Poultry blood from slaughterhouses: development of a biopreservation system to improve microbiological quality prior to transforming blood into by-products

1. The aim of this study was to investigate the use of indigenous lactic acid bacteria (LAB) with specific additives as a Biopreservation System (BS) for poultry blood during its storage in slaughterhouses.

2. The BS consisted of two LAB (Enterococcus faecalis DSPV 008SA or Lactobacillus salivarius DSPV 032SA) with 4 additives (lactose 2 g/l, yeast extract 0.4 g/l, ammonium citrate 0.4 g/l and NaCl 1 g/l). After 24 h storage at 30ºC, lower counts of enterobacteria, coliforms, Pseudomonas spp. and Staphylococcus aureus were evident in blood treated with the BS than in untreated blood.

3. The ability of LAB to prevent haemolysis was evident. A decrease in pH was associated with control of spoilage microorganisms but it needed to be regulated to prevent coagulation of proteins.

4. On the basis of these results it is recommended to supplement blood with a BS to avoid undesirable changes during blood storage before processing.

     

Genetic variation for worm burdens in laying hens naturally infected with gastro-intestinal nematodes

1. Genetic parameters were determined for the worm burden of the most common gastro-intestinal nematodes in two chicken genotypes after being exposed to free-range farming conditions for a laying period.

2. Seventeen-week-old hens of 2 brown genotypes, Lohmann Brown (LB) plus (n = 230) and LB classic (n = 230), were reared for a laying period and subjected to post-mortem parasitological examinations at 79 weeks (LB plus) or 88 weeks (LB classic) of age.

3. There was no significant difference in faecal egg counts between the genotypes. Almost all hens (>99%) were infected with at least one nematode species. Species-specific nematode prevalence ranged from 85.8% to 99.1% between the two genotypes. Heterakis gallinarum was the most prevalent nematode (98.5%), followed by Ascaridia galli (96.2%) and Capillaria spp. (86.1%). Capillaria spp. were composed of C. obsignata (79%), C. caudinflata (16%) and C. bursata (5%).

4. All phenotypic and genetic correlations among worm counts of different parasite species were positive in combined genotypes (r_P ranged from 0.05 to 0.30 and r_G ranged from 0.29 to 0.88). A strong genetic correlation (r_G = 0.88 ± 0.34) between counts of A. galli and H. gallinarum was quantified. Heritability for total worm burden for LB plus and LB classic, respectively, were 0.55 ± 0.18 and 0.55 ± 0.34. Across both genotypes, the heritability of total worm burden was 0.56 ± 0.16.

5. In conclusion, there is a high variation attributable to genetic background of chickens in their responses to naturally acquired nematode infections. The high positive genetic correlation between counts of closely related worm species (e.g. A. galli and H. gallinarum) may indicate existence of similar genetically determined mechanism(s) in chickens for controlling these nematodes.

     

The effect of volatile oil mixtures on the performance and ilio-caecal microflora of broiler chickens

1. The aim of this study was to investigate the individual and combined effects of rosemary, oregano and fennel volatile oil (FVO) supplementation on the performance and ilio-caecal bacteriological flora of broiler chickens.

2. A total of 800 male Ross-308 broiler chickens were divided equally into 8 groups; each contained 100 chickens. The study included a control treatment (NC) with no dietary additives that was supplemented with oils according to the following 7 treatments: 200 mg α-tocopherol acetate/kg (PC), 100 mg oregano volatile oil (OVO)/kg, 100 mg rosemary volatile oil (RVO)/kg, 100 mg FVO/kg and an equal mixture of oregano+rosemary+fennel VO (100, 200, 400 mg/kg, VOM-1, VOM-2 and VOM-3, respectively). The experiment lasted for 6 weeks.

3. At the end of the experiment, dietary supplementation with α-tocopherol, oregano, rosemary and FVO and two different volatile oil mixtures (VOMs) (VOM-2; VOM-3) significantly increased the body weights (BWs) of broilers at 7, 14 and 21 d of age compared to the negative control (NC) (?) and VOM-1 groups. At 0–42 d, birds fed on VOM-3 were considerably heavier and also gained more weight than NC (?) and VOM-1 groups.

4. The blend of VOs at 400 mg/kg significantly increased Lactobacillus spp. in faeces. The blends of oregano, rosemary and FVOs (VOM-3) at 400 mg/kg concentration and also VOM-3 group exhibited stronger antibacterial activity against coliform bacteria compared to the NC (?) group.

5. In conclusion, the blend of oregano, rosemary and fennel VOs at higher concentrations (400 mg/kg concentration) in diets can be used to stimulate the growth and can improve the intestinal microbial balance (including a reduction of coliform bacteria and an increase in Lactobacillus spp. counts) of broiler chickens.

     

Dietary but not in ovo feeding of Silybum marianum extract resulted in an improvement in performance,immunity and carcass characteristics and decreased the adverse effects of high temperatures in broilers

1. A total of 360 fertile eggs from a broiler breeder strain (Ross 308) were used for in ovo feeding (IOF) of 0, 100 and 200 mg/kg Silybum marianum water extract at 17.5 d of incubation.

2. After hatching, 240 chicks were transferred to the experimental cages. The diets consisted of two types; one of them without extract and the other one containing 100 mg/kg of Silybum marianum extract. Then chicks were exposed to elevated temperatures 4°C above optimum from 7 to 28 d of age for 4 h per d and after 28 d they were kept at optimum temperature. The chicks were divided into 6 treatments with 4 replicates as a completely randomised 2 × 3 factorial design.

3. There was no effect of IOF of Silybum marianum extract on hatchability, body weight (BW) of hatched chicks or hatched chick BW/initial egg weight ratio. Chickens fed on the diet containing the extract had the highest feed intake, daily weight gains (DWGs), final BW and lowest feed conversion ratio.

4. At 28 d, the weights of heart, spleen and bursa of birds in the treatment groups given extract were higher, but abdominal fat weights were lower. At 42 d in those fed extract in the diet, the weights of spleen and bursa were higher and abdominal fat weights were lower than the other groups.

5. No differences were observed between groups in body temperature before application of the higher temperature but at 21 d and 28 d the body temperature of chicks given the Silybum marianum extract was lower than the other treatments during the elevated temperatures.

6. In birds fed on the extract in the diet, HDL and cholesterol concentrations were lowest at 28 d, whereas blood glucose levels were higher in the other treatments. At 42 d the cholesterol concentration was significantly lower in birds given extract in their diet.

7. These results indicated that dietary feeding of Silybum marianum extract resulted in an improvement in performance, immunity and carcass characteristics and decreased the adverse effects of the higher temperatures, specifically in reducing blood fat reduction, but IOF of the extract did not have an effect.

     

Comparative evaluation of therapeutic efficacy of sulfadiazine-trimethoprim,oxytetracycline, enrofloxacin and florfenicol on Staphylococcus aureus–induced arthritis in broilers

1. Staphylococcus aureus is an important human and veterinary pathogen that causes economic loss in the poultry industry. This study aimed to compare therapeutic efficacy of 4 commonly used antibiotics in poultry on S. aureus–induced arthritis in broilers.

2. Sixty broilers, 8 weeks of age, were assigned at random into 7 groups as follows: (1) negative control (n = 5); (2) vehicle control (n = 5); (3) sulfadiazine-trimethoprim, 250 ml/1000 l drinking water (n = 10); (4) oxytetracycline 20%, 1 mg/l drinking water (n = 10); (5) florfenicol 10%, 1/1000 v/v in drinking water (n = 10); (6) enrofloxacin 10%, 1/1000 v/v in drinking water (n = 10) and (7) positive control (n = 10).

3. Birds in group 2 were injected with 1 ml of sterile TSB medium into the right tibiotarsal joint on d 0 while other birds (except group 1) were challenged with 1 ml of 1.2 × 10¹⁰ CFU/ml suspension of S. aureus bacteria.

4. Antibiotic therapy was started from d 4 post challenge and continued for 5 d. At the end, birds were weighed and clinical severity of arthritis was determined. After blood collection, birds were slaughtered and tibiotarsal and hip joints were evaluated grossly. The content of inflammatory exudates of tibiotarsal joint and the degree of femoral head necrosis were recorded. Mucin clot test and histopathological evaluation were performed on right tibiotarsal joint. Serum interleukin 6 was also assayed.

5. Sulfadiazine-trimethoprim had higher therapeutic efficiency with regard to most of the assayed criteria, whereas none of the antibiotics significantly affected femoral head necrosis and body weight. These data will help clinicians to have better antibiotic choice in field conditions.

     

Inbreeding depression for economically important traits of Mazandaran native fowls

1. The objective was to investigate inbreeding depression for some economic traits of Mazandaran native fowls using data collected from 1992 to 2012 (21 generations) using a REML animal model of significant fixed and random effects with inbreeding of birds and dams as covariates.

2. The mean inbreeding coefficient (F) for the whole population and dams was 4.67% and 4.12%, respectively, and most of the inbred birds (75.79%) and inbred dams (72.58%) had F < 12.5%.

3. Individual and dam inbreeding trends were 0.55% and 0.53% per year.

4. Inbreeding depression for body weight at hatch, at 8 weeks and 12 weeks of age, age at sexual maturity, weight at sexual maturity, egg weight at 1st d of laying and average egg weight at 28, 30 and 32 weeks of laying due to a 1% increase in individual inbreeding were ?0.11 g, ?3.1 g, ?1.3 g, 0.15 d, 0.59 g, ?0.05 g and ?0.03 g, respectively.

5. A 1% increase in maternal inbreeding resulted in a reduction of 0.06, 0.6 and 3.6 g in body weight at hatch, 8 weeks and 12 weeks of age.

     

Pharmacokinetics of enrofloxacin and marbofloxacin in Japanese quails and common pheasants

1. The pharmacokinetics of enrofloxacin and marbofloxacin was studied in Japanese quails and common pheasants. Healthy mature birds from both species and both genders were treated intravenously and orally with enrofloxacin (10 mg/kg) and marbofloxacin (5 mg/kg).

2. After intravenous administration enrofloxacin was extensively metabolised to ciprofloxacin. Metabolites of marbofloxacin were not detected. Values of volume of distribution were respectively 4.63 l/kg and 3.67 l/kg for enrofloxacin and 1.56 l/kg and 1.43 l/kg for marbofloxacin. In quails, total body clearance values were higher than those in pheasants and other avian species.

3. After oral application enrofloxacin was rapidly absorbed in quails, more rapidly than marbofloxacin. Pheasants absorbed both antimicrobials at a lower rate. Higher bioavailability was observed for marbofloxacin (118%). Relatively low bioavailability was established in quails for enrofloxacin (26.4%), accompanied by extensive conversion to ciprofloxacin.

4. Generally, quails absorbed and eliminated both fluoroquinolones more rapidly than pheasants; the latter showed pharmacokinetics similar to poultry. Because of favourable pharmacokinetic properties, marbofloxacin should be preferred for oral administration in Japanese quails and pheasants for treatment of infections caused by equally susceptible pathogens.

     

Dietary inclusion of different multi-strain complex probiotics; effects on performance in broilers

1. This study was designed to evaluate the effects of two different complex probiotic supplementations on the growth performance, meat quality, excreta microflora, nutrient retention, blood metabolic profile and noxious gas emissions in broilers.

2. A total of 612 conventional healthy 1-d-old Ross 308 broilers with body weight of 41 ± 0.3 g were randomly divided into 3 treatments with 12 replicate cages, with 17 broilers in each cage and fed with the following diets: CON-Basal diet, T1-CON + Probiotic A, T2-CON + Probiotic B.

3. Significant results were observed on body weight gain, but not on feed conversation ratio and feed intake, in the whole experimental period. Increased faecal lactobacillus counts were found with probiotics supplementation. However, no significant effects were found for meat quality, nutrient retention, blood metabolic profile or noxious gas emissions.

4. In conclusion, both multi-strain probiotics had beneficial effects on growth performance, drip loss percentage and faecal Lactobacillus counts in broilers.

     

Effect of starting body fat content and genotype of laying hens on the changes in their live weight,body fat content,egg production and egg composition during the first egg-laying period

1. A total 120 laying hens (60 TETRA BLANCA white egg layers and 60 TETRA SL brown egg layers) were selected from 250 TETRA BLANCA and 250 TETRA SL pullets based on their predicted body fat content by means of computed tomography (CT) at 16 weeks of age. Three groups of pullets were chosen for the investigation with the highest (n = 20), lowest (n = 20) and average (n = 20) body fat content.

2. Changes in the live weight, body fat content, egg production and egg composition of the chosen animals were recorded at 32, 52 and 72 weeks of age.

3. Based on the results, it was established that differences in starting body fat content of the hens remained the same during the experimental period. The differences between the two extreme groups were statistically significant at each age.

4. The starting body fat content of the hens affected the rate of egg production, i.e. hens with high starting body fat content produced 11–14 eggs fewer than the hens with a low or average body fat content but had no effect on the composition of the eggs.

5. Genotype affected almost all of the examined traits: TETRA BLANCA hens had lower live weight and higher body fat content during the experimental period and produced fewer eggs with lower albumen and higher yolk, dry matter and crude fat content than the TETRA SL hens.

     

Antibiotic susceptibility of Lactobacillus strains isolated from domestic geese

1. The aim of this study was to determine the antibiotic susceptibility of 93 Lactobacillus strains isolated from domestic geese raised on Polish farms. The minimal inhibitory concentration (MIC) of 13 antimicrobial substances was determined by the broth microdilution method.

2. All strains were sensitive to the cell wall inhibitors ampicillin and amoxicillin (MIC ≤ 8 μg/ml). Resistance to inhibitors of protein synthesis and to fluoroquinolone inhibitors of replication was found in 44.1% and 60.2% of isolates, respectively; 26.9% strains were resistant to neomycin (MIC ≥ 64 μg/ml), 23.6% to tetracycline (MIC ≥ 32 μg/ml), 15% to lincomycin (MIC ≥ 64 μg/ml), 18.3% to doxycycline (MIC ≥ 32 μg/ml), 9.7% to tylosin (MIC ≥ 32 μg/ml), 56% to flumequine (MIC ≥ 256 μg/ml) and 22.6% to enrofloxacin (MIC ≥ 64 μg/ml).

3. Bimodal distribution of MICs indicative of acquired resistance and unimodal distribution of the high MIC values indicative of intrinsic resistance were correlated with Lactobacillus species. Eleven (11.8%) strains displayed multiple resistance for at least three classes of antibiotics.

4. Data derived from this study can be used as a basis for reviewing current microbiological breakpoints for categorisation of susceptible and resistant strains of Lactobacillus genus and help to assess the hazards associated with the occurrence of drug resistance among natural intestinal microflora.

     

Evaluation of potential probiotic characteristics and antibacterial effects of strains of Pediococcus species isolated from broiler chickens

1. Pediococcus spp. were isolated from poultry rectum, faeces and food as good probiotic candidates in order to select strains to be used as probiotic in poultry feed.

2. A total of 168 lactic acid bacteria were isolated and 51 isolates including 31 Lactobacillus spp. and 20 Pediococcus spp. were able to survive in low pH and bile salt concentration. The Pediococcus spp. were identified and their ability to form biofilm, adhesion to Caco-2 cells and antimicrobial activities against enteric pathogenic bacteria were determined.

3. The results showed the presence of two strains, Pediococcus acidilactici P17 and P19 in rectal swab samples from 21-d old chickens with significant antibacterial activities against Salmonella enteritidis and Escherichia coli.

4. The results suggest that only a few isolates of Pediococcus with potential probiotic activities are present in the poultry industry.

     

Hepatic expression of FTO and fatty acid metabolic genes changes in response to lipopolysaccharide with alterations in m6A modification of relevant mRNAs in the chicken

1. The fat mass and obesity associated (FTO) gene, which encodes a demethylase of m⁶A, has been reported to respond to lipopolysaccharide (LPS) and to serve as a link between inflammation and metabolic responses. The objective of this study was to determine whether LPS-induced changes in the expression of FTO and metabolic genes are associated with alterations of m⁶A in relevant mRNAs.

2. LPS challenge significantly decreased hepatic mRNA expression of carnitine palmitoyl transferase 1 (CPT1) and CPT2, which coincided with a tendency of higher triglyceride accumulation in the liver.

3. LPS significantly down-regulated the full length cFTO1, yet up-regulated the truncated cFTO4 protein in the liver nuclear extracts.

4. Nuclear protein content of cFTO4 in the liver was negatively correlated with the mRNA abundances of CPT1 (r = 0.629) and CPT2 (r = 0.622).

5. Methylated RNA immunoprecipitation analysis revealed that the m⁶A level around the translation start site of CPT1 was markably decreased in the liver of LPS-treated chickens.

6. These results indicate that LPS-induced changes in FTO protein expression are associated with alteration of mRNA m⁶A modification in chicken liver.

     

Single-dose toxicokinetics of permethrin in broiler chickens

1. Single-dose toxicokinetics of permethrin was investigated in broiler chickens.

2. A total of 20 male broiler chickens were assigned at random to two groups of 10 at 30 days of age. A single dose of 10 mg/kg body weight of permethrin was administered intravenously to the first group; in the second group, the same dose was administered into the crop.

3. Serum permethrin was measured using an electron capture detector and gas chromatography equipment. The derived serum permethrin concentration/time curve demonstrated that the distribution kinetics of permethrin was well described by a two-compartment open model.

4. For intravenous permethrin administration, the half-life at λ phase (t_1/2λ), mean residence time (MRT) and area under the concentration–time curve in 0→∞ (AUC_0→∞) values respectively were 4.73 ± 1.00 h, 5.06 ± 1.05 h and 16.45 ± 3.28 mg/h/l. In contrast, the C_max, t_max, t_1/2λ, MRT and AUC_0→∞ values respectively of the group given intra-crop permethrin were 0.60 ± 0.42 μg/ml, 0.55 ± 0.19 h, 5.54 ± 0.78 h, 7.06 ± 0.63 h and 1.95 ± 0.97 mg/h/l. The bioavailability of permethrin was 0.11.

5. For both administration routes, the residence time of permethrin in the body was short and the bioavailability of permethrin was low. These results are relevant for assessing the use and safety of permethrin.

     

Exogenous tannase improves feeding value of a diet containing field beans (Vicia faba) when fed to broilers

1. A total of 72 male Ross 308 broilers were used in a study to investigate the effect of dietary tannase on apparent metabolisable energy (AME), coefficients of dry matter retention (DMR) and nitrogen retention (NR) and fat digestibility (FD) of a diet containing 300 g/kg field beans (Vicia faba). Growth performance variables and gastrointestinal tract development were also measured.

2. Two treatments were used in this study: control (C) and C + 3400 tannase units (TU) per kg feed. Diets were formulated to be nutritionally adequate with the exception that the AME was lower than recommended (12.65 vs 12.97 MJ/kg, respectively).

3. Inclusion of tannase increased AME by 0.4 MJ/kg DM. Tannase supplementation improved dietary DMR, NR and FD by 2.8%, 3.2% and 6.5%, respectively.

4. Birds given tannase had 4.4% reduction in feed intake and 2.6% improvement in gain to feed ratio (P < 0.05). Compared to control diet, birds given tannase had reduced relative to body weight (%BW) proventriculus and gizzard and pancreas weights, 3.29% vs 3.09% and 0.47% vs 0.44%, respectively.

5. The mechanisms of action of the studied enzyme require further elucidation.

     

Comparing the immune responses of two genetically B-complex disparate Fayoumi chicken lines to Eimeria tenella

1. The present study was conducted to compare the susceptibility of congenic Fayoumi lines to Eimeria tenella infection and to assess genetic differences in Eimeria egression.

2. Chickens were orally inoculated with 5 × 10⁴ sporulated E. tenella oocysts and challenged with 5 × 10⁶ oocysts on the 10th day after the primary infection.

3. The Fayoumi M5.1 line exhibited higher levels of body weight gain, less oocyst shedding and higher percentages of B and CD4⁺/CD8⁺ T cells than the M15.2 chickens.

4. These results demonstrate that M5.1 line is more resistant to E. tenella infection than M15.2 line. Furthermore, the percentage of sporozoite egress from peripheral blood mononuclear cells (PBMCs) was higher in the M5.1 line.

5. The results of this study suggest that enhanced resistance of Fayoumi M5.1 to E. tenella infection may involve heightened cell-mediated and adaptive immunity, resulting in reduced intracellular development of Eimeria parasites.

     

Effects of ionised or chelated water-soluble mineral mixture supplementation on growth performance,nutrient digestibility,blood characteristics,meat quality and intestinal microbiota in broilers

1. An experiment was conducted to study the effects of dietary supplementation of water-soluble ionised or chelated mineral mixture on growth performance, nutrient digestibility, blood characteristics, relative organ weight, meat quality and excreta microflora in broilers.

2. A total of 408 Arbor Acres broilers (17 birds in 8 replicate pens) were randomly allocated into one of the following three treatments: (1) Control/basal diet (CON), (2) T1 (basal diet + 0.5% ionised mineral mixture solution, pH 3.0) and (3) T2 (basal diet + 0.5% chelated mineral mixture solution, pH 3.0).

3. The body weight gain was greater and feed conversion ratio was lower in broilers supplemented with ionised or chelated mineral liquid complex compared to CON during the grower and overall phase of the experiment.

4. No significant effect in the concentration of Ca and P in the blood was observed in birds supplemented with ionised or chelated mineral mixture solution. No adverse effects were observed in organ weight and meat quality with ionised or chelated mineral mixture supplementation.

5. Regarding intestinal microbiota counts there was a reduction of Escherichia coli counts in the small intestine in ionised mineral supplemented birds. In the large intestine, E. coli as well as Salmonella populations were reduced in ionised mineral supplemented birds.

6. In conclusion, ionised or chelated minerals have partial positive effects in improving growth performance and reducing pathogenic bacteria load in the gastro-intestinal tract.

     

Dietary fat modulates dl-α-tocopheryl acetate (vitamin E) bioavailability in adult cockerels

1. A trial was designed to assess the effect of fat supplementation (amount and type of fatty acids) on vitamin E bioavailability in adult cockerels.

2. A total of 60 birds were force-fed three different diets: a semi-purified diet without added fat (Control diet) or supplemented with 3% fat as linseed (Linseed diet) or hydrogenated coconut oil (Coconut diet). The three experimental diets were also supplemented with dl-α-tocopheryl acetate to provide 40 mg vitamin E per bird.

3. After one week of depletion, blood was collected from the wing vein before (baseline) and 6, 12, 24 and 96 h after the gavage. Plasma samples were analysed for their α-tocopherol, cholesterol and triglycerides concentrations.

4. Results showed that the addition of 3% fat in the experimental diet increased post-gavage plasma α-tocopherol response by 153% for Linseed diet and by 75% for Coconut diet (P < 0.0001) compared to the Control group. Furthermore, the plasma α-tocopherol response observed with the Linseed diet was 44% greater than that observed with the Coconut diet (P < 0.0001). There was no effect of treatments on either plasma triglycerides (P = 0.91) or cholesterol (P = 0.45) responses.

5. In conclusion, this study shows that the addition of 3% fat to the diet significantly increases dl-α-tocopheryl acetate bioavailability in adult cockerels. Supplementation of fat rich in unsaturated fatty acids also leads to a higher dl-α-tocopheryl acetate bioavailability than fat rich in saturated fatty acids.

     

Influence of an organic acid blend and essential oil blend,individually or in combination,on growth performance,carcass parameters,apparent digestibility,intestinal microflora and intestinal morphology of broilers

1. This study aimed to evaluate the influence of an organic acid (OA) and essential oil (EO) blends, individually or in combination, on growth performance, carcass parameters, apparent digestibility, intestinal microflora and intestinal morphology of broilers.

2. A total of 480 one-d-old male Ross 308 chicks were randomly assigned to 4 treatments consisting of 4 replicates each (n = 30 birds in each replicate). Dietary treatments consisted of a basal diet (control), and basal diet supplemented with 2 g/kg OA blend (OAB), 300 mg/kg EO blend (EOB), or with 2 g/kg OA and 300 mg/kg EO blend (OAB–EOB) for 42 d.

3. The dietary supplementation with EO blend or in combination with OA blend increased body weight gain and improved feed efficiency as compared to control. Dietary treatments had no significant effects on feed consumption or relative organ weights of broilers.

4. The OAB diet increased carcass yield compared to the control diet but the lowest carcass yield occurred with the OAB–EOB combination. Birds fed on EOB and OAB–EOB diets had lower ileum Escherichia coli counts than birds fed on the control diet.

5. There was no significant effect of treatments on apparent digestibility at 16–21 d but the EOB and OAB–EOB diets increased apparent digestibility of dry matter and crude protein during the finisher period (d 37–42) compared to the control diet.

6. Birds fed on the EOB and OAB–EOB diets had greater villus height in the ileum at 21 and 42 d of age and had lower crypt depth in the ileum at 42 d of age than birds given the control diet.

7. In conclusion, beneficial effects of the use of EO blend individually or in combination with the OA blend were observed but the OA blend alone was ineffective. Furthermore, the use of the combination of OA and EO was more effective, in some respects, than their individual use.

     

Alteration of fatty acid profile and nucleotide-related substances in post-mortem breast meat of α-lipoic acid-fed broiler chickens

1. The present study was conducted to determine the effects of α-lipoic acid supplementation on post-mortem changes in the fatty acid profile and concentrations of nucleotide-related substances, especially those of a taste-active compound, inosine 5?-monophosphate, in chicken meat.

2. Mixed-sex broiler chicks aged 14 d were divided into three groups of 16 birds each and were fed on diets supplemented with α-lipoic acid at levels of 0, 100 or 200 mg/kg for 4 weeks. Blood and breast muscle samples were taken at 42 d of age under the fed condition and then after fasting for 18 h. The breast muscle obtained from fasted chickens was subsequently refrigerated at 2°C for one and 3 d.

3. α-Lipoic acid supplementation did not affect any plasma metabolite concentration independently of feeding condition, while a slight increase in plasma glucose concentration was shown with both administration levels of α-lipoic acid. In early post-mortem breast muscle under the fed condition, α-lipoic acid had no effect on concentrations of fatty acids or nucleotides of ATP, ADP, and AMP.

4. In post-mortem breast tissues obtained from fasted chickens, total fatty acid concentrations were markedly increased by α-lipoic acid feeding at 200 mg/kg irrespective of length of refrigeration. This effect was dependent on stearic acid, oleic acid, linoleic acid and linolenic acid. However, among fatty acids, the only predominantly increased unsaturated fatty acid was oleic acid.

5. Dietary supplementation with α-lipoic acid at 200 mg/kg increased the inosine 5?-monophosphate concentration in breast meat and, in contrast, reduced the subsequent catabolites, inosine and xanthine, regardless of the length of refrigeration.

6. Therefore, the present study suggests that α-lipoic acid administration altered the fatty acid profile and improved meat quality by increasing taste-active substances in the post-mortem meat obtained from fasted chickens.

     

An evaluation of in vitro intestinal absorption of iron,calcium and potassium in chickens receiving gold nanoparticles

1. This study evaluated the effect of oral administration of colloidal gold nanoparticles on accumulation of gold in the small intestine and intestinal absorption of iron, calcium and potassium under in vitro conditions.

2. The gold nanoparticles are non-ionic, nanocrystalline, chemically pure particles 5 nm in size, produced in a physical process.

3. In total, 126 one day-old Ross 308 chicks were assigned to 7 experimental groups of 18 birds each (3 replications of 6 individuals each).

4. The control group (G-C) did not receive gold nanoparticles. Groups: Au-5(7), Au-10(7) and Au-15(7) received gold nanoparticles in their drinking water in the amounts of 5 mg l^?1 for group Au-5(7), 10 mg l^?1 for group Au-10(7) and 15 mg l^?1 for group Au-15(7) in 8–14, 22–28 and 36–42 d of life. The birds in groups Au-5(3), Au-10(3) and Au-15(3) received gold nanoparticles in the same amounts, but only in 8–10, 22–24 and 36–38 d of life.

5. The study revealed that nanogold supplied via ingestion leads to dose- and time-dependent accumulation of gold in the intestinal walls.

6. Nanogold present in the jejunum has a negative impact on the absorption of calcium, iron and potassium under in vitro conditions.