Fucoidan Supplementation Improves Antioxidant Capacity via Regulating the Keap1/Nrf2 Signaling Pathway and Mitochondrial Function in Low-Weaning Weight Piglets.

Fucoidan (FC) is known for its antioxidant properties, but it has unclear effects and mechanisms on weaned piglets. Two experiments were conducted to determine the optimal FC dosage in piglet diets and its protective effect against lipopolysaccharide (LPS)-induced oxidative stress. In experiment one, 24 low weight weaned piglets were randomly assigned to four dietary treatments: a basal diet (FC 0), or a diet supplemented with 150 (FC 150), 300 (FC 300), or 600 mg/kg FC (FC 600). In experiment two, 72 low-weaning weight piglets were randomly allocated into four treatments: a basal diet (CON), or 300 mg/kg of fucoidan added to a basal diet challenged with LPS (100 µg LPS/kg body weight) or not. The results showed that FC treatments increased the G:F ratio, and dietary FC 300 reduced the diarrhea incidence and increased the plasma IGF-1 concentrations. In addition, FC 300 and FC 600 supplementation increased the plasma SOD activity and reduced the plasma MDA concentration. LPS challenge triggered a strong systemic redox imbalance and mitochondrial dysfunction. However, dietary FC (300 mg/kg) supplementation increased the activity of antioxidant enzymes, including SOD, decreased the MDA concentration in the plasma and liver, down-regulated Keap1 gene expression, and up-regulated Nrf2, CAT, MFN2, SDHA, and UQCRB gene expression in the liver. These results indicated that dietary fucoidan (300 mg/kg) supplementation improved the growth performance and antioxidant capacity of low-weaning weight piglets, which might be attributed to the modulation of the Keap1/Nrf2 signaling pathway and the mitochondrial function in the liver.

Genome-wide population structure, homozygosity, and heterozygosity patterns of Nero Siciliano pig in the framework of Italian and cosmopolitan breeds.

Analysis of genomic data is becoming more and more common for the effective management of livestock breeding programmes, even in the case of local populations. In this work, the genome-wide data of Nero Siciliano pig breed were compared to that of wild boar, Italian local and cosmopolitan breeds to investigate its genetic structure, and runs of homozygosity (ROH) and heterozygosity patterns. The Nero Siciliano has been reported to have the highest rate of genetic diversity among the Italian breeds, and a genetic variability comparable to that of the cosmopolitan breeds. Analyses of genomic structure and relationships underlined its proximity to wild boar, and an internal substructure probably linked to different family lines. The breed showed a low value of inbreeding estimated from ROH, and the highest diversity index among the Italian breeds, even if lower than that of the cosmopolitans. Four ROH islands in three chromosomes (SSC8, SSC11, and SSC14) and one heterozygosity-rich region (SSC1) were identified in Nero Siciliano, highlighting genomic regions related to productive QTL. Across breeds, SSC8 and SSC14 were the chromosomes with most ROH islands, with Mora Romagnola and wild boar showing the highest level of autozygosity. Chromosomes SSC2, SSC6, SSC8 and SSC13 showed the majority of runs of heterozygosity regions, mainly found in the cosmopolitan pig breeds, which reported several genes associated with health-related QTL. The outlined results can help to better identify the genomic profile of this local breed in order to plan matings, maintain adequate internal diversity and exploit the production system.

Staphylococcus aureus coa gene sequence analysis can prevent misidentification of coagulase-negative strains and contribute to their control in dairy cow herds.

Accurate and precise differentiation of staphylococci isolated from milk is of importance for udder health management. In particular, the rapid and specific identification of Staphylococcus aureus plays an essential role in the prevention and treatment programs for bovine mastitis. Plasma gelatinization in coagulase assays is routinely used to discriminate S. aureus from other species by detecting the presence of extracellular free staphylocoagulase. However, rarely occurring coagulase-deficient S. aureus strains can be responsible for clinical and subclinical mastitis cases. By investigating S. aureus isolates from a single herd over a 10-year period we identified the persistence of a phenotypically coagulase-negative S. aureus strain and pinpointed the possible cause to a single base pair deletion in the coa gene sequence. Our results support the need to integrate primary biochemical tests with molecular/sequence analysis approaches for correctly identifying and discriminating atypical S. aureus in bovine herds, as the coagulase test alone may fail to detect persistent mastitis-causing strains.

Bovine Colostrum Supplementation Modulates the Intestinal Microbial Community in Rabbits.

BC is a nutraceutical that can modulate intestinal microbiota. This study investigates the effects of BC diet supplementation on luminal and mucosa-associated microbiota in the jejunum, caecum, and colon of rabbits. Twenty-one New Zealand White female rabbits were divided into three experimental groups (n = 7) receiving a commercial feed (CTRL group) and the same diet supplemented with 2.5% and 5% BC (2.5% BC and 5% BC groups, respectively), from 35 (weaning) to 90 days of age (slaughtering). At slaughter, the digestive tract was removed from each animal, then both content and mucosa-associated microbiota of jejunum, caecum, and colon were collected and analysed by Next Generation 16SrRNA Gene Sequencing. Significant differences were found in the microbial composition of the three groups (i.e., beta-diversity: p < 0.01), especially in the caecum and colon of the 2.5% BC group. The relative abundance analysis showed that the families most affected by the BC administration were Clostridia UCG-014, Barnesiellaceae, and Eggerthellaceae. A trend was also found for Lachnospiraceae, Akkermansiaceae, and Bacteroidaceae. A functional prediction has revealed several altered pathways in BC groups, with particular reference to amino acids and lactose metabolism. Firmicutes:Bacteroidetes ratio decreased in caecum luminal samples of the 2.5% BC group. These findings suggest that BC supplementation could positively affect the intestinal microbiota. However, further research is needed to establish the optimal administration dose.

Effects of Thymbra capitata essential oil on in vitro fermentation end-products and ruminal bacterial communities.

An in vitro trial was carried out to investigate the effects of natural Thymbra capitata essential oil (NEO) and its main compounds [including carvacrol, p-cymene, γ-terpinene given alone or in a synthetic combination (SEO)] on ruminal fermentation and the bacterial community using batch cultures inoculated with ruminal digesta and incubating two different basal diets [high-forage (F) and high-concentrate (C) diet]. After 24 h of incubation, primary fermentation end-products [gas, methane, volatile fatty acids (VFAs) and ammonia] and rumen microbial diversity were determined. NEO reduced the total VFA concentration (P < 0.05) only in the C diet. In contrast, SEO and carvacrol decreased the total VFA concentration (P < 0.05) only in the F diet. Methane production was not affected (P > 0.05) by any of the experimental treatments or diets evaluated. Microbial diversity analysis showed only a moderate effect of carvacrol and SEO on 13 genera, including, mainly, Atopobium and Blautia (involved in subacute ruminal acidosis) or Candidatus Saccharimonas (related to laminitis). In conclusion, T. capitata EO has a limited potential to attain nutritional or environmental benefits, but further research should be carried out to clarify its effects on animal health and microbial food safety.

A 20-SNP Panel as a Tool for Genetic Authentication and Traceability of Pig Breeds.

Food authentication in local breeds has important implications from both an economic and a qualitative point of view. Meat products from autochthonous breeds are of premium value, but can easily incur fraudulent or accidental substitution or mislabeling. The aim of this study was to identify a small number of SNPs using the Illumina PorcineSNP60 BeadChip for breed traceability, in particular of the Italian Nero Siciliano pig and its derived products. A panel of 12 SNPs was sufficient to discriminate Nero Siciliano pig from cosmopolitan breeds and wild boars. After adding 8 SNPs, the final panel of 20 SNPs allowed us to discriminate all the breeds involved in the study, to correctly assign each individual to its breed, and, moreover, to discriminate Nero Siciliano from first-generation hybrids. Almost all livestock breeds are being genotyped with medium- or high-density SNP panels, providing a large amount of information for many applications. Here, we proposed a method to select a reduced SNP panel to be used for the traceability of pig breeds.

Gut microbiome modifications over time when removing in-feed antibiotics from the prophylaxis of post-weaning diarrhea in piglets.

Post-weaning diarrhea (PWD) in pigs has mainly an infectious basis and control strategies are centred on antibiotics added to the diet. Given concerns on the spread of multi-resistant bacteria, it is necessary to develop alternative prophylactic approaches to control PWD in piglets. The most promising alternative strategies are based on substances that act indirectly on the bacteria by stimulating the immune system or by improving gut health. The aim of this study was to evaluate the effect on the gut microbiota of feed supplemented with a mixture of essential oils (garlic and oregano) in weaning piglets, compared to traditional PWD management (in-feed antibiotics) and to a control group without any diet supplementation. The study involved 197 piglets from 18 litters in a single farm. The piglets were followed from birth to day 58 of age and were weaned at day 26. During the experimental period, the animals were monitored for weight and growth, average daily gain, morbidity and mortality. For the metataxonomics analysis, rectal samples were collected from 17 piglets from the three experimental groups at 4 different time-points (days 1, 12, 26 and 58). Results revealed that the gut microbiota in pre- and post-weaning piglets was dominated by the phyla Firmicutes (51%), Bacteroidetes (25%) and Proteobacteria (16%), which together make up for over 90% of the entire piglet core gut microbiota. The core microbiota comprised 10 taxa before weaning and 43 taxa after weaning, with 7 taxa overlapping between timepoints: two of them (Prevotella 9, p-value = 0.00095; Solobacterium p-value = 0.00821) were significantly more abundant after weaning. All alpha diversity indexes were significantly different between pre- and post-weaning, while only Shannon and Simpson diversity and equitability were significantly different between treatments. Based on the matrix of Bray-Curtis dissimilarities, samples showed clear clustering per timepoint (before and after weaning, p-value < 0.001) and between treatments by timepoint (p-value = 0.0086). The oil-diet group showed a consistently higher F:B ratio at all timepoints. These results show that the pig gut microbiota changes significantly with weaning, and suggest that the use of essential oils as feed supplementation to control PWD does not seem to alter sgnificantly the microbiota nor the growth parameters of piglets, however modifications of specific taxa may occur.

Dietary Administration of L-Carnitine During the Fattening Period of Early Feed Restricted Lambs Modifies Ruminal Fermentation but Does Not Improve Feed Efficiency.

Early feed restriction of lambs may program animals to achieve reduced feed efficiency traits as a consequence of permanent mitochondrial dysfunction. The hypothesis at the background of the present study is that dietary administration of L-Carnitine (a compound that promotes the activation and transportation of fatty acids into the mitochondria) during the fattening period of early feed restricted lambs can: (a) improve the biochemical profile of early feed restricted lambs, (b) improve feed efficiency, (c) modulate the ruminal and intestinal microbiota, and (d) induce changes in the gastrointestinal mucosa, including the immune status. Twenty-two newborn male Merino lambs were raised under natural conditions but separated from the dams for 9 h daily to allow feed restriction during the suckling period. At weaning, lambs were assigned to a control group being fed ad libitum a complete pelleted diet during the fattening phase (CTRL, n = 11), whereas the second group (CARN, n = 11) received the same diet supplemented with 3 g of L-Carnitine/kg diet. The results revealed that even though L-Carnitine was absorbed, feed efficiency was not modified by dietary L-Carnitine during the fattening period (residual feed intake, p > 0.05), whereas ruminal fermentation was improved [total short-chain fatty acids (SCFAs), 113 vs. 154 mmol/l; p = 0.036]. Moreover, a trend toward increased concentration of butyrate in the ileal content (0.568 vs. 1.194 mmol/100 ml SCFA; p = 0.074) was observed. Other effects, such as reduced heart weight, lower levels of markers related to muscle metabolism or damage, improved renal function, and increased ureagenesis, were detected in the CARN group. Limited changes in the microbiota were also detected. These findings suggest that L-Carnitine may improve ruminal fermentation parameters and maintain both the balance of gut microbiota and the health of the animals. However, the improved ruminal fermentation and the consequent greater accumulation of intramuscular fat might have hidden the effects caused by the ability of dietary L-Carnitine to increase fatty acid oxidation at the mitochondrial level. This would explain the lack of effects of L-Carnitine supplementation on feed efficiency and points toward the need of testing lower doses, probably in the context of animals being fed in excess non-protein nitrogen.

Could Dietary Supplementation with Different Sources of N-3 Polyunsaturated Fatty Acids Modify the Rabbit Gut Microbiota?

The present study evaluated the effects of feed supplemented with two dietary sources of n-3 polyunsaturated fatty acids (PUFAs; fish oil and extruded flaxseed) on the gut microbiota, caecal fermentations, gastrointestinal histology, and histochemistry in rabbits. Fifteen male New Zealand White rabbits were divided into three groups (n = 5/group) and fed with different diets from weaning (35 days of age) until slaughtering (90 days of age): C group, fed with a commercial diet; F group, supplemented with 10% of extruded flaxseed; and O group, supplemented with 3.5% of fish oil. At slaughter, the content of the stomach, duodenum, jejunum, ileum, caecum, and colon was collected and analyzed by Next Generation 16S rRNA gene sequencing. Tissue samples of the same tracts were evaluated with histological and histochemical analysis. Ammonia and lactic acid in the caecum were also quantified. Twenty-nine operational taxonomic units (OTUs) were significantly different between groups. Groups receiving n-3 PUFAs supplementation showed an increase in Bacteroidetes and Lachnospiraceae in several gastrointestinal tracts, while Bacilli abundance, as well as Firmicutes/Bacteroidetes ratio, were reduced compared to the control group (for all p < 0.05). Caecal ammonia was lower in the F than C group (p < 0.032), whereas no difference was found for lactic acid. Finally, histological evaluations revealed a mild hemorrhagic infiltration and vessels ectasia in the stomach mucosa of both F and O groups, but no effect of nutritional treatment was evidenced by the histochemical analyses. In conclusion, n-3 PUFAs supplementation could modify the rabbit gut microbiota and fermentation. The increase in beneficial bacterial populations may, at least partially, explain the positive effects of n-3 PUFAs diet supplementation on human and animals' health, although the appropriate dosage should be established.

Dietary Supplementation with Goji Berries (Lycium barbarum) Modulates the Microbiota of Digestive Tract and Caecal Metabolites in Rabbits.

Goji berries show health benefits, although the possible mechanisms of action, including compositional changes in the gut microbiome, are still not fully understood. The aim of this study was to evaluate the effect of Goji berry supplementation on microbiota composition and metabolites in the digestive tracts of rabbits. Twenty-eight New Zealand White rabbits were fed with a commercial feed (control group, C; n = 14) or the same diet supplemented with 3% of Goji berries (Goji group, G; n = 14), from weaning (35 days old) until slaughter (90 days old). At slaughter, samples from the content of the gastrointestinal tracts were collected and analyzed by Next Generation 16S rRNA Gene Sequencing to evaluate the microbial composition. Ammonia and lactic acid were also quantified in caecum. Results showed differences in microbiota composition between the groups for two phyla (Cyanobacteria and Euryarchaeota), two classes (Methanobacteria and Bacilli), five orders, fourteen families, and forty-five genera. Ruminococcaceae (p < 0.05) and Lachnospiraceae (p < 0.01) were more abundant in G than in C group. Lactobacillaceae also showed differences between the two groups, with Lactobacillus as the predominant genus (p = 0.002). Finally, Goji berry supplementation stimulated lactic acid fermentation (p < 0.05). Thus, Goji berry supplementation could modulate gastrointestinal microbiota composition and caecal fermentation.

Comparative secretome analysis of Staphylococcus aureus strains with different within-herd intramammary infection prevalence.

Staphylococcus aureus is a major pathogen causing intramammary infection and mastitis in dairy cows. S. aureus genotypes (GT) can differ significantly in their ability to diffuse and persist in the herd; while the association of virulence gene carriage with epidemiological behavior remains unclear, a role for secreted proteins has been postulated. We characterized the secretome of six S. aureus strains belonging to two genotypes with opposite within-herd prevalence, GTB (high) and GTS (low), corresponding to sequence types (ST) 8 and 398, by high-resolution tandem mass spectrometry and differential analysis with Proteome Discoverer. Data are available via ProteomeXchange with identifier PXD029571. Out of 720 identified proteins, 98 were unique or more abundant in GTB/ST8 and 68 in GTS/ST398. GTB/ST8 released more immunoglobulin-binding proteins, complement and antimicrobial peptide inhibitors, enterotoxins, and metabolic enzymes, while GTS/ST398 released more leukocidins, hemolysins, lipases, and peptidases. Furthermore, GTB/ST8 released the von Willebrand factor protein, staphylokinase, and clumping factor B, while GTS released the staphylococcal coagulase and clumping factor A. Hence, GTB/ST8 secretomes indicated a higher propensity for immune evasion and chronicity and GTS/ST398 secretomes for cellular damage and inflammation, consistent with their epidemiological characteristics. Accordingly, GTS/ST398 secretions were significantly more cytotoxic against bovine PBMCs in vitro. Our findings confirm the crucial role of extracellular virulence factors in S. aureus pathogenesis and highlight the need to investigate their differential release adding to gene carriage for a better understanding of the relationship of S. aureus genotypes with epidemiological behavior and, possibly, disease severity.

Development of quantitative real-time PCR and digital droplet-PCR assays for rapid and early detection of the spoilage yeasts Saccharomycopsis fibuligera and Wickerhamomyces anomalus in bread.

In the present study, for the first time, high sensitive quantitative polymerase chain reaction (qPCR) and digital droplet polymerase chain reaction (ddPCR) assays were developed to detect and quantify total eumycetes with potential application in several food matrices and to specifically determine the level of contamination by Saccharomycopsis fibuligera and Wickerhamomyces anomalus cells directly in bread. Among the candidate target genes used to develop the assays, car1 gene was chosen to detect the two spoilage yeasts S. fibuligera and W. anomalus. The specificity of the PCR assays was tested using purified genomic DNA from 36 bacterial and fungal strains. The sensitivity of the assays was defined by using tenfold serial dilutions of genomic DNA starting from 106 cfu/mL to 1 cfu/mL of S. fibuligera and W. anomalus. Validation of the assays was achieved by enumeration of S. fibuligera and W. anomalus DNA copies from samples of artificially contaminated bread homogenates detecting up to 10 cfu/mL (0.06 ± 0.01 copies/µL) of W. anomalus by using ddPCR. In conclusion, the developed qPCR and ddPCR assays demonstrate strong performance in the early detection of S. fibuligera and W. anomalus in bread, representing promising tools for applying high-throughput approaches to regularly monitor bread quality.

Study of the diversity of 16S-23S rDNA internal transcribed spacer (ITS) typing of Escherichia coli strains isolated from various biotopes in Tunisia.

We investigated the 16S-23S rRNA intergenic spacer region (ISR)-PCR and the phylogenetic PCR analyses of 150 Escherichia coli isolates as tools to explore their diversity, according to their sampling origins, and their relative dominance in these sampling sources. These genetic markers are used to explore phylogenetic and genetic relationships of these 150 E. coli isolates recovered from different environmental sources (water, food, animal, human and vegetables). These isolates are tested for their biochemical pattern and later genotyped through the 16S-23S rRNA intergenic spacer PCR amplification and their polymorphism investigation of PCR-amplified 16S-23S rDNA ITS. The main results of the pattern band profile revealed one to four DNA fragments. Distributing 150 E. coli isolates according to their ITS and using RS-PCR, revealed four genotypes and four subtypes. The DNA fragment size ranged from 450 to 550 bp. DNA band patterns analysis revealed considerable genetic diversity in interspecies. Thus, the 450 and 550 bp sizes of the common bands in all E. coli isolates are highly diversified. Genotype I appeared as the most frequent with 77.3% (116 isolates), genotype II with 12% (18 isolates); genotype III with 9.7% (14 isolates), and the IV rarely occurred with 4% (2 isolates). Distributing the E. coli phylogroups showed 84 isolates (56%) of group A, 35 isolates (23.3%) of group B1, 28 isolates (18.7%) of group B2 and only three isolates (2%) of group D.

Effect of Linseeds and Hemp Seeds on Milk Production, Energy and Nitrogen Balance, and Methane Emissions in the Dairy Goat.

The effect of whole linseeds or hemp seeds on milk production, energy and nitrogen balance, and methane emission was studied in 12 Alpine goats using respiration chambers. Diets tested were a control diet (C) and two diets supplemented with whole linseeds (L) or hemp seeds (H) at 9.3% on a dry matter (DM) basis. DM intake was similar among treatments, whereas DM and organic matter digestibility were lower for L compared to C. Milk yield (2.30 kg/d on average) and rumen fermentation profile were not affected by treatments. Treatment also did not affect the milk composition, with the exception of fat, which was higher in H and L compared to C (4.21, 3.94, and 3.20%, respectively). Oilseed supplementation caused a reduction in the concentration of de novo fatty acids (FA) (41.1, 48.8, and 64.1% of FA, for L, H, and C, respectively). Moreover, L and H diets reduced the sum of saturated FA, and increased monounsaturated FA, whereas only the L diet increased the concentration of polyunsaturated FA. Regarding methane production, and nitrogen and energy balances, no differences were registered among the diets. Our research indicates that including whole linseeds and hemp seeds in the dairy goat diet is an effective strategy for increasing milk fat content and positively modifying the milk FA composition, without a change in nitrogen and energy balances, but also without a reduction in enteric methane emission.

Bovine Milk Microbiota: Comparison among Three Different DNA Extraction Protocols To Identify a Better Approach for Bacterial Analysis.

The bovine udder is colonized by a huge quantity of microorganisms that constitute the intramammary ecosystem, with a specific role in modulating not only udder homeostasis and mastitis susceptibility, but also the quality of the dairy products. However, generating high-quality bacterial DNA can be critical, especially starting from a complex biological matrix like milk, characterized by high fat, protein, and calcium contents. Here, bacterial DNA was recovered from a commercial ultra-high-temperature (UHT) milk sample artificially spiked with a predetermined mock community composition and from three bulk tank milk (raw milk) samples. The DNA was isolated using three different protocols to evaluate the effect of the extraction procedures on the milk microbiota composition. In the mock community experiment, the bacterial profiles generated by the three DNA extraction protocols were profoundly different, with the genera Staphylococcus, Lactobacillus, Listeria, and Salmonella underestimated by all the protocols. Only one protocol revealed values close to the expected abundances for Escherichia/Shigella spp., Bacillus spp., Enterococcus spp., and Pseudomonas spp. On the other hand, the nonspiked UHT milk sample exhibited a similar microbiota composition, revealing the prevalence of Acinetobacter spp., for all the DNA extraction protocols. For the raw milk samples, the three DNA extraction kits performed differently, revealing significant separations in both the microbial richness (alpha diversity) and composition (beta diversity). Our study highlights the presence of significant differences among these procedures, probably due to the different DNA extracting capacities and to the different properties of the milk samples, revealing that the selection of DNA extraction protocol is a critical point. IMPORTANCE The advance of high-throughput technologies has increased our knowledge of the world of microorganisms, especially of microbial populations inhabiting living animals. This study provides evidence that milk, as other complex sources, could be critical for generating high-quality DNA for microbiota analysis. In addition, it demonstrates that the microbial population highlighted by metagenomic studies changes in relation to different DNA extraction procedures, revealing that attention should be paid especially when comparing different studies.

Feeding Pre-weaned Calves With Waste Milk Containing Antibiotic Residues Is Related to a Higher Incidence of Diarrhea and Alterations in the Fecal Microbiota.

The cows receiving antibiotics for intra-mammary infection (IMI) produce milk that cannot be marketed. This is considered waste milk (WM), and a convenient option for farmers is using it as calf food. However, adding to the risk of selecting resistant bacteria, residual antibiotics might interfere with the gut microbiome development and influence gastrointestinal health. We assessed the longitudinal effect of unpasteurized WM containing residual cefalexin on calf intestinal health and fecal microbiota in an 8-week trial. After 3 days of colostrum, six calves received WM and six calves received bulk tank milk (BM) for 2 weeks. For the following 6 weeks, all 12 calves received milk substitute and starter feed. Every week for the first 2 weeks and every 2 weeks for the remaining 6 weeks, we subjected all calves to clinical examination and collected rectal swabs for investigating the fecal microbiota composition. Most WM calves had diarrhea episodes in the first 2 weeks of the trial (5/6 WM and 1/6 BM), and their body weight was significantly lower than that of BM calves. Based on 16S rRNA gene analysis, WM calves had a lower fecal microbiota alpha diversity than that in BM calves, with the lowest p-value at Wk4 (p < 0.02), 2 weeks after exposure to WM. The fecal microbiota beta diversity of the two calf groups was also significantly different at Wk4 (p < 0.05). Numerous significant differences were present in the fecal microbiota taxonomy of WM and BM calves in terms of relative normalized operational taxonomic unit (OTU) levels, affecting five phyla, seven classes, eight orders, 19 families, and 47 genera. At the end of the trial, when 6 weeks had passed since exposure to WM, the phyla Bacteroidetes, Firmicutes, and Saccharibacteria were lower, while Chlamydiae were higher in WM calves. Notably, WM calves showed a decrease in beneficial taxa such as Faecalibacterium, with a concomitant increase in potential pathogens such as Campylobacter, Pseudomonas, and Chlamydophila spp. In conclusion, feeding pre-weaned calves with unpasteurized WM containing antibiotics is related to a higher incidence of neonatal diarrhea and leads to significant changes in the fecal microbiota composition, further discouraging this practice in spite of its short-term economic advantages.

Genotyping and Antimicrobial Susceptibility Profiling of Streptococcus uberis Isolated from a Clinical Bovine Mastitis Outbreak in a Dairy Farm.

Streptococcus uberis, an environmental pathogen responsible also for contagious transmission, has been increasingly implicated in clinical mastitis (CM) cases in Europe. We described a 4-month epidemiological investigation of Strep. uberis CM cases in an Italian dairy farm. We determined molecular characteristics and phenotypic antimicrobial resistance of 71 Strep. uberis isolates from dairy cows with CM. Genotypic variability was investigated via multiplex PCR of housekeeping and virulence genes, and by RAPD-PCR typing. Antimicrobial susceptibility was assessed for 14 antimicrobials by MIC assay. All the isolates carried the 11 genes investigated. At 90% similarity, two distinct clusters, grouping 69 of the 71 isolates, were detected in the dendrogram derived from the primer ERIC1. The predominant cluster I could be separated into two subclusters, containing 38 and 14 isolates, respectively. Strep. uberis strains belonging to the same RAPD pattern differed in their resistance profiles. Most (97.2%) of them were resistant to at least one of the drugs tested, but only 25.4% showed a multidrug resistance phenotype. The highest resistance rate was observed for lincomycin (93%), followed by tetracycline (85.9%). This study confirmed a low prevalence of ß-lactam resistance in Strep. uberis, with only one isolate showing resistance to six antimicrobial classes, including cephalosporins.

Sperm Nuclei Analysis and Nuclear Organization of a Fertile Boar-Pig Hybrid by 2D FISH on Both Total and Motile Sperm Fractions.

A wide range of mammalian hybrids has recently been found by chance or through population-screening programs, but studies about their fertilizing capacity remain scarce and incomplete. Most of them are assumed to be sterile due to meiotic arrest caused by the failure of chromosome pairings. In this study, we evaluated both sperm meiotic segregation, by 2D fluorescent in situ hybridization (FISH) analysis, and sperm quality (Sperm Chromatin Structure Assay) by flow cytometer in a fertile boar-pig hybrid (2n = 37,XY) originating from a Nero Siciliano pig breed (Sus scrofa domesticus) and a wild boar (Sus scrofa ferus). Spermatozoa were also separated by a dual-layer (75-60%) discontinuous Percoll gradient, resulting in two fractions with a significantly better overall quality in the motile sperm fraction. These data were confirmed by FISH analysis also, where the frequencies of spermatozoa with a regular chromosome composition were 27% in total sperm fraction and 64% in motile sperm fraction. We also evaluated the nuclear architecture in all counted spermatozoa, showing a chromatin distribution changing when chromosome abnormalities occur. Our results demonstrate that the chromosome pairing has a minimal effect on the sperm segregation and semen quality of a boar-pig hybrid, making it fertile and harmful for the conservation of autochthonous pig breeds.

Comparison of the response of mammary gland tissue from two divergent lines of goat with high and low milk somatic cell scores to an experimental Staphylococcus aureus infection.

Mastitis represents one of the major economic and health threats to the livestock sector associated with reduction in milk quality, loss of production and is a major reason for culling. Somatic cell score (SCS) is used as a criterion in breeding programmes to select cows genetically less susceptible to mastitis. The relevance of SCS as a predictor of udder health and susceptibility to mastitis is still untested in goats. In this study, two lines of French Alpine goats selected for extreme breeding values for somatic cell scores, one line with high SCS (HSCS) and the other with low SCS (LSCS), were used to test the hypothesis that the mammary response and function differed between the lines. The aim of the present study was to investigate differences in the early immune response in caprine mammary gland tissues challenged with Staphylococcus aureus, one of the main pathogens responsible for the intra-mammary infection in small ruminants, using transcriptomic and histopathology analyses. The comparison between HSCS and LSCS goat lines, showed differences in the response at the histological level for inflammation, presence of neutrophils and micro-abscess formation, and at the molecular level in the expression of CXCL8, IL-6, NFKBIZ and IL-1ß. CXCL8 and CXCL2 genes, which showed a higher level of expression in the experimentally infected HSCS line. The molecular data and histopathology both suggested that following S. aureus infection, mobilization, recruitment, infiltration, and chemotaxis of neutrophil, leads to a more severe inflammation in the HSCS compared to LSCS animals. Our results represent an initial basis for further studies to unravel the genetic basis of early mastitis inflammatory responses and the selection of dairy animals more resistant to bacterial mastitis.