title: Pre-partum monensin supplementation improves body reserves at calving and milk yield in Holstein cows dried-off with low body condition score.
abstract: The objective of this study was to determine the effect of a monensin controlled-release capsule administered intraruminally at drying-off on body condition score (BCS) at calving, milk yield, fertility and concentration of energy-related blood metabolites in Holstein cows dried-off with low BCS (< or = 3.0, scale 1 to 5 with a 0.25 point of increment). Between July and August, 2001, 220 cows from parity 2 or more and dried-off 50-70 days before expected parturition, with a BCS < or = 3.0 were randomly assigned to either a treatment group (n=110; oral capsule of monensin releasing 335 mg/day for 95 days) or a control group (no capsule, n=110). At assignment, on day 21 before expected parturition, at calving, and at 7, 14, and 21 days in milk a blood sample was obtained from a random sub sample of 10 cows per group. Effects of monensin on serum NEFA, BHBA and glucose were measured. Milk yield, milk fat and protein content (%) at DHIA test days during the entire lactation, 305 ME milk production and reproductive responses were compared. Monensin significantly improved BCS at calving, increased milk yield at test days 4 and 8, decreased the percentage of milk protein, did not change the percentage of milk fat, and decreased NEFA and BHBA during the post-partum period.
authors.affiliation: College of Veterinary Medicine, University of Florida, P.O. Box 100136, Gainesville, FL 32610-0136, USA.
authors.forename: P
authors.initials: P
authors.lastname: Melendez
authors.forename: J P
authors.initials: JP
authors.lastname: Goff
authors.forename: C A
authors.initials: CA
authors.lastname: Risco
authors.forename: L F
authors.initials: LF
authors.lastname: Archbald
authors.forename: R
authors.initials: R
authors.lastname: Littell
authors.forename: G A
authors.initials: GA
authors.lastname: Donovan
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001824:Body Constitution; D002417:Cattle / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D007476:Ionophores / Q000494:pharmacology*; D007774:Lactation / Q000187:drug effects* / Q000502:physiology; D008892:Milk / Q000737:chemistry; D008985:Monensin / Q000008:administration & dosage / Q000494:pharmacology*; D036801:Parturition; D011247:Pregnancy; D013997:Time Factors
chemical_list: D007476:Ionophores; D008985:Monensin