Effect of in ovo feeding of vitamin C on antioxidation and immune function of broiler chickens

Hypoimmunity and numerous stresses are two major challenges in broiler industry. Nutrient intervention at the specific time of embryonic stage is a feasible way to improve animal performance. This study was conducted to investigate the possible effects of in ovo feeding (IOF) of vitamin C at embryonic age 15^th day (E15) on growth performance, antioxidation and immune function of broilers. A total of 240 broiler fertile eggs were randomly divided into two groups (0 and 3 mg injected dose of vitamin C at E15), and new-hatched chicks from each treatment were randomly allocated into six replicates with 10 chicks per replicate after incubation. The results indicated that in ovo vitamin C injection improved the hatchability (P < 0.05) and increased immunoglobulin M (IgM) (at the broiler’s age 1^st day, D1), IgG and IgM concentrations (D21), as well as lysozyme activity (D21, P < 0.05) and total antioxidant capacity (D42, P < 0.01) in plasma of broilers. On D21, the splenic expression level of DNA methyltransferase 1 (DNMT1) was up-regulated in vitamin C (VC) group, whereas interleukin (IL)-6, interferon-γ, ten-eleven translocation protein 1 and thymine-DNA glycosylase were down-regulated (P < 0.05). On D42, in ovo vitamin C injection up-regulated splenic expression levels of DNMT1, DNA methyltransferase 3B (DNMT3B) and growth arrest and DNA-damage-inducible protein beta (P < 0.05), whereas down-regulated splenic expression levels of IL-6, tumour necrosis factor-α and methyl-CpG-binding domain protein 4 (P < 0.05). Our findings suggested that IOF of 3 mg vitamin C at E15 could improve, to some extent, the antioxidant activity and immune function in plasma, corresponding with the lower expression of pro-inflammatory cytokines in spleen. However, IOF of vitamin C leading to the changes in the expression of DNA methyltransferases and demethylases may suggest an increased trend of DNA methylation level in spleen and whether DNA methylation variation is associated with the lower expression of pro-inflammatory cytokines in spleen warrants future study.     

Effect of in ovo application of hydroxyapatite nanoparticles on chicken embryo development,oxidative status and bone characteristics

ABSTRACT

Intensive selection in modern lines of fast-growing chickens has caused several skeletal disorders. Therefore, current research is focused on methods to improve the bones of birds. A new potential solution is in ovo technology using nanoparticles with a high specificity for the bone tissue. Thus, the objective of the present study was to evaluate the effect of in ovo application of hydroxyapatite nanoparticles (HA-NP) in different concentrations (50, 100 and 500 μg/ml colloids) on chicken embryo development, with a particular focus on the oxidative status and bone characteristics of the embryo. The results showed that in ovo treatment with HA-NP did not negatively affect hatchability and body weight. However, bone weight was reduced in 500 μg/ml group. The concentrations of calcium, phosphorus and crude ash were not affected. The modulatory effect of HA-NP was observed on the basis of antioxidative markers – superoxide dismutase, total antioxidant status, malondialdehyde in serum and selected tissues. Glutathione concentration in serum suggested higher metabolic stress. Among bone turnover markers, the concentration of osteocalcin was found to be significantly affected by HA-NP injection. Thus, the in ovo application of HA-NP could modify the molecular responses at the stage of embryogenesis but these changes were not reflected in embryo growth and even slowed down bone development. Nevertheless, the question for the follow-up research is whether in ovo administration of HA-NP would affect the antioxidative status and bone turnover resulting in improved bone conditions and body gain in post hatch chickens.     

Eucalyptus leaves powder,antibiotic and probiotic addition to broiler diets: effect on growth performance,immune response,blood components and carcass traits

The study was conducted to investigate the effects of different levels of eucalyptus powder (EP), virginiamycin and probiotic on performance, immunity, blood components and carcass traits of broiler chickens. A total of 250, 1-day-old male broiler chickens (Ross 308) were randomly allocated to five treatments with five replicates and 10 chicks each, as a completely randomized design. The dietary treatments consisted of: basal diet (BD), BD+0.25% EP, BD+0.5% EP, BD+0.01% of diet probiotic (Protexin), BD+0.02% of diet antibiotic (virginiamycin). Dietary supplementation did not affect feed intake, BW gain (BWG) and feed conversion ratio (FCR) during starter and grower phases, but BWG and FCR were affected during the finisher and whole periods (P<0.05).The highest BWG and lowest FCR were obtained in birds fed with virginiamycin and 0.5% EP. Dietary supplementation significantly increased the relative weight of carcass and breast (P<0.05). Treatments had no effect on relative weights of internal organs and small intestine except for bursa that increased by treatments. Relative length of jejunum also increased by treatments (P<0.05). Antibody production against sheep red blood cells did not changed in primary titer (day 35), but it significantly increased in secondary titer (day 42) by 0.5% EP. White blood cell counts were increased and cholesterol decreased by dietary supplementation (P<0.05). In conclusion, the results of this study showed that 0.5% EP served as a useful replacement for antibiotic and would improve performance and immune response of broiler chickens.     

Dissemination of Fluoroquinolone-Resistant Campylobacter spp. within an Integrated Commercial Poultry Production System

While characterizing the intestinal bacterial community of broiler chickens, we detected -proteobacterial DNA in the ilea of 3-day-old commercial broiler chicks (J. Lu, U. Idris, B. Harmon, C. Hofacre, J. J. Maurer, and M. D. Lee, Appl. Environ. Microbiol. 69:6816-6824, 2003). The sequences exhibited high levels of similarity to Campylobacter jejuni and Campylobacter coli sequences, suggesting that chickens can carry Campylobacter at a very young age. Campylobacter sp. was detected by PCR in all samples collected from the ilea of chicks that were 3 to 49 days old; however, it was detected only in the cecal contents of chickens that were at least 21 days old. In order to determine whether the presence of Campylobacter DNA in young chicks was due to ingestion of the bacteria in food or water, we obtained commercial broiler hatching eggs, which were incubated in a research facility until the chicks hatched. DNA sequencing of the amplicons resulting from Campylobacter-specific 16S PCR performed with the ileal, cecal, and yolk contents of the day-of-hatching chicks revealed that Campylobacter DNA was present before the chicks consumed food or water. The 16S rRNA sequences exhibited 99% similarity to C. jejuni and C. coli sequences and 95 to 98% similarity to sequences of other thermophilic Campylobacter species, such as C. lari and C. upsaliensis. The presence of C. coli DNA was detected by specific PCR in the samples from chicks obtained from a commercial hatchery; however, no Campylobacter was detected by culturing. In order to determine whether the same strains of bacteria were present in multiple levels of the integrator, we cultured Campylobacter sp. from a flock of broiler breeders and their 6-week-old progeny that resided on a commercial broiler farm. The broiler breeders had been given fluoroquinolone antibiotics, and we sought to determine whether the same fluoroquinolone-resistant strain was present in their progeny. The isolates were typed by pulsed-field gel electrophoresis, which confirmed that the parental and progeny flocks contained the same strain of fluoroquinolone-resistant C. coli. These data indicate that resistant C. coli can be present in multiple levels of an integrated poultry system and demonstrated that molecular techniques or more sensitive culture methods may be necessary to detect early colonization by Campylobacter in broiler chicks.     

Feeding broilers with dry whey powder and whey protein concentrate affected productive performance,ileal digestibility of nutrients and cecal microbiota community

Dietary interventions are a common practice in the poultry industry to promote optimal performance and health of animals. Here, we aim at assessing the influence of supplementing broiler diets with dry whey powder (DWP) and whey protein concentrate (WPC) on nutrient coefficient of apparent ileal digestibility (CAID) and productive performance. Cecal microbiota composition was also determined using Illumina amplicon sequencing. Dietary treatments were control diet (no supplementation of DWP or WPC), 60-DWP (60 g/kg of DWP), and 80-WPC (80 g/kg of WPC). One-day-old male broilers were randomly assigned to one of three treatments, and housed in floor pens. In Trial 1, 90 1-day-old chicks were allocated to three pens/treatment, with 10 birds/pen, during 21 days for CAID evaluation. Diet 60-DWP increased Ca CAID (P=0.041), while diet 80-WPC improved Ca and P CAID (P<0.001 and 0.002, respectively) when compared with control diet. In Trial 2, 810 one-day-old chicks were allocated to nine pens/treatment, with 30 birds/pen, during 42 days. Feeding chickens with 60-DWP and 80-WPC increased their BW, average daily gain (ADG) and feed intake (FI) during the starter (P<0.001 for all variables) and grower-finisher periods (P<0.001 for BW and FI, and P=0.048 for ADG), and during the entire feeding period (P<0.05), when compared with control diet. Diets 60-DWP and 80-WPC reduced the feed conversion ratio of chickens during the starter period (P<0.001 and 0.003, respectively), while 60-DWP reduced this parameter during the entire feeding period (P=0.048), when compared to control diet. At day 42, cecal microbial communities of chickens that were fed with 60-DWP and 80-WPC differed from those fed with control diet (R=0.776, P=0.008; and R=0.740, P=0.008, respectively). The abundance of Bacteroides fragilis, Bacteroides spp., Escherichia coli/Shigella flexneri and Megamonas furniformis increased when 60-DWP and 80-WPC diets were offered, while the presence of Helicobacter pullorum decreased. Lactobacillus salivarius consistently increased in chickens with better feed conversion ratio, which were those fed with 60-DWP. The results obtained in the present study indicate that growth of chickens is improved by DWP and WPC supplementation because of a higher mineral digestibility, increased feed intake and modulation of cecal microbiota communities.     

Effects of l-leucine in ovo feeding on thermotolerance,growth and amino acid metabolism under heat stress in broilers

Recently, we found that in ovo feeding of l-leucine (l-Leu) afforded thermotolerance, stimulated lipid metabolism and modified amino acid metabolism in male broiler chicks. However, the effects of in ovo feeding of l-Leu on thermoregulation and growth performance until marketing age of broilers are still unknown. In this study, we investigated the effects of in ovo feeding of l-Leu on body weight (BW) gain under control thermoneutral temperature or chronic heat stress. We measured changes of body temperature and food intake, organ weight, as well as amino acid metabolism and plasma metabolites under acute and chronic heat stress in broilers. A total of 168 fertilized Chunky broiler eggs were randomly divided into 2 treatment groups in experiments. The eggs were in ovo fed with l-Leu (34.5 µmol/500 µl per egg) or sterile water (500 µl/egg) during incubation. After hatching, male broilers were selected and assigned seven to nine replicates (one bird/replicate) in each group for heat challenge experiments. Broilers (29- or 30-day-old) were exposed to acute heat stress (30 ± 1°C) for 120 min or a chronic heat cyclic and continued heat stress (over 30 ± 1°C; ages, 15 to 44 days). In ovo feeding of l-Leu caused a significant suppression of enhanced body temperature without affecting food intake, plasma triacylglycerol, non-esterified fatty acids, ketone bodies, glucose, lactic acid or thyroid hormones under acute heat stress. Daily body temperature was significantly increased by l-Leu in ovo feeding under chronic heat stress. Interestingly, in ovo feeding of l-Leu caused a significantly higher daily BW gain compared with that of the control group under chronic heat stress. Moreover, some essential amino acids, including Leu and isoleucine, were significantly increased in the liver and decreased in the plasma by l-Leu in ovo feeding under acute heat stress. These results suggested that l-Leu in ovo feeding afforded thermotolerance to broilers under acute heat stress mainly through changing amino acid metabolism until marketing age.     

Protective potential of Lactobacillus species in lead toxicity model in broiler chickens

To alleviate adverse effects of heavy metal toxicity, diverse range of removing methods have been suggested, that is usage of algae, agricultural by-products and microorganisms. Here, we investigated lead (Pb) biosorption efficacy by two lactic acid bacteria species (LABs) in broiler chickens. In an in vitro study, Pb was added to culture medium of LABs (Lactobacillus pentosus ITA23 and Lactobacillus acidipiscis ITA44) in the form of lead acetate. Results showed that these LABs were able to absorb more than 90% of Pb from the culture medium. In follow-up in vivo study, LABs mixture was added to diet of broiler chickens contained lead acetate (200 mg/kg). Pb exposure significantly increased lipid peroxidation and decreased antioxidant activity in liver. The changes were recovered back to normal level upon LABs supplementation. Moreover, addition of LABs eliminated the liver tissue lesion and the suppressed performance in Pb-exposed chicks. Analysis of liver and serum samples indicated 48% and 28% reduction in Pb accumulation, respectively. In conclusion, results of this study showed that L. pentosus ITA23 and L. acidipiscis ITA44 effectively biosorb and expel dietary Pb from gastrointestinal tract of chickens.     

Effects of Xylo-Oligosaccharides on Broiler Chicken Performance and Microbiota

In broiler chickens, feed additives, including prebiotics, are widely used to improve gut health and to stimulate performance. Xylo-oligosaccharides (XOS) are hydrolytic degradation products of arabinoxylans that can be fermented by the gut microbiota. In the current study, we aimed to analyze the prebiotic properties of XOS when added to the broiler diet. Administration of XOS to chickens, in addition to a wheat-rye-based diet, significantly improved the feed conversion ratio. XOS significantly increased villus length in the ileum. It also significantly increased numbers of lactobacilli in the colon and Clostridium cluster XIVa in the ceca. Moreover, the number of gene copies encoding the key bacterial enzyme for butyrate production, butyryl-coenzyme A (butyryl-CoA):acetate CoA transferase, was significantly increased in the ceca of chickens administered XOS. In this group of chickens, at the species level, Lactobacillus crispatus and Anaerostipes butyraticus were significantly increased in abundance in the colon and cecum, respectively. In vitro fermentation of XOS revealed cross-feeding between L. crispatus and A. butyraticus. Lactate, produced by L. crispatus during XOS fermentation, was utilized by the butyrate-producing Anaerostipes species. These data show the beneficial effects of XOS on broiler performance when added to the feed, which potentially can be explained by stimulation of butyrate-producing bacteria through cross-feeding of lactate and subsequent effects of butyrate on gastrointestinal function.     

Effect of weight and storage time of broiler breeders’ eggs on morphology and biochemical features of eggs,embryogenesis, hatchability,and chick quality

The transfer of hatchability results obtained under experimental conditions to the commercial ground with a positive financial effect proves the value and usefulness of these data. On the other hand, finding results on commercial processes of broiler breeders’ egg incubation in the literature is challenging. The presented study aimed to determine the effects of egg weight and storage time on the physical, biochemical characteristics of hatching eggs, embryogenesis and hatchability in Ross 308 broiler breeders. On the laying day, the eggs were divided into four weight groups: S – small eggs (57–61 g), M – medium eggs (62–66 g), L – large eggs (67–71 g), and XL – extra-large eggs (72–76 g). The eggs were then stored for 3, 7, 14, and 21 days under controlled conditions. As the egg storage time increased, a decrease in the yolk quality (lower index) was observed. The highest Haugh units were found in eggs from the S and M groups. The cholesterol content of the M, L, and XL groups was lower on days 7, 14, and 21 as compared to that of eggs only stored for 3 days. Egg weight loss during incubation decreased with an increase in the egg weight. An extension of the egg storage time caused an increase in the loss of egg weight. On the 14th and 18th days of hatching, an increase in the eggshell temperature was noted with an increase in the weight of the egg. The eggs stored for 7 days were characterised by the highest shell temperature on each day. The highest hatchability percentage was recorded for the M group. The hatchability rate decreased with the prolongation of the storage time, while the number of crippled chicks after hatching increased. The results confirmed that the increased weight of the eggs and prolonged storage time (14 and 21 days) increased the weight and decreased the length of the newly hatched chicks, respectively. Chicks from the heaviest eggs and those stored for 14 and 21 days showed poor results on the Pasgar score® test. The observations indicate the need to adopt various (of those available) methods to assess the quality of newly hatched chicks in hatcheries in order to produce high-quality broiler chickens. The results also indicate that prolonged egg storing beyond 14 days may affect the thyroid hormone economy during the hatching of chicks, especially in the XL group.     

Effect of fat type and lysophosphatidylcholine addition to broiler diets on performance,apparent digestibility of fatty acids,and apparent metabolizable energy content

A completely randomized design study with a 3 × 2 factorial arrangement was conducted to evaluate the effects of three different fat sources (soybean oil, tallow, and poultry fat) with or without emulsifier supplementation on performance, coefficient of total tract apparent digestibility (CTTAD) of fatty acids, and apparent metabolizable energy (AME) content in broiler chickens. Two hundred and fifty-two one-day-old male Arbor Acres broiler chickens were randomly divided into 6 different treatments: (T1) basal diet containing soybean oil without lysophosphatidylcholine (LPC) supplementation, (T2) basal diet containing soybean oil with LPC supplementation, (T3) basal diet containing tallow without LPC supplementation, (T4) basal diet containing tallow with LPC supplementation, (T5) basal diet containing poultry fat without LPC supplementation, and (T6) basal diet containing poultry fat with LPC supplementation. Body weight gains from broiler chicks fed diets containing tallow were lower (P<0.05) than the body weight gains from chicks that were fed diets containing soybean oil or poultry fat in both the starter and grower periods. Birds fed diets containing tallow had the highest FCR (P<0.05), followed by the birds that were fed diets containing poultry fat, and soybean oil. The CTTAD of C16:0, C18:2, and C18:3n3 was greater (P<0.05) for broilers fed diets containing soybean oil than for those fed diets containing tallow or poultry fat in the starter period. The addition of LPC increased (P<0.05) body weight gain of broiler chickens in the starter period and the AME of the diets in the grower period, and tended to reduce FCR (P=0.072) in the starter period. LPC supplementation increased (P<0.05) the CTTAD of C16:0, C18:1n7 and C18:1n9 in the starter period, and of C18:2, and C18:3n3 in the grower period (P<0.05). There were no significant interactions between fat sources and the addition of LPC. These data indicated that LPC supplementation can improve body weight gain of broiler chickens in the starter period. This effect may be associated with an increase of CTTAD of FA due to LPC activity.     

Enzyme supplementation of wheat-based diets for broilers: 2. Effect on apparent metabolisable energy content and nutrient digestibility

Two experiments were conducted to determine the effect of enzyme supplementation on the nitrogen-corrected apparent metabolisable energy (AME_n) and apparent nutrient digestibilities in ileum and excreta from male broiler chickens fed diets containing high amounts of wheat (>80%). Four different enzyme preparations were added to the wheat-based diets in varying levels and combinations. The difference between Experiments 1 and 2 consisted in the addition of different enzymes and enzyme levels. Excreta and ileal content were collected from broiler chickens at 3 and 6 weeks of age. At 3 weeks of age enzyme supplementation increased (P<0.0001) the AME_n from an average value of 13.86 MJ kg⁻¹ dry matter (DM) to an average of 14.60 MJ kg⁻¹ DM in the two experiments. The apparent digestibility of protein (APD) and fat (AFD) were improved significantly as a result of enzyme addition in both experiments. At 3 weeks of age, improvements (P<0.05) in the ileal AFD and APD were on average 13% and 6%, respectively. The effect of enzyme supplementation on AFD measured in excreta from broiler chickens showed the same pattern. The positive effect of enzyme addition on the overall nutrient digestibility and AME_n was reflected in weight gain and feed conversion efficiency (FCE). Significant improvements in AME_n, APD, and AFD were still present in most of the groups fed with enzyme-supplemented diets at 6 weeks of age. The effect of enzyme addition, however, was less pronounced, especially in Experiment 1 where the ileal APD of broiler chickens did not differ significantly from the control group. Apparent starch digestibility (ASD), measured in Experiment 2, was very high in all groups, including the control; however, enzyme supplementation increased ASD (P<0.001) in ileum and excreta at both 3 and 6 weeks of age. The digestibility of total non-starch polysaccharides (NSP) in excreta was improved significantly (P<0.01) as a result of enzyme supplementation (Experiment 2). In addition, pH of caeca content decreased (P<0.02) in broiler chickens fed with enzyme-supplemented diets when compared with the control group. Decreased pH could indicate microbial fermentation of unabsorbed NSP residues and nitrogenous compounds. Overall, the results demonstrated that the nutritive value of wheat-based diets to broiler chickens improve enzyme supplementation. The apparent digestibility of total NSP and of arabinose and xylose residues improved (P<0.02) in the enzyme-supplemented diets indicating that the enzymes were able to break down the cell wall NSP to a certain extent.     

The effect of Boswellia serrata resin diet supplementation on production,hematological, biochemical and immunological parameters in broiler chickens

Boswellia serrata resin (BSR), exhibiting a variety of therapeutic properties, is applied in Asian traditional medicine. These properties can be used in poultry production as well. Application of the resin as a phytobiotic in broiler chicken rearing can increase the productivity and improve meat quality. However, the optimum and maximum levels of BSR in broiler diets need to be assessed. The study determined the effect of different levels of supplementation of BSR (directly derived, unprocessed) in diets for broiler chickens on the production traits, selected slaughter analysis parameters, nutrient digestibility and selected hematological, biochemical and immunological parameters. In total, 200 1-day-old broiler chickens were assigned randomly to four treatments with five replicate cages of 10 broiler chickens/cage (five females and five males). The experiment lasted 6 weeks, and the broiler chickens were fed diets containing 0% (control), 3% (BSR3), 4% (BSR4) or 5% (BSR5). In the broiler chickens receiving diets with addition of resin BSR3 and BSR4, there was an increase in (P<0.05) BW gain, ether extract, ADF, organic matter and energy digestibility of the diets. Moreover, the best carcass quality with a high proportion of muscles and low abdominal fat content (P<0.05) was noted in these groups. The content of uric acid (P<0.01) and the activity of aspartate aminotransferase (P<0.001) and alkaline phosphatase (P<0.05) in blood plasma decreased upon the BSR supplementation. Globulin content increased in blood plasma (P<0.05) along the increasing level of BSR. The blood immunoglobulin A concentration was only affected by the BSR treatments (P<0.05). It may be concluded that BSR can be regarded as a safe and effective dietary additive for broiler chicken.     

Effects of supplementation with vitamin E on the performance and the tissue peroxidation of broiler chicks and the stability of thigh meat against oxidative deterioration

Two experiments were conducted: Expt 1 determined the optimal allowance of vitamin E in the diet for broiler chicks aged 0–3 weeks; Expt 2 investigated the effects of different dietary levels of vitamin E (α-tocopherol) on the performance and the oxidative stability of thigh meat of broiler chicks during storage. In Expt 1, 1-day-old 900 broiler chicks were allocated to five treatments, each with six replicates (cages) of 22 as-hatched chicks for performance evaluation, and another cage of 45 male chicks for determining plasma and hepatic α-tocopherol and thiobarbituric acid reactive substances (TBARS) concentration in blood and liver. The basal dietary α-tocopherol concentration was 13 mg/kg, and the five α-tocopherol acetate supplementation levels were 0, 5, 10, 50 and 100 mg/kg. For 0–3-week-old broiler chicks fed with maize–soya bean meal–soya oil type diet, supplementation of vitamin E did not influence the feed intake, but tended to improve growth and feed utilization, however there was no significant correlation between performance and vitamin E supplementation level. Significant positive correlations existed between dietary supplemental vitamin E level and plasma or hepatic α-tocopherol concentrations (P<0.05), and a negative correlation with hepatic TBARS levels no matter at what age (11, 16 and 21 days). In Expt 2, 2200 broiler chicks were randomly allocated to five treatments with four replicates (pens) in each. Chicks were fed ad libitum five pellet diets supplemented with vitamin E at 5, 10, 20, 50 and 100 mg/kg of diet, respectively. The basal dietary α-tocopherol level of grower and finisher diets were 7 and 6 mg/kg, respectively. Supplementation of vitamin E tended to improve growth and feed utilization of birds during 0–3 weeks of age, but the performance from 0 to 6 weeks of age were not influenced. The hepatic α-tocopherol concentrations of 6-week-old chicks linearly increased with the dietary vitamin E levels (R²=0.98, P<0.001). The content of TBARS in the thigh meat over 4 days of storage under 4°C was significantly decreased by increasing dietary vitamin E level (P<0.05). There was a significant inverse relationship between TBARS value in the thigh meat and the dietary vitamin E level (R²=0.93, P<0.01). Supplementation of vitamin E significantly improved the meat quality stability substantially against oxidative deterioration. Comparing the hepatic α-tocopherol levels of chicks in Expts 1 and 2, total allowance of dietary α-tocopherol of 20–30 mg/kg could sustain relatively constant hepatic α-tocopherol level at round about 2–2.5 μg/kg.     

Effect of Sex and Dietary Organic Zinc on Growth Performance, Carcass Traits, Tissue Mineral Content, and Blood Parameters of Broiler Chickens

Zinc (Zn) is an essential mineral for animal development and function. A study was carried out to evaluate the effect of sex and dietary organic zinc (OZ) on growth performance, carcass traits, tissue mineral content, and blood parameters of broiler chickens. A total of 240 1-day-old male and 240 female broiler chicks (Cobb × Cobb) were assigned to two dietary levels of OZ (2 × 2 factorial) with six replicates per treatment (20 birds/replicate pen). The OZ supplementation levels were 0 and 25 ppm. Results showed that OZ supplementation did not affect the growth performance of male and female broilers, but the males showed significantly better (P < 0.05) growth performance than females did. Similarly, OZ supplementation did not affect the thickness of both the back and thigh skin of male and female broilers; however, males had thicker skin than females. Dietary OZ supplementation did not affect collagen contents in the skin and meat samples. Male broilers had higher skin collagen contents than females, but no sex difference was found in meat collagen contents. OZ supplementation did not affect the shear force values of skin and meat samples. Male broilers had higher shear force values of back skin than females, but not in the meat samples. Dietary OZ supplementation increased (P < 0.05) the thigh meat Zn content in both sexes. The plasma Ca content was significantly (P < 0.05) increased by dietary OZ supplementation; however, other blood parameters were not affected by dietary OZ supplementation. Males had higher plasma glucose and cholesterol content than females. It is concluded that dietary OZ supplementation at the level of 25 ppm does not affect the growth performance and skin quality of broiler chickens but increases the Zn content in thigh meat and Ca content in plasma of broiler chickens. Male broilers had better growth performance and skin quality than females.     

Use of Multilocus Sequence Typing To Investigate the Association between the Presence of Campylobacter spp. in Broiler Drinking Water and Campylobacter Colonization in Broilers

The presence of campylobacters in broiler chickens and throughout the broiler water delivery systems of 12 farms in northeastern Scotland was investigated by sensitive enrichment methods and large-volume filtration. Campylobacter presence was independent of the water source and whether the water was treated. The genotypes of Campylobacter jejuni isolates recovered from chickens and various locations within the water delivery systems were compared by multilocus sequence typing. Matching strains in shed header tanks and birds were found at 1 of the 12 farms investigated. However, the sequence of contamination or whether the source was within or outside the shed was not determined. Nevertheless, these data provide evidence that drinking water could be associated with broiler infection by campylobacters.     

Effects of dietary sodium butyrate supplementation on the intestinal morphological structure,absorptive function and gut flora in chickens

A study was carried out to investigate the effects of dietary sodium butyrate (SB) on the intestine and growth performance in chickens. Three hundred and thirty six day-old AA broiler chicks were allocated at random into four groups with six replicates each. Four groups were fed with basal diet (control) or diets supplemented with SB at the level of 500, 1000, 2000 mg/kg. Body weight gain increased linearly during the period from 0 to 21 days as the dietary supplementation of SB increased (P<0.05). Dietary supplementation of SB influenced feed conversion ratio (FCR) in a positive quadratic fashion during the period from 0 to 42 days (P<0.05). Dietary SB did not influence the absorptive function of jejunum (P>0.05). The concentrations of DNA, RNA, and protein in duodenal mucosa showed negative quadratic responses to the increase of dietary SB supplementation level (P<0.05). The ratio of villus height to crypt depth increased linearly with the increase of dietary SB supplementation (P<0.01). The Lactobacillus count decreased linearly with the increase of dietary SB supplementation (P<0.01).     

Insights into phytase-containing transgenic <Emphasis Type="Italic">Lemna minor</Emphasis> (L.) as a novel feed additive

This study assessed the effect of supplementation of novel transgenic phytase on growth performance and bone mineralization in Korean native broiler chickens. The experiment was designed using four dietary groups: those with a diet supplemented with (A) recombinant phytase, (B) transgenic phytase from the plant Lemna minor, (C) or wild-type L. minor as well as (D) a control group that was supplemented with commercially available feed. Three hundred 1-day-old Korean native broiler chicks were used and divided into these four dietary treatment groups having three replicates of 25 birds each (n?=?75). The results showed increases in growth performance and bone mineralization in Groups B and C; compared with Groups A and D. Hematological analyses revealed notable contrasts in erythrocyte sedimentation rate, red blood cell count, and hemoglobin levels among the experimental groups, whereas no impacts of dietary treatment were observed on total eosinophil, lymphocyte, heterophil, monocyte, and basophil levels. The relative expression profiling of candidate genes showed that the genes involved in growth response, meat quality, and P–Ca metabolism were significantly highly expressed in the phytase-supplemented groups. Hence, it is suggested that dietary supplementation with transgenic phytase plant L. minor for enhancing growth performance is a promising new approach in the broiler feed industry. To the best of our knowledge, we report here the most comprehensive analysis using a broiler model that provides a workable platform for further research on the cost-effective production of feed with different compositions that might be beneficial in the livestock feed industry.     

Genome assisted probiotic characterization and application of Bacillus velezensis ZBG17 as an alternative to antibiotic growth promoters in broiler chickens

The present study describes genome annotation and phenotypic characterization of Bacillus velezensis ZBG17 and evaluation of its performance as antibiotic growth promoter substitute in broiler chickens. ZBG17 comprises 3.89 Mbp genome with GC content of 46.5%. ZBG17 could tolerate simulated gastrointestinal juices prevalent in the animal gut. Some adhesion-associated genomic features of ZBG17 supported the experimentally determined cell surface hydrophobicity and cell aggregation results. ZBG17 encoded multiple secondary metabolite gene clusters correlating with its broad-spectrum antibacterial activity. Interestingly, ZBG17 completely inhibited Salmonella enterica and Escherichia coli within 6 h and 8 h in liquid co-culture assay, respectively. ZBG17 genome analysis did not reveal any genetic determinant associated with reported safety hazards for use as a poultry direct-fed microbial. Dietary supplementation of ZBG17 significantly improved feed utilization efficiency and humoral immune response in broiler chickens, suggesting its prospective application as a direct-fed microbial in broiler chickens.     

Effect of copper nanoparticles administered in ovo on the activity of proliferating cells and on the resistance of femoral bones in broiler chickens

The objective of this study was to evaluate bone resistance after in ovo administration of copper nanoparticles (NanoCu) and to determine the number of cells positive for proliferating cell nuclear antigen (PCNA) in the femoral bones of broiler chickens (n = 12 per group). The study demonstrated that femoral bones from the NanoCu group were characterised by a higher weight and volume and by significantly greater resistance to fractures compared to the Control group. NanoCu promoted the proliferation of PCNA-positive cells in the long bones of chickens. A significantly higher number of PCNA-positive cells in the bones of birds in the NanoCu group compared with the Control group (137 and 122, respectively) indicate a stimulatory effect during embryogenesis. Considering the improvement in bone resistance to fractures and the effect of NanoCu on the number of PCNA-positive cells in femoral bones, NanoCu may be an alternative agent to minimise the ever-present problem of weak bones in broiler chickens.