Effect of cobalt supplementation during late gestation and early lactation on milk and serum measures.
Thirty-six multiparous cows were assigned to a study to determine the effects of dietary Co supplementation during late gestation and early lactation on concentrations of Co in serum and liver, vitamin B12 concentrations in serum and milk, and milk yield. Nonlactating cows received diets containing 0.15, 0.89, or 1.71 mg/ kg of Co (dry matter basis) from 55 d before parturition, and lactating cows received diets containing 0.19, 0.57, or 0.93 mg/kg of Co (dry matter basis) from parturition through 120 d postpartum. Serum vitamin B12 concentrations declined sharply in all cows between 55 and 20 d prepartum. Dietary Co supplementation tended to cause an increase in the concentration of vitamin B12 in colostrum and milk. Cobalt intake did not affect concentrations of Co in liver or serum, but increased the Co concentration of milk (0.089, 0.120, and 0.130 microg of Co/mL) at 120 days in milk. There was no effect of Co supplementation on dry matter intake or yield of milk and milk components. In conclusion, serum concentrations of vitamin B12 are reduced in the early dry period, and added dietary Co may increase ruminal synthesis of vitamin B12 as indicated by a tendency for increased vitamin B12 concentrations in colostrum and milk of cows supplemented with dietary Co.
Kincaid
R L
RL
Animal Sciences Department, Washington State University, Pullman 99164-6310, USA. rkincaid@wsu.edu
Socha
M T
MT
D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001774:Blood Chemical Analysis; D001835:Body Weight / Q000187:drug effects; D002417:Cattle / Q000502:physiology*; D003035:Cobalt / Q000008:administration & dosage* / Q000378:metabolism; D003126:Colostrum / Q000737:chemistry / Q000187:drug effects; D019587:Dietary Supplements; D004435:Eating / Q000187:drug effects; D005260:Female; D007774:Lactation / Q000187:drug effects* / Q000502:physiology; D008099:Liver / Q000737:chemistry / Q000187:drug effects; D008892:Milk / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D011247:Pregnancy; D013997:Time Factors; D014805:Vitamin B 12 / Q000378:metabolism
D003035:Cobalt; D014805:Vitamin B 12