ß-Hydroxy-ß-methylbutyrate: A feed supplement influencing performance, bone metabolism, intestinal morphology, and muscle quality of laying hens: a preliminary one-point study.

Laying hens, selectively bred for high egg production, often suffer from bone fragility and fractures, impacting their welfare and causing economic losses. Additionally, gut health and muscle quality are crucial for overall health and productivity. This study aimed to evaluate the effects of ß-Hydroxy-ß-methylbutyrate (HMB) supplementation on performance, bone metabolism, intestinal morphology, and muscle quality in laying hens. Forty-eight Bovans Brown hens were divided into a control group and an HMB-supplemented group (0.02% HMB in diet). The study spanned from the 31st to the 60th wk of age. Assessments included bone mechanical testing, serum hormonal analysis, histological analysis of bone and intestine, and muscle quality analysis. The HMB supplementation led to decreased feed intake without affecting body weight or laying rate in laying hens. It caused an increase in both mean daily and total egg weight, indicating improved feed utilization, without influencing the feed intake to egg weight ratio. Enhanced bone formation markers and altered intestinal morphometric parameters were observed, along with improved trabecular bone structure. However, no changes in measured other bone quality indices, including geometric, densitometric, or mechanical properties were observed. Muscle analysis revealed no significant changes in overall meat quality, except for a decrease in cholesterol content and alterations in the fatty acid profile, notably a reduction in total n-3 polyunsaturated and total polyunsaturated fatty acids (PUFA). In conclusion, although not all effects of HMB supplementation were unequivocally beneficial, the positive changes in performance data and trabecular bone microarchitecture support further research into various doses and durations of supplementation. Such studies are necessary to fully understand and optimize the benefits of HMB for enhancing the health and productivity of laying hens.

Effects of Anticoccidial Vaccination and Taraxacum officinale Extract on the Growth Performance, Biochemical Parameters, Immunity, and Intestinal Morphology of Eimeria-Challenged Chickens.

A total of 160 Ross 308 male chickens were used in a 2 × 2 factorial design to examine the effects of anticoccidial vaccination (ACV; lack or 1× dose recommended by the manufacturer) and dietary supplementation with Taraxacum officinale (dandelion) extract (DE; with or without) on growth performance, immunity, biochemical parameters, and intestinal morphology in broiler chickens challenged with Eimeria spp. At 20 days of age, all birds were challenged with a 25× dose of ACV, including Eimeria acervulina, E. maxima, E. mitis, and E. tenella. No interaction between ACV and DE was observed in terms of growth performance. Vaccinated birds showed increased feed intake (FI) and feed conversion ratio (FCR) during the 11-20 day period. Meanwhile, DE supplementation led to decreased FI and body weight gain (BWG) during the 1-10 day period. ACV effectively induced immunity against Eimeria, as evidenced by reduced oocyst shedding and less intestinal lesions, decreased levels of pro-inflammatory interleukin-6, and improved BWG during both the post infection (PI) period (21-35 days) and the entire growth period. DE supplementation lowered FCR and increased BWG during the 35-42 day period, increased the concentration of butyric acid in the cecal digesta, and lowered oocyst shedding PI. In vaccinated birds, DE elevated levels of plasma total protein and immunoglobulin M, and influenced tight junction proteins zonula occludens-1 and claudin-3, indicating a more robust epithelial barrier. DE also lowered alanine aminotransferase activity in unvaccinated birds. Both ACV and DE independently improved intestinal morphology in the jejunum, decreasing crypt depth and increasing the villus height-to-crypt ratio. These findings suggest that both ACV and DE could be effective strategies for managing coccidiosis in broiler chickens.

Lactoferrin: Antimicrobial impacts, genomic guardian, therapeutic uses and clinical significance for humans and animals.

Lactoferrin (LF) is a protein found in several bodily fluids, such as milk. This protein has a diverse range of functions and is evolutionarily conserved. Lactoferrin is a multifunction protein with distinct biological abilities affecting mammals' immune structures. Reports indicated that the daily uptake of LF from dairy products is unsatisfactory in detecting further health-promoting abilities. Research has shown that it protects against infection, mitigates cellular senescence, and improves nutritional quality. Additionally, LF is being studied as a potential treatment for various diseases and conditions, including gastrointestinal issues and infections. Studies have also demonstrated its effectiveness against various viruses and bacteria. In this article, we'll look closer at the structure of LF and its various biological activities, including its antimicrobial, anti-viral, anti-cancer, anti-osteoporotic, detoxifying, and immunomodulatory properties. More specifically, the protective effect of LF against oxidative DNA damage was also clarified through its ability to abolish DNA damaging issues without interfacing with host genetic material. Fortification with LF protects mitochondria dysfunction syndromes via sustaining redox status and biogenesis and suppressing apoptosis and autophagy singling. Additionally, we'll examine the potential benefits of lactoferrin and provide an overview of recent clinical trials conducted to examine its use in laboratory and living models.

Yolk Fatty Acid Profile and Amino Acid Composition in Eggs from Hens Supplemented with ß-Hydroxy-ß-Methylbutyrate.

In recent years, a supplementation of livestock animals, including poultry, with ß-Hydroxy-ß-methylbutyrate (HMB) has gained attention for its effects on protein and fat metabolism. This study investigates the effects of HMB in the laying hen diet on egg quality, focusing on amino acid and fatty acid composition. Laying hens were supplemented with 0.02% HMB, with performance parameters and egg components analyzed. HMB supplementation led to increased albumen weight, influencing egg weight while also reducing feed intake per egg without affecting laying rate, yolk indices, fat, or cholesterol content. Notably, the study revealed significant changes in egg amino acid and fatty acid profiles due to HMB supplementation. Various amino acids, including glycine, serine, and isoleucine, were altered in the yolk, impacting nutritional value and potential health benefits. Regarding fatty acids, the study observed changes in both saturated as well as n-6 and n-3 fatty acids, affecting the overall lipid profile of egg yolks. However, the shifts in fatty acid composition could have implications for cardiovascular health due to altered ratios of n-6/n-3 fatty acids. Further research is required to comprehensively understand the implications of these findings for consumer-oriented egg quality and health benefits.

Effects of a Dietary Multi-Strain Probiotic and Vaccination with a Live Anticoccidial Vaccine on Growth Performance and Haematological, Biochemical and Redox Status Indicators of Broiler Chickens.

A total of 256 male Ross 308 chickens were assigned to four treatments in a 2 × 2 factorial design with two levels of the anticoccidial vaccine (ACV) Livacox T (none or 1 × dose) with or without dietary supplementation with the probiotic Protexin® (P). The growth performance parameters for the test periods (1-21, 22-42, and 1-42 d) and oocyst per gram (OPG) at weekly intervals were analysed. Blood samples were collected at 16 post-vaccination (pv) days to measure selected haematological, biochemical, redox, and immunological parameters. ACV administration worsened the performance parameters of the chickens for 1-21 d pv, while supplementation with P reduced this negative effect with a significant improvement in 1-21 d body weight gain and feed conversion ratio. ACV administration increased % phagocytic cells (%PC), phagocytic index (PI), respiratory burst activity, proportion of monocytes, and activities of aspartate aminotransferase (AST) and lactate dehydrogenase, while it decreased the catalase activity and concentration of malondialdehyde and peroxides. The dietary administration of P significantly increased counts of red blood cells and white blood cells and increased %PC and PI, while it decreased the heterophil proportion, heterophil/lymphocyte ratio (p = 0.059), and alanine aminotransferase and AST activities. The oocyst counts were comparable in all sampling periods, except on 14 d pv, as supplementation with P significantly decreased 14 d OPG, thus indicating a positive influence of P on immunity development. In conclusion, dietary supplementation with P led to improved performance, better immunity, and benefits in health status in broilers vaccinated with the ACV, without interfering with the circulating vaccine strains.

Assessing Bone Health Status and Eggshell Quality of Laying Hens at the End of a Production Cycle in Response to Inclusion of a Hybrid Rye to a Wheat-Corn Diet.

The objective of this study was to evaluate whether there are negative effects of the partial replacement of white corn with rye along with xylanase supplementation on overall bone quality, eggshell mineralization, and mechanical strength in laying hens. From the 26th week of life, ISA Brown laying hens were fed either a wheat-corn diet or a diet containing 25% rye, with or without xylanase. The experimental period lasted for 25 weeks, until birds reached their 50th week of age, after which bone and eggshell quality indices were assessed. Eggshell thickness and eggshell Ca content of eggs from rye-fed hens were improved by xylanase supplementation. No differences in the mechanical properties of the eggshells were observed between treatments, except for the diet-dependent changes in egg deformation. Rye inclusion had no effect on the mechanical properties of bone. Xylanase supplementation, irrespective of the diet, had a positive effect on bone strength and increased tibia Ca content, as well as the content of several microelements. Hence, hybrid rye combined with wheat can replace 25% of corn in layer diets without compromising shell quality or bone mineral content. Xylanase supplementation in these diets is recommended since its inclusion improves both bone strength and quality.

Cholesterol Content, Fatty Acid Profile and Health Lipid Indices in the Egg Yolk of Eggs from Hens at the End of the Laying Cycle, Following Alpha-Ketoglutarate Supplementation.

The current study aimed to assess the effects of dietary alpha-ketoglutarate (AKG) supplementation to laying hens on the fatty acid (FA) profile and cholesterol levels of the egg yolk at the end of production cycle. The experiment was performed on forty-eight Bovans Brown laying hens randomly assigned to either a control group (CONT) or a group supplemented with AKG. The CONT group was fed the basal diet, and the AKG group was fed the basal diet plus 1.0% AKG from the 31st until the 60th week of age, when FA profile, fat and cholesterol content of the egg yolks were determined. No significant changes in the cholesterol and total fat content of the egg yolks were observed. However, there were positive (the decrease in n-6 FA and the increase in MUFA), and negative (decrease in PUFA and n-3 FA, increase in TI and n-6/n-3 ratio) changes in FA profile following AKG supplementation. In conclusion, it was shown that dietary AKG after a 30-week long supplementation influence FA profile in egg yolk and its nutritional value.

The Effect of L-Glutamine on Basal Albumen and Yolk Indices, and Albumen Amino Acids Composition.

The current study tested the hypothesis that 1.0% dietary inclusion of L-glutamine (Gln), an non-essential amino acid that influences protein synthesis, can improve internal egg quality, including amino acids profile. Thirty-week-old Bovans Brown laying hens in their middle laying period were assigned to one of the two experimental groups (12 replicate cages, 2 hens/cage) with Gln in the form of alpha-ketoglutarate (10 g/kg) or without Gln inclusion. The experimental period lasted for 30 wks, from the 31st to the 60th week of age of hens, when eggs were collected and selected egg quality indices were determined. Gln supplementation had no effect on albumen and egg yolk share, albumen and yolk basal indices and composition, including yolk cholesterol content. However, Gln decreased the lipid content of the egg albumen (p < 0.001), and influenced albumen amino acid profile, increasing content of asparagine (p < 0.05), phenylalanine (p < 0.05), proline (p < 0.001), tryptophan (p < 0.01), and tyrosine (p < 0.05). In conclusion, the study shows a potential role of Gln supplementation for enhancing nutritional values of eggs by lower lipid content and higher amino acid profile.

Structural Changes in Trabecular Bone, Cortical Bone and Hyaline Cartilage as Well as Disturbances in Bone Metabolism and Mineralization in an Animal Model of Secondary Osteoporosis in Clostridium perfringens Infection.

There is no information regarding whether changes in the microbiological balance of the gastrointestinal tract as a result of an infection with Clostridium perfringens influence the development of metabolic bone disorders. The experiment was carried out on male broiler chickens divided into two groups: control (n = 10) and experimental (n = 10). The experimental animals were infected with Clostridium perfringens between 17 and 20 days of age. The animals were euthanized at 42 days of age. The structural parameters of the trabecular bone, cortical bone, and hyaline cartilage as well as the mineralization of the bone were determined. The metabolism of the skeletal system was assessed by determining the levels of bone turnover markers, hormones, and minerals in the blood serum. The results confirm that the disturbed composition of the gastrointestinal microflora has an impact on the mineralization and metabolism of bone tissue, leading to the structural changes in cortical bone, trabecular bone, and hyaline cartilage. On the basis of the obtained results, it can be concluded that changes in the microenvironment of the gastrointestinal tract by infection with C. perfringens may have an impact on the earlier development of osteoporosis.

The Effect of Feeding Chicken and Geese Broilers with Different Cereals on the Fatty Acids Profile in Meat.

The research was conducted on the effect of bird broilers fed with different hybrid rye doses on the fatty acids profile in muscle. The first experiment was performed on 3 geese broilers groups fed with hybrid rye, oats or hybrid rye and oats mix in proportion 1:1. No effect of the hybrid rye feeding of geese on the SFA level in meat was observed, but the MUFA level was significantly higher and PUFA level and n-6/n-3 PUFA ratio were significantly lower than in geese fed with oats. The second experiment was performed on 3 chicken broiler groups fed with mix of corn, wheat, soybean meal and rapeseed oil (control group), and fed with an addition of 10% or 20% hybrid rye in diet (experimental groups). No effect of hybrid rye feeding of chicken broilers on the meat quality and SFA level was observed. However, the MUFA level was higher and the PUFA level and n-6/n-3 PUFA ratio were lower in meat of chicken broilers fed with hybrid rye. In conclusion hybrid rye is a healthy ingredient in the diet of studied birds and may be used up to 20% in chicken broilers and 50% in the diets of geese. A 100% hybrid rye in geese diet caused lower final body weight.

Modern Hybrid Rye, as an Alternative Energy Source for Broiler Chickens, Improves the Absorption Surface of the Small Intestine Depending on the Intestinal Part and Xylanase Supplementation.

The current study investigated the effects of the inclusion of modern hybrid rye (Brasetto variety) to a corn-wheat-based diet, with or without xylanase, on the absorptive surface of the small intestine of broilers. A total of 224 one-day-old male Ross 308 broiler chicks were randomly divided into four experimental groups with seven replicate cages of eight birds/replicate. A 2 × 2 factorial study design was used, with rye inclusion (0% or 20%) and xylanase supplementation (0 or 200 mg/kg of feed) as factors. Inclusion of rye increased duodenal and ileal crypt depth, villi height, the villus-to-crypt ratio and absorption surface area (p < 0.05), and ileal mucosa thickness and crypt width (p < 0.05). Xylanase supplementation attenuated the effects of rye in the duodenum and ileum and decreased the villi height and villus-to-crypt ratio in the jejunum (p < 0.05). Rye and xylanase had no effect on the spatial distribution of claudin 3 and ZO-1 protein, but xylanase supplementation reduced the amount of claudin 3 in the duodenum and jejunum (p < 0.05). The findings of this study indicate that 20% inclusion of modern hybrid rye to the diets of broilers improved the structure of the duodenum and ileum, but these effects were attenuated by xylanase supplementation.

Standardised Ileal Amino Acid Digestibility in Field Pea Seeds of Two Cultivars Differing in Flower Colour for Broiler Chickens: Effects of Bird Age and Microbial Protease.

This study aimed to determine and compare standardised ileal digestibility (SID) coefficients of amino acids (AA) in raw seeds of the white-(WF) and the coloured-flowered (CF) field pea cultivar as sole sources of AA in the diets fed to broiler chickens aged 14 or 28 days. An additional purpose was to check the influence of exogenous protease added to pea-based assay diets on AA SID in birds at both ages. Each assay diet was offered to six replicate pens. On both sampling days, the contents from the lower half of the ileum were collected for determination of the apparent digestibility values. The SID coefficients were calculated using ileal endogenous AA losses determined from birds fed an N-free diet. Results indicated a substantial advantage of WF pea over CF pea as a source of digestible Lys, Met, Cys, His, Ile, Leu, Phe, Val, Asp and Glu for 14-day-old chickens. With the exception of methionine and cysteine, there was no significant difference between these two cultivars in the SID values of AA in 28-day-old birds. The protease increased SID of nutritionally essential AA from WF pea-based diet at both ages, and from CF pea-based diet in chickens aged 28 days. In conclusion, the SID coefficients of indispensable AA determined at 14 days of age in low-tannin WF peas are not applicable to the formulation of grower-type feeds containing seeds of CF cultivars.

Nisin as a Novel Feed Additive: The Effects on Gut Microbial Modulation and Activity, Histological Parameters, and Growth Performance of Broiler Chickens.

Two independent experiments were performed to evaluate the effect of nisin alone or with monensin on gut microbiota, gut microbial activities, and histomorphology (exp 1) and the effect of nisin application in a dose‒response manner on the growth performance of broiler chickens (exp 2). A total of 900 one-day-old female Ross 308 chicks (400, exp 1; 500, exp 2) were randomly distributed to four groups (exp 1; 10 replicate pens per treatment with 10 birds each), i.e., NA, no additives; MON, monensin (100 ppm); NIS, nisin (2700 IU/kg diet); and MON + NIS, a mixture of monensin (100 ppm) and nisin (2700 IU/kg diet); or 5 treatments (exp 2), NA, no additives; NIS100, nisin (100 IU/kg diet); NIS200, nisin (200 IU/kg diet); NIS400, nisin (400 IU/kg diet); and NIS800, nisin (800 IU/kg diet). Nisin supplementation positively affected the microbiota of the gut by reducing potentially pathogenic bacterial populations in the jejunum and ceca. The bacterial fermentation in the jejunum was significantly lowered by nisin addition. The addition of nisin from 100 IU to 800 IU decreased the FCR value over the entire experimental period. According to the results, nisin can be considered a natural dietary supplement for broiler chickens.

Effect of Soybean Meal Substitution by Raw Chickpea Seeds on Thermal Properties and Fatty Acid Composition of Subcutaneous Fat Tissue of Broiler Chickens.

In this study, the effect of soybean meal substitution by raw chickpea seeds on the thermal properties and fatty acid profile of subcutaneous fat tissue of broiler chickens was examined. The experiment, performed on Ross 308 chickens, lasted for 42 days. Tight subcutaneous fat tissue was analyzed using differential scanning calorimetry (DSC) measurements while the fatty acid composition of subcutaneous adipose tissue was determined chromatographically. There was no effect of soybean meal substitution on fat crystallization temperature or crystallization enthalpy. However, the total calorimetric enthalpy of the melting of low-melting monounsaturated and saturated triacylglycerols differed between groups. Fatty acid proportions in the subcutaneous fat tissue of broiler chickens were also altered. Among others, chickpea seed inclusion decreased the content of main saturated acid (palmitic acid) and increased the content of main monounsaturated (oleic) and tri-unsaturated (linolenic) acids. The results show that the soybean meal substitution by raw chickpea seeds in the feed can affect the structural properties of adipose tissue in broiler chickens, including the thermal transformation of unsaturated fatty acids. Due to the numerous physiological functions of subcutaneous fat tissue, understanding these mechanisms can promote the use of alternative protein both in poultry and human nutrition.

Alpha-Ketoglutarate: An Effective Feed Supplement in Improving Bone Metabolism and Muscle Quality of Laying Hens: A Preliminary Study.

The aim of the experiment was to assess the effect of dietary alpha-ketoglutarate (AKG) supplementation on performance, serum hormonal indices, duodenum and jejunum histomorphometry, meat quality characteristics, bone quality traits and cartilage degradation in laying hens with a mature skeletal system. Forty-eight 30 week-old Bovans Brown laying hens were randomly assigned to a control group or the group fed the basal diet plus 1.0% AKG. The experimental trial lasted 30 weeks. The supplementation of AKG increases blood serum content of leptin, ghrelin, bone alkaline phosphatate and receptor activator of nuclear factor kappa-Β ligand, while osteoprotegerin and osteocalcin decrease. While dietary AKG was given to laying hens negatively influenced villus length, crypt depth, villus/crypt ratio and absorptive surface area in duodenum and jejunum, these changes have no effect on feed intake, weight gain, nor laying performance. In breast muscles, no significant changes in skeletal muscle fatty acid composition were observed, however, a higher shear force and decreased cholesterol content following AKG supplementation were noted, showing the improvement of muscle quality. While dietary AKG supplementation did not affect the general geometric and mechanical properties of the tibia, it increased collagen synthesis and enhanced immature collagen content. In medullary bone, an increase of bone volume fraction, trabecular thickness, fractal dimension and decrease of trabecular space were observed in AKG supplemented group. The trabeculae in bone metaphysis were also significantly thicker after AKG supplementation. AKG promoted fibrillogenesis in articular cartilage, as indicated by increased cartilage oligomeric matrix protein immunoexpression. By improving the structure and maintaining the proper bone turnover rate of highly reactive and metabolically active medullar and trabecular bones AKG showed its anti-osteoporotic action in laying hens.

The Effect of Dietary Rye Inclusion and Xylanase Supplementation on Structural Organization of Bone Constitutive Phases in Laying Hens Fed a Wheat-Corn Diet.

This study was conducted to examine the effect of dietary rye inclusion and xylanase supplementation on the bone quality of ISA Brown laying hens. Ninety-six laying hens were assigned to four groups: fed with wheat-corn diet or rye-wheat-corn diet (25% of hybrid rye inclusion) or nonsupplemented or supplemented with xylanase (200 mg/kg of feed) for a period of 25 weeks, from the 26th to the 50th week of age. X-ray absorptiometry, X-ray diffraction, and Fourier-transform infrared spectroscopy were used to provide comprehensive information about the structural organization of bone constitutive phases of the tibia mid-diaphysis in hens from all treatment groups. Bone hydroxyapatite size was not affected by diet. Xylanase supplementation influenced the carbonate-to-phosphate ratio and crystallinity index in hens fed with both diets. Xylanase had more pronounced effects on bone mineral density and collagen maturity in hens fed with the rye-wheat-corn diet versus those fed with the wheat-corn diet. The results of this study showed that modern rye varieties, when supplemented with exogenous xylanase, can be introduced to the diet of laying hens without any adverse effects on bone structure.

The Efficiency of Xylanase in Broiler Chickens Fed with Increasing Dietary Levels of Rye.

In this paper, we present a study on the evaluation of the effect of xylanase addition to a diet with an increasing content of modern hybrid rye (Brasetto variety) on the performance indices and viscosity of small intestine content in broiler chickens. A total of 560 1-day-old male Ross 308 chickens were randomly assigned to 1 of 10 treatments, each comprising 7 replicate cages, with 8 male birds per cage. A 5 × 2 factorial arrangement was employed, with five dietary levels of ground rye (0%, 5%, 10%, 15%, and 20%). All the diets were either unsupplemented or supplemented with xylanase (200 mg/kg of feed; with minimum xylanase activity 1000 FXU/g). In the starter rearing period (1⁻21 days of age), the inclusion of rye (without xylanase supplementation) to the diet, even at the lowest dietary level (5%), negatively affected body weight gain (p < 0.05); there was no effect on feed intake and feed conversion ratio. In older chickens (the grower-finisher rearing period; 22⁻42 days of age), none of the dietary levels of rye (5⁻20%) affected growth performance indices. Similarly, no significant effect of increasing dietary level of rye was found for the entire rearing period (1⁻42 days of age). Diet supplementation with xylanase improved body weight gain and feed conversion ratio in chickens from 1 to 21 days of age. No positive effect of enzyme was found in older birds. No significant effects of the experimental factors used were noticed on the results of slaughter analysis, i.e., the carcass yield, breast meat yield, abdominal fat, and relative weight of the liver and gizzard. A high dietary concentration of rye (20%) increased the viscosity of small intestine content (p < 0.05); however, diet supplementation with xylanase significantly alleviated this effect. The findings of this experiment indicated that modern hybrid rye grain may be used at a 20% dietary level in broiler diets during the second feeding phase, i.e., from 22 to 42 days of age, without any detrimental influence on growth performance indices, while enzyme (xylanase) positively affected body weight gain and feed conversion ratio in younger chicks (1⁻21 days of age).

Effect of Dietary Crude Protein Level and Supplemental Herbal Extract Blend on Selected Blood Variables in Broiler Chickens Vaccinated against Coccidiosis.

Immunoprophylaxis with a live anticoccidial vaccine is regarded as the most promising alternative in place of in-feed coccidiostats in the poultry industry. An experiment, designed as a 2 × 2 × 2 factorial arrangement with 6 replicate pens per treatment and 8 male Ross 308 chicks per pen, was conducted to evaluate the effect of dietary crude protein (CP) levels (21.6% or 23.6%, during the starter phase) and a herbal extract (HE) blend dietary supplementation (Echinacea purpurea, Salvia officinalis, Thymus vulgaris, Rosmarinus officinalis, Allium sativum, Origanum vulgare; 0 or 2 g/kg of feed) on selected hematological, biochemical, redox, and immunological parameters in broilers vaccinated against coccidiosis (anticoccidial vaccine (ACV); none or 1× dose, administered at 1 d of age). The blood samples were collected at 14 d of age. Anticoccidial vaccination (p < 0.05) had a negative effect on immune responses, as shown by a reduced total white blood cells (WBC) count, a reduced lymphocytes count (L), a higher proportion of heterophils (H) in leukogram assessments, as well as H/L-ratio increase. ACV resulted in a decrease in phagocytic activity assessed as decreased percentage of phagocytic cells, phagocytic index and NBT test, as well as in reductions in plasma glucose and LDL-cholesterol concentrations, and increases in HDL-cholesterol and aspartate aminotransferase (AST) activity. In terms of redox status, ACV significantly increased the catalase (CAT) activity and ferric reducing ability of plasma (FRAP), and decreased malondialdehyde concentrations. An increase in dietary CP in vaccinated chickens resulted in higher relative L and lower relative H counts, a lower H/L ratio, a decrease in AST and an increase in CAT activities, but also a decrease in FRAP and concentrations of lipid peroxides. Vaccinated chickens fed a diet supplemented with HE were characterized by higher relative L and lower relative H counts, a lower H/L ratio, and a decrease in AST activity. A change of diet composition, such as an increase in CP content and dietary HE supplementation, can be recommended in broilers vaccinated against coccidiosis, mainly due to its positive effect in alleviating stress levels. However, the simultaneous increase of CP and HE dietary supplementation offered no additional relevant benefits in most of the blood indices of vaccinated chickens.

Results of a 16-week Safety Assurance Study with Rats Fed Genetically Modified Bt Maize: Effect on Growth and Health Parameters.

INTRODUCTION: The influence of feeding genetically modified MON 810 hybrid maize on the growth and haematological and biochemical indices of rats was tested. MATERIAL AND METHODS: Two conventional (non-GM) and two test (MON 810) lines of maize were used in semi-purified diets at the level of 40% w/w. The non-GM I, MON 810 I, non-GM II, and MON 810 II maize lines were near-isogenic. A total of 40 male 6-week-old Wistar-derived rats were assigned to four equal feeding groups corresponding to the four maize lines for 16 weeks. Overall, health, body weight gain, clinical pathology parameters, gross changes, and appearance of tissues were compared between groups. RESULTS: There were no statistically significant differences in the weight gain or relative organ weights of rats, but there were some non diet-related histopathological changes in the liver, kidneys, and spleen. Except for creatinine level, no diet-related effects were observed in haematology or most of the biochemical indices. Transgenic DNA of MON 810 maize was not detected in the tissues or faeces nor in the DNA of E. coli isolated from the rectum digesta of rats given transgenic feeds. In our experiment, various metabolic indices of rats fed non-GM diets or genetically modified (MON 810) maize for 16 weeks were similar. No adverse nutrition-related health effects were detected. CONCLUSION: MON 810 maize seems to be as safe as the conventional maize lines.

Dietary Probiotics Affect Gastrointestinal Microbiota, Histological Structure and Shell Mineralization in Turtles.

Probiotics are widely used in nutrition, and their mode of action is intensively studied in mammals and birds; however, it is almost unknown in reptiles. In the present study, Trachemys scripta scripta and Sternotherus odoratus were used to assess the effects of dietary probiotics on chelonian gastrointestinal tract microecology. In the first, 20-week experiment, 40 young T. s. scripta were randomly distributed to four experimental groups: 1st, (CON)--with no additives; 2nd, (SSPA) with Bacillus subtilis PB6; 3rd, (MSP)--with multiple strain probiotic; and 4th, (SSPB) with Bacillus subtilis C-3102. The first study has shown that SSPA and MSP decreased the numbers of total bacteria, Enterobacteriace, Staphylococcus sp. and Streptococcus sp. excreted to water and increased the villous height and mucosa thickness in duodenum. SSPB improved the duodenal microstructure; however, it also increased numbers of kanamycin and vancomycin resistant bacteria, Staphylococcus sp. and Streptococcus sp., in water. In the second, 52-week experiment, 30 S. odoratus were randomly assigned to three dietary treatments. CON, SSPA and MSP groups. The MSP preparation increased the body weight gain, crude ash, Ca and P share in the turtles' shells. Both probiotics affected duodenal histomorphology. SSPA decreased the villous height, while MSP increased the villous height and mucosa thickness, and decreased the crypt depth. SSPA decreased the concentrations of bacteria excreted to water. In the case of intestinal microbiota, bacteria suppressing effects were observed in the case of both probiotics. MSP increased the number of Bifidobacterium sp. and Lactobacillus sp./Enteroccoccus sp., and decreased the number of Clostridium perfringens and Campylobacter sp. in the small intestine. In the large intestine it lowered, amongst others, Bacteroides-Pervotella cluster, Clostridium leptum subgroup and Clostridium perfringens numbers. The above-mentioned results suggest that probiotics are useful in turtle nutrition due to their positive effects on growth performance, shell mineralization, duodenal histomorphology and microbiota.