Final answer:
Japanese Yew is highly toxic to cattle, with the primary toxins being taxines. Ingestion of even a small amount can lead to symptoms such as respiratory difficulty and cardiac failure, often resulting in death within hours.
Step-by-step explanation:
The Japanese Yew (Taxus cuspidata) is a plant that is highly toxic to livestock, including cattle. The toxic dose for cattle can be as little as a few hundred grams of leaves, but the exact amount can vary depending on the size and health of the animal. The primary toxins in the Japanese Yew are taxines, which can disrupt the heart's electrical activity, leading to acute cardiac failure and death. Symptoms usually appear shortly after ingestion and can include difficulty breathing, trembling, weakness, and a rapid or slow heartbeat. Unfortunately, there is often little time for treatment, and death can occur within hours of consumption.