Elsevier

Journal of Dairy Science

Volume 87, Issue 9, September 2004, Pages 2896-2901
Journal of Dairy Science

Article
Effects of Urea Infusion on the Uterine Luminal Environment of Dairy Cows

https://doi.org/10.3168/jds.S0022-0302(04)73420-7Get rights and content
Under an Elsevier user license
open archive

Abstract

Previous research indicates that high plasma urea nitrogen (PUN) concentrations are associated with decreased fertility in lactating dairy cows. The objective of this study was to monitor changes in the uterine environment during acute elevation of PUN. Lactating dairy cows (n = 8) were infused with saline or urea (0.01 g of urea/h per kg of body weight) through jugular vein catheters on d 7 after estrus. After 24 h, cows were switched to the opposite treatment for a second 24-h infusion period. Blood samples were collected every 2 h, and the pH within the lumen of the uterine horn ipsilateral to the corpus luteum was recorded every 6 h. At the end of each 24-h infusion period, 30 mL of sterile saline was flushed into the uterine lumen and immediately retrieved. Mean PUN concentration increased from 16.6 ± 1.3 mg/dL during saline infusion to 22.6 ± 1.3 mg/dL during urea infusion. Uterine pH decreased during urea infusion from 7.08 ± 0.07 at 6 h to 6.88 ± 0.08 at 18 h, but was unchanged during saline infusion (7.01 ± 0.08 at 6 h to 7.06 ± 0.07 at 18 h). Protein concentration, PGF2α, and prostaglandin E2 concentrations in uterine lavage samples were not different between treatments. The results of this study indicate that a short-term increase in PUN can exert direct effects on the uterine environment by decreasing uterine pH.

Key words

urea
uterus
reproduction
dairy cow

Abbreviation Key

CA
carbonic anhydrase
PGE2
prostaglandin E2
PUN
plasma urea nitrogen

Cited by (0)

*

Present address: Department of Animal Science, University of Missouri, Columbia 65211.