title: Risk factors associated with Cryptosporidia, Eimeria, and diarrhea in smallholder dairy farms in Mukurwe-ini Sub-County, Nyeri County, Kenya.
abstract: OBJECTIVE
  This study was undertaken to determine the household, calf management, and calf factors associated with the occurrence of Eimeria, Cryptosporidia, and diarrhea in pre-weaned calves reared in smallholder dairy farms in Mukurwe-ini Sub-County of Nyeri County, Kenya. In addition, the study also evaluated factors associated with average daily weight gain in the same pre-weaned calves.
  
  
  METHODS
  A total of 112 newborn calves (63 males and 49 females) on 111 farms (1 set of twins) were followed for 2 months between June 2013 and August 2013. Two calves were lost to follow-up. A pre-tested questionnaire was used to collect data on household characteristics and calf management practices in the 111 selected farms. On the first visit to the farm (within 7 days of the birth of the calf), blood samples were collected from the jugular vein to assess the level of maternal immunity acquired by the calf, by determining the serum total protein and selenium concentration. At 4 and 6 weeks of age, fecal samples from the calves were collected to assess the presence of Cryptosporidia and Eimeria oocysts. Every 2 weeks for 2 months, the calves and their environments were examined, their 2-week consumption and health history were recorded, and weights were estimated with a weight tape. Each of the factors was evaluated in a univariable regression model and only those found to be significant (p≤0.20) were included in a multivariable model. Elimination of non-significant factors was done in the multivariable model through a backward elimination procedure so that only those variables which were confounders, and/or significant at (p≤0.05) remained in the final model.
  
  
  RESULTS
  About 37% (41/110) of the calves experienced diarrhea at least once during the 2-month study period. The overall period prevalence of Eimeria and Cryptosporidia was 42.7% (47/110) and 13.6% (15/110), respectively. Low serum protein was associated with 1.8 and 2.4 times the odds of Eimeria and Cryptosporidia infections, respectively. Lack of supervision of calf birth and low serum total protein were both associated with 1.3 times the odds of diarrhea incidence. Dirty calf pens, feeding <5 L of milk/day, and infection with Eimeria were associated with 0.105, 0.087, and 0.059 kg, respectively, reduced average daily weight gain of the calves.
  
  
  CONCLUSIONS
  In the Kenyan context, calf diarrhea risk could be reduced through better supervision of parturition and colostrum provision. Specifically, the risk of Eimeria and Cryptosporidia infections could be reduced by optimizing the passive transfer of immunity to the newborn calves. Average weight gains of calves could be improved by good colostrum provision, pen hygiene, and preventing Eimeria infections.
authors.affiliation: Department of Clinical Studies, Faculty of Veterinary Medicine, University of Nairobi, P.O. Box 29053-00625, Kangemi, Kenya.
authors.forename: S G
authors.initials: SG
authors.lastname: Peter
authors.affiliation: Department of Clinical Studies, Faculty of Veterinary Medicine, University of Nairobi, P.O. Box 29053-00625, Kangemi, Kenya.
authors.forename: George K
authors.initials: GK
authors.lastname: Gitau
authors.affiliation: Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PEI C1A 4P3, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Richards
authors.affiliation: Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PEI C1A 4P3, Canada.
authors.forename: J A
authors.initials: JA
authors.lastname: Vanleeuwen
authors.affiliation: Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon SK S7N 5B4, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Uehlinger
authors.affiliation: Department of Clinical Studies, Faculty of Veterinary Medicine, University of Nairobi, P.O. Box 29053-00625, Kangemi, Kenya.
authors.forename: C M
authors.initials: CM
authors.lastname: Mulei
authors.affiliation: Department of Public Health, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, P.O. Box 29053-00625, Kangemi, Kenya.
authors.forename: R R
authors.initials: RR
authors.lastname: Kibet
keywords: Cryptosporidium; Eimeria; diarrhea incidence; neonatal dairy calves; risk factors