In today's market, it is important that livestock farmers feed their animals less expensive, efficient feedstuffs to remain profitable in the face of decreasing meat prices and increasing feed prices. This study looks at the use of okara, a waste product from the production of tofu and soymilk, as a protein supplement for lactating ewes. In a replicated four-by-four Latin square trial, eight ewes and their twin lambs were fed four different diets. The four diets were: Diet A, a wheat middling and corn concentrate fed with a mixed grass hay; Diet B, an okara and corn concentrate fed with mixed grass hay; Diet C, a soybean meal and wheat middling concentrate fed with haylage; and Diet D an okara and corn concentrate fed with haylage. Ewe weights, lamb weights and daily feed intakes were recorded and milk samples were taken to determine the effect of the diets on the growth and feed intake of the animals and milk composition. The diets had no statistically significant impact on ewe or lamb growth, overall dry matter intake or growth efficiency, but there was significant difference in the amount of different diet forage and concentrate consumed. There was also no effect on milk composition, though there were some trends observed. Based on these findings, okara is a viable source of protein for lactating ewes and can be used as a supplement without any adverse effects on growth or milk composition.