Which traits were introduced by crossbreeding English cattle with Brahman cattle?

Crossbreeding English cattle with Brahman cattle primarily introduced traits related to heartiness and disease resistance. Brahman cattle, known for their adaptability to harsh climates and resilience against certain diseases, contribute these valuable traits when crossbred with English breeds. The resulting hybrids tend to maintain a strong immune response and exhibit improved health, making them better suited for varying environments and improving the overall viability of the herd.

The other traits listed, such as fertility and size, milk production, or speed and agility, do not appropriately capture the primary advantages gained from this specific crossbreeding. While fertility can be influenced by numerous factors, and size varies greatly across breeds, it is the robust nature and disease resistance imparted by the Brahman genetics that typically stands out in this context. Therefore, the introduction of heart and disease resistance is a key benefit derived from such crossbreeding practices.