3 sentences

1. 这个牧场里养殖了多头良种奶牛。

   zhè​ge mù​chǎng lǐ yǎng​zhí le duō​tóu liáng​zhǒng nǎi​niú.

   This ranch raises many heads of high-quality dairy cows.

   Source: Dong Chinese Dictionary

2. 培育良种是提高农作物产量的关键。

   péi​yù liáng​zhǒng shì tí​gāo nóng​zuò​wù chǎn​liàng de guān​jiàn.

   Cultivating improved varieties is the key to increasing crop yields.

   Source: Dong Chinese Dictionary

3. 那匹母马血统极佳，牧场主正忙着找一匹良种公马去跟它配。

   nà pǐ mǔ​mǎ xuè​tǒng jí jiā, mù​chǎng​zhǔ zhèng máng zhe zhǎo yī pǐ liáng​zhǒng gōng​mǎ qù gēn tā pèi.

   That mare has an excellent pedigree, and the rancher is busy finding a fine stallion to mate with her.

   Source: Dong Chinese Dictionary