Risk factors for, and genetic association with, intestinal atresia in dairy calves

Abstract

Intestinal atresia is a congenital defect, found in a wide variety of species, that results in complete occlusion of the intestinal lumen (Ducharme et al., 1988). The occlusion can occur in the duodenum, jejunum, ileum, colon, or anus, and prevents the normal movement of gut contents and the passing of faecal material. In calves, common presentations include failure to pass meconium and faeces, inappetence and abdominal distension; affected animals usually die within 7 days of birth or are euthanised (Mee, 2021). Atresia is a well-known congenital defect of the gastrointestinal system in calves and investigations into the aetiology of this condition are warranted.

Bovine congenital defects recorded by veterinary practitioners

“…While the number of cases of intestinal atresia recorded here was limited, it did suggest that calves from pluriparae and males were more commonly affected. These trends are borne out by a recent Irish study of 197 cases which found that both pluriparity and male gender were significant risk factors (Keane et al., 2023). As with schistosomus reflexus, this indicates that preventive measures are warranted at a national/supra‐national level.…”

“…The most commonly diagnosed bovine congenital defect has variously been attributed to umbilical hernia (Čítek et al., 2009) or arthrogryposis (Bähr & Distl, 2005). The only Irish studies conducted on intestinal atresia have estimated that it occurs in 0.3%–0.4% of all dairy calves born and in up to 25% of herds (Keane et al., 2023; Mee, 1994). The top ranking of atresia in this study reflects its two common clinical presentations, veterinary‐assisted dystocia and a call out to examine/kill a calf that has become anorexic, bloated, in pain and is not passing faeces.…”

“…This presents challenges when trying to diagnose the aetiology as if there are multiple phenotypes, there may be multiple causes. Recently, a genetic basis for ‘all type atresia’ was established for Irish Holstein Friesian and Jersey cattle (Keane et al., 2023). This has previously been documented for Holstein Friesian (Syed & Shanks, 1992) and Swedish Highland cattle (Nihleen & Eriksson, 1958).…”

Invited review: Bovine neonatal morbidity and mortality—Causes, risk factors, incidences, sequelae and prevention

“…Good herd nutritional and health management reduces risks from these factors. However, the primary preventive focus is on preventing heritable genetic defects via national genetic monitoring programmes by genotyping AI sires to detect carriers for deleterious alleles to prevent recessively inherited defects (Keane et al, 2023).…”