The objective of this study was to assess the potential effect of difructose anhydride III (DFAIII) on calcemia, magnesemia, and milking performance of dairy cows. Sixty-six multiparous Holstein cows in late pregnancy (gestation days = 253.8 ± 2.13 d) were blocked according to their expected calving date and randomly assigned to either receiving no supplementation (Control) or receiving 40 g/d of DFAIII (DFA) between -14 and +7 d relative to calving following a complete randomized block design. Cows on Control received 640 g/d of a pellet containing no DFAIII, whereas DFA cows received the same pellet but containing 6.25%DFAIII. Pellets of each treatment were top-dressed on a daily basis while cows were dry, and were fed via an automatic feeding system twice daily (320 g each feeding) during milking. Dry cows were fed once a day, whereas lactating cows were fed twice daily. Dry matter intake was individually monitored on a daily basis. Cows were milked twice daily and milk production and milk protein and fat contents recorded at every milking. Cows were kept on the study until they reached 21 d postpartum. Cows were weighed at dry-off (about 45 d before study enrolment) and twice daily after calving at the exit of the milking parlor. Three days before the expected calving date and 6, 12, 24, 48 h and 7 and 14 d after calving cows were blood sampled for subsequent determination of serum Ca and Mg concentrations. There were no differences in DMI before calving, but DFA cows consumed more feed than Control cows about 15 DIM. All cows lost BW after calving but DFA cows lost slightly less BW during the first 5 DIM than Control cows. Cows on DFAIII produced more milk around 10 DIM compared with Control cows, and DFAIII cows produced more milk protein than Control cows after 3 d post-calving. Serum Ca concentrations were not affected by DFAIII supplementation; however, serum Mg concentrations at 6, 12, and 24 h after calving were greater in DFA than in Control cows. In conclusion, DFAIII did not affect postpartum calcemia but improved magnesemia between 6 and 24 h post-calving. Milk production in DFA cows was improved around 10 d post-calving and milk protein yield after 3 d postpartum compared with Control cows. The mechanism leading to increased Mg availability is not clear and warrants further research.
Keywords: calcium; magnesium; mineral absorption; post-partum.
The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).