title: Short communication: Factors affecting vitamin B12 concentration in milk of commercial dairy herds: An exploratory study.
abstract: Only bacteria can synthesize vitamin B12, and this requires adequate Co supply. The natural source of vitamin B12 in human diets comes from animal products, especially those from ruminants. This study aimed to describe variability regarding vitamin B12 concentration in milk among and within commercial dairy herds in early lactation. A secondary objective was to explore potential causes for this variability such as genetic variation and diet characteristics. In total, 399 dairy cows (135 primiparous and 264 multiparous; 386 Holstein and 13 Jersey cows) in 15 commercial herds were involved. Milk samples were taken at 27.4±4.1 and 55.4±4.1d in milk. Neither parity (primiparous vs. multiparous) nor sampling time affected milk concentrations of vitamin B12. Nevertheless, vitamin B12 concentration in milk was highly variable among and within dairy herds. The lowest vitamin B12 concentration in milk of cows was observed in the Jersey herd. Among herds, vitamin B12 concentration in milk ranged from 2,309 to 3,878 pg/mL; one glass (250mL) of milk from those herds would provide between 23 and 40% of the vitamin B12 recommended daily allowance. Among individual cows, however, this provision varied between 16 and 57% of the recommendation. In spite of the limited size of the studied population, the heritability value was 0.23, suggesting that genetic selection could modify milk vitamin B12 concentration. We observed a positive relationship between milk vitamin B12 concentration and dietary acid detergent fiber content and a negative relationship between milk concentration of vitamin B12 and dietary crude protein content.
authors.affiliation: Département des Sciences Animales, Université Laval, Québec, G1V 0A6, Canada; Agriculture et Agroalimentaire Canada, Centre de Recherche et Développement de Sherbrooke, Sherbrooke, Québec, J1M 1Z3, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Duplessis
authors.affiliation: Département des Sciences Animales, Université Laval, Québec, G1V 0A6, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Pellerin
authors.affiliation: Department of Animal Science, McGill University, Ste-Anne-de-Bellevue, Québec, H9X 3V9, Canada.
authors.forename: R I
authors.initials: RI
authors.lastname: Cue
authors.affiliation: Agriculture et Agroalimentaire Canada, Centre de Recherche et Développement de Sherbrooke, Sherbrooke, Québec, J1M 1Z3, Canada. Electronic address: Christiane.Girard@agr.gc.ca.
authors.forename: C L
authors.initials: CL
authors.lastname: Girard
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002417:Cattle; D004032:Diet / Q000662:veterinary*; D004043:Dietary Fiber / Q000008:administration & dosage / Q000032:analysis; D004044:Dietary Proteins / Q000008:administration & dosage / Q000032:analysis; D005260:Female; D007774:Lactation; D008892:Milk / Q000737:chemistry*; D010298:Parity; D064167:Recommended Dietary Allowances; D014805:Vitamin B 12 / Q000032:analysis*
chemical_list: D004043:Dietary Fiber; D004044:Dietary Proteins; D014805:Vitamin B 12
keywords: dairy cow; diet characteristic; genetic variation; milk; vitamin B(12)