The transfer of aflatoxin M1 in milk of ewes fed diet naturally contaminated by aflatoxins and effect of inclusion of dried yeast culture in the diet.

An experiment was carried out to investigate 1) the transfer of aflatoxin M1 (AFM1) into the milk of dairy ewes fed diets naturally contaminated with aflatoxin B1 (AFB1); 2) the effect of the addition of dried yeast culture in the diet on this transfer; and 3) the alteration of enzymatic activities in the liver of ewes fed diets contaminated with AFB1. Twenty-four Sarda dairy ewes were divided in 4 groups and fed a concentrate mix containing 4 amounts of wheat meal naturally contaminated with aflatoxins. The diet of the control group had no wheat meal, whereas that of treated groups had low, medium, or high amounts of contaminated wheat, which corresponded to 1.13, 2.30, and 5.03 microg of AFB1/kg of feed, respectively. The experiment lasted 14 d. On d 8 to 14 from the beginning of the trial, 12 g/d of a commercial dried yeast product (DYP) of Kluyveromyces lactis was added to the diet of each ewe. The AFM1 concentration in individual milk samples and the blood serum metabolites were measured periodically. The presence of AFM1 was first detected in milk on d 1 of administration, and then its concentration increased and approached a steady-state condition on d 3 simultaneously in all treated groups. The AFM1 in milk at the steady-state condition, which was linearly related to the AFB1 intake, was 39.72, 50.38, and 79.29 ng/L in the low-aflatoxin, medium-aflatoxin, and high-aflatoxin groups, respectively. The AFM1 concentration in milk of the high-aflatoxin group was approximately 1.5-fold greater than the European Commission maximum tolerance level (50 ng/kg). The addition of DYP to the diet did not affect the AFM1 concentration in milk. After the withdrawal of the contaminated concentrate mix, the AFM1 mean concentrations decreased quickly and were no longer detected after 3 d in all treated groups. Daily milk yield and composition did not differ because of aflatoxin treatment. Blood serum parameters (creatinine, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, gamma glutamyl transferase, alkaline phosphatase, lactate dehydrogenase, cholesterol, protein, urea, calcium, and phosphorus) were not influenced by AFB1 intake. Therefore, the effect of DYP on certain blood parameters (gamma glutamyl transferase, urea, creatinine, and calcium) could not be attributed to amelioration of the aflatoxin-contaminated diet. In conclusion, diet contamination by AFB1 near the European Union tolerance level (0.005 mg/kg) in complete feed for dairy animals (e.g., high-aflatoxin group) can result in an AFM1 milk concentration higher than the European Commission maximum tolerance level. Transfer of aflatoxin from feed to milk was not affected by dietary addition of a commercial DYP

Maternal and fetal fatty acid composition in ovine muscle tissues

In species characterized by a cotyledonary placenta, as sheep, the relative contribution of maternally derived and placenta synthesized fatty acids is not fully understood. For this reason, the FA composition of mother muscle and the deposition of FA in the fetal muscle were studied by gas-chromatography. Five pregnant Sarda ewes were slaughtered at approximately 145 days of pregnancy. Semitendinosus, semimembranosus and femoral biceps muscles were immediately removed from ewes and fetuses. Data were analyzed by a paired t-test, to detect differences in FA composition between fetus and mother tissues. Results showed that FA profile of fat muscle differed markedly between fetus and mother. The intramuscular fat content were 6.38% and 11.79% on DM basis in fetus and mother muscle, respectively. Linoleic (LA; 18:2n-6), and linolenic (ALA; 18:3n-3) acid were found at smaller concentrations in fetus (0.77 and 0.01 mg/100 mg total FA for LA and ALA, respectively) than in maternal muscle (5.55 and 1.04 for LA and ALA, respectively). On the contrary, a higher proportion of their long-chain polyunsaturated metabolites, like arachidonic (AA; 20:4n-6) and docoexadienoic (DHA; 22:6n-3) acid in fetus compared to mother tissue (AA, 2.32 vs 1.30; DHA, 0.83 vs 0.09 mg/100 mg total FA) indicates a preferential fetal accumulation of those FA which are important for fetuses growth and central nervous system development. The c9,t11 Conjugated linoleic acid (CLA) isomer concentration in mother tissue was 0.72 mg/100 mg FA. It was found also in fetus muscle (0.11 mg/100 mg total FA) suggesting a transplacental fatty acid passage to fetal tissues or a desaturation activity on vaccenic acid (VA; 18:1 t11) in the placental or in the fetal tissue. Surprisingly, the c9,t11-CLA was not the most abundant CLA isomer found in fetus fat. Others CLA isomers, separated but not identified, were found in concentration of 0.17, 0.15 and 0.53 mg/100 mg of FA. Concentrations of these CLA isomers were lower in mother tissue (0.12, 0.05 and 0.10 mg/100 mg of FA). The concentration of VA was 0.46 and 0.90 in fetus and mother muscle, respectively. Correlation analysis between FA profile of mothers and fetuses evidenced a close relationship only for odd-numbered long-chain fatty (r = -0.72 for C15:0 and r = -0.88 for C17:0). The results suggested a different FA metabolism in the muscle tissue of mother and fetus in dairy sheep

The Evolution of mammary glands at different stages in Sarda dairy ewes: preliminary results

The significance of cytological evolution of alveolar cells explains differences in milk yield that resulted in a different shape of lactation curve. In this paper, investigation of cellular background for this pattern was studied morphometrically in mammary gland of dairy ewes prior to lambing to involution. The ratio of epithelial to the luminal area was greatest at 7 days from lambing, it diminished on day 30 and 60 of lactation and it increased thereafter on day 150 of lactation and on day 7 of involution. The evolution of mammary tissues shows a clear decrease in stromal mass from prepartum until 60 DIM. Structural changes of mammary tissues during late pregnancy, lactation and dry off, can be used as a basis to estimate the evolution of the number of secretory cells in dairy ewes

Effects of short-term feed restriction on milk yield and composition, and hormone and metabolite profiles in mid-lactation Sarda dairy sheep with different body condition score

Ten Sarda dairy ewes (5 with high Body Condition Score: H-BCS, BCS>2.5; BW 48.8±5.4 kg; 5 with low BCS: L-BCS, BCS<2.5; BW 36.2±4.7 kg) were subjected, after 7-day preliminary (Prel) period, to short-term feed restriction (FR, 50% of nutrient requirements) for three days followed by refeeding (Re-Fed, 100% requirements) for three days. Milk yield and composition (protein, fat, lactose, MUN, SCC, fatty acids), and blood parameters (glucose, NEFA, BUN, insulin, GH, IGF-I, leptin) were monitored. Milk yield decreased during FR in both BCS groups: at day 3 it was 38% and 35% of Prel values in HBCS and L-BCS ewes, respectively, reaching Prel levels at Re-Fed in both groups. Milk fat concentration was influenced by BCS¥sampling, increasing in H-BCS ewes during FR, but not varying in L-BCS ewes throughout the trial. During FR, milk protein increased as milk yield decreased. There was no change in milk urea nitrogen concentration during FR, but this decreased in both BCS groups during Re-Fed. FR modified the FA profile of milk fat in both BCS groups, increasing LCFA at the expense of SCFA and MCFA. Some blood parameters (NEFA, GH and IGF-I) were influenced by BCS, whereas almost all parameters were influenced by sampling. There was a rapid return to initial levels in all parameters except milk urea, blood urea and insulin at Re-Fed

Colorimetric Analysis and Determination of Histamine in Samples of Yellowfin Tuna (<i>Thunnus albacares</i>) Marketed in Sardinia (Italy) by a Combination of Rapid Screening Methods and LC-MS/MS

The consumption of fishery products has been steadily increasing in recent decades. Among the quantitatively more important species, the yellowfin tuna (Thunnus albacares), is one of the main at-risk species as regards the possibility to present important levels of histamine and to be associated with the so-called “Scombroid Fish Poisoning”. The main aim of the present study was to evaluate the colorimetric parameters, the occurrence, and the quantification of histamine contamination in yellowfin tuna samples marketed in Sardinia (Italy) by a combination of rapid screening and official control methods. A total of 20 samples of yellowfin tuna loins collected from large retailers, fishmongers and local markets were analyzed for the qualitative and quantitative determination of histamine by the lateral flow test HistaSure™ Fish Rapid Test and LC-MS/MS, respectively. Moreover, all the samples were examined to assess the conformity with the EU rules on labelling and subjected to colorimetric analysis according to the CIE-L*a*b* standard. Visual inspection of yellowfin tuna labels highlighted a 30% of non-compliances. A significant (p L *), redness (a *), and yellowness (b *). The results of histamine occurrence agreed with the food safety criteria (p < 0.00001) was pointed out. Moreover, the two methods showed an agreement rate of 85%. The results of the present study confirmed the utility of lateral flow tests for the fast qualitative determination of histamine in yellowfin tuna. Rapid screening test should be strengthened by comparison with the official method especially in case of uncertain or positive results

Seafood Choice and Consumption Behavior: Assessing the Willingness to Pay for an Edible Sea Urchin

Consumers’ behavior towards sea urchin and preferences towards their origin certification and place of consumption may condition their market. In this context, the aim of this research was to elicit the preferences and perceptions of Italian sea urchin dishes using a discrete choice experiment (DCE) approach. A field survey of 453 respondents in Apulia (southern Italy) was conducted for this purpose. The DCE revealed that the origin certification of sea urchin provided Apulia’s consumers a high utility with a great pleasurable service in restaurants in which this species was served as a principal dish or seasoned with pasta or pizza. The DCE also showed that the consumption utility of sea urchin was related to a greater influence by place of purchase, place of consumption, technique of conservation, appearance, quality label, fishing zone, low price, male buyer, and, finally, medium and high incomes. Furthermore, Apulian consumers were willing to pay EUR 10.53/dish as an overall average for safe and certified sea urchin consumption. Given this, this research may promote the creation of a local sea urchin brand through the adoption of a market policy and a particular regulation related to the certification of origin, enhancing the competitiveness of this marine heritage species

Polychlorodibenzodioxin and -furan (PCDD and PCDF) and dioxin-like polychlorobiphenyl (DL-PCB) congener levels in milk of grazing sheep as indicators of the environmental quality of rural areas

An observational study was set up to evaluate how the quality of the environment may influence the levels of of PCDDs, PCDFs, and DL-PCBs in sheep's milk. Seven farms under natural and anthropogenic pressures were considered, along with an inventory of the surrounding regular and natural sources of emissions. Analysis by HRGC-HRMS revealed the highest cumulative levels (2.1 pg of WHO1998-TE/g fat) in one organic and one conventional farm, each close to a relevant bushfire. Their pattern was characterized by a noticeable contribution (24%) from mono-ortho-PCB congeners to the cumulative WHO-TE. For the other farms, close to potential anthropogenic sources, the levels recorded in milk ranged from 0.7 to 1.3 pg of WHO-TE/g fat. The health and reproductive indicators were in all herds within the physiological range. Results suggest the environmental quality in extensive farming system should be eligible as a food safety factor, also for organic productions

Plankton dynamics across the freshwater, transitional and marine research sites of the LTER-Italy Network. Patterns, fluctuations, drivers

A first synoptic and trans-domain overview of plankton dynamics was conducted across the aquatic sites belonging to the Italian Long-Term Ecological Research Network (LTER-Italy). Based on published studies, checked and complemented with unpublished information, we investigated phytoplankton and zooplankton annual dynamics and long-term changes across domains: from the large subalpine lakes to mountain lakes and artificial lakes, from lagoons to marine coastal ecosystems. This study permitted identifying common and unique environmental drivers and ecological functional processes controlling seasonal and long-term temporal course. The most relevant patterns of plankton seasonal succession were revealed, showing that the driving factors were nutrient availability, stratification regime, and freshwater inflow. Phytoplankton and mesozooplankton displayed a wide interannual variability at most sites. Unidirectional or linear long-term trends were rarely detected but all sites were impacted across the years by at least one, but in many case several major stressor(s): nutrient inputs, meteo-climatic variability at the local and regional scale, and direct human activities at specific sites. Different climatic and anthropic forcings frequently co-occurred, whereby the responses of plankton communities were the result of this environmental complexity. Overall, the LTER investigations are providing an unparalleled framework of knowledge to evaluate changes in the aquatic pelagic systems and management options