Sir ,

Certailnly it will make difference since there are difference in carrying weight as we lift 50Kg in bar or 50 kg in material.

Buth however the Carrying weight of Jockeys will be made equal to Handicap weight; If carrying weight of Horse is 59Kg and Trevor is 54Kg - Excess 5Kg will be loaded. If a horse carries 59Kg and L Rozario 48Kg(-4Kg Allowance) - Excess 7Kg will be loaded; When Horse handicap weight is 53.5Kg and Y S Srinath weighing 56Kg, than horse will be varrying over weight of +2.5Kg. 

Hi Manjunath , A good jockeys always maintain balance over horse back when it's running , most important thing .. some mediocre jockey will be imbalanced on horse back when then start whipping or pushing the horse .. weight howmuch ever be Balanced stance is important.. in simpler way we all know on school days we were carrying bag on our back , now think if Bag is tightly strapped over back we can run faster than the bag which is loosely strapped because Bag will be wobbling while we run n it causes imbalance to run when loosely strapped .. i hope u understood what I want to convey .. Play Safe Enjoy Sport