Influence of 2,4-D and 2,4,5-T on in vitro Digestion of Forage Samples

Abstract

Influence of 2,4-D and 2,4,5-T on I n Vitro Digestion of Forage Sal A. E. SMITH Highlight: The influence of 2,4-D [(2,4-dichlorophenoxy) acetic acid] and 2,4,5-T [(2,4,5-trichlorophenoxy) acetic acid] on in vitro digestion of dried ground corn silage (Zea mays L.) and bermudagrass (Cynodon dactylon L.) foliage was determined using a modification of the Tilley and Terry method for determining in vitro dry matter digestibility of forage plants. Neither herbicide influenced the digestion of plant samples when treated with a herbicide concentration range of 10-to 1 0-4 M. Solutions containing I 0-4 M of either herbicide did not influence the growth of microbial populations in incubated rumen liquor. The influence of rumen microorganisms on degradation of 2,4-D and 2,4,S-T was also investigated. Samples containing sucrose or plant material, buffered rumen liquor, and I0-4 M concentrations of either herbicide were incubated for 10 day periods. Data from periodic quantification of herbicide remaining in the samples indicated that neither herbicide used in these experiments was degraded by the rumen microorganisms. Results indicate that: (1) 2,4-D and 2,4,5-T do not alter the rumen microbial functions or development and (2) these herbicides are not readily degraded in the rumen by the rumen microorganisms.

Increasing Importance and Control of Mayweed Chamomile in Forage Crops1

“…Soil was carefully washed from roots, and plant samples were divided into leaf, stem, and root tissues, freeze dried, and each tissue was ground to pass a 1-mm screen and stored in a desiccator (-5 oq until extraction or IVDMD was determined. Digestibility was determined on the ground tissue according to the method described by Tilley and Terry (24) and modified by Smith (21).…”

Fescue Forage Production and Quality Response to Sequential Nitrogen Applications1

“…The forage was dried in a forced draft drier (75 C), weighed, and subsamples were ground to pass through a 40 mesh screen. In vitro dry matter digestibility (IVDMD) of the ground subsamples was determined on three replications for each subsample according to the method described by Tilley and Terry (12) and modified according to Smith (10). The total research area was mowed following plot sampling and the mowed forage was removed from the research area.…”