Bismillah.
Volume 2, Book 26, Number 748:
Narrated Abu Huraira (radiallaahu `anhu):
Allah's Apostle (sallallaahu `alayhi wasallam) saw a man driving his Badana (sacrificial camel). He said, "Ride on it." The man said, "It is a Badana." The Prophet (sallallaahu `alayhi wasallam) said, "Ride on it." He (the man) said, "It is a Badana." The Prophet (sallallaahu `alayhi wasallam) said, "Ride on it." And on the second or the third time he (the Prophet (sallallaahu `alayhi wasallam)) added, "Woe to you."
Volume 2, Book 26, Number 749:
Narrated Anas (radiallaahu `anhu):
The Prophet (sallallaahu `alayhi wasallam) saw a man driving a Badana. He said, "Ride on it." The man replied, "It is a Badana." The Prophet (sallallaahu `alayhi wasallam) said (again), "Ride on it." He (the man) said, "It is a Badana." The Prophet (sallallaahu `alayhi wasallam) said thrice, "Ride on it."
What do you say to a person who doesn't listen to you even when you give him an instruction three times? Answer: woe to you! (It has various interesting translations in Urdu btw.) :P
Coming to the point, one may ride the animal he/she is going to use as hadi (sacrificial animal for Hajj). There are certain conditions as to the minimum age of the animal. In Fataawa al-Lajnah al-Daa’imah, it says:
The shar’i evidence indicates that what is acceptable in the case of sheep is that which has reached the age of six months; in the case of goats it is that which has reached the age of one year; in the case of cattle it is that which has reached the age of two years; and in the case of camels it is that which has reached the age of five years. Anything younger than that is not acceptable as a hadiy or udhiyah. This is what is meant by “a Hady such as you can afford,” because the texts from the Qur'aan and Sunnah explain one another.
And Allah is the source of strength; may Allah send blessings and peace upon our Prophet Muhammad and his family and Companions. End quote.
Taken from IslamQA
Taken from: http://ilookilisten.wordpress.com/2013/03/27/hajj-ridin-the-animal-of-sacrifice-ahadith-1448-1449/