When the environmental temperature falls below 30°F, the normal diet of a young calf should be supplemented with _______________

When the environmental temperature falls below 30°F, the normal diet

1.	When the environmental temperature falls below 30°F, the normal diet of a young calf should be supplemented with _______________
A.	Protein
B.	Energy
C.	Vitamin A
D.	None of the above
Answer» C. Vitamin A