Objective—To compare plasma total calcium, phosphorus,
magnesium, nonesterified fatty acids (NEFA),
beta hydroxy butyrate (BHB), and glucose concentrations
in parturient dairy cows that were fed an anionic
prepartum diet between those with and without
retained fetal membranes (RFM) at 24 hours after parturition.
Animals—152 Holstein cows that calved during
October through December of 1997.
Procedure—All cows were fed an anionic prepartum
diet. Blood sample was taken within 6 hours after parturition
from randomly selected cows. Thirty-nine
cows had a diagnosis of RFM at 24 hours after parturition;
113 were not affected with RFM. At calving,
body condition score (BCS; 1 [thin] to 5 [obese]), parity,
and calving difficulty score were recorded. Plasma
calcium, phosphorus, magnesium, NEFA, BHB, and
glucose concentrations were compared between
cows with or without RFM.
Results—Cows with RFM had significantly lower
plasma calcium concentration soon after calving,
compared with cows without RFM. Cows with a parity
of ≥ 3 had significantly lower plasma concentrations
of calcium and higher concentrations of magnesium,
compared with cows with a parity of 1 or 2.
Cows with a BCS of ≥ 3.25 at calving had significantly
higher plasma concentrations of BHB than cows
with a BCS of 2.75 to 3.0. Cows with dystocia had
significantly higher plasma concentrations of glucose,
compared with cows without dystocia.
Conclusions and Clinical Relevance—In parturient
cows fed a prepartum anionic diet, those with RFM
have lower plasma calcium concentrations than cows
without RFM, although this association does not
prove a cause-effect relationship. (Am J Vet Res
Objective—To determine the effect of a controlled-release monensin capsule administered at cessation of lactation on incidence of calving-related disorders, fertility, and milk yield in dairy cows.
Animals—290 dairy cows treated with monensin and 290 untreated control cows.
Procedure—Treated cows received a capsule that released monensin at 335 mg/d for 95 days. Incidence of calving-related disorders; daily milk yield up to 20 days postpartum; test-day milk yield, fat, protein, and mature-equivalent 305-day milk production; and body condition score at calving were determined. Reproductive variables were conception rate at first service, pregnancy rate, and calving-to-conception interval.
Results—Cows treated with monensin were 2.1 times as likely to develop dystocia and 0.8 times as likely to develop metritis as control cows. For milk yield, there was an interaction of treatment ×time ×parity. In multiparous cows, monensin significantly improved milk yield at test days 4 and 7. In addition, monensin increased body condition score at calving.
Conclusions and Clinical Relevance—Despite increasing the likelihood of developing dystocia and metritis, administration of monensin improved the lactational performance of multiparous cows and may be a promising additive for use at the time of cessation of lactation.