pregnant mare serum

例句：

1. 1. The pregnant mare serum has been shown to improve the health of horses during pregnancy.
   怀孕母马血清已被证明在怀孕期间可以改善马匹的健康。
2. 2. The mare serum is used to treat wounds and infections in horses.
   马血清用于治疗马的伤口和感染。
3. 3. The use of mare serum has been controversial due to its potential side effects on human health.
   马血清的使用因可能对人类健康的潜在副作用而受到争议。