Sayyiduna Dirar bin al-Azwar (may Allah be pleased with him) said: A milch she-camel was given as a gift to the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) ordered me to milk her. I milked her until I had emptied the udders, so he (peace and blessings be upon him) stopped me and said: "Leave something for its young as well."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النفقات / 15821