Total Crude Protein Research Articles

Sustainable Large-Scale Aquaculture of the Northern Hemisphere Sea Lettuce, Ulva fenestrata, in an Off-Shore Seafarm

The growing world population demands an increase in sustainable resources for biorefining. The opening of new farm grounds and the cultivation of extractive species, such as marine seaweeds, increases worldwide, aiming to provide renewable biomass for food and non-food applications. The potential for European large-scale open ocean farming of the commercial green seaweed crop Ulva is not yet fully realized. Here we conducted manipulative cultivation experiments in order to investigate the effects of hatchery temperature (10 and 15 °C), nutrient addition (PES and 3xPES) and swarmer density (500 and 10,000 swarmers ml−1) on the biomass yield and biochemical composition (fatty acid, protein, carbohydrate, pigment and phenolic content) of off-shore cultivated Ulva fenestrata in a Swedish seafarm. High seedling densities were optimal for the growth of this northern hemisphere crop strain and significantly increased the mean biomass yield by ~84% compared to low seedling densities. Variations of nutrients or changes in temperature levels during the hatchery phase were not necessary to increase the subsequent growth in an open-water seafarm, however effects of the factors on the thallus habitus (thallus length/width) were observed. We found no significant effect of the environmental factors applied in the hatchery on the total fatty acid or crude protein content in the off-shore cultivated Ulva. However, low seedling density and low temperature increased the total carbohydrate content and furthermore, high temperature in combination with high nutrient levels decreased the pigment content (chlorophyll a, b, carotenoids). Low temperature in combination with high nutrient levels increased the phenolic content. Our study confirms the successful and sustainable potential for large-scale off-shore cultivation of the Scandinavian crop U. fenestrata. We conclude that high seedling density in the hatchery is most important for increasing the total biomass yield of sea-farmed U. fenestrata, and that changing temperature or addition of nutrients overall does not have a large effect on the biochemical composition. To summarize, our study contributes novel insights into the large-scale off-shore cultivation potential of northern hemisphere U. fenestrata and underpins suitable pre-treatments during the hatchery phase of seedlings to facilitate a successful and cost-efficient large-scale rope cultivation.

Proximate Composition and Amino Acid Profile of the Edible Muscle of European Crayfish Astacus astacus L. Inhabiting the Orchomenos Region in Central Greece

The aim of this study was to determine the proximate composition and amino acid profile of the edible muscle of European crayfish Astacus astacus L. Animals were collected from Orchomenos region in Central Greece and muscle tissue samples were collected for chemical analysis. Total crude protein and crude lipid content of muscle tissues were determined using the Kjeldahl method and Folch’s procedure, respectively. Amino acids profile was performed by Ultra Performance Liquid Chromatographic (UPLC) determination of the acid hydrolysed muscle extract after derivatization with AccQ-Tag reagent (Waters, USA). The results showed that protein and lipid content of crayfish muscle tissue were 16.55 ± 0.4 g 100 g-1 and 0.52 ± 0.20 g 100 g-1, respectively. Also, the moisture and ash content were 80.93 ± 0.36 g 100 g-1 and 1.25 ± 0.14 g 100 g-1, respectively. Amino acids analysis of muscle tissue revealed that the highest values were those of glutamic acid (2.98 g 100 g-1) and arginine (2.19 g 100g-1) as well as those for aspartic acid (1.88 g 100 g-1), lysine (1.47 g 100 g-1) and leucine (1.33 g 100 g-1). The lowest values were found for histidine (0.35 ± 0.03 g 100 g-1) and methionine (0.47 ± 0.01 g 100 g-1). The results of this study showed that the crayfish of Orchomenos region can be considered as an important source of essential nutrients in the human diet due to its protein and essential amino acids content, which are relatively comparable to those of farmed sea bream (Sparus aurata L.), as well as to farmed and wild sea bass (Dicentrarchus labrax). However, the lipid content of Orchomenos crayfish was found to be insignificant and negligible. Overall, the protein quality of European crayfish can be considered as a main factor in selecting this species as a candidate species for European aquaculture diversification.

Proximate Composition and Amino Acid Profile of the Edible Muscle of European Crayfish Astacus astacus L. Inhabiting the Orchomenos Region in Central Greece

The aim of this study was to determine the proximate composition and amino acid profile of the edible muscle of European crayfish Astacus astacus L. Animals were collected from Orchomenos region in Central Greece and muscle tissue samples were collected for chemical analysis. Total crude protein and crude lipid content of muscle tissues were determined using the Kjeldahl method and Folch’s procedure, respectively. Amino acids profile was performed by Ultra Performance Liquid Chromatographic (UPLC) determination of the acid hydrolysed muscle extract after derivatization with AccQ-Tag reagent (Waters, USA). The results showed that protein and lipid content of crayfish muscle tissue were 16.55 ± 0.4 g 100 g-1 and 0.52 ± 0.20 g 100 g-1, respectively. Also, the moisture and ash content were 80.93 ± 0.36 g 100 g-1 and 1.25 ± 0.14 g 100 g-1, respectively. Amino acids analysis of muscle tissue revealed that the highest values were those of glutamic acid (2.98 g 100 g-1) and arginine (2.19 g 100g-1) as well as those for aspartic acid (1.88 g 100 g-1), lysine (1.47 g 100 g-1) and leucine (1.33 g 100 g-1). The lowest values were found for histidine (0.35 ± 0.03 g 100 g-1) and methionine (0.47 ± 0.01 g 100 g-1). The results of this study showed that the crayfish of Orchomenos region can be considered as an important source of essential nutrients in the human diet due to its protein and essential amino acids content, which are relatively comparable to those of farmed sea bream (Sparus aurata L.), as well as to farmed and wild sea bass (Dicentrarchus labrax). However, the lipid content of Orchomenos crayfish was found to be insignificant and negligible. Overall, the protein quality of European crayfish can be considered as a main factor in selecting this species as a candidate species for European aquaculture diversification.

STATIC MAGNETIC FIELD WITH 2 MT STRENGTH CHANGES THE STRUCTURE OF WATER MOLECULES AND EXHIBITS REMARKABLE INCREASES IN THE YIELD OF PHASEOLUS VULGARIS

In this study, we aimed to examine the effects of a 2 mT strength static magnetic field, which is generated by placing a permanent magnet in water for 1 h, on the physical properties of magnetized water, such as its viscosity, conductivity, and pH value. The growth and yield of Phaseolus vulgaris irrigated with tap water and magnetized water were also examined and compared. We further evaluated its morphological characteristics, such as plant height, number of pods per plant, number of seeds per pod, and fresh and dry weight of seeds, and physiological parameters (i.e., chlorophyll content, total sugar content, some elements, and crude protein concentration). As per our findings, the measured parameters of plants irrigated with magnetized water exhibited remarkable increases compared to those irrigated with tap water, in addition to increased seed production at harvest and changes in the concentration of elements. Despite the weak strength of the magnetic field, the pH value increased by 11.6%, viscosity by 10%, and conductivity by 10%.

Effects of Harvest and Fertilization Frequency on Protein Yield and Extractability From Flood-Tolerant Perennial Grasses Cultivated on a fen Peatland

Paludiculture, and in particular the cultivation of perennial grasses as biomass feedstock for green biorefineries, may be an economic and environmentally sustainable option for agricultural peatlands in temperate regions. However, the optimal biomass quality for protein extraction from flood-tolerant grasses is largely unknown. The aim of this study was to define the combined effect of harvest and fertilization frequency, with one to five annual cuts, on protein yield and extractability for the grasses tall fescue (TF) and reed canary grass (RCG), cultivated on an agricultural fen peatland in Denmark.The content of protein fractions was determined according to the Cornell Net Carbohydrate and Protein System (CNCPS). We assessed protein extractability by lab-scale biorefinery techniques using a screw-press followed by acid precipitation of true protein. The two methods were compared to correlate potential extractable protein yields with actual biorefinery outputs. We found the highest annual biomass and crude protein (CP) yields in the two cut treatments, with 13.4 and 15.6 t dry matter (DM) ha−1 year−1, containing 2.9–3.4 t CP ha−1 year−1for TF and RCG, respectively. The highest neutral-extractable (fractions B1and B2) true protein yields of 1.1 and 1.5 t ha−1 year−1were found in the two cut treatments, representing 39% (TF) - 45% (RCG) of total CP. Using biorefining techniques, we were able to precipitate up to 2.2 t DM ha−1 year−1of protein concentrate, containing up to 39% CP. Significant correlations between methods were found, with a distinct relationship between CNCPS fractions B1+ B2and CP yield of the protein concentrate, indicating the suitability of the CNCPS as an indicator for extractable protein yields. Biomass and CP yields were not significantly improved beyond two annual cuts. However, timing and harvest frequencies significantly affected plant maturity and consequently extractable CP contents and protein concentrate yields. We conclude that TF and RCG are promising feedstocks for green biorefineries due to high biomass, extractable CP, and protein concentrate yields, and highlight the potential of flood-tolerant grasses, cultivated on wet agricultural peatlands, for an enhanced valorisation beyond the common utilisation for bioenergy.

Proximate composition, amino acids and fatty acids profiles of wild and cultured Climbing Perch, Anabas testudineus (Bloch, 1795)

The availability and compositions of foods in the aquatic system have a direct influence on nutritional compositions of fish muscle. This research aimed to determine the nutritional compositions of wild and cultured climbing perch, Anabas testudineus, between pre-monsoon and post-monsoon. The proximate compositions, total amino acid, and fatty acid profiles were determined by AOAC, HPLC and GC, respectively. The results in dicated that proximate (e.g., moisture, ash, protein and lipid), amino acid and fatty acid profile varied significantly (p<0.05) between wild and cultured fishes depend on season. The highest amount of moisture (79.62±0.92%) was found in wild A. testudineus and lowest amount of ash (2.50±0.09%) was found in cultured A. testudineus during pre-monsoon. For both cultured and wild A. testudineus, amount of protein was higher in post-monsoon than in pre-monsoon period. The protein and amino acids contents as well as lipid and fatty acids of the fish species showed a significant (p<0.05) seasonal variations. Among the 14 recorded amino acidsthe major amino acids in the total crude protein were histidine, methionine, isoleucine, lysine, glutamic acid, and glycine. The ratio of Essential Amino Acid (EA)/Non-Essential Amino Acid (NEA) was highest (0.34) in cultured fish of post-monsoon season and lowest (0.25) in wild fish of pre-monsoon season. The major fatty acid so wild and cultured A. testudineus were oleic acid (18:1), palmitic acid (16:0), linoleic acid (18:2), stearic acid (18:0), palmitoleic acid (16:1), andmyristic acid (14:0).Some fatty acids [Lauric acid (C12:0), Pentad cyclic acid (C15:0), Arachidic acid (C20:0)]were not detected in cultured fish but present in wild fish. The n-3/n-6 ratio was highest (0.48) in wild fish of post-monsoon season and lowest (0.14) in cultured fish of pre-monsoon season. Therefore, a comprehensive study on wild and cultured climbing perch is required for further confirmation of the result of the present study.
 Bangladesh J. Zool. 48(2): 365-378, 2020

EFFECT OF GUM ARABIC AS PREBIOTIC ON PROBIOTICS AND QUALITY OF YOGHURT DURING COLD STORAGE

This study was conducted to determine the effect of gum Arabic concentrations (0%, 0.7%, 0.9%or 1%) as prebiotic in yoghurt quality and probiotics, experiments were conducted using fresh cow’s milk with 3% starter culture during cold storage in two types of yoghurt (plain and Flavored). The physicochemical parameters included: (moisture, ash content, total solids content, crude protein, fat content, lactose content, pH value and titratable acidity) were measured. Whereas microbial analyses were achieved including: total viable bacteria, lactic acid bacteria, total coliform, E.coli bacteria, yeasts and moulds, as well as the sensory evaluation of produced yoghurt was done. The results showed that no significant difference (p≤0.05) in all parameters. While showed significant difference (p≤0.05) in moisture content in the first day. While the addition of Gum Arabic on yoghurt samples during cold storage led to decreased in total viable bacteria, lactic acid bacteria and improve the quality and microbial properties through increasing the percentage of total solids, protein, fat, lactose and free from total coliform, yeast and mould. Organoleptic properties of the yogurt increased as the percentage of GA advanced in all tested samples. Yogurt produced using (1%) GA had acceptable characteristics. Addition of Gum Arabic to yoghurt product led to improve the quality and microbial properties. This improvement could be due to high amount of uronides.

Potential of Gracilaria tenuistipitata var. liui grown in Nuniachara, Cox’s Bazar, Bangladesh

During selection of Gracilaria tenuistipitata var. liui (red seaweed) growing naturally at Nuniachara sand-flat south-east of Moheshkhali channel, Cox’s Bazar local fishermen informed that Rakhaine and Chakma tribes of Cox’s Bazar and Bandarbon consume the seaweed. To ascertain the quality of the organism as “Seafood” analysis of its nutritional status was carried out using three replicates in many cases. Percentage composition of total crude protein, crude fiber, crude lipid, carbohydrates, ash and moisture were 25.55 ± 0.18, 5.65 ± 0.13, 0.16 ± 0.03, 45.93 ± 1.53, 10.61 ± 0.69 and 12.10 ± 0.25%, respectively. Mineral contents such as phosphorus, calcium, magnesium, iron and copper were 596.90 ± 10.4, 132.75 ± 3.4, 3.90 ± 1.2, 80.13 ± 2.45 and3.99 ± 1.2mg/100gdry wt., respectively. Heavy metals such as Pb, As, Cr and Cd were 0.031, 0.01, 0.06 and 0.02 mg/kg dry wt. respectively, which are below tolerance level. The seaweed contained 9.03% nine essential amino acids and 7.52% five non-essential amino acids. The quantity of total energy, β-carotene and vitamin C were 294.56 Kcal/100g, 11.54 ± 1.20 and 2.5 mg/100g, respectively. Presence of high crude protein, amino acid profiles, β-carotene, phosphorus and low crude lipid and heavy metals made Gracilaria tenuistipitata var. liui to be considered as a good human food supplement.
 Bangladesh J. Sci. Ind. Res.56(1), 39-46, 2021

Effect of Hay Soaking Duration on Metabolizable Energy, Total and Prececal Digestible Crude Protein and Amino Acids, Non-Starch Carbohydrates, Macronutrients and Trace Elements

Soaking hay before feeding has been documented to reduce airborn respirable particles and water-soluble carbohydrate (WSC) content which may have positive benefits for horses suffering from Equine Asthma (EA) or Equine Metabolic Syndrome (EMS). Prolonged soaking also leaches minerals, but to-date no measurement of the loss of small intestine digestible crude protein has been documented. One aim of this study was to investigate various soaking durations on nutrient contents of hay, WSC, macronutrients, and trace elements levels. Another objective was to determine the prececal digestible crude protein (pcd CP) and amino acid (pcd AA) fraction contents and prececal digestibility (pcD). Four different batches of meadow hay were soaked in water (20° C during preparation) for 0 minutes, 15 minutes, 30 minutes, 60 minutes, and 12 hours and drained for 20 minutes. A 15 minutes soaking duration significantly reduced the levels of nearly all investigated nutrients (e.g. for fructans, and WSC, macronutrients and trace elements). However, the crude fiber, acid detergent fiber (ADF), and acid detergent lignin content increased. Metabolizable energy (ME) contents decreased by 5−15 %, pcd CP and pcd AA fell by 35 %, and the pcD declined by up to 49 %. In contrast, the pcD was 56 % before soaking. Longer soaking durations did not enhance the wash-out effect. Horse owners should be aware that soaking hay, regardless of reason, may negatively alter the nutritional value. The wide range of wash-out effects may pose risks in calculating the correct dry matter portion to prevent weight loss and maintain ME, pcd CP and pcd AA requirements, especially for horses with EMS and EA.

Nutritional value and biological properties of Chilean wild and commercial edible mushrooms

The nutritional value and biological properties of 24 samples of Chilean edible mushrooms were evaluated. The nutritional value was determined by measuring moisture, protein, fat, ash and carbohydrate contents. The biological activity was determined by using antibacterial, antifungal and antioxidant tests. The mushrooms showed high total carbohydrate (83.65–62.97 g/100 g dw) and crude protein (23.88–8.56 g/100 g dw) contents, but low fat contents (6.09–1.05 g/100 g dw). Ch2Cl2-extracts were more active against bacteria and fungi than MeOH-extracts. Ch2Cl2-extracts of B. loyo, C. lebre, L. edodes, M. conica and R. flava inhibited the growth of Gram-positive bacteria. The Ch2Cl2-extracts of A. cylindracea, B. loyo, and G. gargal showed strong effects against fungi. R. flava showed the highest phenolic content and antioxidant activity. The Chilean species B. loyo, C. lebre and G. gargal exhibited interesting nutritional value and biological properties, showing potential to be used as a dietary nutritional supplement.

Determination of in vitro dry matter, protein, and fiber digestibility and fermentability of novel corn coproducts for swine and ruminants.

New processes are being used in some dry-grind ethanol plants in the United States and Brazil to improve ethanol yield and efficiency of production while also providing nutritionally enhanced corn coproducts compared with conventional corn distillers dried grains with solubles (DDGS). The objectives of this study were to determine the chemical composition and in vitro digestibility of 5 conventional corn DDGS sources and 10 emerging novel corn coproducts for swine and ruminants, and compare coproducts produced using similar processes in the United States and Brazil. Chemical composition, on a dry matter (DM) basis, among the 15 coproducts ranged from 18.5% to 54.7% for crude protein (CP), 12.3% to 51.4% for neutral detergent fiber (NDF), 1.6% to 8.6% for acid detergent fiber, 4.7% to 12.3% for ether extract, and 1.6% to 8.6% for ash. For swine, in vitro hydrolysis of DM and CP were greater (P < 0.01) for the three U.S. corn DDGS sources compared with the two Brazilian corn DDGS sources, but in vitro fermentability of DM was comparable (P > 0.05) among all sources except one U.S. DDGS source that had less fermentable DM. High-protein and yeast dried distillers grains (Ultramax, UM; StillPro, SP) coproducts also had comparable (P > 0.05) DM fermentability for swine, but UM coproducts had greater (P < 0.01) DM and CP hydrolysis compared with SP. High-protein distillers dried grains (HP-DDG) from Brazil had greater (P < 0.01) DM and CP hydrolysis, but less (P < 0.01) DM fermentability for swine than HP-DDG produced in the United States, using the same process. For ruminants, total DM digestibility was greater (P < 0.01) in conventional DDGS sources from the United States compared with the two DDGS sources from Brazil. Total protein digestibility for ruminants was comparable and above 81% for all coproducts except for a DDGS source from Brazil, a HP-DDG source from the United States, and a UM sample. Interestingly, the corn fiber + solubles coproduct had not only relatively high digestibility of NDF (67.9%), DM (91.6%), and total CP (81.9%) for ruminants, but it also had relatively high total tract digestibility of DM (86.2%) and CP (69.9%) for swine. These results suggest that nutrient digestibility of conventional DDGS sources produced in the United States appear to be greater than corn Brazilian DDGS sources, but new process technologies being implemented in ethanol and coproduct production in both countries can enhance the nutritional value of corn coproducts for both swine and ruminants.

Antifungal Properties of Protein Extracts from Thai Medicinal Plants to Opportunistic Fungal Pathogens

Antifungal proteins or peptides (AFPs) are the natural products produced by several life forms including plants as the first-line defenses to infections. The AFPs from Thai plants can be used as new therapeutic agents in the world with growing resistance to conventional antifungals. This study determined the antifungal activities of protein extracts from Thai medicinal plants against important human opportunistic fungi, Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus, and Talaromyces marneffei. Total crude protein supernatants and their precipitated proteins from 10 Thai medicinal plants with the historical usage for treatment of fungal infection were prepared. Most of the protein extracts showed antifungal activities to the tested fungi. The most effective reactivity found in the extracts from Rhinacanthus nasutus, Andrographis paniculata, and Psidium guajava by showing highest activity to T. marneffei ATCC200051 (yeast phase), followed by C. neoformans ATCC90112, C. albicans ATCC90028, T. marneffei ATCC200051 (mold phase), and A. fumigatus NCPF7367. The precipitated proteins from R. nasutus and A. paniculata containing antifungal properties were selected for partial purification by size cut-off membrane centrifugation and tested for antifungal activities. A colorimetric broth microdilution method was used to determine the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) to anti-T. marneffei. The partially purified fractions from A. paniculata, and R. nasutus showed anti-T. marneffei activity with the MIC and MFC values ranged from 2 to 128 μg/mL and 16 to &gt;128 μg/mL, respectively. Therefore, A. paniculata and R. nasutus can be further subjected to the study of the therapeutic antifungals.

The effects of rumen nitrogen balance on intake, nutrient digestibility, chewing activity, and milk yield and composition in dairy cows vary with dietary protein sources

The objective was to study the interaction effects of rumen nitrogen balance (RNB) and dietary protein source on feed intake, apparent total-tract digestibility (ATTD), eating and ruminating activity, milk yield (MY), and milk composition in lactating dairy cows. Twenty-four lactating Holstein cows were divided in 4 groups, which were randomly assigned to the dietary treatments included in a replicated 4 × 4 Latin square experimental design that consisted of four 20-d periods, each with 12 d of adaptation to the experimental diets and 8 d of sampling. The dietary treatments followed a 2 × 2 factorial arrangement with 2 main protein sources, faba bean grain (FB) and SoyPass (SP; Beweka Kraftfutterwerk GmbH), offered at 2 dietary RNB levels: RNB0 (RNB of 0 g/kg of dry matter) and RNB- (RNB of -3.2 g/kg of dry matter; i.e., 4 treatments). The composition of concentrate mixtures was adjusted to create diets with the desired RNB levels. Each of the protein sources supplied ≥35% of the total dietary crude protein (CP). Both diets within a protein source had similar forage sources and forage to concentrate ratios and were iso-energetic, but differed in CP concentrations. The main effects of RNB, protein source, and their interactions were tested by PROC MIXED in SAS 9.4 (SAS Institute Inc.). Interaction effects were observed for daily dry matter intake and energy-corrected MY, which were lower for RNB- than RNB0 in diets containing FB (23.5 vs. 24.4 kg dry matter/d; 28.6 vs. 30.6 kg milk/d), but similar in diets containing SP (24.2 vs. 24.3 kg dry matter/d; 31.3 vs. 31.7 kg milk/d). The ATTD of NDF was lower for RNB- compared with RNB0 in the FB (44.9 vs. 49.1 g/100 g) and SP (48.5 vs. 51.9 g/100 g) diets, and greater for the SP than for FB diets. There were interaction effects for ATTD of CP and concentrations of milk urea nitrogen, which were lower for RNB- compared with RNB0 in both, FB (55 vs. 63.1 g/100 g of CP; 5.65 vs. 11.3 mg/dL milk) and SP diets (60 vs. 64.4 g/100 g of CP; 8.74 vs. 13.4 mg/dL milk). However, differences between RNB levels were greater for FB than for SP diets. Furthermore, proportions of milk fatty acids followed the same pattern as that of dietary fatty acids, but biohydrogenation appeared to be greater for RNB- than RNB0 for both protein sources and in FB than in SP diets for both RNB levels. There was an interaction effect on total number of chews per unit of NDF intake, which was greater for RNB- compared with RNB0 for both protein sources. However, the differences between RNB levels were greater in FB than in SP diets. Overall, differences in the animal responses to negative RNB between FB and SP diets suggest a need to better understand the effect of negative RNB levels with different dietary ingredients at similar utilizable CP supply.

Effects of boric acid on the growth performance and nutritional content of rainbow trout (Oncorhynchus mykiss)

In this study, boric acid was added to the rainbow trout (Oncorhynchus mykiss) feed at ratios of 0.00%, 0.01%, 0.05%, 0.10%, and 0.20%. The feeding period of this study continued for 90 days. The effect of boric acid on the growth parameters and nutritional composition of rainbow trout were investigated. In this research, effects on live weight gain (LWG), amount of feed intake, feed conversion rate (FCR), protein efficiency rate (PER), specific growth rate (SGR), survival rate, economic conversion rate (ECR), and economic profit index (EPI) were evaluated as growth parameters. As for nutritional contents, the total crude protein, lipid, raw ash, and humidity ratios were calculated. Rainbow trout with an initial weight of 92.04 g reached up to 195.05 ± 1.69 g, 202.69 ± 1.94 g, 217.53 ± 2.84 g, 195.25 ± 2.18 g, and 181.20 ± 1.89 g, respectively in the different levels of boric acid at the end of the trial period. The best growth performance was obtained in the group with 0.05% boric acid added, while the lowest growth performance was observed in the group with 0.20% boric acid added. It was concluded based on the results of this study that the amount of boric acid up to 0.05% in the fish feed positively affected the growth parameters and the addition of higher amounts had either no benefit or negative effects on the growth performance of rainbow trout. Furthermore, boric acid in feed affected the nutritional composition of fish meat.

Optimum grape pomace proportion in feedlot cattle diets: ruminal fermentation, total tract nutrient digestibility, nitrogen utilization, and blood metabolites.

Because of its high content of polyphenolic compounds, the dietary inclusion of grape pomace (GP) in ruminant diets can reduce reactive nitrogen (N) and methane emissions and enhance the shelf life and beneficial fatty acids (FAs) content of meat. However, the dietary inclusion of GP beyond a threshold that is still to be determined for feedlot cattle can also compromise nutrient supply and, thus, growth performance. This study investigated the optimum proportion of GP in finishing cattle diets. Nutrient intake and apparent total tract digestion, ruminal pH and fermentation, estimated microbial protein synthesis, route of N excretion, and blood metabolites were measured. Six ruminally fistulated crossbred beef heifers (mean initial body weight ± SD: 714 ± 50.7 kg) were used in a replicated 3 × 3 Latin square with 21-d periods. Dietary treatments were 0%, 15%, and 30% of dietary dry matter (DM) as GP, with diets containing 84%, 69%, and 54% dry-rolled barley grain, respectively. There was a linear increase (P = 0.07) in DM intake and quadratic change (P ≤ 0.01) in neutral detergent fiber (NDF) intake. There was a quadratic change (P ≤ 0.04) in apparent total tract DM, NDF, and crude protein digestibility as dietary GP content increased. However, there were no treatment effects (P ≥ 0.18) on total ruminal short-chain FA concentration and duration and area pH < 6.2, 5.8, and 5.5. Although N intake did not differ (269, 262, 253 g/d; P = 0.33) across dietary treatments, feeding GP led to a tendency for a quadratic change (P ≤ 0.07) in ruminal ammonia-N and plasma urea-N concentrations. Total N excretion also changed (quadratic, P = 0.03) because of changes (quadratic, P = 0.02) in fecal N excretion as urinary excretion of N and urea-N did not differ (P ≥ 0.15) across treatments. Feeding GP led to quadratic changes (P ≤ 0.01) in fecal excretion of fiber-bound N. Microbial N flow and apparent N retention also changed (quadratic, P ≤ 0.04) as dietary GP proportion increased. In conclusion, responses to dietary GP proportion were mostly quadratic with indications that nutrient supply as reflected by changes in apparent total tract nutrient digestibility, microbial N supply, and apparent N retention could be compromised beyond a 15% dietary inclusion level.

Potential Viable Products Identified from Characterisation of Agricultural Slaughterhouse Rendering Wastewater

The composition of challenging matrices must be fully understood in order to determine the impact of the matrix and to establish suitable treatment methods. Rendering condensate wastewater is a complex matrix which is understudied. It is produced when the vapour from rendering facilities (heat processing of slaughterhouse waste material) is cooled as a liquid for discharge. This study offers a full physicochemical characterisation of rendering condensate wastewater and its potential for valorisation via production of viable by-products. A study of seasonal variation of levels of dissolved oxygen, chemical oxygen demand, total nitrogen and ammonia was carried out on the wastewater. The results show that the wastewater was high strength all year-round, with a chemical oxygen demand of 10,813 ± 427 mg/L and high concentrations of total Kjeldahl nitrogen (1745 ± 90 mg/L), ammonia (887 ± 21 mg/L), crude protein (10,911 ± 563 mg/L), total phosphorous (51 ± 1 mg/L), fat and oil (11,363 ± 934 mg/L), total suspended solids (336 ± 73 mg/L) and total dissolved solids (4397 ± 405 mg/L). This characterisation demonstrates the requirement for adequate treatment of the condensate before releasing it to the environment. While there is a reasonably constant flow rate and dissolved oxygen level throughout the year, higher chemical oxygen demand, total nitrogen and ammonia levels were found in the warmer summer months. From this study, rendering condensate slaughterhouse wastewater is shown to have potential for production of marketable goods. These products may include ammonium sulphate fertilizer, protein supplements for animal feeds and recovery of acetic acid calcium hydroxyapatite, thus enhancing both the financial and environmental sustainability of slaughterhouse operations. This work demonstrates a valuable assessment of a complex wastewater, while taking advantage of on-site access to samples and process data to inform the potential for wastewater reuse.

The effects of rumen nitrogen balance on nutrient intake, nitrogen partitioning, and microbial protein synthesis in lactating dairy cows offered different dietary protein sources

The aim was to study the effects of rumen N balance (RNB), dietary protein source, and their interaction on feed intake, N partitioning, and rumen microbial crude protein (MCP) synthesis in lactating dairy cows. Twenty-four lactating Holstein cows were included in a replicated 4 × 4 Latin square experimental design comprising four 20-d periods, each with 12 d of adaptation to the experimental diets and 8 d of sampling. The dietary treatments followed a 2 × 2 factorial arrangement (i.e., 4 treatments) with 2 main protein sources [faba bean grain (FB) and SoyPass (SP; Beweka Kraftfutterwerk GmbH, Heilbronn, Germany)] offered at 2 dietary RNB levels each [0 g/kg of dry matter, DM (RNB0) and -3.2 g/kg of DM (RNB-)]. The RNB was calculated as the difference between dietary crude protein (CP) intake and the rumen outflow of undegraded feed CP and MCP and divided by 6.25. Composition of concentrate mixtures was adjusted to create diets with desired RNB levels. Each of these protein sources supplied ≥35% of total dietary CP. Both diets for each protein source were isoenergetic but differed in CP concentrations. The DM intake (kg/d) was lower for RNB- than for RNB0 in diets containing FB, whereas no differences were seen between the RNB levels for SP diets. The RNB- decreased N intake and urinary N excretion but increased milk N use efficiency in both FB and SP diets, with greater differences between the RNB levels for FB diets than for SP diets. Similarly, duodenal MCP synthesis (g/kg of digestible organic matter intake) estimated from purine derivatives in the urine was lower for RNB- than for RNB0 in FB diets but similar between the RNB levels in diets containing SP. Low RNB of approximately -65 g/d (approximately -3.2 g/kg of DM) in diets reduced feed intake, N balance, and performance in high-yielding dairy cows with possibly more pronounced effects in diets containing rapidly degradable protein sources.

Total Crude Protein and Fat in Meat of African Catfish (Clarias gariepinus) Fed a Diet Containing Dried Larvae of Black Soldier Fly (Hermetia illucens)

Total Crude Protein and Fat in Meat of African Catfish (Clarias gariepinus) Fed a Diet Containing Dried Larvae of Black Soldier Fly (Hermetia illucens)

The effect of wet-salting preservation method on the physicochemical and microbial quality of Dasyatis sp.

Microbial Dasyatis sp. (stingray fish) was a popular fish in Indonesia. Commonly, this fish is processed into smoked fish and perishable products. Therefore, it needs a preservation method through the handling process. Wet salting was considered as an efficient and inexpensive preservation method. This study aimed to determine the effect of brine concentration on the physicochemical and microbial quality of Dasyatis sp. The research used a Completely Randomized Design with factor of brine concentration (i.e. 10%, 20% and 30%). The statistical analysis consists of variance analysis (ANOVA) and followed by LSD or DMRT test (α=5%). The fish sample was soaked in brine solution at different concentrations for one hour. Total crude protein, physicochemical (total volatile basic nitrogen/TVB-N, tri-methyl amine/TMA, and pH), and (total plate count/TPC) were analyzed. The results showed that the brine concentration effect of physicochemical and microbiological of Dasyatis sp (p&lt;0.05). The best treatment was obtained at the application of 10% brine concentration, which had physicochemical parameters as follows: 6.92 pH, 6.110 mgN/100g TVB-N, 5.520 mgN/100g TMA, 16.78 % protein, and 0.537x105 CFU/ml TPC.

Nutritional potential of marine and freshwater algae as dietary supplements for growing rabbits

The aim of this study was to investigate the effect of including marine and freshwater algae in rabbit diets on their performance, digestibility, carcass characteristics, and blood metabolites. One hundred growing male rabbits, aged 30 d and weighing 783.5 ± 2.01 g initial body weight, were randomly assigned to five treatment groups (n = 20 rabbits). Five comparable dietary groups were formulated as follows: the control diet was a basal diet without aquatic plants inclusion, while the diets for the other four treatments included the basal diet plus 4% of marine algae (U. lactuca and P. capillacea) or freshwater algae (S. polyrrhiza and C. aegagropila). Compared with the control group, final body weight, daily weight gain, and feed conversion ratio improved significantly in UL group; followed by those in PC and SP groups (p < .05). Total digestible nutrients and digestible crude protein increased significantly in UL, PC and SP groups. Rabbits in the CA group had lower nitrogen intake, N digested, and N balance decreased than the other groups (p < .05). The UL group had dressing weight and meat protein significant increases, but the SP and CA groups had significant increases in liver, kidney, and spleen weights (p < .05). Including marine and freshwater algae reduced (p < .05) total lipids, total bilirubin, triglycerides, and cholesterol especially in the UL and PC groups, and similarly, HDL and LDL levels were lower in the UL, PC, and SP groups compared to the CA and control groups. In conclusion, the responses in performance, digestibility, and blood metabolites suggest that aquatic plants (with the exception of CA) have the potential to be a sustainable feedstock for growing rabbits' diets. Highlights Ulva lactuca, Pterocladia capillacea and Spirodela polyrrhiza improve rabbits' performance. Marine and freshwater algae inclusion showed no signs of disease. Marine and freshwater algae reduced total lipids, triglycerides, and cholesterol.