Crude Protein Basis Research Articles

Comparison of microalgae and rapeseed meal as supplementary protein in the grass silage based nutrition of dairy cows

Two experiments were conducted to evaluate microalgae as a protein supplement in the nutrition of lactating dairy cows in relation to unsupplemented and rapeseed meal supplemented diets. In both experiments multiparous Finnish Ayrshire cows were fed separately fixed amount of cereal-sugar beet pulp based concentrate (11kg/d in Exp. 1 and 12kg/d in Exp. 2), and grass silage ad libitum. In Exp. 1, six cows (212days in milk; DIM) were used in a replicated 3×3 Latin square. Diets were supplemented isonitrogenously with rapeseed meal (pelleted rapeseed supplement, RSS), mixture of Spirulina platensis and Chlorella vulgaris microalgae (1:1 on dry matter (DM) basis; ALG) or a mixture of RSS and ALG (1:1 on crude protein (CP) basis; RSS-ALG). In Exp. 2, four intact cows and four rumen cannulated cows (190 DIM) were used in a replicated 4×4 Latin square. Treatments consisted of basal diet without protein supplement (NEG) or supplemented similarly as in Exp. 1 with the exception of RSS-ALG and ALG containing only S. platensis. Protein supplementation increased fibre and N digestibility but did not affect dry matter intake (DMI) or milk yield. The substitution of rapeseed by microalgae did not affect total DMI or milk yield in neither of the experiments, but changed the quality of DMI in Exp.2 by linearly decreasing concentrate:forage ratio of the diet due to poorer palatability of microalgae. The efficiency of N utilisation (NUE) in milk production varied from moderate (Exp. 1) to high (Exp. 2), and in Exp. 2 was decreased by both protein supplementation and microalgae inclusion in the diet. Protein supplementation or microalgae inclusion in the diet did not affect ruminal pH or major volatile fatty acids in Exp. 2, but both increased ruminal NH3-N concentration. There was likely a shortage of N for rumen microbes on NEG in Exp. 2 as indicated by low milk urea N and increased microbial N flow on protein supplemented diets. In both experiments, only minor differences were observed in plasma metabolites when microalgae substituted rapeseed. Even though arterial histidine concentrations were high, arterial histidine and carnosine concentrations (Exp. 1 and 2) and milk protein yields (Exp. 2) decreased by microalgae inclusion suggesting that histidine supply may become suboptimal on microalgae supplemented diets. Experiments demonstrated the suitability of microalgae as protein supplement for dairy cows, however, the protein value of microalgae is likely slightly lower than that of rapeseed meal.

Net effects of nitrogen fertilization on the nutritive value and digestibility of oat forages

Applications of soil amendments containing N are part of routine forage-management strategies for grasses, with a primary goal of increasing forage yield. However, the effects of N fertilization on forage nutritive value, estimates of energy density, and in vitro dry matter or neutral detergent fiber disappearance sometimes have been erratic or inconsistent. Our objectives were to evaluate the effects of N fertilization on the nutritive value of a single cultivar (ForagePlus, Kratz Farms, Slinger, WI) of fall-grown oat fertilized at planting with 20, 40, 60, 80, or 100 kg of N/ha of urea or 2 rates of dairy slurry (42,300 or 84,600 L/ha). Nitrogen fertilization exhibited consistent effects on fiber components; forages fertilized with urea or dairy slurry had greater concentrations of fiber components compared with those harvested from unfertilized check plots (0 kg of N/ha), and fiber concentrations increased linearly with urea fertilization rate. In contrast, concentrations of water-soluble carbohydrates were greatest for unfertilized forages (21.2%), but declined linearly with urea fertilization, exhibiting a minimum of 13.5% at the 80 kg of N/ha urea application rate. Similarly, nonfiber carbohydrates also declined linearly, from 34.8% for unfertilized check plots to a minimum of 24.6% at the 80 kg of N/ha urea application rate. Fertilization with urea resulted in consistent linear increases in crude protein (CP), neutral detergent soluble CP, neutral detergent insoluble CP, and acid detergent insoluble CP; however, the partitioning of CP on the basis of association with specific fiber fractions could not be related to N fertilization when concentrations were expressed on a percentage of CP basis. The summative calculation of energy, expressed as total digestible nutrients was closely related to N fertilization rate during both the 2013 (y = -0.038x + 72.2; R2 = 0.961) and 2014 (y = -0.040x + 69.2; R2 = 0.771) production years. Following 30- or 48-h incubations in buffered rumen fluid, in vitro dry matter disappearance was greater for unfertilized forages compared with those fertilized with either urea or dairy slurry, and disappearance declined linearly with urea fertilization rate; however, these responses were not detected for neutral detergent fiber disappearance. Overall, the forage nutritive value of fall-grown oat declined mildly in response to N fertilization, but these responses were not nearly strong enough to offset the advantages obtained by improved forage yields.

Influence of the origin of the beans on the chemical composition and nutritive value of commercial soybean meals

Commercial samples of soybean meal (SBM) from USA (n=180), Brazil (BRA; n=165) and Argentina (ARG; n=170) were collected from 2007 to 2015 to study the effects of the origin of the beans on chemical composition, crude protein (CP) quality and nutritive value of the meals. Samples were collected at the country of origin or at the arrival of vessels from these countries to Europe. On a dry matter (DM) basis, USA and BRA meals had more CP than ARG meals (532, 532 and 517g/kg, respectively; P<0.001). On a CP basis, Lys content was higher (6.17, 6.07 and 6.11% CP; P<0.001) in USA than in BRA meals, with ARG meals being intermediate. USA meals had more sucrose (84, 64 and 78g/kg) and stachyose (64, 53 and 57g/kg) but less neutral detergent fibre (90, 118 and 102g/kg) and raffinose (11, 16 and 14g/kg) than BRA and ARG meals (P<0.001). Ether extract was highest for the BRA meals (P<0.05). Mineral content depended on SBM origin, with BRA meals having more Fe but less Ca, P and K than USA and ARG meals (P<0.001). The AMEn for poultry and net energy for pigs, estimated from published equations, were higher (P<0.001) for the USA meals than for the South American meals. Protein quality indicators varied also with SBM origin. Urease activity was lowest for ARG meals, but the differences were of little practical interest. Protein dispersibility index, KOH protein solubility and trypsin inhibitor activity were higher (P<0.001) for the USA meals than for the BRA and ARG meals. Heat damage indicator, a variable that measures indirectly the incidence of Maillard reactions, was lowest in the USA meals (P<0.001). The correlations among chemical analyses, protein quality indicators and nutritive value traits were numerous and depended on the origin of the beans. The correlation between CP (g/kg DM) and Lys (% CP) contents was negative (P<0.001) for the USA SBM, positive (P<0.001) for the BRA SBM and not significant (P>0.10) for the ARG SBM. In summary, chemical composition, protein quality and nutritive value of the SBM varied widely with the origin of the beans. At equal CP content, USA meals had less fibre, more sucrose and Lys and better protein quality than South American meals. Consequently, nutritionists should consider the country of origin of the beans when preparing matrices for evaluating the nutritive value of commercial SBM.

Chemical, physical and technological properties of milk as affected by the mycotoxin load of dairy herds

Abstract. The aim of the study was to determine the impacts of different levels of mycotoxin load of Czech dairy herds on the larger scale of the milk indicators including milk physical and technological properties. During three subsequent years individual milk samples (IMSs) were collected from four herds of Czech Fleckvieh (C) and from four herds of Holstein cows (H). The IMSs were collected regularly twice in summer and twice in winter, resulting in a total of 936 IMSs. The feeding rations consisted mainly of conserved roughage and supplemental mixtures according to milk yield and standard demands. Samples of feedstuffs were collected at the same time as IMSs and were analysed for content of deoxynivalenol (DON), fumonisins (FUM), zearalenone (ZEA), aflatoxin (AFL), and T-2 toxin using enzyme-linked immunosorbent assay (ELISA) methods. Based on the mycotoxin load, herds were divided into three groups – Load 1 (negligible, n = 36), Load 2 (low, n = 192), and Load 3 (medium, n = 708). All feedstuff samples were positive for at least one mycotoxin. The most frequently occurring mycotoxins were FUM, DON, and ZEA. Relatively high incidence of AFL (56 % positive samples) was observed. The following milk indicators were influenced by the mycotoxin load of herds: fat, acetone (Ac), log Ac, pH, electric conductivity, alcohol stability, curds quality, curd firmness, whey volume, whey protein, non-protein nitrogen (NPN), urea N in NPN, fat ∕ crude protein ratio, and casein numbers on crude and true protein basis, respectively (P &lt; 0.05). The overall level of mycotoxin load was relatively low, with no clear effect on milk characteristics.

Relationship between somatic cell count and milk casein level obtained by two different methods

The purpose of the present work was to investigate the impact of somatic cell count (SCC) on the content of milk casein and to compare the sensitivity of different methods for the determination of the casein level in milk. Two different methods were employed in order to determine the casein level: routine method - infrared spectrophotometry and reference method - Kjeldahl. Data array of 26, 169 milk samples of the livestock control was used to analyse milk casein variation by SCC limits. Mean casein values (investigated by the routine method) varied from 2.47% to 2.8% (2.65 ± 0.09) and casein number (in % on crude protein basis) - CN% varied from 79.5% to 81.1%. The present analysis showed that the relation between SCC and casein content obtained by the routine method correlated significantly (Pearson correlation rp = 0.644, P < 0.05, R2 = 0.414, Spearman correlation rs = 0.786, P < 0.05). Evaluated results obtained by the least squares method, and linear approximation of variation indicators presented a noticeable decline in casein percentage - 0.27%, when SCC increased by 80 × 103/ml, but only when the studies were done by the reference method.

Effect of dietary Ximenia caffra kernel meal on blood and liver metabolic substrate content and the general clinical biochemistry of Sprague Dawley rats.

We investigated (at the University of the Witwatersrand: GPS coordinates 26°10' 52.96″S; 28°2' 33.61″E) the effects of substituting soya bean meal (SBM) with Ximenia caffra kernel meal (XCKM) as a dietary protein source on blood and liver metabolic substrates content, serum markers of liver and kidney function and the general clinical biochemistry of Sprague Dawley (SD) rats. Five diets with similar energy and protein content were formulated (D1-D5) where XCKM replaced SBM on a crude protein basis at 0, 25, 50, 75 and 100%. Forty weanling male SD rats were randomly assigned to diets D1-D5, fed for 37days and weighed twice weekly. The rats were then fasted overnight, and fasting blood glucose and triglyceride concentrations were determined from tail-vein-drawn blood. Immediately thereafter, the rats were euthanised and blood was collected via cardiac puncture. Serum was used to assay for markers of the general health profile. Livers were removed and weighed, and samples were used to determine lipid and glycogen content. Rats fed D4 (75% substitution level) had significantly lower (p<0.05) blood triglyceride content compared with rats fed D2 (25% level of substitution). The substitution of SBM with XCKM did not affect (p>0.05) fasting blood glucose and cholesterol concentrations, liver glycogen and lipid content. Additionally, it had no effect (p>0.05) on serum activity/concentration of surrogate markers of liver (alanine aminotransferase and alkaline phosphatase activity and urea, total bilirubin, globulin and albumin concentrations) and kidney (phosphorus, calcium and creatinine concentrations) function and the general clinical biochemistry of the rats. Defatted XCKM could substitute SBM in rat diets without compromising blood glucose and cholesterol homeostasis, liver and kidney function and the general clinical biochemistry of growing male Sprague Dawley rats.

Evaluation of growth performance and intestinal barrier function in Arctic Charr (Salvelinus alpinus) fed yeast (Saccharomyces cerevisiae), fungi (Rhizopus oryzae) and blue mussel (Mytilus edulis)

Arctic charr (Salvelinus alpinus) were fed for 99 days on experimental diets with 40% of fish meal replaced, on a crude protein basis, with intact yeast (Saccharomyces cerevisiae) (ISC), extracted yeast (ESC), Rhizopus oryzae fungus (RHO) or de-shelled blue mussels (Mytilus edulis) (MYE). The fish were evaluated for growth performance, nutrient digestibility and fish intestinal function. Growth performance, retention of crude protein and sum of amino acids were not affected in fish fed diets ISC or MYE compared with those fed the reference (REF) diet. However, fish fed diet ISC displayed decreased digestibility of crude protein and indispensable amino acids and decreased intestinal barrier function compared with fish fed the REF diet. Fish fed diet ESC exhibited decreased growth performance and protein retention, but had comparable digestibility to fish fed the REF diet. Fish fed diets MYE and RHO showed similar performance in terms of growth, nutrient digestibility and intestinal barrier function. Overall, the results indicated that blue mussel and intact S. cerevisiae yeast are promising protein sources for Arctic charr.

The net contribution of dairy production to human food supply: The case of Austrian dairy farms

Due to their ability to convert human-inedible fibrous plant materials into high quality animal products, ruminants have always played an important role as net food producers. However, to meet the animals' nutritional requirements, today's rations for high yielding dairy cows also contain substantial amounts of potentially human-edible feeds (e.g. cereals and pulses), which increases competition between animal feed and human food availability. The aim of the present study was therefore to calculate the human-edible feed conversion efficiency (heFCE) for 30 Austrian dairy farms operating under different production systems in order to evaluate their contribution to net food production. The heFCE was calculated at farm gate level on a gross energy and crude protein basis, and was defined as potentially human-edible output in the form of animal products (milk and meat) divided by the input of potentially human-edible feedstuffs. The potentially human-edible fraction of all feedstuffs used on the 30 farms was estimated based on available literature using a “low,” “medium,” and “high” scenario, representing low, average, and above average extraction rates of human-edible nutrients from feedstuffs, respectively. The human-edible fraction ranged from 0% for some fibrous feedstuffs up to 100% for some cereals in the high scenario. For the “medium” scenario, heFCE ranged from 0.50 up to 2.95 for energy and from 0.47 up to 2.15 for protein. About half of the analysed farms showed a heFCE below 1, indicating a net loss in food supply. For both energy and protein, heFCE was negatively correlated with the amount of concentrates per kg milk and the total amount of concentrates per cow and year. In addition, we found a positive correlation between heFCE and the area of grassland utilized per ton of milk, as well as a negative correlation between heFCE and the area of arable land required per ton of milk. Therefore, feeding large amounts of concentrates to dairy cows has to be questioned in terms of the heFCE. The results of this study clearly show that grass-based dairy production highly contributes to net food production, particularly if the amount of concentrates per kg milk is reduced.

Oxya hyla hyla (Orthoptera: Acrididae) as an Alternative Protein Source for Japanese Quail.

Nutrient composition of the grasshoppers Oxya hyla hyla showed that they are a rich nutrient source containing 687.7 g protein/kg of dry body weight. Their antinutrient values fell within nutritionally acceptable values of the poultry bird Coturnix japonica japonica (Japanese quail). The most required essential amino acids and fatty acids were also present in sufficient amount. For feeding trial nine diets were formulated on an equal crude protein (230 g/kg) basis with grasshopper meal, fish meal, and soybean meal. Three sets of diets with grasshopper meal were prepared with 50 g/kg, 100 g/kg, and 150 g/kg grasshopper of total feed. Similarly, other diet sets were prepared with fish meal and also with soybean meal. Results were compared with another group of Japanese quails fed on a reference diet that was considered as control. Two experiments were conducted with a total number of 600, seven-day-old, Japanese quails. In experiment 1 for determination of growth performance, quails were randomly distributed into ten groups of males and ten groups of females containing 30 birds each. In experiment 2 for determination of laying performance, identical ten groups were prepared in ten repetitions (2 females and 1 male in each group) from the six-week-old birds of experiment 1. Birds of diet set GM2 have gained the highest body weight (male 4.04 g/bird/day; female 5.01 g/bird/day) followed by birds of FM3 diet set (male 3.72 g/bird/day; female 4.40 g/bird/day), whereas birds of reference diet have gained 3.05 g/bird/day for male and 3.23 g/bird/day for female. Feed conversion ratio (FCR) of birds fed with GM2 was the lowest (male 3.33; female 2.97) whereas FCR of R group was higher (male 4.37; female 4.65) than grasshopper meal and fish meal based diets. Hen day production percentage was higher (72.2) in GM2 group, followed by FM3 (63.5) group. R group had lower 1st egg weight (9.0 g), weight gain (8.2 g), percentage of hen day production (41.8%), higher feed intake (33.6 g/day/bird), and age at 1st laid egg than the grasshopper meal and fish meal based diets. So growth and laying performance of the birds were significantly better in grasshopper meal and fish meal added diet fed sets than the reference diet fed group; among all the dietary groups 100 g/kg grasshopper meal added diet mostly gave significantly better results followed by 150 g/kg fish meal added diets. It was ascertained that the O. hyla hyla meal had pronounced positive response on the birds. So, the quails could be easily fed 100 g/kg grasshopper meal added diet as it was the most suitable alternative feedstuff compared to the conventional protein source based diets.

Practical supplementation of shrimp and fish feeds with crystalline amino acids

Abstract In 2011, aquaculture accounted for almost 64 million MT of fish, crustaceans and mollusks (FAO, 2012). Fish meal has historically been the protein source of choice in aquatic feeds, but global supplies have reached a plateau making it less available and more expensive. As a consequence, the use of cheaper proteins made from processed plant proteins, byproducts from agriculture, fisheries or the slaughtering of terrestrial production animals was popularized within the aquaculture feed industry. Although these alternative ingredients may contain a crude protein (CP) content comparable to fish meal, they may be less digestible and deficient in one or more of the ten essential amino acids (EAAs). This has required the adoption of more modern formulation approaches which take into account nutrient availability, especially in regard to EAAs. EAA requirements have been established for a number of species of fish and shrimp. Methionine (Met) followed by lysine (Lys) are the first limiting amino acids in plant and rendered animal byproducts. Formulating for EAAs by simply increasing the dietary inclusion levels of the feedstuffs that contain intact sources of the targeted EAAs can lead to overformulated feeds with excessive levels of CP and other nutrients. A more rational approach is to supplement the diet with crystalline amino acids (CAAs). A first step to the application of a nutrient-based formulation approach is knowledge of the digestible EAA content of the ingredients available for use in the formula. It is highly desirable to formulate on a CP, EAA and energy digestibility basis in line with current formulation practices of most modern feed companies. Further expansion of current EAA digestibility values across ingredients and farmed aquatic species will further enable nutrient based formulation. By formulating on an EAA basis across farmed aquatic species, nutritionists have realized least cost formulation opportunities with the use of CAAs which are now available throughout the world at accessible prices. The CAAs mostly used by the animal feed industry, in order of usage, are the following: dl -methionine or Met analogs, l -lysine, l -threonine, l -tryptophan, l -isoleucine and l -valine. Met and Lys are the most currently used due to their wide availability and importance as most limiting EAAs in plant protein ingredients, such as soy and corn based meals. There is a relatively wide variation in the dietary Met and Lys requirement values for farmed fish and shrimp. This is due to differences in species requirements, culture systems, developmental stage and composition of experimental diets. The dietary Met requirements for fish and shrimp range from 0.5 to 1.5% and from 0.7 to 0.9% of the diet, respectively (NRC, 2011). The dietary Lys requirements range from 1.2% to 3.3% of the diet for cultured fish and from 1.6 to 2.1% of the diet for cultured shrimp. Appropriate dietary Met and Lys levels improve the use of other EAAs because they have the ability to reduce the oxidation rate of other amino acids. The present review discusses bioavailability, requirements and sources of EAAs and practical considerations for their application in aquaculture feeds. The appropriate supplementation of crystalline amino acids in feeds for fish and shrimp represents an opportunity to reduce formulation costs in the face of the volatile commodity market of protein ingredients and the short supply of fish meal. Competitiveness in the aquatic animal feed industry today depends upon application of modern and environmentally-sound formulation techniques based on nutrient value and supplementation with crystalline EAA to meet animal nutrient requirements.

In situ protein degradation of alfalfa and birdsfoot trefoil hays and silages as influenced by condensed tannin concentration

Dairy cattle often make poor use of protein when offered diets comprising high proportions of alfalfa (Medicago sativa L.) hay or silage because nonprotein N formed during forage conservation and ruminal fermentation exceeds requirements for rumen microbial protein synthesis; however, condensed tannins (CT) may reduce proteolysis in the silo and in the rumen, thereby potentially improving the efficiency of crude protein (CP) use in ruminant diets. Two harvests, yielding 12 hays and 12 silages made from alfalfa and birdsfoot trefoil (Lotus corniculatus L.) that varied in concentrations of CT, were evaluated for in situ disappearance kinetics of CP in 6 ruminally cannulated lactating Holstein dairy cows (627±56.3kg). Prior to conservation, alfalfa contained no detectable CT, whereas CT in fresh lyophilized birdsfoot trefoil ranged from 1.16 to 2.77% of dry matter, as determined by a modified acetone-butanol-HCl assay. Percentages of CP remaining at each incubation time were fitted to nonlinear regression models with or without a discrete lag time. Effective ruminal disappearance of CP (rumen-degradable protein, RDP) was calculated by 3 procedures that included (1) no discrete lag (RDPNL), (2) discrete lag (RDPL), and (3) discrete lag with a lag adjustment (RDPLADJ). Regardless of the calculation method, RDP declined linearly with increasing CT concentrations (R2=0.62 to 0.97). Generally, tests of homogeneity showed that conservation type (hay or silage) or harvest (silage only) affected intercepts, but not slopes in regressions of RDP on CT. A positive relationship between lag time and CT suggests that the RDPLADJ approach may be most appropriate for calculating RDP for legumes containing tannins. With this approach, regression intercepts were mainly affected by conservation method, and RDPLADJ averaged 77.5 and 88.7% of CP for hay and silage, respectively, when no CT was present. Greater estimates of RDP for silages were related to extensive proteolysis in laboratory silos resulting in conversions of protein into nonprotein N forms, which readily washed out of Dacron bags. When RDPLADJ and CT were expressed on a CP basis, regression slopes indicated that each unit of CT protected 0.61 units of CP from ruminal degradation in hays and silages. Applying this relationship to a typical mid-maturity forage legume containing 21% CP suggests that a CT concentration of 3.8% of DM would be required to reduce RDP from 81% to a 70% target considered optimal for improving protein utilization and milk yields by dairy cattle.

Effect of dietary bacterial lysine by-product meal supplementation on growth performance and excretion of purine base derivatives in growing-finishing pigs

The present study was designed to test the hypothesis that bacterial lysine by-product meal (BLBM) as a substitute of soybean meal in the diet on equivalent crude protein basis can regulate growth performance and the excretion of purine base derivatives in growing-finishing pigs. One hundred Duroc×Landrance×Yorkshire crossbred castrated male pigs (41.7±3.9kg body weight) were randomly allotted to 4 treatments with 5 replications (pens) per treatment, and 5 pigs per pen. Dietary treatments were: 1) CON (basal control diet), 2) BLBM-10 (BLBM replaced 10% crude protein in soybean meal), 3) BLBM-25 (BLBM replaced 25% crude protein in soybean meal), and 4) BLBM-50 (BLBM replaced 50% crude protein in soybean meal). In addition, two metabolism trials were conducted to determine the impact of BLBM on nitrogen metabolism and the excretion of purine base derivatives. Compared with the control pigs, BLBM-10 and BLBM-25 pigs had similar average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G/F) during the growing period. The BLBM-50 treatment decreased ADG and elevated G/F during the growing and the whole period (P<0.05). The BLBM-50 treatment had greater ADFI and G/F than other treatments during the finishing period (P<0.05). The nitrogen digestibility and nitrogen biological value in pigs fed BLBM-10 and BLBM-25 diets were similar to the CON treatment, while those criteria in pigs fed BLBM-50 diets were lower than those on the CON treatment (P<0.05). The serum urea nitrogen values increased in response to BLBM supplementation during the growing and finishing period (P<0.05), and the pigs had the greatest urea nitrogen concentrations when they were fed the BLBM-50 diets (P<0.05). The urinary excretion of purine base derivatives and the concentrations of uric acid, xanthine, and hypoxanthine in plasma increased with increasing dietary content of BLBM (P<0.05). In conclusion, the nitrogen metabolism in growing-finishing pigs was unaffected when up to 25% of crude protein in soybean meal was replaced by BLBM. The excretion of purine base derivatives were increased by BLBM levels in diets. It is feasible that BLBM substitutes 25% of crude protein in soybean meal for growing-finishing pig diets.

The evaluation of practical diets on a basis of digestible crude protein, lysine and methionine forLitopenaeus vannamei

A feeding trial was conducted to evaluate the efficacy of replacing fish meal (FM) with blood meal (BM), poultry by-product meal (PBM), meat and bone meal (MBM) and shrimp head meal (SHM), rapeseed meal (RM) and peanut meal (PM) on a digestible basis of crude protein and lysine and methionine in five practical diets for the Pacific white shrimp at the FM levels of 300, 250, 200, 150 and 100 g kg−1 under laboratory conditions. Each of the five experimental diets was hand-fed to four replicate tanks of shrimp with an average weight of 0.33 ± 0.03 g to satiation at each meal. The shrimp were fed three times a day over a six-week period. The per cent weight gain of initial body weight (WG%) was significantly lower in shrimp fed 100 g kg−1 FM diet, but the value for hepatosomatic index (HSI) and the level of blood urea nitrogen (BUN) tended to be higher in shrimp fed 100 g kg−1 FM diet than those in shrimp fed other diets. The lowest value for feeding rate (FR) occurred for shrimp fed the basal diet and was significantly lower than that in shrimp fed the FM diets at 100–150 g kg−1. Shrimp fed diets containing 200 g kg−1 or lower FM had significantly lower feed utilization than those fed the 250 g kg−1 FM diet and the basal diet. The protein efficiency ratio (PER) in the shrimp fed the basal diet was significantly higher than in the other FM diets. Decreasing the FM replacement level significantly reduced nutrient digestibility except in the cases of ash and gross energy, but it did not affect the survival, condition factor (CF), body composition, digestive enzyme activity or plasma transaminase activity. The results of the study indicate that feeding a diet formulated on a digestible basis and involving FM replacement with other protein sources at a greater replacement proportion will not produce a level of shrimp growth equal to that achieved by feeding the basal diet.

Unchanged interleukin 6 level of protein and energy restricted goats during late gestation: the role of elevated blood nitric oxide

Twelve pregnant goats were assigned to three dietary treatments during late gestation, namely control (C: metabolizable energy, 5.75 MJ/kg; crude protein, 12.6% and dry matter basis), 40% protein restricted (PR) and 40% energy restricted (ER), to examine the effects of nutrient restriction on the immune status of pregnant goats. Plasma was sampled on day 90, 125 and 145 from pregnant goats to determine cytokine production (interleukin 2 (IL2), IL6) and tumor necrosis factor α (TNFα)). Peripheral blood mononuclear cells were obtained on day 145 and activated by lipopolysaccharide to determine cytokine production, and then exposed (PR and ER) to sodium nitroprusside (SNP), a nitric oxide (NO) donor, or control to NG-nitro-l-arginine methyl ester hydrochloride (l-NAME), an NO synthase inhibitor to explore the role of NO in regulating cytokine production. Plasma IL2, IL6 and TNFα were not altered during gestation, but NO was increased (P<0.05) at gestation day 145 for PR and ER. In vitro, compared with control, NO was lower for PR and ER (P<0.001), but IL6 was higher for PR (P<0.001) and ER (P=0.11). The addition of SNP decreased IL6 (P<0.001, PR; P=0.12, ER) in the malnourished group, and l-NAME increased (P<0.001) IL6 in control compared to those treatments without SNP or l-NAME. The results indicate that plasma NO acted as a regulator of cytokine function exhibiting negative feedback to maintain steady plasma IL6 concentration in PR or ER goats during late gestation.

Availability of essential amino acids, nutrient utilisation and growth in juvenile black tiger shrimp, Penaeus monodon, following fishmeal replacement by plant protein

Two trials with juvenile black tiger shrimp ( Penaeus monodon) were undertaken to study the effects of replacing fishmeal by different levels of plant proteins on growth performances and nutrient utilisation of shrimp in semi-intensive conditions (Expt. 1) and on the availability of dietary nitrogen (N) and amino acids (Expt. 2). Five isoproteic diets (on crude protein basis) were formulated to contain 34, 24, 16, 8, or 0% fishmeal, with fishmeal being replaced by a mixture of plant protein (corn gluten meal, wheat gluten, and rapeseed meal). In Expt. 1, the shrimp (initial body weight, IBW 1.5 ± 0.1 g) were reared in earthen ponds for 144 days and fed one of the experimental diets. Apparent digestibility of nutrients and AA were assessed in Expt. 2, using 150 L tanks and shrimp of 12.8 ± 0.4 g IBW. After 144 days in grow-out ponds, shrimp fed the diet with 24% of fishmeal had similar growth as those fed the control diet containing 34% fishmeal (0% replacement). When 50% or more of the fishmeal were replaced, weight gain as well as N and energy gains significantly decreased. Digestibility of dry matter, protein and energy was also significantly lower in all fishmeal-replaced diets. In particular, leucine digestibility decreased by 26% at 100% replacement, which was significantly correlated to an increased incorporation of corn gluten meal. Our data confirm the need to improve our knowledge on AA availability and raw material quality in order to improve fishmeal replacement in P. monodon diets.

Proximate Composition, Total Phenolic Content, and Antioxidant Activity of Seagrape (Caulerpa lentillifera)

The proximate composition of seagrape (Caulerpa lentillifera) from culture ponds in Penghu, Taiwan was analyzed. The phenolic content and the antioxidant activities including the 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity, ferric ion-reducing activity, hydrogen peroxide scavenging activity, and ferrous ion chelating (FIC) activity of the ethanolic extracts of dry seagrape samples using 2 drying methods of freeze drying and thermal drying were compared with the ethanolic extract of Oolong tea as a reference. The contents (dry weight basis) of carbohydrate, crude protein, crude lipid, crude fiber, and ash of seagrape obtained from culture ponds in Taiwan were 64.00%, 9.26%, 1.57%, 2.97%, and 22.20%, respectively. The total phenolic content (1.30 mg gallic acid equivalent [GAE]/g dry weight) of the ethanolic extract of thermally dried seagrape was significantly lower (P < 0.05) than that (2.04 mg GAE/g dry weight) of freeze-dried seagrape, and both were significantly lower than that (13.58 mg GAE/g dry weight) of Oolong tea. At the same phenolic content, the antioxidant activities of freeze-dried seagrape were significantly higher (P < 0.05) than those of thermally dried seagrape. Compared with Oolong tea, seagrape, irrespective of drying method used, generally had strong hydrogen peroxide scavenging activity; but it was weak in DPPH radical scavenging activity, ferric ion-reducing activity, and FIC activity. The antioxidant activity of seagrape and Oolong tea was significantly influenced by their phenolic contents. The proximate composition, total phenolic content, and antioxidant activity of seagrape (Caulerpa lentillifera) in Taiwan were determined in this research to indicate nutritionally of this edible seaweed to human health, and compared these results to previous studies.

Apparent digestibility coefficients of several protein sources, and replacement of fishmeal by porcine meal in diets of Japanese seabass, Lateolabrax japonicus, are affected by dietary protein levels

A digestibility and a growth trial were conducted in this study respectively. Firstly, the apparent digestibility coefficients (ADC) of nutrients and energy in meat and bone meal, porcine meal (PM), hydrolysed feather meal, poultry by-products meal, fishmeal (FM), soybean meal and spray-dried blood meal were determined. In experiment 2, an 8-week growth trial was conducted to evaluate the effects of the substitution of FM by PM under the digestible ideal protein concept at two protein levels in the diets of Japanese seabass, Lateolabrax japonicus. A FM-based control diet (FM diet; FM: 320 g kg−1, crude protein: 434.9 g kg−1, crude lipid: 124.6 g kg−1) and three other diets were formulated to contain 115 g kg−1 PM and only 160 g kg−1 FM. Two diets were formulated on a crude protein basis without (PM diet) or with (PMA diet) essential amino acid (EAA) supplementation respectively. A low-protein diet was designed (LPMA diet, crude protein: 400.9 g kg−1, crude lipid: 96.3 g kg−1) with the same level of FM and PM but with the same digestible protein/ digestible energy and EAA profile as the FM diet. The results showed that nitrogen and total amino acid digestibility of the tested ingredients were ranged from 85.6% to 95.5% and from 87.6% to 95.5% respectively. Apparent digestibility coefficients of protein for FM and PM were 91.2% and 95.9% respectively. In the growth trial, the weight gain rate and feed conversion ratio of fish fed the PMA diet did not show a significant difference from those of the control group, but were significantly higher than those of the PM and LPMA groups (P<0.05). Growth was related linearly to lysine and methionine intakes. It was shown that PM could be utilized in the Japanese seabass diet up to 115 g kg−1 to replace about 160 g kg−1 of FM protein under an ideal protein profile. Essential amino acid deficiency (diet PM) or a lower protein level despite having an ideal amino acid profile (diet LPMA) could not support the optimal growth of Japanese seabass.

Effect of using okara meal, a by-product from soymilk production as a dietary protein source for Nile tilapia (Oreochromis niloticus L.) mono-sex males

The main objectives of this study was to evaluate the effect of partial and total replacement of fishmeal protein by okara meal (OM) protein in practical diets on growth performance, feed utilization and body composition of Nile tilapia (Oreochromis niloticus L.) mono-sex males. Fish of an average initial weight of 2.67 ± 0.01 g were stocked in 15 glass aquariums (80 L each) at a rate of 15 fish per aquarium. Fishmeal protein (18% of the diet) was used as the sole source of animal protein in the control diet. Percent replacement of fish meal (FM) by OM on the basis of crude protein was as follows: 0% (control diet A), 25% (diet B), 50% (diet C), 75% (diet D) and 100% (diet E). Diets were fed to fish at a rate of 5%, and then gradually reduced to 4% of the total fish biomass daily, for a period of 12 weeks. The results revealed that the fish fed diets A (100% FM control), B (25% OM), C (50% OM) and D (75% OM) had significantly the best average body weight, weight gain g, specific growth rate (SGR % day−1), weight gain % and feed intake g fish−1 compared with diet E (100% OM) which had the lowest values. There were no significant differences (P > 0.05) among all experimental diets and control in terms of feed conversion ratio (FCR), protein efficiency ratio (PER) and survival rate %. Whole body protein contents for fish fed diets B, C and D were superior to the control diet. Incorporation of OM in the diets increased significantly whole body fat content. Incorporation of OM in the diets significantly increased apparent digestibility coefficient of crude protein crude fat and energy. Therefore, these findings suggest that up to 75% of FM protein can be replaced by OM protein in Nile tilapia, mono-sex male diets.

ORIGINAL ARTICLE: Effect of rendering on protein and fat quality of animal by-products

This work studies the effect of rendering on quality of meat and bone meals (MBM) processed in two Spanish rendering plants according to the standard procedure recommended by 96/499/EC Directive for MBM category III. Twelve samples of raw animal by-products and their corresponding meals were analysed for chemical composition, amino acids (AA) content, FDNB-reactive lysine content, pepsin digestibility, protein dispersibility index (PDI) and fatty acids (FA) content. There was a high variation in MBM composition between and within plants, mainly in the ash and fat content. Rendering caused a decrease in the total (p < 0.05) and the essential (p < 0.01) AA content (in crude protein basis) in both plants, because of a decrease in lysine (p < 0.001), methionine (p < 0.05), threonine (p < 0.01), leucine (p < 0.01), valine (p < 0.01) and phenylalanine (p < 0.01). Besides, there was a reduction in the cystine (p < 0.001), serine (p < 0.01) and aspartic acid (p < 0.01) content. The FDNB-reactive lysine to total lysine ratio and pepsin digestibility only decreased (p < 0.001) in the plant with more severe treatment conditions, whereas the PDI increased (p < 0.05) by the process in both plants. The saturated to unsaturated FA ratio increase on average from 0.73 to 0.88 after rendering, because of the decrease in both linoleic and linolenic acids content and the increase in palmitic and stearic acids content. The results indicate that rendering has negative effects on protein and fat quality of MBM. Variability between and within plants is attributed to differences in raw material, processing conditions and fat removing efficiency. Therefore, a continuous monitoring is recommended to assure the quality of each batch before use.

Nutrition evaluation of sesame seed meal, Sesamum indicum (L.) as alternative protein source in diets of juvenile mono-sex Nile tilapia (Oreochromis niloticus).

he main objective of this study was to evaluate the effect of partial and total replacement of fish meal protein by sesame seed meal (SSM) protein in commercial diets on growth performance, feed utilization and bodycomposition of juvenile mono sex Nile tilapia, Oreochromis niloticus (L.). Fish of an average initial weight of 0.60 ± 0.01 g were stocked in 15 glass aquaria (80 l each) at a rate of 15 fish per aquarium. Fish meal protein (18% of the diet) wasused as the sole source of animal protein in the control diet. Percent replacements of fish meal by sesame seed meal on the basis of crude protein were as follows: 0 % (control diet A), 25 % (diet B), 50 % (diet C), 75 % (dietD) and 100 % (diet E). All tested diets were almost isonitrogenous and fed at a rate of 4 % of fish body weight, and then gradually reduced to 3 % of the total fish biomass daily, for a period of 16 weeks. The results of this study revealedthat, fish fedon diet A (100 % FM) had the highest average body weight, specific growth rate (SGR), weight gain %, feed conversion ratio (FCR), and protein efficiency ratio (PER), but the lowest was obtained with fish fed diet E (100 %SSM). The same parameters of fish fed on diets B (25 % SSM) and diet C (50 % SSM) were not significantly different (P > 0.01) from those of fish fed on the control diet A. Proximate composition of the whole body moisture and ashcontents were not significantly affected (P>0.05) by the dietary treatments.Whole body protein contents for fish fed on diets B, C and D were superior to the control diet. Incorporation of sesame seed meal in the fish diets increasedsignificantly whole body fat content. Incorporation of sesame seed meal in the diets significantly increased apparent digestibility coefficients of crude protein, crude fat and energy. Therefore, these results suggest that up to 50 % of fishmeal protein can be replaced by sesame seed protein in mono sex Nile tilapia diets without any adverse effect on growth performance and feed utilization,body composition and digestibility.