The Effect of Yucca Schidigera inclusion in milk replacer for veal calves on health status, antimicrobial use and growth performance
This study evaluates the effect Yucca Schidigera inclusion in the milk replacer of veal calves on immune functionality and growth performances.
The trial involved 1015 male Friesian calves divided in two groups: control (CON) and treatment (TREAT), differing for the inclusion of Yucca Schidigera extracts.
The zootechnical performances were evaluated: mortality, morbidity and slaughtering performances such as carcass weight, incidence of underweight carcasses, average daily gain and meat colour. At the slaughterhouse, pulmonary score was performed to understand the severity and incidence of respiratory diseases. In terms of immune functionality and health status, the number, type and days of treatments were analysed. Also, on 30 calves per group blood samples were taken to evaluate the serum antioxidant capacity, and the haemoglobin level at d0 and d90.
In terms of zootechnical performance, no statistically significant differences were found. The incidence of pulmonary lesions was comparable in the two groups. No statistically significant differences were found also in terms of haemoglobin levels and oxidative stress. ROM’s and Oxy levels were similar between groups (284,92 in TREAT vs 365,23 in CON for ROM and 237,90 HClO/mL in TREAT vs 228,45 HClO/mL in CON for Oxy) in the treatment group. In terms of antibiotic use, the control group received more mass treatment (17 in TREAT vs 21 in CON) and a higher number of individual treatments (140 calves treated in TREAT vs 300 in CON), with an average increase of the days on treatment per animal (44,85 in TREAT and 57,52 in CON).
The inclusion of Yucca Schidigera allowed a reduction of the antibiotics use, but not affects growth performance and carcass characteristics.