An investigation on determining protected (by-pass) protein values of dairy compounds exposed to different treatments

Abstract

This study was carried out to determine the degradation characteristics of dairy compound feeds (DCF) subjected to various treatments. (fat, F; tannic acid, TA: fat+tannic acid, (F+TA), as well as the combination of all levels of F and TA). In the in situ trial, ruminal dry matter (DM) degradabilities, organic matter (OM) degradabilities, crude protein (CP) degradabilities and degradation parameters belonging to degradability values (a, b, c, a+b) and pepsin soluble nitrogen contents of 25 DCF were subjected to F (1. 2. 3 and 4%), TA (2.5, 5.0, 7.5 and 10%) and F+TA (a combination of all levels of F and TA). They were examined after 4, 8, 12 and 24 incubation in 3 ruminal cannulated Karayaka wethers. According to the in situ DM, OM and CP degradability values the most resistant feed to microbial degradation is 3F+2.5TA. The highest pepsin solubility was obtained from 1F+2.5TA and 2F+2.5TA. Of feed exposed to TA treatment, the most resistant to microbial degradation was 1 OTA. In terms of pepsin solubility, the highest value was found for 7.5TA, while no difference could be determined between 2.5TA. 5.0TA and 7.5TA (P>0.05). When the feeds exposed to F treatment were evaluated in terms of degradation characteristics it was seen that 2F gave better results when compared to the other feeds.