PSXI-22 Effects of a palatability enhancer and olive bioactives on performance and physiological status of veal calves after farm reception

Abstract Veal calves have to deal with several stressors early in life, such as transport and commingling with animals of unknown health histories from multiple different origins; making the reception a possible critical period where animals should adapt to all these challenges. Previous studies in unweaned rosée calves have shown that the use of feed additives (FA) to enhance intake and immunity at farm arrival could be a strategy to minimize the negative effects of stress and feed restriction during transportation. The aim of this study was to evaluate the effects of a palatability enhancer (PE) and olive bioactives (OB) on performance and serum biomarkers in veal calves. Dairy beef calves [n = 252; BVD-free; body weight (BW) = 44.6 ± 3.63 kg] coming from auction market were distributed in 3 treatments (84 animals/tr) during 8 wk: i) calves fed concentrate and MR without FA (negative control, NC); ii) calves fed concentrate and MR with a PE based on sweeteners (PE); and iii) calves fed concentrate with PE and MR with PE and OB (PEOB). On farm arrival animals were housed individually until 5 wk of age, when animals were grouped in pens of 4 calves. Performance was monitored during the trial and serum samples were collected 48 h after the mixing (25 animals/tr) to analyze several biomarkers related to immune system (MILLIPLEX MAP Kit) and energy status (BHBA). Performance data were analyzed with a mixed-effects model and serum biomarkers by One-Way Anova with Fisher’s LSD correction for multiple comparisons (normally distributed data) or by non-parametric Kruskal-Wallis test with Dunn’s correction (data not normally distributed). Final BW was greater (P = 0.01) in PE and PEOB groups compared with NC (+2.2 kg and +2.6 kg, respectively). Concentrate feed intake (FI) during first 4 wk tended (P = 0.06) to be greater in PEOB compared with NC (+15%); however, after grouping (wk 5 to wk 8), PE showed a ldecreased FI compared with NC (-9.5%, P = 0.01). Forty-eight hours after animal grouping, PEOB showed reduced concentration of tumor necrosis factor (TNF) α than NC and PE (P = 0.03). Moreover, PEOB and PE had a greater concentration of interleukin (IL) 36Rα (P < 0.05) and IP10 (P < 0.01) compared with NC. Besides PEOB tended (P < 0.15) to have decreased concentrations of MIP1α, IL1α, and BHBA compared with PE. In conclusion, the addition of a PE and OB improved the adaptation of veal calves after reception, resulting in greater final BW. The improvement in early FI and the immunomodulatory effect in challenging situations displayed by the treatments may partially explain the observed benefits.