コイ実用飼料における適正タンパク質および可消化エネルギー含量

抄録

Feeding experiments were conducted with small size of carp in the aquarium to reconfirm the practical levels of protein and energy in carp diets which have been determined with large size of carp raised in the net cages in Lake Kasumigaura. For this purpose juvenile carp weighing 5-7g were fed on experimental diets prepared using practical ingredients and commercial diets for 3-6 weeks.
The feeding results in the aquarium were found to be almost the same as those obtained with large size of carp in the net cages. Namely, it was found that the dietary protein level can be reduced from 39% to 31-35% without reduction of growth and feed efficiency by elevating digestible energy (DE) level above 350kcal/100g diet. On the other hand, some commercial diets low in the amount of available phosphorus resulted in poor growth. The results also indicated that the contents of crude protein, DE and available phosphorus are important factors affecting the growth performance and feed efficiency together with nitrogen excretion in terms of the protein utilization efficiency.