Graduate Thesis Or Dissertation

 

Assessing the phosphorus and potassium balances in Oregon's dairies Public Deposited

Contenu téléchargeable

Télécharger le fichier PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/b5644t995

Descriptions

Attribute NameValues
Creator
Abstract
  • A field study was conducted to assess phosphorus (P) and potassium (K) concentrations of both lactating and dry cow diets on Oregon's dairies. Thirty-seven dairy farms, located in western Oregon, were grouped according to geographic region, valley (V) or coast (C), and herd size, small (S) or large (L). Farms were visited on three separate occasions. During each visit, lactating and dry cow diets were recorded and corresponding feed ingredients were collected and analyzed for P and K. For each diet recorded, fecal and urine samples were collected and analyzed for P and K. When available, milk production data was obtained. During the initial visit, a survey was issued to producers to assess P and K knowledge as well as gather herd data and management information. Survey responses received indicated that two-thirds of participants were knowledgeable about P and its affects within the environment. Knowledge of K appeared to be less than that of P. Average P concentration of the lactating cow diet was 0.40% (DM basis) and did not differ between region (P=0.12) or herd size (P=0.76). Fecal P excretion did not differ between region (P=0.08) or herd size (P=0.27), however, a trend for larger fecal excretion in V farms contributed to the lower calculated apparent P digestibility for V than C. Potassium in lactating cow diet was greater (P=0.01) for C than V, however, but no difference between herd size (P=0.10) was determined. Overfeeding of K also occurred in dry cow diet with no difference between region (P=0.40) and herd size (P=0.72). Combining the fecal and urinary fractions, an individual lactating cow consuming 0.40% P (89.8 g) and 1.71% K (384.3 g) per day will excrete 24.0 kg of manure P and 76.3 kg of manure K annually. The magnitude of plant available P and K produced; requires Oregon producers to acquire additional land, an additional two-tenths ha/cow, to be to apply P and K at agronomic rates.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Déclaration de droits
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using ScandAll PRO 1.8.1 on a Fi-6770A in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Des relations

Parents:

This work has no parents.

Dans Collection:

Articles