Invited review: Iodine level in dairy products-A feed-to-fork overview.

The theme of iodine in the dairy sector is of particular interest due to the involvement and the interconnection of several stakeholders along the dairy food chain. Iodine plays a fundamental role in animal nutrition and physiology, and in cattle it is an essential micronutrient during lactation and for fetal development and the calf's growth. Its correct use in food supplementation is crucial to guarantee the animal's recommended daily requirement to avoid excess intake and long-term toxicity. Milk iodine is fundamental for public health, being one of the major sources of iodine in Mediterranean and Western diets. Public authorities and the scientific community have made great efforts to address how and to what extent different drivers may affect milk iodine concentration. The scientific literature concurs that the amount of iodine administered through animal feed and mineral supplements is the most important factor affecting its concentration in milk of most common dairy species. Additionally, farming practices related to milking (e.g., use of iodized teat sanitizers), herd management (e.g., pasture vs. confinement), and other environmental factors (e.g., seasonality) have been identified as sources of variation of milk iodine concentration. Overall, the aim of this review is to provide a multilevel overview on the mechanisms that contribute to the iodine concentration of milk and dairy products.

Effect of the supplementation with a blend containing short and medium chain fatty acid monoglycerides in milk replacer on rumen papillae development in weaning calves.

Feeding of neonates with artificial milk formulas is a popular trend toward early weaning of newborn dairy calves. These milk replacers (MR) should accelerate the rumen development, determining early solid feed intake and leading to better performances in cattle. Previous research demonstrated that sodium butyrate supplementation in MR can affect both small intestine and rumen development. Also acetate and propionate showed similar properties, while only a few studies indicate some potential benefit of monoglycerides on gut functions. The present study is aimed to determine the effect of the supplementation of a blend containing short and medium chain fatty acids monoglycerides (SMCFA) in milk replacer on rumen papillae development and growth performances in weaning calves. Twenty bull calves (about 2 weeks old, weighing around 43kg) were randomly allocated into two groups: control (C) and treated (T). Besides MR and starter diet, the latter offered at libitum, T calves received 0.2% SMCFA in MR. Animals were slaughtered after 56 days from the beginning of the trial. No difference was found between groups either in growth performances or in mean number of papillae/cm(2) of mucosa, total surface of papillae (mm(2))/cm(2) of mucosa or papillary size. In both groups, the morphology of the rumen epithelium was typical of parakeratosis. The cells of the stratum spinosum were directly transformed into swollen, ovoid, still nucleated keratinocytes, particularly at the papillary tip, probably as a result of unphysiological osmolarities caused by high concentrate intake. Degenerated squamous horn cells covered the "balloon like" cells forming several layers, particularly in the places of the rumen mucosa more protected from an abrasive action of solid feed. This was more evident in C animals. The squamous cells covering the papillary tip showed cytoplasmic protrusion, representing remains of the attachment sites of desmosomes, which increased the total absorptive surface and were more numerous and higher in T compared to C animals. It might be hypothesized that SMCFA supplementation in MR could better regulate epithelial cell proliferation and probably have an "emollient effect" leading to an easier "peeling" that might increase efficiency for nutrient transport across the epithelium.

Use of Silybum marianum fruit extract in broiler chicken nutrition: influence on performance and meat quality.

The present study aimed at evaluating the effects of different doses of silymarin in diet on broiler performances and meat quality. For the trial, 180 male chicks (ROSS 508), were allocated in to three groups (S0, S40 and S80) of 60 animals each receiving a basal diet supplemented with 0 ppm, 40 ppm and 80 ppm of a sylimarin (provided by a dry extract of Silybum marianum fruits) respectively. During the trial feed consumption and live body weight were taken every 20 days. At the age of 40 and 60 days blood samples were taken in order to evaluate protein, aspartate aminotransferase, cholesterol, tryglicerides and uric acid. At the age of 60 days animals were slaughtered, dressing percentages were evaluated and samples of breast and meat were taken to evaluate chemical composition and susceptibility of lipid peroxidation by means of thiobarbituric acid reactive substances. Silymarin at the tested doses did not affect growth performances but slightly affected slaughtering yields negatively, no specific hepatoprotective effect was found. Treatments reduced lipid content of both breast and thigh and increased muscles resistance to oxidative stress.