Effects of birdsfoot trefoil and alfalfa supplementation on gastrointestinal nematode egg shedding in young dairy cattle

The main objective of this thesis was to investigate if birdsfoot trefoil (BF), a plant rich in condensed tannins (CTs), could be used to reduce the gastrointestinal nematode (GIN) egg shedding in young dairy cattle. The experiments were conducted to measure the effect of fresh or bailed BF supplementation on GIN egg shedding of artificially infected dairy cattle. For six weeks, animals were fed in treatment groups of fresh or bailed alfalfa, BF, and grass. During the feeding trials, there were differences in forage consumption between treatments, with alfalfa being consumed in a greater amount than BF, for both the fresh and dried forages. Contrary to our expectations, GIN egg shedding did not differ between forage treatments, even after accounting for differences in forage consumption. The amount of forage CTs consumed by individuals may have been insufficient to have a therapeutic effect on animals that were artificially infected with GIN.