Abstract
Leucaena (Leucaena leucocephala) is a productive, nutritious, leguminous forage tree with high capacity for ruminant liveweight gain. The plant does, however, contain the non-protein amino acid, mimosine, which is degraded within the rumen to 3-hydroxy-4(1H)-pyridone (3,4-DHP) with potential to cause adverse effects on animal health and production. Stock can be protected via rumen inoculation with the bacterium Synergistes jonesii, which is capable of degrading the toxin. However, surveys have demonstrated that subclinical toxicity persists in Queensland herds (Dalzell et al. 2012). Currently, testing for toxicity involves analysis of urine samples using high performance liquid chromatography (HPLC); a colorimetric urine test protocol has also been developed with the aim of providing a robust and reliable means for routinely testing herds (Graham et al. 2013). A significant problem affecting interpretation of the results from either method is the high variation in the concentrations of toxins excreted by animals on similar diets and by individual animals over time (Dalzell et al. 2012). Factors such as feed intake, water consumption and urine volume, as well as timing of sampling may be the cause of this variation. This research investigated the effects of sample timing by measuring the time taken for mimosine and its breakdown products to present in the urine following the introduction of leucaena to the ration of cattle naive to the plant.
Highlights
Leucaena (Leucaena leucocephala) is a productive, nutritious, leguminous forage tree with high capacity for ruminant liveweight gain
Mimosine and 3,4-DHP were detected in urine approximately 9 h after the commencement of leucaena feeding
Mean mimosine concentrations peaked at 11.6 ppm 35 h into the leucaena feeding period and remained low, but persisted for 67 h until cessation of the leucaena feeding (Figure 1)
Summary
Leucaena (Leucaena leucocephala) is a productive, nutritious, leguminous forage tree with high capacity for ruminant liveweight gain. Testing for toxicity involves analysis of urine samples using high performance liquid chromatography (HPLC); a colorimetric urine test protocol has been developed with the aim of providing a robust and reliable means for routinely testing herds (Graham et al 2013). A significant problem affecting interpretation of the results from either method is the high variation in the concentrations of toxins excreted by animals on similar diets and by individual animals over time (Dalzell et al 2012). Factors such as feed intake, water consumption and urine volume, as well as timing of sampling may be the cause of this variation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
