Abstract
Summary
Insulin averaged 2.6 ng/ml in mammary arterial and venous sera collected from 30 min before to 70 min after milking of cows lactating 5-12 weeks. During the same period in cows lactating 37-57 weeks insulin increased to 3.5 ng/ml. Milking did not affect insulin concentrations during early or late lactation. Arteriovenous (A-V) differences averaged 0.17, 0.14 and 0.22 ng/ml for 30 min before, 0-20 min after and 30-70 min after milking. Stage of lactation (and yield of milk) did not affect A-V differences. Mammary uptakes of insulin averaged 1.6 and 1.4 μg/min in early and late lactating cows, respectively. Maintenance of uptakes of insulin may be associated with uptake of metabolites essential for maintenance of lactation.
Get full access to this article
View all access options for this article.