Evaluating the use of stable isotopes, nirs, and microbial populations to detect dietary changes in dairy calves

• Main Author: Cooley, Kathryn Marie
• Other Authors: Brian J. Rude
• Format: Others
• Language: en
• Published: MSSTATE 2013
• Subjects: Animal and Dairy Sciences
• Online Access: http://sun.library.msstate.edu/ETD-db/theses/available/etd-03312013-195932/

<p>Three different methods were developed to evaluate nutritional status: stable isotopes, near infra-red reflectance spectroscopy (NIRS), and microbial populations. In the first method, hair samples were collected, analyzed, stable isotope content greatly differed (P < 0.01) between pre- and post-weaning samples. The second method used NIRS spectral patterns and analyzed fecal samples, and a difference was found around 2100 to 2250 nm where diets containing milk showed a peak, and non-milk diets showed a plateau. Finally, the third method involved profiling microbial populations from fecal samples as calves experienced dietary shifts. Total anaerobes, enterics, and clostridium were different (P<0.05) from pre to post-weaning states. Total anaerobe samples differed (P < 0.005) from milk, milk-grain diets to grain and grain-hay diets. Total aerobes, streptococci, and clostridium samples differed (P <0.001) from the milk diet to the other diets. In summary, all three methods showed differences when comparing pre- to post-weaning states.</p>