Cattle have been important in Irish culture and society since the earliest times, their ownership a mark of wealth and importance. Archeological evidence indicates that cattle appeared in Ireland sometime around 3,500 BC, it is thought that these early cattle were similar to the present day Kerry cattle, which are black.
Cattle raids seem to have been almost a way of life for many if not all tribes, figuring prominently in folklore, the Cattle raid of Cooley being the prime example. The Black Pigs Dyke an extensive earthworks beginning in southern Ulster and stretching discontinuously as far as Connacht, radio carbon dating places wood used in its construction at around 390-370 BC, it is thought its main use was to combat cattle raids. The dyke derives its name from Irish fokelore which attributed the dyle as the work of a huge black boar.
Cattle were first domesticated in Greece about 6000 BC pigs in Russia a [Kerry cattle a very old breed.] little earlier, neither came to Ireland with the first settlers. The prospect of milk and meat from the cattle and the fast mauring qualities of the pig caused the use of these anima ls to spread rapidly across Europe, possibly as a result of both trade and war. The staple diet of the Irish was grain and no doubt oxen were soon pressed into service to plough the land.
Horses have been known in Western Europe since the end of the last ice age, the concept of riding or using the horse for draught purposes only occurred to man about four thousand years ago on the Eurasian steppes, and spread slowly to the rest of the world, previously they had just been eaten. By the time the Celts arrived in Ireland [Read about Kerry cattle on Wikipedia.] the horse was well established, whether the horse was here prior to their arrival is unclear. We do know that they made extensive use of the horse, particularly in warfare using it to pull their chariots, it also figured prominently in their culture and folklore.
The pig evolved in the forests, it is happiest there grubbing a living from the forest floor eating acorns nuts and roots. The Celts no more predisposed to unnecessary work than anyone else, probably soon discovered they could turn a herd of pigs into a forest tended by a swineherd, and produce some tasty bacon and pork with little effort. This practice however in the long term must have contributed significantly to deforestation the pigs consuming the seeds and saplings. As time passed the old trees died and with nothing to take their place, the forest became grass or scrub land.~
Sheep would have been grazed on any available piece of [Black face sheep well suited to mountain pasture.] land; they were kept mainly for their wool, a fleece would have yielded about 1.7 kg (3.5 lbs) of wool, this being spun into yarn and knitted or woven into garments. The Brat was a shoulder fastened cloak worn by both men and women, this would have been fastened with a broach, the quality of both the brat and broach would have made a statement of social position. The combined grazing of sheep and pigs no doubt decimated the woodlands; probably in a comparatively short period of time.