Metabolic and hormonal control of energy utilization and partitioning from early to mid lactation in Sarda ewes and Saanen goats.

In a recent study, we observed that starch-rich diets used in mid lactation induced lower milk production persistency and higher body fat accumulation in dairy ewes compared with dairy goats. Because these species differences could be linked to hormonal mechanisms that drive energy partitioning, in the same experiment, we explored the evolution of metabolic and hormonal status during lactation to test this hypothesis. Twenty mature Sarda dairy ewes and 20 mature Saanen goats [15-134 ± 11 d in milk (DIM), mean ± SD] were compared simultaneously. In early lactation, each species was allocated to one dietary treatment: high-starch diet [HS: 20.4% starch, on dry matter (DM) basis], whereas from 92 ± 11 DIM, each species was allocated to 1 of 2 dietary treatments: HS (20.0% starch, on DM basis) and low-starch (LS: 7.8% starch, on DM basis) diets. Blood samples were collected in the morning to analyze glucose, nonesterified fatty acids (NEFA), growth hormone (GH), insulin, and insulin-like growth factor I (IGF-I). Data were analyzed using the PROC MIXED procedure of SAS with repeated measurements (SAS Version 9.0). The HS and LS diets applied in mid lactation did not affect metabolic status of the animal within species; thus, only a comparison between species was carried out. From early to mid lactation, plasma glucose concentration was higher in ewes than in goats (54.57 vs. 48.35 ± 1.18 mg/dL), whereas plasma NEFA concentration was greater in goats than in ewes (0.31 vs. 0.25 ± 0.03 mmol/L). Goats had higher plasma GH concentration and lower plasma insulin content than ewes (4.78 vs. 1.31 ng/mL ± 0.47; 0.11 vs. 0.26 µg/L ± 0.02). Plasma IGF-I concentration did not vary between species. The comparison of metabolic and hormonal status of lactating Sarda dairy ewes and Saanen goats, carried out by studying simultaneously the 2 species in the same stage of lactation and experimental conditions, suggests that the higher insulin and glucose concentration observed in Sarda ewes explains why they partitioned more energy toward body reserves than to the mammary gland, especially in mid lactation. This can justify the negative effect of high-starch diets in mid-lactating Sarda ewes. Conversely, the highest GH and NEFA concentration observed in Saanen goats explain why they partitioned more energy of starch diets toward the mammary gland than to body reserves and justify the positive effect of high-starch diet in mid lactation. Together, these different responses contribute to explain why specialized dairy goats, such as the Saanen breed, have a higher milk production persistency than specialized dairy sheep breeds, such as the Sarda.

The Relationship between S. aureus and Branched-Chain Amino Acids Content in Composite Cow Milk.

The early diagnosis of mastitis is an essential factor for the prompt detection of the animal for further actions. In fact, if not culled, infected cows must be segregated from the milking herd and milked last, or milked with separate milking units. Besides microbiological analysis, the somatic cell count (SCC) commonly used as predictor of intramammary infection, frequently lead to a misclassification of milk samples. To overcome these limitations, more specific biomarkers are continuously evaluated. The total amino acid content increases significantly in mastitic milk compared to normal milk. S. aureus requires branched-chain amino acids (BCAAs-isoleucine, leucine, and valine) for protein synthesis, branched-chain fatty acids synthesis, and environmental adaptation by responding to their availability via transcriptional regulators. The increase of BCAAs in composite milk has been postulated to be linked to mammary infection by S. aureus. The aim of this work is to demonstrate, by a direct ion-pairing reversed-phase method, based on the use of the evaporative light-scattering detector (IP-RP-HPLC-ELSD), applied to 65 composite cow milk samples, a correlation between the concentration of isoleucine and leucine, and S. aureus load. The correlation coefficient, r, was found to be 0.102 for SCC (p = 0.096), 0.622 for isoleucine (p < 0.0001), 0.586 for leucine (p < 0.0001), 0.013 for valine (p = 0.381), and 0.07 for tyrosine (p = 0.034), standing for a positive correlation between S. aureus and isoleucine and leucine concentration. The link between the content of BCAAs, isoleucine and leucine, and udder infection by S. aureus demonstrated with our study has an important clinical value for the rapid diagnosis of S. aureus mastitis in cows.

Fate of selected pathogens in spiked «SALAME NOSTRANO¼ produced without added nitrates following the application of NONIT™ technology.

This study evaluated the effect of a novel formulation for starter culture associated with specific ripening conditions (NoNit™ technology) vs. a commercial¼ starter on the fate of selected pathogens and hygiene indicators during the fermentation and ripening of experimentally spiked salame nostrano (Italian dry sausage). Selected strains of Staphylococcus aureus 27R, Escherichia coli CSH26 K 12, Listeria innocua ATCC 33090 and Salmonella Derby 27 were inoculated into salami batter and challenged with two formulations of starter cultures (a commercial formulation and the NoNit™ formulation, consisting of Lactococcus lactis ssp. lactis, strain 340; L. lactis ssp. lactis, strain 16; Lactobacillus casei ssp. casei, strain 208 and Enterococcus faecium strain 614) with ripening at a low temperature. The proposed technology (NoNit™) performed better than the commercial formulation and limited the growth of spiked Escherichia coli, Staphylococcus aureus (including the production of enterotoxin), Salmonella Derby and Listeria innocua, yet maintained the basic product appearance and texture.

Microbiological and parasitological survey of zoonotic agents in apparently healthy feral pigeons.

Microbiological and parasitological investigation was carried out on a colony of feral pigeons, located in a green area near the main hospital of a Central Italy city. One hundred pigeons were submitted to clinical examination. Cloacal swabs, grouped in pool of 4 samples, were analyzed to detect the presence of Coxiella burnetii, Chlamydia psittaci, Chlamydophila spp. using a biomolecular procedure, while individual cloacal samples were examined for Salmonella spp., Campylobacter spp., and yeasts by means of a specific culture media. An ELISA test was used to determine the presence of Giardia spp., and Cryptosporidium spp. coproantigens. Individual serological samples were also tested with the modified agglutination test (MAT) in order to detect antibodies against Toxoplasma gondii. The pigeons did not show any clinical signs. The cloacal pools proved to be negative for C. burnetii DNA while three pools were positive for C. psittaci or Chlamydophila spp. DNAs. Salmonella spp. was not detected. C. jejuni and C. coli were found in 13% and 4% of the samples, respectively. No Giardia spp. and Cryptosporidium spp. were detected. Thirty-three out of 100 samples (33%) were positive for yeast colonies. The seroprevalence for T. gondii was 8%. Although with moderate incidence, potentially zoonotic agents were present thus highlighting the need for sanitary surveillance on feral pigeon colonies.

Evolution under different storage conditions of anomalous blue coloration of Mozzarella cheese intentionally contaminated with a pigment-producing strain of Pseudomonas fluorescens.

Several widespread occurrences of anomalous blue coloration of Mozzarella cheese have been recorded in the United States and some European countries. Official laboratory analysis and health authorities have linked the occurrences to contamination of the processing water with strains of Pseudomonas fluorescens, although several experts questioned how to unequivocally link the blue color to the presence of the microorganism. To establish a method to determine whether a given Pseudomonas spp. strain is responsible for the defect and study the evolution of the coloration under different storage conditions, we developed an in vitro system for the evaluation of blue coloration of Mozzarella cheese intentionally contaminated with strains of P. fluorescens. The purpose of the system was to determine whether P.fluorescens strains, isolated from Mozzarella cheese with anomalous blue coloration, were able to reproduce the blue coloration under controlled experimental conditions. Thirty-six trials of experimental inoculation of Mozzarella cheese in different preservation liquids were conducted using various suspensions of P.fluorescens (P. fluorescens ATCC 13525, P.fluorescens CFBP 3150, and P. fluorescens 349 field strain isolated from blue-colored Mozzarella cheese) at different concentrations and incubated at different temperatures. Growth curves of all tested P.fluorescens strains demonstrated that after 3 d of incubation the concentration was generally >10(6) cfu/g of Mozzarella cheese incubated in either tryptic soy broth (control) or conditioning brine. Prolonged incubation for 5 d at either 20 °C or 8 °C led to concentrations up to 10(9) cfu/g of Mozzarella cheese incubated in tryptic soy broth and up to 10(8) cfu/g of Mozzarella cheese incubated in preservation liquid. All Mozzarella cheeses inoculated with the field strain of P. fluorescens, except those opened 1h after packaging and stored at 8 °C, showed the characteristic anomalous blue coloration, which appeared from 1 to 72 h after opening the packaging, and was proportional to colony count, duration of storage, and storage temperature. With the proposed system, which enabled a larger number of samples to be analyzed under controlled experimental conditions and a large amount of data to be generated in a short time, we described precisely how and under which conditions the presence of P. fluorescens in Mozzarella cheese is responsible for the anomalous blue coloration. The system will help producers intercept contaminated batches and help consumers avoid the conditions under which the defect can appear.

Effects of UV irradiation in a continuous turbulent flow UV reactor on microbiological and sensory characteristics of cow's milk.

The dairy industry under current pasteurization conditions (15 s at 72°C) and sanitary standards achieves a safe product with excellent quality. In an ever-competitive market there is still a need to improve product quality and extend shelf life of dairy products to increase competitiveness and open up new markets. In an attempt to test the effect of UV irradiation on microbiota of fluid milk, a continuous flow UV system at 254 nm was used to treat 3.5 and 2% fat milk at two UV doses (880 and 1,760 J liter(-1)). Milk was obtained from three processors, and two lots from each processor were assessed. To assess the impact on the most descriptive native microbiota in pasteurized milk after UV illumination, the product was held at two storage temperatures (4 and 7°C) and tested weekly for 5 weeks for aerobic plate counts (psychrotrophic and mesophilic bacteria), laboratory pasteurization counts, aerobic sporeformers, coliform organisms, and titratable acidity. Microbial counts for all tested microorganisms were lower in UV-treated milk when compared with control throughout storage at 4 and 7°C in both 3.5 and 2% fat milk. Sensory analysis indicated that there is a sensory defect associated with UV treatment at the wavelength used.

Effect of selected dairy starter cultures on microbiological, chemical and sensory characteristics of swine and venison (Dama dama) nitrite-free dry-cured sausages.

The aim of this study was the evaluation of selected lactic acid bacteria (LAB) starter culture of dairy origin in the production of nitrite-free low-acid fermented venison (Dama dama) sausage (salame di daino) produced in a small-scale plant in Umbria (Italy), and their effect on microbiological, physico-chemical and sensorial properties of the products. Salame di daino was obtained with two different processes: with and without the addition of selected LAB starter cultures. Microbial counts of Enterobacteriaceae, coliform organisms and Pseudomonas spp. were lower in salami made with the addition of starter cultures. Staphylococcus aureus, Salmonella spp, and Listeria monocytogenes after the first week of ripening were only detected from control salami. Control salami were paler and harder, whereas those made with the addition of starter cultures were slightly saltier, juicier and in general more acceptable. Selected dairy-origin starter (SDS) cultures did prevent the growth of both indicators of food safety and of process hygiene and increased the acceptability of full-ripened salami.

Cadmium chronic administration to lactating ewes: reproductive performance, cadmium tissue accumulation and placental transfer.

20 lactating ewes were allotted to two groups: 10 subjects received orally 100 mg/day of CdCl2 for 108 consecutive days, and the remaining 10 acted as control. Reproductive performance in ewes and cadmium tissue accumulation, both in ewes and their lambs, were investigated. The results showed that in ewes: 1) the regular cadmium intestinal intake negatively influences all reproductive parameters; 2) cadmium is particularly accumulated in kidney and liver, but also in mammary gland, although at a distinctly lower level; 3) chronic administration does not increase cadmium placental transfer in lactating pregnant subjects.

A 3D study of intra and extracellular structures of liver in beta-thalassemia intermedia: an OsO4 maceration analysis.

A scanning electron microscopy study of liver changes has been carried out in three patients affected by beta-thalassemia intermedia (BTI). Applying a new osmium maceration method, recently developed in our laboratory, we had the opportunity to obtain, at SEM, tridimensional images of intra and extracellular structures. Other than the previously reported lesions in BTI, we observed the following pathological findings: disarrangement of the cell structure by a high number of hemosiderin loaded lysosomes; alterations in shape and in diameter of the nuclear pores; presence of apoptotic bodies scattered among the parenchymal cells; deposition of collagen fibers in the space of Disse to form a perihepatocytic dam; enlargement of the sinusoidal endothelial cell fenestrae of the sieve plate. By complete digestion of liver cells, we evidenced a diffuse pericellular fibrosis, made up of interlacing fibrils. Our study evidences some not yet reported morphological lesions in BT. Since patients affected by BTI do not need blood transfusions, these lesions could be considered intrinsic of the disease.