| Abstract: | Continuing previous investigations, two test feedstuffs whose fishmeal content had been reduced to 5% and which were supplemented with 4.5 g methionine and 5.0 g lysine per kg resp. 6 g methionine and 6 g lysine per kg were proofed in comparison with a fattening feed for trout as customary in trade and with a fish meal content of 35%. The content of animal protein in the control feed was at least 75% (crude protein content 41%), in test feed I at most 35% (crude protein content 35.4%), in test feed II at most 17% (crude protein content 33.9%). All feedstuffs had the same energy content. The tests were made with rainbow trout (Salmo gairdneri) of 80...100 g at the beginning and at water temperatures of 11...12 degrees C. They were conducted over a period of 112 days. After giving the same amount of feed, growth of and feed expenditure for the fish feed with the test feedstuffs were less suitable than of those fish which had received the control feed. Concerning the protein efficiency ratio, the productive protein value and the energetic expenditure too, the best results were achieved with the control feed. |
