Effects of oleanolic acid on acute liver injury triggered by lipopolysaccharide in broiler chickens.

1. Infectious injury caused by lipopolysaccharide (LPS), a metabolite of gram-negative bacteria, can induce stress responses in animals and is a significant cause of morbidity and mortality in young birds. The purpose of this study was to investigate the effects of dietary supplementation with oleanolic acid (OA) on acute liver injury in broiler chickens challenged with LPS.2. In total, 120 broiler chickens were randomly divided into six groups and fed a basal diet containing 0, 50, 100, or 200 mg/kg OA or 100 mg/kg aureomycin. On d 15, broiler chickens were injected with either LPS or an equivalent volume of normal saline. Six hours after LPS injection, two broiler chicks were randomly selected for sampling in each replicate.3. The results indicated that dietary aureomycin was ineffective in alleviating LSP-associated liver injury, but protected broiler chickens from LPS-induced liver damage. This promoted a significant reduction in the levels of malondialdehyde and an increase in the levels of superoxide dismutase in liver. In addition, OA was found to cause significant reductions in the relative expression of IL-1ß, IL-6, and TNF-α in broiler liver tissues, whereas the relative expression of IL-10 was significantly increased.4. In conclusion, oleanolic acid can alleviate oxidative stress and injury in the livers of broiler chickens induced by lipopolysaccharide. Consequently, oleanolic acid has potential utility as a novel anti-inflammatory and antioxidant feed additive.

Dietary supplementation with different alternative to in-feed antibiotic improves growth performance of broilers during specific phases.

The effects of substituting Bacillus subtilis, Astragalus membranaceus, and enzymes for aureomycin to improve the growth performance of broilers during specific phases were studied to develop alternatives to in-feed antibiotics and decrease drug residues in meat food and antibiotic resistance. Six hundred one-day-old broilers were randomly assigned to 5 groups. Broilers in the control group were supplied with basal diets (CT), and those in the remaining 4 groups were supplied with feed containing aureomycin premix (AU), B. subtilis powder (BS), A. membranaceus root powder (AM), and enzyme compound powder (EN), respectively. Compared to the control group, broilers in the other groups exhibited better growth performance during different phases. Microbial analysis of cecal contents suggested that treatment with BS or EN significantly increased the abundance of Lactobacillus or Bifidobacteria but inhibited Escherichia coli or Clostridium welchii; however, these bacteria were suppressed by AU treatment except C. welchii. The digestibility of the feed in vitro was significantly enhanced by adding BS or EN to the feed, consistent with findings for growth performance. In conclusion, dietary supplementation with 3 additives could improve the growth performance of broilers during specific phases. Future studies should focus on designing suitable schedules to partially replace in-feed antibiotics.

Adsorption and transformation of tetracyclines on alpha alumina particles with surface modification by anionic surfactant.

The adsorption and transformation of tetracyclines (TCs) antibiotics, including oxytetracycline (OTC), chlortetracycline (CTC), and tetracycline (TC), on the sodium dodecyl sulfate (SDS) surfactant-modified α-Al2O3 particles were comprehensively investigated in this study. The TCs adsorption was significantly enhanced by using the modified adsorbents compared with the use of the unmodified adsorbents. The experimental conditions were systematically optimized and found to be pH 4, NaCl 1 mM, the contact time of 180 min, and the adsorbent dosage of 25 mg. mL-1. The high maximum adsorption capacities were approximately 320, 85, and 91 mg. g-1 for TC, OTC, and CTC, respectively. Meanwhile, the great removal efficiencies of the three antibiotics TC, OTC, and CTC were correspondingly 91.85, 88.4, and 98.3%. The TCs adsorption isotherm and kinetics on the SDS-modified α-Al2O3 particles mainly governed by the electrostatic and hydrophobic interactions were clarified by a suitable two-step model, the Fourier transform infrared spectroscopy (FT-IR) and zeta potential measurements. Meanwhile, the TCs structural transformation determined by the liquid chromatography with tandem mass spectrometry (LC-MS/MS) measurement was promoted through the adsorption on the α-Al2O3 surface. The TCs transformation rates strongly affected by the TCs adsorption were in the order of CTC > TC > OTC. The found results are promised that the SDS-modified α-Al2O3 particles might behave as high-performance adsorbents to remove the TCs from aqueous solutions.

Cyclic adenosine monophosphate (cAMP) analog and phosphodiesterase inhibitor (IBMX) ameliorate human sperm capacitation and motility.

OBJECTIVES: Human sperm quality is decreasing progressively. One of the foremost reasons for infertility is the failure in sperm capacitation. We examined the influence of a cAMP (cyclic-adenosine mono phosphate analog)+IBMX (3-isobutyl-1-methylxanthine) on the motility and capacitation rate of human sperm over time. MATERIAL AND METHODS: Samples were gotten from 20 asthenozoospermic infertile patients referring to the Academic Center for Education, Culture and Research unit of the infertility research center, Qom, Iran. Samples were processed with a Density Gradient Centrifuging. Spermatozoa were divided into 4 groups: control, experimental 1, 2 and 3 (E1, E2, E3) based on the dose/time schedules (cAMP 5mmol+IBMX 0.2mmol/2, 4, and 6h, respectively). The computer-assisted sperm analysis and chlortetracycline assays were used to measure sperm motility and capacitation. RESULTS: After incubation with a cAMP analog and IBMX, the levels of progressive motile sperms considerably improved in all experimental groups compared to the control group (E1=18.89±7.1, E2=30±9.7, E3=26.3±9.6 vs Control=10.28±6.2, P<0.05) especially in E2 group (P<0.05), indicating a greater effect of db cAMP (5mmol) and IBMX (0.2mmol) for 4h compared to the same doses at 2 and 6h. Also, non-progressive motile sperms significantly decreased in E2 group compared to the other groups (P<0.05). Moreover, both patterns C and B were substantially improved in all experimental groups especially in E2 group (P<0.05). CONCLUSION: Our findings support that the supplementation of sperm with db cAMP+IBMX specially for 4h, could be useful for men with asthenozoospermia to improve the success of assisted reproductive technology.

Effects of honeycomb extract on the growth performance, carcass traits, immunity, antioxidant function and intestinal microorganisms of yellow bantam broilers.

Although many studies have already described the physiological effects of bee products, such as honey, propolis, pollen, and royal jelly, on livestock farming, the health benefits of the honeycomb are still not fully understood. The problem of drug residues and bacterial resistance caused by the abuse of antibiotics is becoming increasingly serious. For this reason, a safe, green substitute has to be sought. We conducted a comparative study of honeycomb extract (HE) and an antibiotic on growth performance, carcass traits, immunity, antioxidant function and intestinal microorganisms of yellow bantam broilers. A total of four hundred eighty 21-day-old female yellow bantam broilers were randomly divided into 5 groups of 6 replicates of 16 birds each. The 5 groups were as follows, with birds receiving a basal diet supplemented with 150 ppm (mg/kg) of chlortetracycline (CTE), a basal diet without HE (control group), and a basal diet with 0.1%, 0.15%, or 0.2% HE for 60 days. The results showed that HE addition significantly increased average daily feed intake (ADFI), average daily gain (ADG), decrease feed gain ratio (F/G) from 21 to 80 and 51 to 80 days of age compared to the control group, with all 3 HE addition groups having statistically identical values to the antibiotic group. HE implementation dramatically increased spleen index, serum immunoglobulin A (IgA), immunoglobulin M (IgM,), glutathione peroxide (GSH-Px), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and total cecum bacteria and Lactobacillus compared to the control group, numerically at the same level as, or even better than, the antibiotic group. HE and CTE both markly reduced serum malondialdehyde (MDA) concentration compared to the control group, with higher concentrations of HE reducing the effect more dramatically than antibiotics. Both HE and CTE significantly raised dressed yield compared to the control group. In summary, HE, as a potential antibiotic alternative, improved growth performance, carcass traits, immune function, serum antioxidant capacity and intestinal microorganisms in yellow bantam broilers. According to the cubic regression analyses, the recommended supplemental dose of HE was calculated to be 0.15 to 0.17% for female yellow bantam broilers between 21 and 80 d of age.

Enhanced chlortetracycline removal by iron oxide modified spent coffee grounds biochar and persulfate system.

Chlortetracycline (CTC) is a tetracycline derivative antibiotic that has been widely used in the livestock industry for prophylactic and therapeutic purposes. Effective measures should be taken to decrease the environmental risks associated with CTC-rich waste. Biochar produced by biomass waste showed great potential for organic contaminants removal by adsorption and catalytic degradation. This study prepared iron oxide-modified coffee grounds biochar (CGF) at different temperatures for enhanced CTC removal by adsorption and degradation. The main mechanism for CTC removal was found to be electrostatic interaction. In addition, pore diffusion, hydrogen bonds, and π-π bonds also contributed to CTC adsorption. Maximum CTC adsorption capacity was 223.63 mg/g for CGF800 (CGF prepared at 800 °C pyrolysis). The free radical content of CGF600 (CFG prepared at 600 °C pyrolysis) was higher than CGF800, and there were no significant advantages in using biochar prepared at a higher temperature for persulfate activation. The ion mass-to-charge ratio (M/z) is used to describe the ratio of mass to charge of an ion or peak, which can infer compound structure. The structure of CTC degradation products was analyzed by UPLC-MS, and the M/z values were determined as 444, 273, and 154. Thus, pyrolysis of coffee grounds at higher temperatures increased CTC adsorption capacity, and CGF can indirectly assist in CTC degradation by persulfate activation.

Research Note: Effects of Bacillus coagulans X26 on the production performance, intestinal structure, short-chain fatty acids and flora composition of laying hens during the peak laying period.

This study investigated the effects of Bacillus coagulans X26 on the production performance, egg quality, intestinal structure, intestinal short-chain fatty acids, and microbial diversity of laying hens during the peak laying period and explored the possibility of using B. coagulans X26 as an alternative to antibiotics. The results showed that adding 1.0 × 106 CFU/g B. coagulans X26 to the basal diet had the best effect: the average laying rate increased by 4.20% (P < 0.05), the survival rate increased by 7.15% (P < 0.05), the feed intake decreased by 3.06% (P < 0.05), the ratio of feed to egg decreased by 7.42% (P < 0.05), the rate of soft-broken eggshell decreased by 73.04% (P < 0.05), the average egg weight increased by 2.94% (P < 0.05), and the content of egg white protein increased by 5.77% (P < 0.05). The production performance and egg quality of laying hens reached the same level as that of hens fed a diet supplemented with chlortetracycline hydrochloride in this study, and there were significant advantages in the average laying rate and feed-egg ratio (P < 0.05). Both chlortetracycline hydrochloride and B. coagulans X26 altered the flora composition and the SCFA content of the intestinal contents; however, B. coagulans X26 also significantly increased the villus height of the ileum and the ratio of villus height to crypt depth (P < 0.05).

Antibiotic Chlortetracycline Causes Transgenerational Immunosuppression via NF-κB.

The extensive and increasing global use of antibiotics results in the ubiquitous presence of antibiotics in the environment, which has made them "pseudo persistent organic contaminants." Despite numerous studies showing wide adverse effects of antibiotics on organisms, the chronic environmental risk of their exposure is unknown, and the molecular and cellular mechanisms of antibiotic toxicity remain unclear. Here, we systematically quantified transgenerational immune disturbances after chronic parental exposure to environmental levels of a common antibiotic, chlortetracycline (CTC), using zebrafish as a model. CTC strongly reduced the antibacterial activities of fish offspring by transgenerational immunosuppression. Both innate and adaptive immunities of the offspring were suppressed, showing significant perturbation of macrophages and neutrophils, expression of immune-related genes, and other immune functions. Moreover, these CTC-induced immune effects were either prevented or alleviated by the supplementation with PDTC, an antagonist of nuclear factor-κB (NF-κB), uncovering a seminal role of NF-κB in CTC immunotoxicity. Our results provide the evidence in fish that CTC at environmentally relevant concentrations can be transmitted over multiple generations and weaken the immune defense of offspring, raising concerns on the population hazards and ecological risk of antibiotics in the natural environment.

Effects of a mixture of mono-glycerides of butyric-, capric-, and caprylic acid with chlortetracycline on the growth performance, intestine morphology, and cecal microflora of broiler birds.

This study aimed to investigate the effects of a mixture of mono-glycerides of butyric-, capric-, and caprylic acid (MMG) on the growth performance, intestinal morphology, and cecal microflora of broilers. A total of 960 male Arbor Acre broilers were offered basal diets with or without Chlortetracycline additive (CA) at 500 g/t, and MMG at 3,000, 1,000, or 650 g/t, with 8 replicates of 20 birds per treatment. The results confirmed 500 g/t CA with/without 1,000 g/t MMG increased the average daily weight gain (ADG) of birds compared to the control group 1 during the 42-d experimental period (P < 0.05). Comparing to the control group 1, 500 g/t CA with either 650 g or 1,000 g/t MMG or 1,000 g MMG alone increased the ADG of birds during the late growth stage (22-42 d) (P < 0.05). On d 42, the serum triglyceride levels were higher (P < 0.05) in groups supplemented with CA and CA + 1,000 g/t MMG comparing to the control group; while urea nitrogen level was higher in the control group comparing to the rest of treatment groups Compared to the control group 1, 1,000 g/t MMG alone without CA decreased the abundance of Faecalibacterium and Bacteroides but increased the abundance of Escherichia/Shiegella. About 500 g/t CA alone treatment group had higher abundance of Lactobacillus comparing to the rest of groups. In conclusion, dietary supplement with MMG showed beneficial efficacy on the growth and intestinal function of broilers, demonstrating the potential value of MMG to poultry industry. In terms of dosage, the current trial shows that 3,000 g/t (1-21 d) and 1,000 g/t (22-42 d) MMG without CA was the appropriate dietary supplemented rate for broilers. And the mixed use of 500 g/t CA and 1,000 g/t MMG was benefit for broilers at 22 to 42 d.

Effects of chlortetracycline on growth performance and intestinal functions in weaned piglets.

AIM: Weaning stress can cause serious damage to piglet's health. Chlortetracycline (CTC) is widely used to ameliorate weaning stress and prevent infectious diseases in weaned piglets. However, antibiotics as growth promoters have to be limited because of increased antimicrobial resistance. In this study, we evaluated the effects of CTC on growth performance and intestinal functions in order to provide evidence for seeking antibiotic substitutes in weaned piglets. METHODS AND RESULTS: A total of 20 weaned piglets were fed a basal diet or a diet supplemented with 75 mg/kg CTC. CTC decreased the crypt depth and increased the ratio of villus height to crypt depth, whilst failing to affect growth performance and serum biochemical parameters and cytokines. 16S rRNA sequencing suggested that CTC supplementation had no effect on the diversity and composition of colonic microbiota. CONCLUSION: We speculated that gut microbiota is no longer sensitive to a low concentration of CTC due to the long-term use and low bioavailability of CTC in weaned piglets.

Removal of chlortetracycline from water using spent tea leaves-based biochar as adsorption-enhanced persulfate activator.

Antibiotic compounds have caused serious environmental concerns. In this study, we developed an effective technology for treatment of chlortetracycline (CTC), a widely used antibiotic compound. A natural heteroatom-doped spent tea leaves-based biochar (STLB) with excellent adsorption and catalytic property was prepared by simple thermal treatment. An adsorption-promoted persulfate-based advanced oxidation process (PS-AOP) using STLB was studied for CTC removal. The results showed that the as-prepared STLB presented favorable adsorption affinity towards CTC with the maximum adsorption capacity of 627 mg g-1. Meanwhile, CTC enriched on the surface of STLB was good for in-situ decomposition of CTC and nearly 97.4 % of CTC was removed within 30 min of pre-adsorption and 60 min of subsequent degradation. The STLB had excellent recyclability and wide pH tolerance range of 3.0-9.0 in combined pre-adsorption and PS-AOP. Reactive oxygen species analysis confirmed that CTC degradation was mainly due to non-radical (singlet oxygen, 1O2) and radicals (SO4- and OH). This study suggests that STLB is a promising adsorption-enhanced PS activator for the treatment of refractory wastewater and also provides a strategy of waste control by spent tea leaves.

Effects of dietary citrus extract on growth performance, carcass characteristics and meat quality of pigs.

This study investigated the effects of citrus extract on growth, carcass and meat quality of Duroc × Landrace × Large White pigs. One hundred and eight pigs (54 barrows, 54 females) were assigned to one of three dietary treatments for 138 days. The dietary treatments were (1) basic diet; (2) basic diet supplemented with 75 mg/kg chlortetracycline; and (3) basic diet supplemented with citrus extract (0.25 ml/kg during 56-112 days of age and 0.20 ml/kg during 113-194 days of age). No significant differences among treatments were found for growth performance, carcass characteristics, meat quality and free amino acids (p > 0.05). Feeding citrus extract tended to increase intramuscular fat (p = 0.052). Citrus extract and chlortetracycline increased C15:0 concentration (p = 0.016) and superoxide dismutase activity (p = 0.004). The pigs that received chlortetracycline exhibited the lowest (p = 0.033) muscle malondialdehyde concentration. Overall, citrus extract ameliorated some meat quality indicators without adverse effects on pig growth or carcass performance.

Chlortetracycline alters microbiota of gut or faeces in pigs and leads to accumulation and migration of antibiotic resistance genes.

In this study, we investigated the effect of long-term use of chlortetracycline (CTC) on the gut microbiota composition and metabolism profiles in pigs, and the variation of antibiotic resistance genes (ARGs) and microbial communities in faeces and manure during aerobic composting (AC) and anaerobic digestion (AD). The pigs were fed the same basal diet supplemented with or without 75 mg/kg CTC, and fresh faeces of 30-, 60-, 90-, and 120-day-old pigs were collected from the CTC group. The results showed that CTC reduced the diversity of the gut microbiota significantly and changed its structure. Metabolomics analysis of intestinal contents revealed 23 differentially abundant metabolites, mainly organic acids, carbohydrates, and amino acids. Metabolic pathways, such as the TCA cycle, propionate metabolism, and pyruvate metabolism, were changed. From 30 to 120 days of age, the amount of CTC residues in faeces and the abundance of 3 tetracycline resistance genes increased significantly, and it was positively correlated with tetC, tetG, tetW, sul1 and intI2. CTC residue levels and ARGs abundance gradually decreased with fermentation time, and AC was better than AD at reducing ARGs abundance. The results suggest that in-feed CTC can reduce the diversity of the gut microbiota, change the structure, function and metabolism of the bacterial community, and increase the abundance of ARGs in faeces.

Effects of replacing dietary Aureomycin with a combination of plant essential oils on production performance and gastrointestinal health of broilers.

The objective of this study was to investigate the effects of replacing antibiotics with a combination of plant essential oils on the growth performances and gastrointestinal health of broilers. A total of 720 1-day-old male AA broilers were randomly divided into 3 treatments: the control treatment (CON), the Aureomycin supplementation treatment (AGP), and the combined plant oils supplementation treatment (POC), with a 42-D period feeding procedure. Growth performances, carcass performances, intestinal sections, and cecal microbiota were investigated. Results indicated that POC supplementation decreased the feed conversion ratio compared with CON and AGP treatments, though not significantly. No significant differences were found for feed intake, BW gain, and culling rate among the 3 treatments (P > 0.05). In addition, no significant differences were seen on carcass performance. For the aspects of intestinal section, POC supplementation did not make significant effects on intestinal wall thickness, villus heights, crypt depths, and the ratio of villus heights/crypt depths compared with CON and AGP treatments. Cecal microbiota results demonstrated that bacterial diversity and some representative probiotic bacteria were significantly increased in numbers (P < 0.05) after POC supplementation. In conclusion, the combination of essential oils promoted intestinal health through improving gut bacterial diversity and probiotic bacteria, as well as improving feed conversion ratio of broilers. These results indicated that the combination of essential oils may benefit the gastrointestinal health and be applied as an antibiotic alternative.

Effects of a microencapsulated formula of organic acids and essential oils on nutrient absorption, immunity, gut barrier function, and abundance of enterotoxigenic Escherichia coli F4 in weaned piglets challenged with E. coli F4.

The objective was to study the effects of microencapsulated organic acids (OA) and essential oils (EO) on growth performance, immune system, gut barrier function, nutrient digestion and absorption, and abundance of enterotoxigenic Escherichia coli F4 (ETEC F4) in the weaned piglets challenged with ETEC F4. Twenty-four ETEC F4 susceptible weaned piglets were randomly distributed to 4 treatments including (1) sham-challenged control (SSC; piglets fed a control diet and challenged with phosphate-buffered saline (PBS)); (2) challenged control (CC; piglets fed a control diet and challenged with ETEC F4); (3) antibiotic growth promoters (AGP; CC + 55 mg·kg-1 of Aureomycin); and (4) microencapsulated OA and EO [P(OA+EO); (CC + 2 g·kg-1 of microencapsulated OA and EO]. The ETEC F4 infection significantly induced diarrhea at 8, 28, 34, and 40 hr postinoculation (hpi) (P < 0.05) in the CC piglets. At 28 d postinoculation (dpi), piglets fed P(OA+EO) had a lower (P < 0.05) diarrhea score compared with those fed CC, but the P(OA+EO) piglets had a lower (P < 0.05) diarrhea score compared with those fed the AGP diets at 40 dpi. The ETEC F4 infection tended to increase in vivo gut permeability measured by the oral gavaging fluorescein isothiocyanate-dextran 70 kDa (FITC-D70) assay in the CC piglets compared with the SCC piglets (P = 0.09). The AGP piglets had higher FITC-D70 flux than P(OA+EO) piglets (P < 0.05). The ETEC F4 infection decreased mid-jejunal VH in the CC piglets compared with the SCC piglets (P < 0.05). The P(OA+EO) piglets had higher (P < 0.05) VH in the mid-jejunum than the CC piglets. The relative mRNA abundance of Na+-glucose cotransporter and B0AT1 was reduced (P < 0.05) by ETEC F4 inoculation when compared with the SCC piglets. The AGP piglets had a greater relative mRNA abundance of B0AT1 than the CC piglets (P < 0.05). The ETEC F4 inoculation increased the protein abundance of OCLN (P < 0.05), and the AGP piglets had the lowest relative protein abundance of OCLN among the challenged groups (P < 0.05). The supplementation of microencapsulated OA and EO enhanced intestinal morphology and showed anti-diarrhea effects in weaned piglets challenged with ETEC F4. Even if more future studies can be required for further validation, this study brings evidence that microencapsulated OA and EO combination can be useful within the tools to be implemented in strategies for alternatives to antibiotics in swine production.

Preliminary Study on the Effect of Bacillus amyloliquefaciens TL on Cecal Bacterial Community Structure of Broiler Chickens.

Probiotics can promote the health and growth performance of animals through modulation of intestinal microbiota. When used as a feed additive, they have the potential to minimize or abolish the use of antibiotics. In this study, we investigated the effect of the probiotic strain Bacillus amyloliquefaciens TL on the growth performance and cecum microflora composition in Cobb 500 broiler chickens. In total, 180 broilers were randomly divided into three groups-each group comprised 4 pens, and each pen contained 15 chickens. The three groups were fed either a control diet, or a diet supplemented with either the antibiotic chlortetracycline or B. amyloliquefaciens TL. Broilers were weighed, and cecum contents were collected on days 7, 14, 21, and 35, respectively. The broilers in both the antibiotic and probiotic groups exhibited significant weight gain compared with controls, exhibiting increases of 16.02% and 13.40%, respectively, after 35 days (P < 0.01). Similarly, the feed conversion ratio (FCR, 1-35 days) of broilers in the chlortetracycline and B. amyloliquefaciens TL groups was lower than that of the controls. HiSeq high-throughput sequencing of 16S rRNA of the cecal microbiota was performed on days 7, 14, 21, and 35, respectively. The Firmicutes/Bacteroidetes ratio was higher in the chlortetracycline and B. amyloliquefaciens TL groups than in the control group on days 14, 21, and 35, and especially on day 21. The prevalence of genera Oscillospira, Ruminococcus, Butyricicoccus, and Faecalibacterium (Firmicutes) was higher in the antibiotic and probiotic groups, while that of Bacteroides, Parabacteroides (Bacteroidetes), and Lactobacillus was higher in the control group. In this study, the changes in the microbiota of the probiotic group were similar to those in the antibiotic group. These results suggest that the probiotic strain B. amyloliquefaciens TL can modulate the cecal microbiota of broilers similar to chlortetracycline.

Exploring microbial community structure and biological function in manured soil during ten repeated treatments with chlortetracycline and ciprofloxacin.

The changes of enzyme activities, microbial community structure and function, and the diversity and resistance level of antibiotic-resistant bacteria (ARB) were studied in soil during ten repeated treatments with chlortetracycline (CTC) and/or ciprofloxacin (CIP) together with organic manure (OM) under laboratory conditions. The activities of neutral phosphatase (NPA) and catalase (CAT) displayed the suppression-recovery-stimulation trend in the OM&CTC treatment but the stimulation trend in the OM&CTC&CIP treatment. The NPA was stimulated but the CAT was little affected in the OM&CIP treatment. Soil microbial functional diversity displayed the suppression-recovery-stimulation trend in the OM&CTC and OM&CTC&CIP treatments and the stimulation-suppression trend in the OM&CIP treatment with the treatment frequency. Metagenomic analysis showed that the relative abundances of Actinobacteria and Firmicutes in the antibiotic treatment significantly increased by 0.5-235.6%, but that of Proteobacteria decreased by 0.2-27.3% compared to the control with the treatment frequency. Furthermore, the relative abundances of dominant bacterial genera including Streptomyces, Actinomadura, Mycobacterium, and Streptococcus in the antibiotic treatment significantly increased by 1.1-10433.3% compared to the control. Meanwhile, repeated antibiotic treatments induced a significant increase in the diversity and resistance level of ARB isolates, especially in the OM&CTC treatment. It is concluded that repeated treatments with CTC and/or CIP can alter enzyme activities, microbial community structure and function, and increase the diversity and resistance level of ARB isolates.

Effects of palygorskite composites on growth performance and antioxidant status in broiler chickens.

This work aimed to investigate the effects of the palygorskite (PAL) composites on the growth performance and antioxidant status in broiler chickens. A total of 192 one-day-old Ross 308 broilers were randomly divided into 3 treatment groups. Broilers were fed basal diets supplemented with either 50 mg/kg chlortetracycline (CTC group), 1 g/kg ZnO/PAL (ZnO/PAL group), or 1 g/kg chitooligosaccharides/ZnO/PAL (COS/ZnO/PAL group), respectively. The results showed that PAL composites were found to exhibit similar effects on growth performance as CTC (P > 0.05). ZnO/PAL and COS/ZnO/PAL enhanced the activity of serum glutathione peroxidase (GSH-Px) compared with CTC both at 21 and 42 d (P < 0.05). Compared with the CTC group, COS/ZnO/PAL enhanced serum catalase (CAT) activity at 21 d (P < 0.05), and decreased serum malondialdehyde (MDA) content at 42 d (P < 0.05). Compared with the CTC group, ZnO/PAL decreased duodenal mucous MDA content at 21 d, while ZnO/PAL did not affect activities of superoxide dismutase (SOD) and GSH-Px in the duodenum (P > 0.05). The duodenal mucous activities of SOD and GSH-Px were the highest in the COS/ZnO/PAL group at 42 d (P < 0.05). At 21 d, broilers in the COS/ZnO/PAL group had the lowest MDA content and the highest total antioxidant capacity (T-AOC) in the jejunum (P < 0.05). Palygorskite composites decreased ileum mucous MDA content compared with CTC treated broilers at 21 d (P < 0.05). At 42 d, ileum mucous T-AOC was increased both in the ZnO/PAL and COS/ZnO/PAL groups compared with the CTC group (P < 0.05). The ileum mucous GSH-Px activities both in the ZnO/PAL and COS/ZnO/PAL groups were increased compared with the CTC group (P < 0.05). In conclusion, the broilers given the basal diet supplemented with the PAL composites exhibited similar growth performance to their counterparts in the AGP group. Additionally, the PAL composites improved the antioxidant status of broilers and the beneficial effects of COS/ZnO/PAL on the antioxidant status are more pronounced.

Macleaya cordata helps improve the growth-promoting effect of chlortetracycline on broiler chickens.

Chlortetracycline (CTC), one kind of common antibiotic for prevention and treatment of various diseases, also exhibits good performance in accelerating the growth of livestock. Macleaya cordata, a traditional Chinese medicine, is usually used as a natural additive in livestock because of its anti-microbial, anti-fungal, anti-inflammatory, and pesticidal activity. In this work, we studied whether M. cordata helps regulate the growth-promoting effect of CTC on broiler chickens. It is demonstrated that M. cordata improves the growth-promoting effect of CTC on growth performance indices of broiler chickens, such as survival rate, daily weight, and feed to weight rate. M. cordata also delays the maximum of CTC residues in plasma. It may depend on the higher values of operational taxonomic unit (OTU) and the indices of α diversity driven by simultaneous use of CTC and M. cordata.

Effects of Lactobacillus reuteri LR1 on the growth performance, intestinal morphology, and intestinal barrier function in weaned pigs.

The objective of this study was to investigate the effects of Lactobacillus reuteri LR1, a new strain isolated from the feces of weaned pigs, on the growth performance, intestinal morphology, immune responses, and intestinal barrier function in weaned pigs. A total of 144 weaned pigs (Duroc × Landrace × Yorkshire, 21 d of age) with an initial BW of 6.49 ± 0.02 kg were randomly assigned to 3 dietary treatments with 8 replicate pens, each of per treatment and 6 pigs. Pigs were fed a basal diet (CON, controls), the basal diet supplemented with 100 mg/kg olaquindox and 75 mg/kg aureomycin (OA) or the basal diet supplemented with 5 × 1010 cfu/kg L. reuteri LR1 for a 14-d period. At the end of study, the ADG, ADFI, and G:F were calculated, and 1 randomly selected pig from each pen was euthanized for sample collection. The LR1 increased ADG (22.73%, P < 0.05) compared with CON. The villus height of the ileum was increased (P < 0.05) and crypt depth in duodenum was reduced (P < 0.05), along with increased (P < 0.05) villus height to crypt depth ratio of the jejunum and ileum by LR1 compared with CON and OA. LR1 increased (P < 0.05) ileal mucosal content of IL-22 and transforming growth factor-ß compared with OA. Compared with CON, LR1 increased (P < 0.05) and OA decreased (P < 0.05) the ileal content of secretory immunoglobulin A (sIgA), and the abundance of transcripts of porcine ß-defensin 2 and protegrin 1-5. Compared with CON, LR1 increased (P < 0.05) tight junction protein zonula occludens-1 and occludin transcripts in the mucosa of the jejunum and ileum, and those of mucin-2 in ileal mucosa. The relative expression of toll-like receptor 2 (TLR2) and TLR4 were increased (P < 0.05) in ileal mucosa in pigs fed LR1 compared with CON. In conclusion, these data indicated that dietary LR1 supplementation at 5 × 1010 cfu/kg improved growth performance, intestinal morphology, and intestinal barrier function in weaned pigs.