calf and much higher milk yields have been recorded. Due to their heat tolerance and high milk production they have been exported to other Asian countries, Africa, Caribbean and around the world. As oxen, they are docile and slow, making them more useful for slow work. Their colour can range from reddish brown to red, with varying amounts of white on the neck, and the underline. In males, the colour darkens towards the extremities, such as the head, legs and tails. Sahiwal breed arrived in Australia via New Guinea in the early 1950s. In Australia, the Sahiwal breed was initially selected as a dual-purpose breed. It played a valuable role in the development of the two Australian tropical dairy breeds, the Australian milking zebu and the Australian Friesian Sahiwal. Sahiwal breeds are now used in Australia for beef production, as crossing high-grade Sahiwal sires with Bos taurus animals produced a carcass of lean quality with desirable fat cover. The Sahiwal breed is the heaviest milker of all zebu breeds and displays a well-developed udder. It sires small, fast-growing calves and is noted for its hardiness under unfavourable climatic conditions. Harappa One of the ancient civilizations on archaeological evidence dated 3300 B.C. southwest from downtown in suburb of Harapa which was the northern city of Indus Valley civilization. Harrapa is now a large village in the Sahiwal Division of Punjab, southwest of the district capital. Archaeologists think that in ancient times Harappa was the urban centre in the upper Indus region, much like Mohenjo-daro dominated the lower Indus Valley and Ganweriwal might have been the urban centre for what is now Rajasthan. The site at Harappa was first excavated by archaeologist Alexander Cunningham in 1872–73, two decades after Brick Robbers carried off the visible remains of the city. He found an Indus seal of an unknown origin. The first extensive excavations at Harappa were started by Rai Bahadur Daya Ram Sahni in 1920. His excavations at Mohenjo-daro called attention to the Indus Valley civilization as one of the earliest urban culture in the Indian subcontinent. His work was followed later in the decade by that of Madho Sarup Vats, also of the Archaeological Survey of India. Excavations continued in the 1930s. In 1946, Sir Mortimer Wheeler excavated the fortification walls and found the first pre-Indus Valley civilization (Kot Dijian) deposits. After Independence in 1947, Harappa was excavated by Mohammed Rafique Mughal