The effect of long-term storage of fish meals on the response of chickens to the amino acid supplementation of diets containing such meals.

In three experiments fish meals of different origin and treatment were given to chickens in short-term feeding trials after varying storage periods. Diets were supplemented with amino acids in these experiments, most of which were of factorial design, in such a way that the first limiting amino acids of the meals could be established. The body moisture content of three or four groups of chickens per treatment served as criterion of nitrogen (N) retention by the chickens. In the first experiment consisting of two trials, a pilchard meal stored for over 70 weeks and an anchovy meal stored for 74 weeks were both shown to have methionine as first limiting amino acid but only whenthe former was stabilised with ethoxyquin and the latter was not. Several of the trials in the second experiment involved fish meals stored under nitrogen. Such meals have not been used in similar experiments before. L-lysine hydrochloride supplementation of diets which contained full (i.e. with solubles added) fish meals depressed N retention, as did L-isoleucine when added at a high level (0.5%). This effect of lysine was also demonstrated when used in a diet which contained a commercial pilchard full meal which had been stored for about 6 months. On the other hand, lysine was shown to be the first limiting amino acid of a fish meal to which solubles had not been added. When the stabilised full meal used in Experiment II had been in storage for 108 weeks a positive reponse in chicken N retention to methionine supplementation of diets containing this meal occurred (Trial IId). In subsequent trials with these ageing stabilised meals cystine and/or methionine supplementation and later particularly supplementation with glycine led to better N retention by chickens. Unstabilised stored meals seem to have a sulphur-containing amino acid as first limiting. In most instances where comparison was possible diets containing stabilised fish meals gave greater chicken body N retention than those containing similar unstabilised meal.     

Effect of heat treatment of fish meals,fines and the addition of lysine as related to gizzard erosion in chickens

The effect was studied of certain properties of fish meal on their tendency to predispose chickens to develop gizzard lesions when used in starter diets. These properties relate to the degree of heat treatment to which the meals had been subjected, the fineness of the meal, and the fish species involved. The effect on gizzard erosion of addition of dietary lysine was also considered. The results suggest that the use of meals heated to 130°C or higher, but not of meals stored at lower temperatures, is more likely to result in the development of gizzard lesions, while the fineness of the fish meal had no effect on this phenomenon. In some instances added dietary lysine reduced gizzard erosion incidence. No relationship was found between chicken liveweight gain during the experimental period and gizzard lesion scores. A 7-day biological test was used in these studies.     

Utilisation of free and protein-bound methionine sulphoxide by the chicken

The biological availability of free and protein-bound methionine sulphoxide (MSO) was examined in nine growth experiments with chickens. The source of protein-bound MSO was fish meals oxidised with hydrogen peroxide. Bound MSO in oxidised fish meals was equally well utilised by the chicken as was bound methionine in unoxidised fish meals when the meals were the sole protein sources in the diet. When used as supplements to a low-methionine diet, oxidised fish meals were slightly less well utilised than L -methionine and unoxidised meals at the highest supplementation levels. At a low level there was no difference. Free L -MSO was less well utilised than free L -methionine when added to a soya bean meal diet and when used in purified diets. In the latter cystine was found to improve the utilisation of MSO. High levels of MSO were found in muscle extracts of chickens even when no MSO was present in their diet.     

Effect of dietary fish oil on fatty acid composition, lipid oxidation and sensory property of chicken frankfurters during storage

Broilers fed with three levels of fish oil (0, 2 and 4%) for 6 weeks were used in the manufacture of chicken frankfurters. The meat samples were vacuum-packed and stored at 0°C for 0, 10, 20 and 30 days. Cooking yield, proximate and fatty acid composition, lipid oxidation, microbial and sensory properties of the meat products were measured. Cooking yield, moisture, fat, protein, ash and cholesterol contents of frankfurters were not affected (P>0.05) by levels of dietary fish oil. Frankfurters processed from chickens fed diets enriched with 2 and 4% of supplemental fish oil had a higher (P<0.05) level of n-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid), but had a lower level of n-6 fatty acids (P<0.05) than the controls (0% fish oil). TBA values and pH values of meat samples were not affected (P>0.05) by levels of supplemental fish oil in the diets, however, pH values of the vacuum-packaged chicken frankfurters decreased (P<0.05) as the storage time increased. No differences (P>0.05) in total anaerobic plate counts were observed among the fish oil treatments during storage. Supplementation of 2 and 4% fish oil in the diets did not increase (P>0.05) the intensity of fishy flavor in chicken frankfurters.     

Evaluation of processed cheese fortified with fish oil emulsion

Processed cheese fortified with fish oil is an excellent food for the delivery of omega-3 long-chain polyunsaturated fatty acids (omega-3 LC PUFA). However, oxidation and the “fishy” flavour of fish oil limit the level of fortification. The physical properties, lipid oxidation, and sensory perception of model processed cheese slices fortified with a fish oil emulsion (encapsulated fish oil) were examined and were compared with those of samples fortified with straight fish oil. Peroxide values, the results of thiobarbituric acid reactive substances (TBARS) tests, and propanal values showed that cheese samples fortified with fish oil emulsion had lower levels of oxidation than cheese samples fortified with non-encapsulated fish oil. A sensory panel detected a “fishy” flavour at a higher level of fish oil addition in the samples fortified with fish oil emulsion. This suggests that a fish oil emulsion made with a milk protein complex is a useful carrier for elevating the fortification level of omega-3 LC PUFA in processed cheese products.     

Feeding fish meal and extruded soybeans enhances the conjugated linoleic acid (CLA) content of milk

Twelve multiparous Holstein cows averaging 65 (33 to 122) DIM were used in a 4 x 4 Latin square for 4-wk periods to determine whether feeding fish oil as fish meal would stimulate increased amounts of milk conjugated linoleic acid (cis-9, trans-11 C18:2; CLA) and transvaccenic acid (trans-11 C18:1; TVA) when the cows were fed extruded soybeans to supply additional linoleic acid. Treatment diets were 1) control; 2) 0.5% fish oil from fish meal; 3) 2.5% soybean oil from extruded soybeans; and 4) 0.5% fish oil from fish meal and 2% soybean oil from extruded soybeans. Diets were formulated to contain 18% crude protein and were composed (dry basis) of 50% concentrate mix, 25% corn silage, and 25% alfalfa hay. Intake of DM was not affected by diet. Milk production was increased by diets 2, 3, and 4 compared with diet 1 (control). Milk fat and milk protein percentages decreased with diets 3 and 4. Milk fat yield was not affected by treatments, but yield of milk protein was increased with supplemental fish meal and extruded soybeans or their blend. When diets 2, 3, or 4 were fed, concentrations of cis-9, trans-11 CLA in milk fat increased by 0.4-, 1.4-, and 3.2-fold, and TVA concentrations in milk fat increased by 0.4-, 1.8-, and 3.5-fold compared with the control milk fat. Increases in TVA and cis-9, trans-11 CLA were 91 to 109% greater when a blend of fish meal and extruded soybeans was fed than the additive effect of fish meal and extruded soybeans. This suggested that fish oil increased the production of CLA and TVA from other dietary sources of linoleic acid such as extruded soybeans.     

Effects of fish meals on rumen bacterial fermentation in continuous culture

Effects of various forms of fish meal on microbial metabolism were investigated in continuous cultures of rumen contents. Five diets were formulated to contain 12% ruminally degradable protein and 47 to 48% nonstructural carbohydrate. Soybean meal was the major protein source in the control diet, whereas in the other four diets, various fish meals were substituted for 6% of total diet DM. Fish meals were: fish meal containing 34.4% FFA, fish meal containing 34.4% FFA with CaCl2 added, fish meal containing 65.6% FFA, and fish meal defatted using 1:1 ethanol:ether extraction. The five treatments were fermented with pH either held constant at 6.2 or not controlled. When pH was maintained at 6.2, the inclusion of any fish meal except defatted fish meal reduced the acetate:propionate ratio, decreased protein digestion, and reduced microbial N produced/per kilogram DM digested when compared with the soybean control. When not controlled, pH decreased after feeding to 6.0 or lower. Under these conditions, the soybean control had a lower acetate:propionate ratio and lower NDF digestion than all diets containing fish meal. In this study, oil-containing fish meal affected microbial metabolism more negatively when the fermentation pH was held at 6.2 than when the pH was 6.0 or lower.     

Sensory quality of marinated frozen stored chicken thighs as affected by dietary fish fat and vitamin E

The effects of diets containing fish meal (0 or 4%), fish silage (0 or 4%) and vitamin E (60 or 200 mg kg^–1) and the processing effect of marinating with sodium citrate (0.24 or 0.48%) or ascorbate (0.31 or 0.62%) have been studied to test the hypothesis that oxidative stability of frozen stored chicken thighs can be improved by such treatments. A trained sensory panel assessed the samples after storage at –25 °C for 1 week, 3 and 6 months. Feed with 4% fish meal resulted in increased fish flavour and odour of the thighs while 4% fish silage had a smaller effect on these attributes. Fish meal and fish silage added together into the feed by an amount of 4% each, caused strong fish flavour and odour in the product and accelerated the rancidity process. High concentration of vitamin E (200 mg kg^–1) in the feed reduced rancidity when 4% fish products had been added to the feed, but no effect was noted when 4% fish meal plus 4% fish silage had been added together. High concentration of ascorbate in the brine (0.62%) decreased sensory score for rancidity attributes (hay, grass, soap and paint), while high concentration of citrate (0.48%) increased these parameters in frozen stored chicken thighs.     

The introduction of Arcobacter spp. in poultry slaughterhouses

Despite the presence high levels of Arcobacter spp. on chicken carcasses, the source of arcobacter contamination in slaughterhouses still remains unclear. It has been hypothesised in the literature that Arcobacter species that contaminate carcasses originate in in-plant slaughterhouses and/or supply water. The present study aimed to determine the source of Arcobacter contamination in two poultry slaughterhouses in The Netherlands. Carcasses and intestinal tracts from 3 hen flocks and 2 broiler flocks were collected. Water draining off carcasses during processing in 2 slaughterhouses and supply water in one slaughterhouse were also taken. For one flock, cloacal swabs and faecal samples were taken on the farm before slaughtering. ERIC-PCR was applied to study the genetic diversity and relationship among the isolates. No Arcobacter spp. were found in the supply water but on almost all of the sampled carcasses and in carcass-draining-off water arcobacters were identified. Arcobacter spp. were detected in the gut systems of chickens, ranging from 20% to 85% in hens and 3.3% and 51% in broilers. Similar ERIC-PCR genotypes were detected in gut contents as well as on carcasses from the same flock. The present study demonstrated that Arcobacter spp. can be detected in chicken intestines at slaughter and could be brought in this way into slaughterhouses where the bacteria contaminate carcasses during processing.     

Yield, Lipid, Cholesterol and Fatty Acid Composition of Spent Hens Fed Full-Fat Oil Seeds and Fish Meal Diets

Yield, proximate and fatty acids composition of white and dark meats and whole carcasses were determined in spent hens fed flax or canola seeds, fish meal and a control diet. Live weights and percent carcass cut-up yield were not affected by the diets fed. However, hens fed flax seed diets contained significantly (P< 0.05) lower levels of cholesterol in the dark meat than the control group. The inclusion of oil seeds, in particular flax seeds in the hens diet, enriched the meats with omega-3 fatty acids (C18:3ω>3; C20:5ω3; C22:5ω3). Omega-3 fatty acids enriched poultry meats from spent hens could be useful in the development of “health oriented” further processed poultry products.     

Nutritional value of fish visceral meals

Viscera from white fish and herring were azeotropically dried and their amino acid compositions were compared with those of an azeotropically dried whole herring and of four commercial fish meals. The gut meals were similar in composition to the whole herring meal and the commercial meals, though the herring gut meals contained appreciable quantities of nitrogen not identified in the Moore & Stein amino acid analysis. An attempt was made to relate the nutritive value of the azeotropically dried meals to their amino acid compositions. The nutritive values of the meals for rats when given as the sole protein source were apparently related to their histidine content, and in tests with chicks, in which the meals were given with a cereal-based ration, nutritive quality was related to total lysine content. The visceral meals were relatively rich in soluble nitrogen, and in a meal manufactured during warm weather there was considerable autolysis to free amino acids. Autolysis and bacterial spoilage may lower the histidine content of visceral meals with possible production of toxic substances. With efficient processing fish viscera could provide protein-rich concentrates of fair quality. Some technological problems are discussed.     

Quantitative risk assessment of human campylobacteriosis associated with thermophilic Campylobacter species in chickens

A quantitative risk assessment comprising the elements hazard identification, hazard characterization, exposure assessment, and risk characterization has been prepared to assess the effect of different mitigation strategies on the number of human cases in Denmark associated with thermophilic Campylobacter spp. in chickens. To estimate the human exposure to Campylobacter from a chicken meal and the number of human cases associated with this exposure, a mathematical risk model was developed. The model details the spread and transfer of Campylobacter in chickens from slaughter to consumption and the relationship between ingested dose and the probability of developing campylobacteriosis. Human exposure was estimated in two successive mathematical modules. Module 1 addresses changes in prevalence and numbers of Campylobacter on chicken carcasses throughout the processing steps of a slaughterhouse. Module 2 covers the transfer of Campylobacter during food handling in private kitchens. The age and sex of consumers were included in this module to introduce variable hygiene levels during food preparation and variable sizes and compositions of meals. Finally, the outcome of the exposure assessment modules was integrated with a Beta-Poisson dose-response model to provide a risk estimate. Simulations designed to predict the effect of different mitigation strategies showed that the incidence of campylobacteriosis associated with consumption of chicken meals could be reduced 30 times by introducing a 2 log reduction of the number of Campylobacter on the chicken carcasses. To obtain a similar reduction of the incidence, the flock prevalence should be reduced approximately 30 times or the kitchen hygiene improved approximately 30 times. Cross-contamination from positive to negative flocks during slaughter had almost no effect on the human Campylobacter incidence, which indicates that implementation of logistic slaughter will only have a minor influence on the risk. Finally, the simulations showed that people in the age of 18-29 years had the highest risk of developing campylobacteriosis.     

Amino acid composition of Brazilian surubim fish (Pseudoplatystoma coruscans) fed diets with different levels and sources of fat

Surubim (Pseudoplatystoma coruscans) is a river fish from the Brazilian São Francisco basin which presents a great potential for commercialization. The amino acid composition of carcasses of surubim fed isoproteic diets with variable levels and sources of fat were determined. The increase of soybean oil at levels of 4%, 8% and 12% in the rations promoted a corresponding increase in nitrogen fixation in the fish carcass, reflected by higher amino acid contents. However, the application of 12% added amounts of pig lard, corn oil, linseed oil or soybean oil, as different sources of fat, did not promote much variation in the fish amino acid fixation. The determination of the essential amino acid composition in the fish carcasses and the A/E ratios of individual amino acids provided a pattern of amino acid requirements of surubim fish.     

Fish meal and egg taint

A ‘fishy’ or ‘crabby’ taint in brown eggs from commercial flocks was associated with the use of capelin meal as a protein supplement and was reproduced under controlled conditions. Analysis of eggs and samples of the meal established that trimethylamine (TMA) was responsible for the taint and that the meal may contain rich sources of TMA in the form of TMA oxide and choline. Only certain hens were affected and their ability to metabolise TMA was very low as indicated by the oxidation of an intravenous dose of ¹⁴C-TMA and the activity of hepatic TMA oxidase. Oxidation of the ¹⁴C-TMA was further depressed by feeding the meal or injecting non-radioactive TMA. Experiments with hens and chickens which had been bred for sensitivity to the inhibition of TMA oxidation by thionamides (and rapeseed meal) gave no indication that the meal supplied a potent inhibitor of this kind. It was concluded that the tainting is caused by overloading hens with TMA and that these hens have a genetic defect which impairs their synthesis of TMA oxidase and consequently their ability to metabolise TMA. The removal of this defect from commercial flocks by selective breeding would probably prevent tainting by both fish and rapeseed meals.     

Fishmeal and oil from lantern fish (Myctophidae) with special emphasis on protein quality

Fishmeal made from lantern fish (family: Myctophidae; genus: Benthosema pterotum) had proximate, mineral, amino acid and fatty acid composition within the range reported for fishmeal made from conventional fish. Similarly, the pressed-out oil had a fatty acid composition and content of unsaponifiables as reported for conventional fish oil. The content of unsaponifiables in the body fat of the fish indicated that wax esters contributed a minor part of the lipids of this species of lantern fish. Determined in chicks, the true digestibility of the amino acids varied from 92% (arginine) to 73% (hydroxyproline) which for most of the amino acids was 1-3% units lower than that found for a high-quality capelin fishmeal. No differences in rate of mortality, growth rate and feed consumption and utilisation were found between lantern and capelin fishmeal when they replaced increasing amounts (0 to 100%) of soya bean meal as protein supplements (72% of total protein) to cereal diets, both fishmeals reducing feed consumption and causing a significant improvement in feed utilisation compared with soya bean meal. The data indicate that lantern fish may be used for the production of fishmeal.     

Effect of feeding fermentable fibre-rich feedstuffs on meat quality with emphasis on chemical and sensory boar taint in entire male and female pigs

Skatole, androstenone and other compounds such as indole cause boar taint in entire male pork. However, female pigs also produce skatole and indole. The purpose of this experiment was to minimise boar taint and increase overall impression of sensory quality by feeding entire male and female pigs with fibre-rich feedstuffs. The pigs have been fed three organic diets for either 1 or 2 weeks prior to slaughter of which two diets contained different fermentable fibre-rich feedstuffs – 10–13.3% dried chicory roots or 25% blue lupines. These two treatments were compared with pigs fed with an organic control diet for either 1 or 2 weeks prior to slaughter. Lupines significantly reduced skatole in blood and backfat for both genders after 1 week. Moreover, lupines showed negative impact on growth rate and feed conversion whilst chicory showed no significant differences in this respect. However, the indole concentration was significantly lower in chicory than lupine fed pigs. From a sensory perspective, chicory and lupine feeding reduced boar taint since odour and flavour of manure related to skatole and urine associated to androstenone were minimised. The level of boar taint in the entire male pigs was most effectively reduced after 14 days by both fibre-rich feeds while lupine had the largest influence on “boar” taint reduction in female pigs.     

Influence of dietary rapeseed meals and selenium on egg production and egg tainting in laying hens

In 3 experiments 152 hens of differing strains were fed diets containing 0, 50 or 100 g Span, Canadian or European rapeseed meal per kg. Two strains, Shaver 288 and Babcock B300, laid white-shelled eggs while three other strains, Shaver 585, Warren 14 and Thomber 404 laid brown-shelled eggs. Egg production performance was not significantly affected by the inclusion of rapeseed meal in the diet. However the strains laying brown-shelled eggs laid a high proportion of tainted eggs when rapeseed meal was included in the diet. All rapeseed meals led to a similar degree of tainting. Supplementing the diets with 1 or 2 mg selenium per kg did not significantly affect the incidence of tainting. Shell thickness, albumen height and Haugh unit were unaffected by the presence of rapeseed meal in the diet, and yolk colour was improved by the inclusion of Canadian and European rapeseed meals. On the basis of these and other findings it is recommended that rapeseed meal be omitted from diets at least for hens that lay brown-shelled eggs until the taint problem has been solved.     

Blood amino acids and milk composition from cows fed soybean meal, fish meal, or both

Twelve multiparous Holstein cows at 48 +/- 8 d in milk were used in a 4 x 4 Latin square with 21-d periods to determine the effect on feed intake, milk yield, milk composition, and blood amino acids when soybean meal was replaced with fish meal. Fish meal substituted for soybean meal on an isonitrogenous basis at 0, 25, 50, and 100% of supplemental protein. Total mixed diets were (dry matter basis) 25% corn silage, 25% alfalfa hay, and 50% concentrate mix. Intake of dry matter (27.9, 27.8, 26.1, and 25.8 kg/d for diets 1 to 4, respectively) was similar for all diets. Milk yield (37.5, 37.8, 37.2, and 37.7 kg/d) was not affected by diets. Milk protein percentages (3.23, 3.24, 3.31, and 3.35) increased with 100% fish meal supplementation and tended to be higher, with 50% fish meal supplementation compared with 100% soybean meal diet. Milk fat percentages (3.18, 2.99, 3.04, and 2.87) and yields were lower with the 100% fish meal than with the 100% soybean meal diet. Molar proportions of ruminal volatile fatty acids and ammonia were not greatly affected by diet. Fish meal supplementation slightly improved Met status, as shown when blood amino acid data were evaluated. Both extraction efficiency and transfer efficiency of amino acids from the blood by the mammary gland indicated that Met, Lys, and Phe were the most limiting amino acids in all diets. Replacing as much as 50 or 100% of dietary soybean meal with fish meal may improve the amino acid balance and increase the protein content in milk; however, feeding 100% fish meal will likely decrease milk fat percentages.     

Substitution of fish silage protein and a free amino acid mixture for fish meal protein in a chicken diet

White Leghorn chickens were fed a basal diet with about 550 g kg^?1 of the protein from fish meal. Graded amounts of fish silage protein or an amino acid mixture simulating fish meal protein were substituted for parts of the dietary fish meal protein. In two experiments 150 and 300 g kg^?1 of fish meal protein were replaced by fish silage protein or by an amino acid mixture simulating fish meal. In one experiment graded amounts of 0, 50, 100, 200, 300 and 400 g kg^?1 of fish meal protein were replaced by fish silage protein. Growth and feed efficiency were the same or better when some of the protein was from fish silage. The results showed that replacement of dietary fish meal with fish silage did not reduce the dietary quality of the feed for young growing chickens. It is concluded that it might be advantageous to substitute fish silage for some of the fish meal under the experimental conditions used.     

Influence of dietary fish meal on egg fatty acid composition

Changes in the fatty acid composition of egg-yolk fat of hens fed diets with increasing fish meal content are studied by total fatty acid analysis. The fatty acid composition of the major lipid fractions in egg-yolk fat after feeding a high-level fish meal diet was determined by a combination of thin layer chromatography (t.l.c.) and gas-liquid chromatography (g.l.c.) The changes produced show a fatty acid pattern similar to those of the diets themselves. Long-chain polyunsaturated fatty acids are deposited preferentially in the phospholipids, reaching the highest concentration in cephalin and lecithin.