Date of Award

12-2023

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Animal and Veterinary Sciences

Committee Chair/Advisor

Dr. Matias Aguerre

Committee Member

Dr. Thomas Jenkins

Committee Member

Dr. Gustavo Lascano

Abstract

The objective of this study was to assess the effects of feeding gelatin capsules treated with alcoholic solutions of flavoring agents followed by drying containing fish oil on lactation performance, rumen fatty acids content and milk enrichment of fatty acids. In Trial 1, four multiparous ruminally-fistulated Holstein cows were randomly assigned to one of four dietary treatment sequences in a 4 x 4 Latin square design. Treatments consisted of 1) Control with no capsules, 2) Control plus 200 untreated capsules per cow/day, mixed with the TMR; 3) Control plus 200 treated capsules per cow/day placed directly into the rumen, 4) Control plus 200 treated capsules per cow/day, mixed with the TMR. The total dose in treated and untreated capsules was 28 g of EPA and 13 g of DHA. In Trial 2, three fistulated Holstein and three fistulated Jersey multiparous cows were randomly assigned to three dietary treatment sequences in a replicated 3 x 3 Latin square design. Treatments consisted of 1) Control with no capsules fed to the cows, 2) Control plus 180 untreated capsules per cow/day, and 3) Control plus 180 treated capsules per cow/day. The total dose in treated and untreated capsules was 15.58 g of EPA and 12.75 g of DHA. Compared to control, feeding fish oil capsules significantly (Trial 1) or numerically (Trial 2) reduced milk fat concentration and yield. Furthermore, feeding untreated or treated capsules in both trials did not affect animal performance or milk composition. Compared to controls, supplementing the diet with fish oil capsules in both trials consistently increased total trans-C18:1 isomers and DHA concentration in the rumen and milk fat. However, for both trials, capsule protection treatment had a minimal effect on the concentration of any of the reported rumen and milk fatty acids. When assessed under laboratory control conditions, the treated capsule weight was increased by 40% due to water absorption, while resistance to pressure decreased by 84% after 2 hours of incubation in water. Results of this study suggest that due to reduced capsule shell resistance to abrasion, treated capsules marginally prevented the release of fish oil in the rumen.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.