Table 2.

Manuscripts comparing Cryptosporidium in calves with and without a period of extended maternal contact (at the herd level or animal level)¹

Study	Country	Breed2	Study design	Groups compared (length of dam- calf contact)	n (calves)	No. of herds (groups)	Herd types	Diagnostic	Conclusion
Kvac et al., 2006	Czech Republic	Varied	Fecal samples taken from calves in herds using either full contact or separation	Full contact for 5 d or immediate separation (with colostrum fed for 5 d followed by milk replacer)	2,056 (samples)	22	Dairy and beef	Floatation-sedimentation, staining, and microscopy	Fewer Cryptosporidium parvum positive samples for calves raised with dams compared with individually raised calves [PR (CI)3 = 0.37 (0.29–0.48) sample level]	+
Duranti et al., 2009	Italy	Not specified	Fecal samples paired with management questionnaire	Not specified	2,024	248	Dairy, beef, and dual	Fecal ELISA and immunofluorescent assay	C. parvum infection less likely in herds where calves are housed with the dam [OR (CI)4 = 0.1 (0.04–0.30)]	+
Garro et al., 2016	Argentina	Not specified	Fecal samples paired with management questionnaire	Calves grouped by contact with dam	552	27	Dairy	Acid-fast staining and microscopy	Time calf stayed with dam was protective against C. parvum infection at univariable stage [PR (CI) = 0.58 (0.39–0.86)]. No difference in multivariable stage	+/=
Maldonado-Camargo et al., 1998	Mexico	HF	Fecal samples paired with interviews on management	Separation time categorized as before nursing, after nursing, 2 to 12, or 13 to 24 h	512	31	Dairy	Acid-fast staining and microscopy	Whether calves received colostrum by suckling and duration of dam contact were not risk factors for calf-level C. parvum shedding. Suckling vs. bottle: PR (CI) = 0.88 (0.60–1.28); separation at 13–24 h vs. 2–12 h: PR (CI) = 0.97 (0.53–1.75)	=
Mohammed et al., 1999	United States	Not specified	Fecal samples paired with management questionnaire	Separation time categorized as immediately, after nursing, <12, 12 to 24, >12 h, or no separation	2,943	109	Dairy	Centrifugation concentration flotation	Time of calf separation from dam was not associated with risk of C. parvum infection	=
Delafosse et al., 2015	France	HF, Normandie, and others	Fecal samples paired with management questionnaire	Calves grouped by ≤2, 2 to 6, 6 to 12, or >12 h of contact with dam	968	97	Dairy	Acid-fast staining and microscopy	Time calf spent with the dam not associated with C. parvum shedding	=
Trotz- Williams et al., 2008a	Canada	Not specified	Fecal samples paired with management questionnaire	Separation time categorized as: immediately vs. other	1,089	119	Dairy	Sucrose wet mount method	Delaying separation was associated with increased within-herd prevalence [PR (CI) = 1.5 (1.1–2.2)] at univariable stage but not at multivariable stage	=/−
Quigley et al., 1994	United States	Jersey	2 × 2 factorial: 2 levels of dam-calf contact, 2 individual housing types	4 d full contact or immediate separation (fed 2 L of colostrum by bottle for 1 d)	96	1 (4)	Dairy	Modified flotation technique and microscopy	Calves that nursed the dam had higher prevalence of cryptosporidium at 1 wk of age. No significant difference thereafter.	−
Trotz- Williams et al., 2007	Canada	Not specified	Fecal samples paired with management questionnaire	Calves grouped by ≤1 or >1 h contact with dam	990	11	Dairy	Sucrose wet mount method and microscopy	Calves left with dam for >1 h had increased risk of C. parvum diarrhea OR (CI) = 1.59 (1.35–1.85)	−

¹Listed for each study are country, breed of cattle, study design, groups compared (in reference to length of cow-calf contact), total number of calves sampled, the number of herds included (and groups within herds where applicable), the type of herd, the diagnostic(s) used, and the authors' conclusion and direction of effect (with + signifying a beneficial effect of suckling or cow-calf contact, − signifying a negative effect, and = representing no difference. Studies are ordered chronologically within effect direction).

²HF signifies that breed was reported as Holstein, Friesian, or Holstein-Friesian. This designation includes country-specific variants such as Danish Holstein.

³PR (CI) = prevalence ratio (95% CI).

⁴OR (CI) = odds ratio (95% CI).