Biosafety assessment of laying hens fed different treatments of black soldier flies (Hermetia illucens) under doxycycline stress.

The black soldier fly (BSF, Hermetia illucens) is a resource insect that can utilize livestock and poultry feces. However, BSFs may also increase the risk of transmission of antibiotic resistance genes (AGRs) that are widespread in livestock and poultry farm environments. Therefore, we aimed to evaluate the biosecurity risks of different BSF treatments in the laying chicken food chain using the "chicken manure-BSF-laying hens" model.

The tigecycline resistance gene tetX has an expensive fitness cost based on increased outer membrane permeability and metabolic burden in Escherichia coli.

Livestock-derived tetX-positive Escherichia coli with tigecycline resistance poses a serious risk to public health. Fitness costs, antibiotic residues, and other tetracycline resistance genes (TRGs) are fundamental in determining the spread of tetX in the environment, but there is a lack of relevant studies. The results of this study showed that both tetO and tetX resulted in reduction in growth and an increased in the metabolic burden of E.

Breed differences in the expression levels of gga-miR-222a in laying hens influenced HS production by regulating methionine synthase genes in gut bacteria.

Background: The microbiota in the cecum of laying hens is crucial for host digestion, metabolism, and odor gas production. The results of recent studies have suggested that host microRNAs (miRNAs) can regulate gene expression of the gut microbiota. In the present study, the expression profiles of host-derived miRNAs in the cecal content of two laying hen breeds; Hy-line Gray and Lohmann Pink, which have dissimilar HS production, were characterized; and their effects on HS production by regulating the expression of gut microbiota-associated genes were demonstrated.

Microbial Diversity and Community Variation in the Intestines of Layer Chickens.

The intestinal microbiota is increasingly recognized as an important component of host health, metabolism and immunity. Early gut colonizers are pivotal in the establishment of microbial community structures affecting the health and growth performance of chickens. White Lohmann layer is a common commercial breed.

The microbiota structure in the cecum of laying hens contributes to dissimilar HS production.

Background: Host genotype plays a crucial role in microbial composition of laying hens, which may lead to dissimilar odor gas production. The objective of this study was to investigate the relationship among layer breed, microbial structure and odor production.

Results: Thirty Hy-Line Gray and thirty Lohmann Pink laying hens were used in this study to determine the impact of cecal microbial structure on odor production of laying hens.

The metabolism and morphology mutation response of probiotic Bacillus coagulans for lead stress.

Lead is among the most common toxic heavy metals and its contamination is of great public concern. Bacillus coagulans is the probiotic which can be considered as the lead absorption sorbent to apply in the lead contaminant water directly or indirectly. A better understanding of the lead resistance and tolerance mechanisms of B.

Bacillus coagulans R11 maintained intestinal villus health and decreased intestinal injury in lead-exposed mice by regulating the intestinal microbiota and influenced the function of faecal microRNAs.

Lead contamination is an environmental problem, especially in developing countries; due to the nondegradable characteristics of lead, it is easily deposited in human and animal bodies by the food chain. Probiotics are regarded as a good tool to remove lead ions in the intestine and maintain gut health conditions, but previous studies failed to elucidate the relationship among probiotics, the host and the gut microbiota. In the present study, B.

Effect of different sulfadimidine addition methods on its degradation behaviour in swine manure.

Sulfadimidine (SM2) is commonly used in the swine industry and enters the environment via faeces. In recent years, advances in the ecotoxicology of SM2 have become a popular research interest with two common research methods including swine manure collection from swine fed with a diet containing SM2 and directly adding SM2. The purpose of this experiment was to compare SM2 degradation behaviour in pig manure with two different SM2 addition methods.

In vitro fermentative capacity of swine large intestine: comparison between native Lantang and commercial Duroc breeds.

Native Lantang and commercial Duroc pigs were used as animal models to evaluate the differences existing in dietary fiber utilization ability between breeds. Animals were fed the same diet from weaning (4 weeks) to 4 months of age. Neutral detergent fiber (NDF) from wheat bran (as substrate) and fecal samples from the two breeds (as inoculum) were used in an in vitro gas production trial.

The excretion and environmental effects of amoxicillin, ciprofloxacin, and doxycycline residues in layer chicken manure.

The excretion rates and ecological risk to the environment of three commonly used veterinary antibiotics (VAs), amoxicillin, ciprofloxacin, and doxycycline, in layer hen manure during the application and withdrawal periods were investigated in a study consisting of a control group fed with VA-free basal diet and nine treatment groups consisted of three levels (200 mg/kg, 100 mg/kg, and 50 mg/kg) of amoxicillin (AMX), ciprofloxacin (CIP), or doxycycline (DOC). Each treatment group was replicated seven times with three layer hens per replication. Results of the study showed that the average excretion rates of AMX in the 200, 100, and 50 mg/kg groups were 67.

Co-addition of manure increases the dissipation rates of tylosin A and the numbers of resistance genes in laboratory incubation experiments.

The behavior of veterinary antibiotics in the soil is commonly studied using the following methods to add antibiotics to the soil: (A) adding manure collected from animals fed a diet that includes antibiotics; (B) adding antibiotic-free animal manure spiked with antibiotics; and (C) the direct addition of antibiotics. However, most studies have only used methods (B) and (C) in their research, and few studies have simultaneously compared the different antibiotic addition methods. This study used tylosin A (TYLA) as a model antibiotic to compare the effects of these three commonly used antibiotic addition methods on the dissipation rates of TYLA and the numbers of resistance genes in laboratory incubation experiments.

Effect of different oxytetracycline addition methods on its degradation behavior in soil.

The degradation behavior of veterinary antibiotics in soil is commonly studied using the following methods of adding antibiotics to the soil: (i) adding manure collected from animals fed with a diet containing antibiotics, (ii) adding antibiotic-free animal manure spiked with antibiotics and (iii) directly adding antibiotics. No research simultaneously comparing different antibiotic addition methods was found. Oxytetracycline (OTC) was used as a model antibiotic to compare the effect of the three commonly used antibiotic addition methods on OTC degradation behavior in soil.

[Development of SNP multiplexes utilizing universal reporter primers for forensic purposes].

Objective: To establish a simple, fast and economical technique for multiplex-typing SNPs and to explore its potential forensic application.

Methods: Five Y-SNP loci (IMS-JST164520, IMS-JST021354, IMS-JST003305, M119 and M134) were selected and the allele specific primers of each locus were designed with the universal reporter primers tailed at their 5' end. Alleles of these loci were amplified first by allele specific primers, then amplified by universal reporter primers tagged by fluorescent dye.