Dietary nucleotide supplementation attenuates disease severity and modulates clinicopathological responses in lambs with neonatal diarrhea syndrome

Neonatal diarrhea syndrome (NDS) is a major cause of morbidity and mortality in lambs during early life. Dietary nucleotides modulate the immune response and enhance tissue development and cellular proliferation. This study evaluated the effects of a nucleotide-rich yeast extract on the clinical course of NDS and associated hematological, biochemical, and oxidative stress responses under field conditions. Ninety-six newborn lambs were allocated to a nucleotide-supplemented group (NG, n = 48) or a control group (CG, n = 48). NG lambs received 1 g/day of a nucleotide-rich yeast extract (Nucleoforce®, Bioiberica SAU, Spain) orally during the first 15 days of life, whereas CG lambs received no supplementation. Clinical examinations were performed daily for 20 days. Hematological, biochemical, oxidative stress, and acute phase response analytes were assessed, and etiological investigations were conducted using fecal and post-mortem samples. Diarrhea occurred in 83/96 lambs, affecting 39/48 (81.3%) NG lambs and 44/48 (91.7%) CG lambs (P > 0.05). All investigated cases were associated with mixed Cryptosporidium spp. and rotavirus A infection. NG lambs showed a significantly shorter diarrhea duration and lower diarrhea index than CG lambs (5.3 vs. 7.8; P < 0.05), required less antibacterial treatment (17.9% vs. 47.7%; P < 0.05), and exhibited fewer dehydration-related abnormalities (P < 0.05). Supplemented lambs also had higher hematocrit values, lower white blood cell, lymphocyte, and platelet counts, greater antioxidant capacity, and higher haptoglobin concentrations (P < 0.05). These findings indicate that dietary nucleotide supplementation reduced disease severity and improved clinical and physiological responses in lambs with NDS.