Evaluation of probiotic supplementation to enhance growth, immune response, intestinal function, and survival in extensively raised neonatal alpacas in the Peruvian Central-southern Andes

This study aimed to evaluate the effects of multi-strain probiotics on growth, immune response, intestinal function, and survival in neonatal alpacas in the Peruvian Central-southern Andes. A total of 96 neonatal alpacas were selected, with an average weight of 7.89 ± 0.93 kg, regardless of breed (Huacaya and Suri). The study employed a completely randomized design. The neonates were randomly assigned to three groups (n = 32): control (T1), Probiolyte® WS (T2), and Polimeve Solúve (T3). Probiotics were administered orally on days 1, 7, 14, 21, and 30 of age. Body weight gain and size were recorded on days 1, 15, 30, 60, and 90; immune response was assessed on 30 and 90 days; and intestinal functional status was evaluated on day 90. The neonates supplemented with Polimeve exhibited greater thoracic circumference after 60 days of age, and increased height at the withers and rump at 15 days (p < 0.05). At 90 days, the Polimeve group had a higher proportion of basophils, while the Probiolyte and control groups showed higher proportions of monocytes (p < 0.05). IgG concentrations at 30 and 90 days did not differ significantly among groups. Probiotic supplementation did not affect ileal villus length; however, it influenced the depth of jejunal and cecal crypts (p < 0.05). Morbidity and mortality rates did not differ significantly between groups. In conclusion, probiotics did not significantly influence growth, immune response, or intestinal function; however, Polimeve may improve weight gain in neonates, while Probiolyte can increase IgG concentrations during the first 30 days of life.