Three hundred and twenty Holstein Friesian milking cows were used in two trials to evaluate the effect of replacing whole cotton seed cake (WCS) with cotton seed cake (CSC) in daily rations on milk yield , milk fat content and the cost of feeding .

The experimental animals were distributed into two equal groups (Trials 1 and 2) of 160 cows each. Each group was subdivided into two groups of 80 cows each based on milk production .In Trial 1 the group had initially a lower milk yield (25–30 liters/cow/day) than the group in Trials 2 (30–35 liters/cow/day). In both Trials 80 cows were fed WCS and the other 80 were fed CSC in the feeding ration for a period of 5 weeks (one week adaptation and four weeks experimental period) . The  results revealed no significant difference (P>0–05)in neither milk yield nor milk fat content but there was a significant difference (P˂0.05)in the cost of replacing whole cotton seed by seed cake .Hence incorporating cotton seed cake (CSC) in dairy ration had an economical advantage .