Fish Hatchery Management - fisheries & aquaculture

NUTRITION AND FEEDING 257TABLE 32.SUGGESTED FEEDING FREqUENCIES FOR SALMONIDS. (SOURCE, WASHING-TON DEPARTMENT OF FISHERIES' UNPUBLISHED']SP!]CI ESFISH SIZE (NUMBER/POUND)tjoo lpt, to soo zso- -rN zs to l0 LARCERTIMES PER DAYCoho salmonFall chinooksalmonTrout66bbody weight, they would receive 10 feedings per day; if they receive l% ofbody weight in feed per day it would be fed in one feeding'Channel catfish reared in raceways produce more gain when fed twicedaily than when they are fed only once daily. In some situations' morethan two feedings per day will not improve the feed consumPtion orgrowth rate in Pond fed catfish.The following statements relate to feeding frequency:The feeding frequency does not significantly influence the mortality offry once they pass the initial feeding stage'Frequently fed fingerlings utilize their feed more efficiently than thosefed less frequently, resulting in better feed conversion'Frequent feeding of fingerlings reduces starvation and stunting of thesmall fish in a group. Generally, more frequent feeding results in greateruniformity in fish size.The accumulation of waste feed on the bottom of a rearing unit due tothe infrequent feeding of large amounts of feed is a principal factor causinginefficient utilization of feed.whenuneaten feed lies on the bottom of the tank, water-soluble nutrientsare leached out, resulting in poor utilization of the feed.In general, the number of feedings per day should be greater for dryfeed than for soft moist feeds.A rule of thumb is that 90%, of the feed should be eaten in 15 minutes orless.Feed SizesThe size of feed particles is critical in the feeding of fish. If particles aretoo large, the fish will not be able to ingest them until the water disintegratesthe feed to an acceptable size. When this occurs, nutrients leachout of the pellet, wasting feed and possibly polluting the water. when the