Uso di un prodotto commerciale a base di estratti vegetali nella dieta di vitelli a carne bianca: impatto sullo stato sanitario, sul benessere e sulle prestazioni produttive

-The considerable, and sometimes irrational, use of antibiotics in intensive farming has led to the emergence and spread of antibiotic resistance, with significant repercussions on animal, public, and environmental health. In white veal calf farming, the use of antibiotics for therapeutic and prophylactic purposes is still widespread today in order to prevent and treat respiratory and gastrointestinal diseases. However, in recent years, the emergence of the problem of antibiotic resistance has led the livestock sector to seek alternative, less impactful solutions, such as the use of phytotherapeutic products, i.e., products that exploit the plant extracts of certain plants and are regularly used in human medicine as a means of prevention but also as a cure. In this regard, numerous studies have been conducted in recent years that have highlighted the beneficial effects of these products, such as their anti-inflammatory, antioxidant, antimicrobial, gastroprotective, analgesic, immunomodulatory, and antipyretic properties. This thesis focuses on the administration of a product based on two plant extracts obtained from Salix alba and Filipendula ulmaria called Normoterm fluid, produced by TECNOZOO Spa, a leading manufacturer of feed and supplements for farm animals, not only nationally but also internationally. This product was administered (in milk) to white meat calves in three different stages of administration with dosages increasing from one cycle to the next. Thirty animals (29 males and one female) were involved in the experimental trial, divided into eight pens. The animals were of French origin, all crossbreeds: Charolaise x Montbeliarde. The trial was structured by dividing the animals into two groups (Control and Experimental) consisting of 15 animals each. The experimental group was given the plant extract-based product in their milk, while the control group did not receive any supplements in their diet. The experimental group was therefore given the product at the beginning of the cycle for ten days at a dosage of 10 cc per meal; at 55 days of rearing at a dosage of 20 cc per meal; and the last administration from the 138th day of rearing until slaughter at a dosage of 30 cc per meal Throughout the entire rearing cycle, three individual weighing measurements were taken to assess the possible effect of the product: at the start of the rearing cycle, after 63 days of rearing, and after 184 days of rearing, in order to determine the animals' growth performance. In addition, four blood samples were taken at 20, 70, 110, and 150 days of rearing to assess hemoglobin (HGB) levels, mean corpuscular volume (MCV), and red cell distribution width (RDW). In addition to these, four further blood samples were taken at the beginning and end of the first and third cycles of Normoterm fluid administration in order to assess the animals' blood chemistry profile. During the trial period, the animals' health, morbidity, mortality, and barn temperature and humidity were also assessed; and at the time of slaughter, measurements were taken on the carcasses of the calves. At the end of the trial, it emerged that the differences found in the average weights of the animals and in their average daily growth did not show statistical significance between the two groups, the same for the parameters evaluated post mortem The product did not cause any differences in the blood parameters considered (HGB, MCV, RDW), while the evaluation of the blood chemistry profile highlighted some positive aspects regarding the antioxidant and metabolic status of the animals in the experimental group.