Bacterial contamination of colostrum fed to newborn calves in Québec dairy herds.
A convenience sample of 234 colostral specimens, collected directly from the nursing bottle immediately prior to the first feeding, was studied. Samples originated from 6 farms and were collected over 24 months. Routine bacteriologic techniques were used to quantify the bacterial load of the colostrum, as well as to identify the bacteria. Overall, at least 1 microorganism was cultured from 221 colostral samples (94.4%). By using the upper tolerance level of 100,000 bacteria/mL, 84 samples (35.9%) were considered contaminated. Staphylococcus spp. (57.7%), gram-negative rods (47.9%), coliforms (44.0%), and Streptococcus uberis (20.5%) were among the most frequently isolated bacteria. The relative risk (RR) of contamination with more than 100,000 bacteria/mL was significantly greater in warm months [RR = 2.55, 95% confidence interval (CI): 1.63 to 4.02] than in cool months and in colostrum offered to male calves (RR = 1.55, 95% CI: 1.09 to 2.20). Bacterial load was also associated with the farm of origin (P < 0.0001). When assessing colostrum management, one should consider bacterial contamination. Multiple factors are likely associated with the degree of contamination, and farm-specific factors may be important. Further studies are necessary to evaluate the impact of bacterial contamination of colostrum on neonatal health.
Département de sciences cliniques (Fecteau), Faculté de médecine vétérinaire, Université de Montréal, C.P. 5000, St-Hyacinthe, Québec J2S 7C6.
Gilles
G
Fecteau
Paul
P
Baillargeon
Robert
R
Higgins
Julie
J
Paré
Madeleine
M
Fortin
D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000382:microbiology*; D001419:Bacteria / Q000302:isolation & purification*; D001431:Bacteriological Techniques; D001903:Bottle Feeding / Q000662:veterinary; D002417:Cattle; D015169:Colony Count, Microbial / Q000662:veterinary; D003126:Colostrum / Q000382:microbiology*; D005260:Female; D005506:Food Contamination; D005511:Food Handling / Q000379:methods; D007112:Immunity, Maternally-Acquired; D008297:Male; D011792:Quebec; D012306:Risk; D012621:Seasons