title: Influence of nitrogen and sulfur intake on bovine uterine pH throughout the luteal phase.
abstract: Previous research has reported that diets high in protein and sulfur decreased uterine pH in cattle. The objective of this study was to determine the effect of high N and high S intake on uterine pH. Holstein (n = 15) and Angus-cross (n = 5) heifers (337.5 ± 8.4 kg of BW) were randomly assigned to 1 of 4 diets: control (CON; 13.4% CP and 0.17% S); high nitrogen (HN; CON plus urea supplement); high sulfur (HS; CON plus calcium sulfate); or both high nitrogen and sulfur (HNS). Diets were individually fed at 2.6% of BW on a DM basis using Calan gates and estrus was synchronized to occur on d 13 (d 0 = start of dietary treatment). Blood samples were collected on d -2 and daily (d 1 to 28) at 1400 h to determine concentrations of plasma urea nitrogen (PUN), sulfate (d 1, 4, 8, 12, 16, 20, 24, and 28), and progesterone. Uterine pH was measured on d 16, 20, 24, and 28 (d 3, 7, 11, and 15 of the estrous cycle). There was a treatment, time, and treatment by time interaction (P < 0.01) on concentrations of PUN. There was an effect of treatment (P < 0.01) on concentrations of sulfate, with concentrations being increased in HS compared with CON, HN, and HNS (P < 0.01), and HNS increased compared with CON (P < 0.01) and HN (P < 0.01). Uterine pH was increased in HN and HNS compared with CON (P < 0.02), whereas HS was not different from any treatment (P > 0.11). There was no effect of time (P = 0.26) or treatment by time interaction (P = 0.71) on uterine pH. In summary, uterine pH was increased in HN and HNS compared with CON, whereas HS was intermediate and was associated with increased concentrations of PUN.
authors.affiliation: Department of Animal Sciences, South Dakota State University, Brookings, 57007, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Grant
authors.forename: P L
authors.initials: PL
authors.lastname: Steichen
authors.forename: C L
authors.initials: CL
authors.lastname: Wright
authors.forename: K A
authors.initials: KA
authors.lastname: Vonnahme
authors.forename: M L
authors.initials: ML
authors.lastname: Bauer
authors.forename: J S
authors.initials: JS
authors.lastname: Jennings
authors.forename: G A
authors.initials: GA
authors.lastname: Perry
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001806:Blood Urea Nitrogen; D002417:Cattle / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D005260:Female; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000378:metabolism*; D011374:Progesterone / Q000097:blood; D013455:Sulfur / Q000378:metabolism*; D013997:Time Factors; D014599:Uterus / Q000502:physiology*
chemical_list: D011374:Progesterone; D013455:Sulfur; D009584:Nitrogen