearly with flock age from 0·31 mg/(d·g·Torr) at the beginning of the first breeding season to 0·40 mg/(d·g·Torr) at its end after 77 weeks (=4·21 and 5·44 mg/(d·100 g·kPa), respectively).

4.?After forced moulting GH₂Osp increased from 0·35 to 0·41 mg/(d·g·Torr) (=4·76 and 5·58 mg/(d·100 g·kPa), respectively).

5.?The coefficients of variation of GH₂Osp increased with flock age from 14% at the beginning of the breeding season to 31% at the end of the second breeding season.

6.?In order to preserve normal incubation water loss for maximising hatchability, the humidity setting of an incubator should increase gradually, with flock age, from 53% RH to 66% RH in the first laying season and from 61% RH to 67% RH after forced moulting.

7.?A 3·5-fold increase (from 2 to 7%) in the difference between mean and median GH₂Osp of egg batches with flock age was found, indicating increasing frequency of microscopic cracks in eggshells with flock age. This has to be taken into account when setting the humidity regime in the incubator.     

Effect of dietary energy restriction on retention of protein,fat and energy in broiler chickens

1. Broiler chickens were fed 60–100% of recommended energy intakes to study the effects of energy restriction on protein and fat retention.

2. At an energy retention of 179 kJ/kg W ^0·75 d, only protein was retained. At higher energy intakes, each increment in retention had a rather constant composition: about 85% energy in fat and 15% in protein. At lower energy intakes body fat was mobilised whereas protein was deposited.

3. The efficiencies of energy retention in protein and fat were estimated to be 0·66 and 0·86 respectively.

4. The rather constant composition of additional retained energy after additional energy supply provides an explanation for a linear relationship between energy intake and energy retention.     

Characterisation of tetra-nucleotide microsatellite loci in the ostrich (Struthio camelus)

1. Eleven polymorphic tetra-nucleotide microsatellite loci were identified in the ostrich (Struthio camelus) using a selective enrichment protocol.

2. The average number of alleles observed was 6·6 with an average heterozygosity of 0·4.

3. The population was found to be in Hardy-Weinberg equilibrium and two of the loci had a greater than 95% probability of having null alleles.

4. These microsatellite loci will add to the existing pool of markers available for the ostrich and help to facilitate analysis of population structure and pedigree determination.     

Effects of short intermittent lighting on food consumption and performance of dwarf broiler breeders and progeny

1. Two hundred and sixty four dwarf broiler breeder hens were subjected to ad libitum or restricted feeding and to four lighting patterns: 15L (bright light):9D (dark), 15L:9d (dim light), 2L:10d: 1L:11d, (0.5L:3.5d) × 6.

2. Breeder hens fed ad libitum and subjected to either conventional or intermittent lighting ingested respectively, 25 g and 14 to 17 g more than hens restricted to 115 g/d.

3. Body weight was greater in hens fed ad libitum irrespective of the lighting pattern and of the amount of food intake.

4. Persistency of egg production was impaired by intermittent lighting.

5. Ad libitum feeding reduced egg fertility. The decrease was larger in breeder hens on intermittent lighting.

6. Hatchability was increased in hens submitted to the symmetrical lighting pattern (0.5L:3.5d).

7. Egg and chick weights were higher in hens fed ad libitum.

8. Shell index and shell breaking strength increased in restricted hens on the intermittent lighting pattern (0.5L:3.5d) × 6.

9. The best performance was obtained in restricted hens on the conventional lighting pattern.     

Xylanase in broiler diets with differences in characteristics and content of wheat

1. Experiments were conducted to measure the effect of xy‐lanase supplementation on the performance of broilers fed on wheat‐based diets containing high and low extract viscosity wheat (experiment 1), baking and feeding quality wheat (experiment 2) and with variation in wheat content (experiment 3).

2. Xylanase supplementation improved food conversion ratios by 2·2–2·9% and body weight gain by 0·2–2·5%. This was independent of wheat characteristics but slightly dependent on the wheat content of the diet. These effects were related to a lowering of digesta viscosity.

3. Differences in extract viscosity of wheat were not reflected in broiler digesta viscosity.

4. Reduction of digesta viscosity resulted in only a slight improvement of litter score. Reduced intestinal viscosity decreased relative pancreas weight and to a lesser extent relative small intestinal weight.

5. Baking quality wheat Baldus gave better performance than the feed quality wheats Apollo and Slejpner.

6. It was concluded that xylanase supplementation of wheat‐based diets invariably had a positive effect on broiler performance.     

Effect of egg composition on hatchability and on growth and slaughter characteristics of meat-type chicks

1.?Using the so-called TOBEC (Total Body Electrical Conductivity) method, which allows the determination of egg composition in vivo, correlations between egg composition, hatchability and hatched chicks’ development were studied.

2.?A total of 1500 hen eggs (Ross-308) were measured by TOBEC, and eggs with extremely high (10%, n = 150), extremely low (10%, n = 150) and average (10%, n = 150) electrical conductivity values were chosen for further investigation.

3.?During the incubation period, it was observed that eggs with high electrical conductivity had a significantly higher mortality than eggs with low electrical conductivity.

4.?It was observed that both the increase in electrical conductivity at the same egg weight, and the increase in egg weight at the same electrical conductivity resulted in an increase in the hatching weight.

5.?It was found that the dry matter, protein and fat content of the chicks hatched from eggs with low electrical conductivity was higher at hatching than that of the chicks hatched from eggs with high electrical conductivity.

6.?At 42 d of age the liveweight of cocks and pullets hatched from eggs with low electrical conductivity was 3·2 and 8·2% higher than the liveweight of cocks and pullets hatched from eggs with high electrical conductivity.

7.?Because of the higher liveweight at slaughter, there was a significant superiority of the chicks hatched from eggs with low electrical conductivity in the case of the examined carcase traits at slaughter.

8.?Similar tendencies were found also in the ratios of carcase variables to liveweight, but the between group differences were not statistically significant in this case.

9.?Based on the results it was concluded that TOBEC seems to be a useful method for separating eggs with different composition.

10.?This could be a good starting point for further in vivo investigations in order to clarify the effect of egg composition on hatchability and further development.     

Nutritive value of triticale fed to cockerels and chicks

1. The chemical composition, and amino acid and starch bioavailabilities of 18 triticale varieties were studied. In addition, the water soluble pentosan (WSP) content of 8 varieties was determined.

2. A wide variation in protein (149 to 203 g/kg DM), starch (563 to 629 g/kg DM) and WSP (27·7 to 50·9 g/kg DM) was found between varieties.

3. The TMEn reproductibility was assessed in two laboratories, using Leghorn cockerels, Isabrown cockerels and 3‐week‐old chicks. There were no sismificant differences in the TMEn values (range 14·0 to 15·2 MJ/kg DM) between the two types of cockerel. The TMEn values of the varieties were similar for chicks (range 13·6 to 14·9 MJ/kg DM) and for cockerels, with the exception of one variety.

4. The bioavailability of starch (range 96·5 to 99·4%) of some varieties was higher for cockerels than for chicks. The mean bioavailability of amino acids for cockerels was 94·5%.

5. TMEn prediction equations were derived from the chemical composition of the varieties. Best‐fit equations were obtained for starch (R ² = 0·62, RSD = 0·24), ash (R ² = 0·58, RSD = 0·25) and WSP (R ² = 0·52, RSD = 0·27).     

Effects of a higher incubation temperature between embryonic day 9 and 12 on growth and meat quality characteristics of turkeys

1. The study investigated the influence of manipulating incubation temperature for a short period on the post-hatch development up to week 16 in male and female BUT Big 6 turkeys.

2. Eggs were incubated at a control temperature of 37·5°C and 55% RH until d 18 when transferred to a hatcher at 37·5°C and 85% RH. For a 4 d period between embryonic day 9 (ED 9) and 12, eggs were incubated at 38·5°C and 55% RH (HT).

3. Birds were slaughtered at 16 weeks of age to analyse meat quality parameters of the Musculus pectoralis superficialis (MPS).

4. Across both incubation treatments, the turkey males had significantly higher live and breast weights, but lower breast yields than the females. The sex of the animals only influenced the yellowness of the MPS with lower values in the males.

5. Temperature manipulation resulted in significantly decreased live weights of HT birds compared with the control animals across all ages in both sexes. No impact of incubation treatment on meat quality characteristics was found.

6. The results indicate a negative effect of higher incubation temperature on the post-hatch growth, possibly by influencing the mechanisms that regulate the hypertrophic growth of the muscle fibres.     

Microbiological and shelf life assessment of chilled eviscerated whole chicken broilers in Saudi Arabia

1. The microbiological quality and shelf life of chicken carcasses marketed in Riyadh, Saudi Arabia were assessed.

2. The mean initial microbial counts (log₁₀ count/cm²) were 4·67, 4·14, 2·21, 2·78 and 2·96 for total aerobes, psychrotrophs, coliforms, Staphylococcus aureus and yeasts and moulds, respectively; these counts suggest a moderate level of contamination during processing.

3. Yeasts and moulds were present in relatively large numbers and constituted a considerable portion of the spoilage flora.

4. The mean shelf life of chicken broilers was 9·6, 6 and 4·4 d at 4, 7 and 10°C, respectively. Storage at 4°C resulted in better keeping than storage at 7°C or 10°C, while there was no significant difference between 7° and 10°C.

5. The initial totals of aerobes, psychrotrophs and yeasts and moulds were found to negatively correlate with shelf life.     

The effect of glycerol inclusion on broiler performance and nutrient digestibility

1. Crude glycerol from biodiesel production was offered ad libitum to broiler chickens in a 21-d feeding and digestibility trial. The study was designed as a 3*2?+?1 factorial design with 3 concentrations (33, 67, 100?g/kg) of glycerol from 2 sources, A and B (PRS Environmental Ltd and John Thompson and Sons Ltd) and a control diet. The diets were formulated to contain apparent metabolisable energy (AME) of 12·95?MJ/kg (assuming 14·6?MJ/kg for glycerol).

2. No significant interactions occurred, so only the main effects were discussed. At 7–14?d, feed conversion ratio (FCR) showed a significant linear response with increased glycerol inclusion. However quadratic responses on FCR were observed for the 21–28?d period and 7–28?d.

3. Glycerol digestibility was significantly greater with birds offered the 67?g/kg and 100?g/kg glycerol-based diets in contrast to the digestibility of 33?g/kg glycerol-based diets.

4. Glycerol inclusion level also had an effect on AME, which increased linearly with increasing glycerol inclusion. Birds offered the diets containing glycerol also required less energy per unit gain in contrast to birds offered the control diet.

5. When examining the effect of source of glycerol, source A glycerol resulted in the highest AME (15·20 vs. 14·72?MJ/kg). There was no significant effect of glycerol source on the other performance parameters.

6. Glycerol digestibility was significantly greater with glycerol from source B (John Thompson and Sons, Ltd) with a mean value of 0·848 in contrast to source A (PRS Environmental), which had a somewhat lower mean glycerol digestibility of 0·757.

7. In conclusion, glycerol source did not affect performance and increasing level of glycerol improved FCR, with 67?g/kg inclusion resulting in the most efficient conversion of feed to gain without any negative effects upon nutrient digestibility.     

Effects of reduced dietary calcium and phytase supplementation on calcium and phosphorus utilisation in broilers with modified mineral status

1.?The impact of modified mineral status and dietary Ca:P ratio on Ca and P utilisation was measured in chicks with or without phytase supplementation.

2.?In a preliminary study, 4 diets were given to chicks from 3 to 15 d of age: D1 (6·5 g P/kg and Ca:P = 1·5) and D2, D3 and D4 (6·0, 5·4 and 5·0 g P/kg, respectively, and Ca:P = 1·2). Growth performance was similar across diets. Tibia ash was similar in chicks given D1 and D2, but was gradually depressed from D2 to D4 (?22%).

3.?In the depletion period, two groups of chicks, with similar performance, but with different mineral status were achieved by feeding them, from 5 to 15 d of age, diets with a similar Ca:P ratio of 1·2, but containing 6·3 or 5·2 g P/kg.

4.?During the subsequent 11 d of the repletion period, chicks from each of the two previous groups were given one of the 4 diets containing 5·7 g P/kg, but differing in their Ca (8·3 and 5·3 g Ca/kg) and microbial phytase (0 or 1000 FTU, Natuphos®) levels in a 2 × 2 × 2 factorial arrangement.

5.?At the end of the repletion period, the initially depleted chicks could not be differentiated from the non-depleted chicks, indicating the capacity of chicks to compensate for their initial depleted mineral status.

6.?Interaction between dietary Ca and phytase levels was not significant. Phytase improved growth performance and bone characteristics. Reduced dietary Ca enhanced feed intake and growth rate, but depressed bone dry matter and ash weight.

7.?At the end, diets supplemented with phytase maximised bone ash weight when chicks were fed with a Ca:P ratio of 1·5 but elicited the highest growth rate when chicks were fed with a Ca:P ratio of 0·9.     

Comparison of marine algae (Spirulina platensis) and synthetic pigment in enhancing egg yolk colour of laying hens

1. The objective of this experiment was to determine the effects of dietary marine algae (Spirulina platensis) on egg yolk colour, and compare the effectiveness of Spirulina and synthetic pigment in enhancing egg yolk colour of laying hens fed on a wheat-based diet.

2. In total, 160 Hy-line W36 laying hens of 63 weeks of age were studied by dividing them into 5 groups, 32 birds in each. Except for the control group (based on wheat and soyabean meal), the feed for three other groups contained 1·5, 2·0 and 2·5% of Spirulina; while one group contained synthetic pigments (BASF Lucantin® yellow: 30?mg/kg, and BASF Lucantin® red: 35?mg/kg).

3. Egg production, feed intake, feed conversion ratio (FCR), egg weight and egg yolk colour were determined.

4. A significant increase in egg yolk colour was observed in the treatments that received the Spirulina and synthetic pigment, compared with the control diet.

5. There were no significant differences between the treatments with 2·5% Spirulina and synthetic pigment in enhancing egg yolk colour. Finally, the results indicated that the diet containing 2·5% Spirulina could be as effective as the diet with synthetic pigment in producing an agreeable egg yolk colour.     

Effect of in ovo threonine supplementation on early growth,immunological responses and digestive enzyme activities in broiler chickens

1.?The effects of injecting threonine in ovo on early growth, some immunological responses and the activity of digestive enzymes of broiler chicks were investigated. Fertile eggs were distributed into 6 groups, each of 60. These were: untreated control, sham control, 10, 20, 30 or 40 mg threonine. Threonine was dissolved in 0·5 ml sterile saline and inoculated into the yolk sac of the 14-d-old embryo through the narrow end of the egg.

2.?The ratio of chick to egg weight was 1·6% higher in the group given 30 mg threonine and at 28 d of age chicks receiving threonine were 29 to 79 g heavier than untreated controls.

3.?Food conversion ratio until 7 d after hatching was improved in those chicks receiving 10, 20 or 40 mg threonine but there was no significant effect on the activities of amylase, pepsin or trypsin.

4.?The humoral response to sheep red blood cells was significantly greater in those groups receiving 10, 20 or 30 mg threonine supplementation than in untreated controls.

5.?The response to phytohaemagglutinin-P, a measure of the cell-mediated immune response, was not affected, however.

6.?It is concluded that injections of 20 to 30 mg threonine into yolk sac can improve post-hatching growth and humoral responses of broiler chicks.     

Neurogenic inflammation in the upper digestive tract of the mule duck: effect of a chemical algogen and force-feeding

1.?The objectives were to quantify the presence of neurogenic inflammation in 4 regions of the upper digestive tract of anaesthetised ducks (post-pharynx, pseudo-crop, transition between the pseudo-crop and the proventriculus, and proventriculus) after application of HCl stimulation of up to 4?M in the pseudo-crop.

2.?The second objective was to quantify the presence of neurogenic inflammation in the same digestive tract regions as mentioned above during 4 feeding periods of foie gras production (rearing, preparation to force-feeding, and second and last meals of the force-feeding period).

3.?Extravasation increased above a HCl stimulation threshold of 2?M. Furthermore, more extravasation was observed in the proventriculus compared to the other regions (P?

4.?Highest extravasation responses were observed in the proventriculus and the pseudo-crop at the end of the preparation period, and in the proventriculus after the second forced meal, compared with the rearing period (P?

5.?Such a kinetic could be indicative of a relative mildness of the irritant components associated with this feeding practice.