|Abstract or Summary
- The nutritive values of two fishery by-products, i.e. fish
protein hydrolysate (FPH) and liquefied fish (LF), were studied.
Three trials using Hubbard broilers, and Yorkshire pigs (starter
and grower phase) were conducted. The FPH was used in the broiler
trial and LF in the swine grower trial as supplemental protein
sources, that replaced partially the soybean meal protein. The FPH
was used to completely substitute for the skim milk component in
milk replacer for the pig starter trial. Sensory evaluation of
the edible tissue was conducted at the end of the broiler and swine
grower trials to evaluate the carcass quality changes associated
with feeding fish-containing diets.
The FPH derived from four different substrates (Hake, Dover
sole, Brown rock cod and Atlantic cod) were incorporated into diets
to provide 5% of the total dietary protein in the broiler trial and
compared to Herring meal and soybean meal diets. Mean body weight
(MBW) and feed conversion (FC) were determined when chicks were 4
weeks of age. The MBW of chicks fed the Hake, Brown rock diets
were lower (P<.05) than those fed the corn-soy, Herring and Atlantic cod meal diets. However, FC was found not to be influenced
(P>.05) by the supplemental protein sources. Edible tissue samples
were subjected to a sensory evaluation. Fishy flavor and off-flavor
were detected (P<.05) in carcasses of broilers fed Herring and
Dover sole meal. Juiciness of meat was the same (P>.05) in all
broilers receiving different diets.
LF, prepared from Dover sole fillet scraps, was formulated to
provide 24% (7.4% LF) or 12% (3.4% LF) of the total dietary protein
in the rations for the swine grower trial. Initial weight for
pigs used in the grower trial ranged from 26-28 kg. Pigs receiving
the diet containing 7.4% LF had lower FC (P<.05) and average daily
gain (ADG) (P<.01) than either the 3.7% LF or control groups.
Growth of pigs fed the 3.7% LF group was not different (P>.05)
from the control group. Similar results were obtained from the
sensory evaluation of the edible tissue. Flavor, juiciness and
overall desirability of edible tissue from pigs finished on 7.4% LF
diet were different (P<.05) from pigs fed either the 3.7% LF and
control. No difference (P>.05) in carcass quality was observed
between 3.4% LF group and the control group.
Milk replacer diets containing either skim milk or FPH
contributed 20% of dietary protein, were fed to young pigs from
6.7 to 22.5 kg of body weight. .FC and ADG were not different
(P>.05) between groups. The scouring problem was more severe in
FPH fed pigs. However, the nutritive value of fish protein was
shown to be similar to milk protein in the milk replacer diet for
piglets. Based on the results of these trials, protein sources derived
from fishery wastes can be effectively used as supplemental protein
sources for poultry and swine. Adverse effects in carcass quality
might be obtained if they are used at high levels.