Effect of copper nanoparticles on the mineral content of tissues and droppings,and growth of chickens

We hypothesised that copper nanoparticles (NanoCu), because of their high physicochemical reactivity and bioavailability, could be used in much smaller quantities than bulk Cu, consequently reducing excretion of Cu into the environment. The objective of the study was to evaluate the effects of various levels of NanoCu on the development and growth of broiler chickens, in order to establish an optimum level of NanoCu dietary supplementation. Broiler chickens were randomly divided into five groups of 10 birds each. The control group received 7.5 mg Cu/kg feed (standard level) as CuSO₄, while groups fed with complexes of NanoCu and starch received 25%, 50%, 75% and 100% of the standard level of Cu used in the control group. Chicken growth and excretion of Cu, Fe and Zn were measured during the growth period from d 7 to 42. At d 42, the slaughter characteristics, the content of Cu, Fe and Zn in the breast muscle and liver, and the oxidative status were analysed. The results indicate that using NanoCu can reduce the standard level of Cu from CuSO₄ supplementation by 75% without jeopardising animal growth, and at the same time significantly decreasing Cu excretion into the environment.     

Efficacy of dietary supplemental insoluble fibrous materials in ameliorating adverse effects of coccidial challenge in broiler chickens

ABSTRACT

The current experiment was designed to examine effects of dietary supplemental sunflower hulls (SH) and rice hulls (RH) on growth performance, carcass traits, intestinal morphology, lesion score and oocyst shedding in broiler chickens exposed to coccidial challenge. A total of 540 broiler chickens (Ross 308) were assigned to six dietary treatments based on a factorial arrangement (2 × 3) across 1–14, 14–28 and 28-42-d periods. Experimental treatments consisted of broiler chickens without or with coccidial challenge each offered with three different diets: a basal diet or basal diet supplemented with either RH or SH at 40 g/kg diet, respectively. Infection with Eimeria impaired daily weight gain (DWG) and feed conversion ratio (FCR) of broiler chickens during growing period (p < 0.05) while supplementation of SH or RH reduced the adverse effect of coccidiosis so that birds had similar DWG to those fed the basal diet without infection. However, only dietary SH improved the FCR of broilers challenged with coccidiosis. Regardless of coccidial challenge, dietary access to insoluble fibre improved performance of broilers across the growing period (p < 0.05); however, this effect was not observed during the entire rearing period. Relative weights of liver and pancreas were increased in birds subjected to coccidial challenge on d 21 of age (p < 0.05). Moreover, relative weights of the intestinal segments were enhanced (p < 0.05). Furthermore, gizzard weights were higher in birds receiving diets added with fibre (p < 0.05). Infection with coccidiosis decreased villus height and villus height to crypt depth ratio in duodenum of broilers which received the basal diet compared with those fed the same feed without coccidial challenge (p < 0.05). However, supplemental SH could decrease the negative effect of infection on the noted intestinal morphometric attributes. Similarly, a marked reduction was observed for lesion score and faecal oocyst excretion of challenged broilers fed on dietary supplemental fibre (p < 0.05). In conclusion, supplementation of insoluble fibre could ameliorate negative effects of coccidial challenge on DWG of broiler chickens and inclusion of SH in diet of birds exposed to Eimeria infection could be recommended.     

Cloacal temperature responses of broiler chickens administered with betaine and ascorbic acid during the hot-dry season

The experiment was performed to evaluate cloacal temperature (CT) responses in broiler chickens, administered with betaine and ascorbic acid (AA) during the hot–dry season. Broilers were divided into four groups: Group I (control) was given sterile water; Group II, betaine at 250 mg/kg; Group III, AA at 50 mg/kg and Group IV, betaine (250 mg/kg) + AA (50 mg/kg). The different solutions were given orally for 42 days. Dry-bulb temperature (DBT), relative humidity (RH) and temperature-humidity index (THI) in the pen, and CT of each broiler chicken were measured bihourly (06:00–18:00 h) on days 28, 35 and 42. DBT, RH and THI values were outside the thermo-neutral zone for broiler chickens. Results showed that AA lowered (p < 0.001) CT, while betaine + AA increased (p < 0.001) CT, compared with controls. In conclusion, betaine + AA or AA alone modulated CT responses of broiler chickens subjected to the thermal stress in the hot–dry season.     

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.     

Plant extract supplementation as a strategy for substituting dietary antibiotics in broiler chickens exposed to low ambient temperature

ABSTRACT

The present study was conducted to investigate the effects of two plant extracts as alternatives to dietary antibiotics in broiler chickens exposed to low ambient temperature. A total of 300 one-day-old male broiler chickens were randomly assigned to four dietary treatments (5 replicate pens; 15 broiler chickens each) which consisted of starter (d 0 to 10), and grower (d 10 to 28) diets. Dietary treatments included a basal diet (negative control, NC) and three similar diets that were either supplemented with 200 mg/kg of Prosopis farcta extract (PFE), Rhus coriaria L. extract (RCE) or an antibiotic premix containing oxytetracycline (positive control, PC). In order to simulate low ambient temperature, room temperature was maintained at 32°C during the first 3 d of the trial and afterwards, the temperature was gradually reduced by approximately 1.5°C each day to 14°C on d 21. PFE and PC treatments exerted a significant effect on body weight gain at d 28. Diet PFE was effective in reducing mortality when compared with diet NC (p < 0.05). Furthermore, diet PFE caused increases in ileal digestibility of gross energy, dry matter and organic matter when compared with diet NC (p < 0.05). Diets PFE and PC decreased coliforms, total aerobic bacteria and total anaerobic bacteria loads in the caeca when compared with diet NC (p < 0.05). Moreover, the addition of PFE to the diet improved villous height in all small intestinal segments as well as villous height:crypt depth ratio in the duodenum when compared with diet NC (p < 0.05). The results indicated that PFE is not only a valid alternative to oxytetracycline under cold stress conditions, with no antibiotic resistance, but also has the potential to increase the resistance of broiler chickens against ascites syndrome. Moreover, the addition of RCE at the concentration of 200 mg/kg to the diet was not sufficient to improve the performance of broiler chickens (similar to diet PC) but maybe more effective at higher concentrations.     

Effects of chicken intestinal antimicrobial peptides on humoral immunity of chickens and antibody titres after vaccination with infectious bursal disease virus vaccine in chicken

Abstract

Sixty chickens were randomly divided into two groups (30 chickens in each group) to determine the effect of oral administration of chicken intestinal antimicrobial peptides (CIAMP) on the humoral immune response. Chickens of both groups were fed the same diet. In the treatment group chickens received drinking water supplemented with CIAMP (1 µg/ml) right after hatching. Samples of blood, bursa of Fabricus, spleen and intestine were taken at day 1, 4, 7, 10 and 17 of experiment. CIAMP supplementation enhanced the content of IgG and IgM in serum from day 4 – 10 and day 10 – 17, respectively, (p < 0.05), IgM-forming cells in bursa of Fabricus and spleen at the age of 7 days (p < 0.05) and IgG-forming cells in bursa of Fabricus at the age of 4 days (p < 0.05). In addition, CIAMP enhanced the IgA-forming cells in caecal tonsils diffuse area at day 4 (p < 0.05). Furthermore, CIAMP enhanced the antibody response to infectious bursal disease virus vaccine (IBDV) in chickens 21 days following IBDV vaccine administration (p < 0.05). These results suggested that CIAMP could modulate the humoral immune response of chickens and increased the antibody titres of infectious bursal disease virus vaccine.     

Effects of High Dietary Fluorine on Erythrocytes and Erythrocyte Immune Adherence Function in Broiler Chickens

Fluoride can exert toxic effects on soft tissues, giving rise to a broad array of symptoms and pathological changes. The aim of this study was to investigate on erythrocytes and erythrocyte immune adherence function in broiler chickens fed with high fluorine (F) diets by measuring the total erythrocyte count (TEC), the contents of hemoglobin (Hb), packed cell volumn (PCV), erythrocyte osmotic fragility (EOF), erythrocyte C_3b receptor rosette rate (E-C_3bRR), and erythrocyte immune complex rosette rate (E-ICRR). A total of 280 1-day-old healthy avian broiler chickens were randomly allotted into four equal groups of 70 birds each and fed with a corn–soybean basal diet containing 22.6 mg F/kg (control group) or same basal diets supplemented with 400, 800, and 1,200 mg F/kg (high F groups I, II, and III) in the form of sodium fluoride for 42 days. Blood samples were collected for the abovementioned parameters analysis at 14, 28, and 42 days of age during the experiment. The experimental results indicated that TEC, Hb, and PCV were significantly lower (p?<?0.05 or p?<?0.01), and EOF was higher (p?<?0.05 or p?<?0.01) in the high F groups II and III than that in the control group from 14 to 42 days of age. The E-C_3bRR was significantly decreased (p?<?0.01) in the three high F groups, whereas the E-ICRR was markedly increased (p?<?0.01) in the high F groups II and III from 14 to 42 days of age. It was concluded that dietary F in the range of 800 to 1, 200 mg/kg could significantly cause anemia and impair the integrity of erythrocyte membrane, the transport capacity of oxygen and carbon dioxide, and erythrocyte immune adherence function in broiler chickens.     

Effects of glyceryl polyethylene glycol ricinoleate on nutrient utilisation and performance of broiler chickens

A completely randomised design study with a 2 × 2 factorial arrangement was conducted to observe effects of an emulsifier (glyceryl polyethylene glycol ricinoleate (GPR)) on nutrient utilisation and performance of broiler chickens. A total of 384 male broiler chickens were used to determine the influence of GPR (without addition or added at 0.04% of diet) and two levels of apparent metabolisable energy (AME_N) (according to standard requirements (Diets SE) or energy reduced by 0.4 MJ/kg diet (Diets LE)) on birds’ performance and apparent total tract digestibility (ATTD). ATTD of ether extract (EE) and AME_N were measured on d 14 and 35, and ATTD of neutral detergent fibre (NDF) was measured on d 35. All diets were based on wheat–maize–soybean meal with rapeseed oil and lard (blend of 50:50) as fat sources. During the grower period and the whole trial, birds fed Diets supplemented with GPR were characterised by higher body weight gain (BWG) and lower feed conversion ratio (FCR) compared to chicken receiving diets without GPR (p < 0.05). At the end of experiment, birds fed Diet LE without GPR were characterised by lower BWG and higher FCR (p < 0.05). Supplementation with GPR caused a higher ATTD of EE for diets SE and LE at d 14 and 35 (p < 0.05). Moreover, the GPR addition to Diet LE improved ATTD of NDF at d 35 (p < 0.05). In conclusion, the findings suggest that GPR effects the digestion of a blend of animal fat/rapeseed oil positively, even in a practical maize–wheat-based broiler diet with decreased AME_N level.     

Effects of Enterococcus faecium and dried whey on broiler performance,gut histomorphology and intestinal microbiota

Abstract

The experiment was conducted to study the effects of supplementing a broiler starter diet with the probiotic Enterococcus faecium NCIMB 10415 and dried whey (80% lactose) on chick performance, gut histomorphology and intestinal microbiota. One-day-old male Ross 308 strain broiler chickens were fed diets containing: (i) control feed, (ii) control + 3.5% dried whey, (iii) control + 0.2%E. faecium, and (iv) control + 3.5% dried whey + 0.2%E. faecium. Birds were maintained in battery brooders confined in an environmentally controlled experimental room. The experiment lasted for 21 days. Birds fed E. faecium or E. faecium + dried whey exhibited significantly improved weight gain and feed conversion rate (FCR). Weight gain and FCR of treatment groups 1 – 4 were 628.7, 657.8, 690.9, 689.3 and 1.218, 1.193, 1.107, 1.116, respectively. Lactic acid bacteria counts in both the ileal content and excreta were significantly affected by dietary treatment. Supplementation of the E. faecium and dried whey separately and in combination increased lactic acid bacteria colonization in the ileal content from 4.2 to 5.0, 7.8 and to 5.1 log cfu/g, respectively (treatments 1 – 4). Similarly, supplementation of dried whey and E. faecium separately and in combination increased lactic acid bacteria in the excreta from 5.3 to 5.5, 8.0 and to 7.2 log cfu/g, respectively. Addition of the probiotic E. faecium increased villus height in the ileum (p < 0.05). Thus, supplementation of E. faecium enhanced broiler chick performance with respect to weight gain and FCR. No additive effect of E. faecium and dried whey was detected. Further studies are needed to investigate the relationship between E. faecium and dried whey with respect to gut histomorphology.     

Effect of Dietary Phytase Supplementation on Bone and Hyaline Cartilage Development of Broilers Fed with Organically Complexed Copper in a Cu-Deficient Diet

Tibial mechanical, chemical, and histomorphometrical traits were investigated for growing male Ross 308 broiler chickens fed diets that had copper (Cu) from organic source at a lowered level of 25% of the daily requirement (4 mg kg^?1 of a premix) with or without phytase. Dietary treatments were control non-copper, non-phytase group (0 Suppl); 4 mg kg^?1 Cu non-phytase group (25%Cu); and 4 mg kg^?1 Cu + 500 FTU kg^?1 phytase group (25%Cu + phyt). The results show that birds fed with the addition of phytase exhibited improved weight gain and final body weight and had increased serum IGF-1 and osteocalcin concentrations. The serum concentration of Cu and P did not differ between groups; however, Ca concentration decreased in the 25%Cu + phyt group when compared to the 25%Cu group. Added Cu increased bone Ca, P, Cu, and ash content in Cu-supplemented groups, but bone weight and length increased only by the addition of phytase. Bone geometry, yield, and ultimate strengths were affected by Cu and phytase addition. A decrease of the elastic stress and ultimate stress of the tibia in Cu-supplemented groups was observed. The histomorphometric analysis showed a positive effect of Cu supplementation on real bone volume and trabecular thickness in the tibia metaphyseal trabeculae; additionally, phytase increased the trabeculea number. The supplementation with Cu significantly increased the total articular cartilage and growth plate cartilage thickness; however, the changes in thickness of particular zones were dependent upon phytase addition. In summary, dietary Cu supplements given to growing broilers with Cu in their diet restricted to 25% of the daily requirement had a positive effect on bone metabolism, and phytase supplementation additionally improved cartilage development.     

Effects of Aflatoxin B1 Exposure and Sodium Selenite Supplementation on the Histology,Cell Proliferation,and Cell Cycle of Jejunum in Broilers

The aim of this study was to investigate the effects of aflatoxin B₁ (AFB₁) exposure and sodium selenite supplementation on the histology, cell proliferation and cell cycle of jejunum in broilers. A total of 240 1-day-old male AA broilers were divided into four groups of 60 each, fed with basal diet (control group), 0.3 mg/kg AFB₁ (AFB₁ group), 0.4 mg/kg supplement Se (Se group), and 0.3 mg/kg AFB₁?+?0.4 mg/kg supplement Se (AFB₁ + Se group) for 21 days, respectively. Compared with the control group, decreased jejunal villus height, villus height/crypt ratio, and proliferation cell nuclear antigen (PCNA)-positive cells, and G₂/M phase arrest and shedded epithelial cells on the tip of jejunal villus were observed in AFB₁ groups at 7 and 14 days of age. However, the villus/crypt ratio, PCNA-positive cells and cell percentage of G₀/G₁, S, and G₂/M phases had no significant differences between AFB₁ group and control group at 21 days. Simultaneous supplementation with sodium selenite restored these parameters to be close to those in control group. In conclusion, 0.3 mg/kg AFB₁ in the diet inhibits the development of broiler’s jejunum by reducing cellular proliferation and inducing G₂/M arrest during only the first 2 weeks after hatching. Supplementation of dietary sodium selenite at the concentration of 0.4 mg/kg Se had protective action against these toxic effects of AFB₁.     

Chicken oviduct—the target tissue for growth hormone action: effect on cell proliferation and apoptosis and on the gene expression of some oviduct-specific proteins

The aim of this study was to examine the in vivo effect of growth hormone (GH) on cell proliferation and apoptosis and on the gene expression of selected proteins in the chicken oviduct before sexual maturity (first oviposition). Ten-week-old Hy-Line Brown chickens were injected three times a week with 200 μg?·?kg^-1 body weight of recombinant chicken GH (cGH) until 16 weeks of age. Control hens received 0.9 % NaCl with 0.05 % bovine serum albumin as a vehicle. Treatment with cGH increased (P?<?0.05) oviduct weight at 16 weeks of age, i.e. 1–2 weeks before onset of egg laying. The highest number of proliferating (determined by proliferating cell nuclear antigen [PCNA] immunocytochemistry) and apoptotic (determined by TUNEL assay) cells in the oviduct was found in the mucosal epithelium, and the lowest in the stroma. Administration of cGH did not increase (P?>?0.05) the number of PCNA-positive cells but it decreased (P?<?0.01) the number of TUNEL-positive cells, thus increasing the proliferating-to-apoptotic cell ratio in the oviduct. Gene expression (determined by real-time polymerase chain reaction) of apoptosis-related caspase-2 in the magnum and caspase-3 in the magnum and isthmus and their activity (determined by fluorometric assay) in the magnum were attenuated (P?<?0.05) in cGH-treated hens. The gene expression of the magnum-specific ovalbumin and the shell-gland-specific ovocalyxins 32 and 36 was increased (P?<?0.05) in cGH-treated chickens. In contrast, the expression of Bcl-2 and of caspases 8 and 9 was not affected by cGH in any of the oviductal segments. The results suggest that GH, via the orchestration of apoptosis and expression of some oviduct-specific proteins, participates in the development and activity of the chicken oviduct prior to the onset of egg laying.     

The effect of polyphenols and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature

The aim of this study was to determine the effect of a polyphenol product (PP) (Proviox) and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature. The experimental materials comprised 120 ROSS 308 broilers (6 treatments, 10 replications, 2 birds per replication). Dietary supplementation with vitamin E and PP was applied in the following experimental design: group I (negative control) – without supplementation; group II (positive control) – without supplementation; group III – supplementation with 100 mg vitamin E/kg; group IV – 200 mg vitamin E/kg; group V – 100 mg vitamin E/kg and 100 mg PP/kg; group VI – 200 mg PP/kg. In groups II–VI, broiler chickens aged 21–35 d were exposed to increased temperature (34°C for 10 h daily). In chickens exposed to high temperature, dietary supplementation with antioxidants, mostly PP, improved growth performance parameters, including body weight, body weight gain and feed intake until 28 d of age. Vitamin E added to broiler chicken diets at 200 mg/kg and vitamin E combined with PP was most effective in improving the total antioxidant status of birds, enhancing blood antioxidant enzyme activities and increasing vitamin E concentrations in the liver and breast muscles. Broilers fed diets supplemented with 200 mg/kg of vitamin E alone and vitamin E in combination with PP were characterised by a higher percentage content of breast muscles in the carcass. Dietary supplementation with antioxidants improved the water-holding capacity of meat, reduced natural drip loss and increased the crude ash content of meat. The breast muscles of chickens fed diets supplemented with PP had a lower contribution of yellowness. The breast muscles of chickens receiving diets with 100 mg vitamin E/kg(group III) and diets supplemented with PP (groups V and VI) were characterised by the highest concentrations of polyunsaturated fatty acids. The PP can be a valuable component of diets for broiler chickens exposed to high temperature.     

Efficacy of live B1 or Ulster 2C Newcastle disease vaccines simultaneously vaccinated with inactivated oil adjuvant vaccine for protection of Newcastle disease virus in broiler chickens

Two hundred, one-day-old broiler chicks were divided into groups 1, 2 and 3 containing 60, 70 and 70 chicks, respectively. The groups were divided into subgroups of 10 chicks that were vaccinated according to the following scheme: group 1 unvaccinated control, group 2 vaccinated subcutaneously at 1 day old with inactivated oil adjuvant vaccine (IOAV) in combination with live B1 vaccine. Group 3 was vaccinated in the same mode as group 2 with IOAV and live Ulster 2C vaccine. All birds were challenged when they were 28 days old. Mortality rate, body weight gain and feed conversion ratio (FCR) were monitored before and after challenge. All the chickens in group 1 died, indicating that there was no disease resistance of this unvaccinated control group of chickens. Conversely, the monitored disease resistance of chickens in groups 2 and 3 was 68.57% ± 18.64 and 88.57% ± 9.00, respectively (P < 0.05). The morbidity of chickens in groups 2 and 3 was 37.89% ± 14.36 and 14.76% ± 12.40, respectively (P < 0.05). The body weight gain, feed intake and FCR of group 3 were significantly better than those of group 2 (P < 0.05) during 1–42 days old. The simultaneous vaccination with B1 or Ulster 2C and IOAV of 1-day-old chicks gave some protection of 28-day-old broilers without a booster vaccination.     

Biomechanical response of impacted bony pelvis: influence of the morphometry and bone density

Mechanical properties of human pelvic bone tissue according morphological parameters were few studied in anterior–posterior compression tests and few data are available to correctly validate finite element pelvis models. In order to reduce this gap, 12 pelvic bones were removed from male and female embalmed cadavers and compressed. Anatomic angles were measured and bone's density was calculated after each test.

Fractures observed during those tests were coherent with those observed in real life. Bone's density and percentage of mineralisation were not significantly different between the male and female groups. The retropubic angle was significantly larger in the female group (p < 0.05). Mean load necessary to obtain the collapse was significantly higher in the male group (p < 0.05).     

Effects of breeds and dietary protein levels on the growth performance, energy expenditure and expression of avUCP mRNA in chickens

The physiological mechanisms of thermogenesis, energy balance and energy expenditure are poorly understood in poultry. The aim of this study was designed to investigate the physiological roles of avian uncoupling protein (avUCP) regulating in energy balance and thermogenesis by using three chicken breeds of existence striking genetic difference and feeding with different dietary protein levels. Three chicken breeds including broilers, hybrid chickens, and non-selection Wuding chickens were used in this study. Total 150 chicks of 1 day of age, with 50 from each breed were reared under standard conditions on starter diets to 30 days. At 30 days of age, forty chicks from each breed chicks were divided into two groups. One group was fed low protein diet (LP, 17.0 %), and the other group was fed high protein diet (HP, 19.5 %) for 60 days. Wuding chickens showed the lowest feed conversion efficiency (FCE) and the highest expressions of avUCP mRNA association with high plasma T3 and insulin concentrations. Hybrid chickens showed the lowest expressions of avUCP mRNA association with high FCE and energy efficiency. Expressions of avUCP mRNA association with diet-induced thermogenesis (DIT) were only observed in broiler and hybrid chickens. The expressions of avUCP mRNA were positive association with plasma insulin, T3 and NEFA concentrations. Age influence on the expression of avUCP mRNA were observed only for hybrid and broiler chickens. It seems that both roles of avUCP regulation thermogenesis and lipid utilisation as fuel were observed in the present study response to variation in dietary protein and breeds.     

Intestinal concentrations of free and encapsulated dietary medium-chain fatty acids and effects on gastric microbial ecology and bacterial metabolic products in the digestive tract of piglets

The influence of low dietary levels of free and encapsulated medium-chain fatty acids on their concentrations in the digesta, the gastric microbial ecology and bacterial metabolic products in the gastrointestinal tract (GIT) in weaned piglets was studied. Starting after weaning, 36 piglets were fed a diet without (Control) or with medium-chain fatty acids uncoated (MCFA) or coated with vegetable fat and lecithin (MCFAc). After 4 weeks, the animals were killed, and digesta from the stomach and different sections of the GIT were collected. The concentrations of caprylic (p < 0.001) and capric (p = 0.001) acids were higher in the stomachs of piglets fed diets MCFA and MCFAc compared to the Control group. The concentrations dropped rapidly along the GIT, regardless of encapsulation, and tended to be higher in groups MCFA and MCFAc compared to the Control. Compared to the Control group, ingestion of diet MCFAc led to an increase in the number of eubacteria (p = 0.001), enterobacteriaceae (p < 0.001), clostridial clusters I (p = 0.001) and IV (p = 0.019), Lactobacillus johnsonii (p < 0.001) and Lactobacillus amylovorus (p = 0.001) in gastric contents. A similar trend was seen with diet MCFA. Relative concentrations of short-chain fatty acids were characterised by lower propionic acid levels (p = 0.045), numerically (p < 0.1) higher acetic, lower n-butyric and i-valeric acid concentrations in the small intestine. Lactic acid concentrations were not significantly changed in the GIT, but ammonia concentrations increased (p < 0.001) in the distal small intestine in the MCFA and MCFAc groups. In conclusion, medium-chain fatty acids affected microbial ecology parameters in the gastric contents and bacterial metabolites in the small intestine. At low dietary levels, medium-chain fatty acids may be regarded as modulators of the gastric microbiota in weaned piglets.     

Effects of source and level of magnesium on catalase activity and its gene expression in livers of broiler chickens

Abstract

The effects of dietary supplemental magnesium oxide (MgO), magnesium-L-aspartate (MgAsp) and monomagnesium-di-L-aspartate (MgdiAsp) on hepatic catalase (CAT) activity and its mRNA expression were investigated. A total of 360 one-day-old male Abor Acre broiler chickens were allocated to ten treatments, i.e. control plus 9 treatments from 3×3 factorial arrangement (Mg source, Mg level), each treatment with six replicates of 6 chickens. The birds were fed with the basal diet alone or supplemented with magnesium (Mg) at 0.9, 1.8, 2.7 g/kg of the diet from MgO, MgAsp or MgdiAsp. Results showed that hepatic Mg concentration increased quadratically as MgO or MgAsp supplementation increased (p < 0.01). Hepatic CAT activity increased linearly in birds fed with MgAsp or MgdiAsp (p < 0.01) and quadratically in birds fed with MgO (p < 0.05) as dietary Mg supplementation level increased. Hepatic CAT mRNA was linearly correlated with the dietary Mg supplementation level (p < 0.01). There were positive correlations among hepatic CAT activity, its mRNA expression level and hepatic Mg concentration (p < 0.01). No effect of Mg²⁺ on the purified CAT activity was detected in vitro enzymatic reaction system (p > 0.05). Supplemental MgAsp or MgdiAsp was more efficient to increase hepatic Mg concentrations, enhance hepatic CAT activity and its mRNA expression than MgO (p < 0.01). It can be concluded that dietary Mg supplementation could increase hepatic Mg concentration, enhance CAT mRNA expression and consequently enhance CAT activity, and the organic Mg (MgAsp or MgdiAsp) is much more efficient than the inorganic form (MgO).     

Effects of conjugated linoleic acids on growth performance,serum lysozyme activity,lymphocyte proliferation,and antibody production in broiler chicks

Abstract

This study was conducted to investigate the effect of dietary conjugated linoleic acids (CLA) on growth performance and immune responses in broiler chicks. A total of 240 day-old Arbor Acre male broiler chicks were randomly allotted into four dietary treatments with different inclusion levels of CLA (0, 2.5, 5.0 or 10.0 g/kg) for six weeks. Growth performance, peripheral blood lymphocyte (PBL) proliferation, lysozyme activity, phagocytic activity (carbon clearance) and serum antibody titers against Newcastle disease virus (NDV) vaccine were examined. There were no significant differences in growth performance among treatments (p > 0.05). Chicks fed CLA diets produced more lysozyme activity in serum than the control group at 2 and 6 weeks of age (p < 0.05). Dietary CLA enhanced the PBL proliferation in response to concanavalin A (ConA) at the age of 42 d (p < 0.05). Phagocytic ability was also affected by dietary CLA and chicks fed CLA diets had faster carbon clearance rate (p < 0.05), but antibody titers to NDV was not influenced by dietary CLA. The results of the study suggested that dietary CLA could enhance innate and cellular immune response in broiler chicks, and not affect the growth performance.     

Effect of In Ovo Feeding of Folic Acid on Subsequent Growth Performance and Blood Constituents Levels in Broilers

This study designed to determine effect of in ovo feeding of folic acid on subsequent growth performance and blood constituents levels in broilers. A total of 1000 fertile broiler eggs were divided into four groups. Control group (1) received no injection. In group 2, eggs received in ovo feeding of distiller water (40 µg). Group 3 received in ovo feeding of folic acid (40 µg). Groups 4 and 5 were similar to Group 3, except eggs injected with 80 and 120 µg of folic acid. All eggs were incubated and after hatch chickens were randomly assigned into their experimental groups. On days 1 and 42 post-hatch, chicken randomly selected and blood constituents, carcass characteristics, food intake, body weight gain and food conversion ratio were determined. According to the results, no significant difference detected on hatchability rate of the in ovo injected eggs (P?>?0.05). Dose dependent increase observed in glucose and folic acid levels in chicken in ovo injected with folic acid on day 1 post hatch (P?=?0.001). Blood glucose, folic acid and phosphorous levels increased (P?=?0.001) while cholesterol, triglyceride, HDL and LDL, calcium and alkaline phosphatase decreased in ovo injected with folic acid on day 42 post hatch (P?=?0.001). Food conversion ratio increased by in ovo injection of the folic acid (P?=?0.001). These results suggest folic acid had positive effects in broiler chicken.