465 Czech J. Anim. Sci., 56, 2011 (10): 465–474 Original Paper In ovines, similarly like in other ruminants, the gastrointestinal tract undergoes major changes in the first days of life (Sangild et al., 2000; Blätter et al., 2001; Bessi et al., 2002a,b; Poole et al., 2003; Pauletti et al., 2007). The ingestion of colostrum is respon- sible for providing essential and non-essential nu- trients and also significant amounts of hormones, such as growth factors and immunoglobulins (Odle et al., 1996; Kráčmar et al., 1999, 2004; Antunović et al., 2001; Krenková and Čanderle, 2001; Gajdůšek et al., 2001; Georgieva et al., 2003; Zándoki et al., 2006; Kinal et al., 2007). The intake of growth fac- tors is related to the modulation of gastrointestinal growth and maturation, as well as digestive and absorptive functions (Blum and Hammom, 2000; Blum and Baumrucker, 2002). Besides the beneficial effects of colostrum in- take, some species such as ovines and caprines have Intestinal histology of Santa Ines lambs fed bovine or ovine colostrum R. Machado-Neto 1 , I.H. Grigolo 1 , D.B. Moretti 1 , L. Kindlein 2 , P. Pauletti 1 1 Laboratory of Animal Anatomy and Physiology, Department of Animal Science, University of São Paulo, São Paulo, Brazil 2 Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil ABSTRACT: The aim of this study was to investigate histology characteristics in the small intestine of Santa Ines lambs fed bovine or ovine colostrum. At 0 and 6 h of life, 12 newborn lambs received 250 ml of first milking bovine colostrum (BC) and another 12 animals received 250 ml of first milking ovine colostrum (OC). Samples of duodenum, jejunum and ileum were collected at 24 and 72 h of life. Six animals were sam- pled at birth, without colostrum intake (0 h). The histomorphologic analysis revealed differences between BC and OC groups in the jejunum and ileum segments. BC group had higher amounts of colostrum-filled vacuoles in the intestinal epithelium compared to OC group and the latter group had a higher number of empty vacuoles. However, at 72 h of life both groups revealed the end of the intestinal colostrum absorption. Regardless of the treatment, apical nuclei and vacuoles were mainly observed in the villi of animals at 0 and 24 h of life, and at 72 h the enterocytes had basal nuclei and cytoplasm without the presence of vacuoles. An interaction between treatment and period was observed in villus height and crypt depth in the jejunum (P < 0.05). In this segment, BC group showed the lowest villus height at 24 h of life (710.37 ± 115.79 µm) while OC group had the larger villus height (883.79 ± 207.24 µm) at 24 h than at 0 h of life (791.43 ± 129.19 µm) (P < 0.05). Lambs from BC group showed the deepest crypts at 72 h (157.15 ± 41.81 µm), followed by 24 h (100.08 ± 23.40 µm) and 0 h (84.89 ± 21.10 µm), and in OC group the deepest crypts were observed at 0 h (84.89 ± 21.10 µm), without the colostrum ingestion (P < 0.0%). The effects of treatment on the crypt depth were observed in the ileum (P < 0.05), crypts in BC group were deeper than in OC group (92.67 ± 21.47 and 83.12 ± 13.85 µm, respectively). The histological changes related to the ingestion of bovine colostrum did not apparently determine any consequences for enteric physiology. Thus, the results concerning the histologic and histomorphometric aspects confirm a possibility of successfully using bovine colostrum as a substitute for ovine colostrum in newborn lambs. Keywords: newborn lambs; ovines; intestinal mucosa; histomorphometry; milk colostrum