Specific memory B cells and antibodies are a reliable read-out of vaccine efficacy. We analysed these biomarkers after one and two doses of BNT162b2 vaccine. The second dose significantly increases the level of highly specific memory B cells and antibodies. Two months after the second dose, specific antibody levels decline, but highly specific memory B cells continue to increase, thus predicting a sustained protection from COVID-19. We show that although mucosal IgA is not induced by the vaccination, memory B cells migrate in response to inflammation and secrete IgA at mucosal sites. We show that the first vaccine dose may lead to an insufficient number of highly specific memory B cells and low concentration of serum antibodies, thus leaving vaccinees without the immune robustness needed to ensure viral elimination and herd immunity. We also clarify that the reduction of serum antibodies does not diminish the force and duration of the immune protection induced by vaccination. The vaccine does not induce sterilizing immunity. Infection after vaccination may be caused by the lack of local preventive immunity because of the absence of mucosal IgA.

Twelve milking Girgentana goats were allocated into 3 groups and fed 3 diets ad libitum in a 3 × 3 Latin square design with 3 periods. The diets were Sulla fresh forage ad libitum (SUL), Sulla fresh forage ad libitum and 800 g/d of barley meal (SULB), and mixed hay ad libitum and 800 g/d of barley meal (HB). Changes were observed in total polyphenol intake, plasma oxidative status, plasma polyphenol content, metabolic status, milk polyphenol content, and total antioxidant capacity. The fresh forage diets (SUL and SULB) increased dry matter, total polyphenol, nontannic polyphenol and tannin intakes, and the milk total protein, casein, milk total polyphenols, and milk free polyphenols compared with the HB diet. The intake of condensed tannins was higher in the SUL than in the HB group, and an intermediate value was recorded for the SULB group. Plasma from the SUL-and SULBfed goats exhibited greater total antioxidant capacity and greater total polyphenol and free polyphenol levels compared with the plasma from the HB group. Positive correlations between plasma total antioxidant capacity and condensed tannins intake (r = 0.43), plasma total polyphenol and total polyphenol intake (r = 0.61), and plasma free polyphenol and milk total polyphenols (r = 0.38) were observed. The correlation between milk free polyphenols and whey total antioxidant capacity (r = 0.42) highlights the role of free polyphenols in the determination of the antioxidant activity of milk. These results indicate that Sulla fresh forage exerts an antioxidant activity due to its secondary compounds that provide additional antioxidant value and that Sulla forage appears to be a promising strategy for improving product quality.

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This study compared the effects of a short daily grazing time with those of permanent free-stall housing on the behaviour, oxidative status, immune response, and milk production of organically reared cows. During a 63-day period, two homogeneous groups of eight lactating Brown cows were allocated to either housing (H) in a free-stall building for 24 h/day. Feeding was based on a total mixed ration or grazing (G) on barley grass for 5 h/day, and housing in a free-stall structure with feeding was based on the same total mixed ration offered to the H group. With regard to behaviour, H cows spent more time idling, walking, drinking, and self-grooming, whereas G cows showed a greater intent to eat and interact socially. Moreover, G cows exhibited slightly higher reactive oxygen metabolites and similar biological antioxidant potential concentrations than the H group, which indicates that short grazing resulted in an almost negligible increase in oxidative stress and an unchanged antioxidant capacity. Skin tests, performed by injecting phytohemoagglutinin intradermally, indicated that G cows had thicker skin than H cows at the end of the trial, an index of a better cell-mediated immune response. Grazing did not affect milk yield but improved milk quality in terms of an increase in fat and a reduction in urea content, somatic cell count, and total microbial count. Milk from G cows was richer in saturated fatty acids, likely because of the contribution of palmitic acid present in the grazed barley grass, and also showed higher contents of some healthy fatty acids, such as rumenic acid and α-linolenic acid, and a lower omega-6/omega-3 ratio. These results show that including a short grazing time in the diets of organic dairy cows does not have negative consequences for milk production and contributes to improved milk quality as well as to a more efficient immune response in the cows.

Simple SummaryIn the near future, the expected increase in world population will enhance feed versus food competition between animals and humans to face the increasing demand by humans. For this reason, it is of paramount importance to feed ruminants with sources alternative to those representing themselves foods for humans. Durum wheat bran (DWB), similar to other by-products of the agri-food industry, can meet this need, its fiber content is high and represents also a remarkable source of phenolic acids, especially ferulic acid. This compound exerts antioxidant properties improving the health status of animals, and allows the production of functional foods more and more requested by consumers. Accordingly, this experiment demonstrated the suitability of using DWB for dairy cows feeding, because it led to clear advantages in terms of oxidative status of animals, quality of dairy products, and feeding costs. Furthermore, DWB improved the human-edible feed conversion efficiency reducing the use of human-edible feed.AbstractDurum wheat bran (DWB) is a by-product mostly used in feeding ruminants, contributing to decrease in the utilization of feeds suitable as foods for human consumption, thus improving the sustainability of livestock production. However, the potential benefits of DWB, due to its content in phenolic acids, mainly consisting of ferulic acid with antioxidant properties, have not been well clarified yet. Accordingly, in this experiment, 36 lactating cows divided into three groups received, over a period of 100 days, one of three concentrates including DWB at 0% (DWB0), 10% (DWB10), or 20% (DWB20). The concentrates were formulated to be isoproteic and isoenergetic and, to balance the higher fiber content of the concentrates with DWB, the hay in the diets was slightly reduced. During the trial, the group feed intake and the individual milk production were monitored, and cheese was made with bulk milk from each group. Milk yield and microbiological characteristics of milk and cheese were similar among groups, indicating no DWB effect on cows performance and fermentation process. Milk from DWB20 group resulted slightly higher in casein and curd firmness (a2r). In cows fed DWB, the higher polyphenol intake was responsible for higher blood contents of these bioactive compounds, that seemed to have contributed in reducing the level of reactive oxygen metabolites (ROMs), which were higher in DWB0 cows. DWB20 cheeses showed a higher polyphenol content, lower number of peroxides, and higher antioxidant capacity than DWB0 cheeses. DWB20 and DWB10 diets resulted less expensive. In addition, the DWB20 group showed the best indexes heFCE (human edible feed conversion efficiency = milk/human edible feed) and NFP (net food production = milk − human edible food), expressed as crude protein or gross energy. In conclusion, the DWB fed to dairy cows at 12% of diet dry matter (DM) can lead to benefits, such as the improvement of oxidative status of cows, milk quality, shelf-life, and functional properties of cheese, and mig...