Protein Digestibility Coefficients Research Articles

The effects of using hydrolyzed feather meal, amino acids, and probiotics in the diet of juvenile rainbow trout on growth, digestibility, and expression of growth-related genes

AbstractThe study investigated the effect of replacing fishmeal by varying levels of hydrolyzed feather meal (HFM) as well as dietary probiotic supplementation on growth performance, digestibility, histology, and gene expression of juvenile rainbow trout (Oncorhynchus mykiss). Five iso-nitrogenous (average of 50.60% crude protein), iso-energetic (average of 21.79 kJ/g), and iso-lipidic (average of 21.86% crude lipid) diets were formulated and fed to triplicate groups of juvenile rainbow trout weighing 29.65 ± 0.39 g (mean ± SD) for 75 days. Dietary treatments included one control (50% fishmeal) and four experimental diets, each containing 2 g/kg probiotics (Lactobacillus plantarum and Bacillus subtilis). The experimental diets included HFM30 (150 g/kg HFM, 9 g/kg lysine, and 4 g/kg methionine), HFM35 (175 g/kg HFM, 11 g/kg lysine, and 5 g/kg methionine), HFM40 (200 g/kg HFM, 13 g/kg lysine, and 6 g/kg methionine), and HFM45 (225 g/kg HFM, 15 g/kg lysine, and 7 g/kg methionine). Up to 40% replacement of fishmeal with HFM showed no significant difference compared to control group in growth performance (P > 0.05). Feed utilization of HFM45 was slightly lower than control and all the other experimental groups. There was no statistically significant difference in FCR value between HFM40 and control groups (P > 0.05). The apparent digestibility coefficients (ADCs) for protein and amino acids were very high in all groups (P < 0.05). Intestinal mucosa and sub‐mucosa layers of experimental fish showed general tissue integrity with no signs of tissue necrosis. For intestinal morphology, where 45% HFM replacement was applied, villus length to crypt depth (VL to CD) and villus surface area (SA) decreased by 46.01% and 44.44%, respectively, compared to the control group (P < 0.05). This situation shows that intestinal morphology can be damaged when the highest level (HFM45) of feather meal is used. Dietary HFM upregulated growth-related genes such as IGF-II, IGFBP-1b, IGFr1a, GDF9, and FGF2 and downregulated GHR-I and IGF-I. Overall, inclusion of HFM at 40% showed similar results to control group in juvenile rainbow trout feeding.

Effect of taurine on growth and immune response of Pacific white shrimp (Litopenaeus vannamei) cultured at different temperatures

Low temperature is a common challenge in the culture of Pacific white shrimp (Litopenaeus vannamei), and taurine is a potential nutrient that may improve its cold-resistance. This experiment aimed to investigate effects of dietary taurine on growth and immune response of Pacific white shrimp cultured at normal and cold temperatures. Six diets were supplemented with increasing levels of taurine (0, 0.2, 0.4, 0.6, 0.8 and 1.0%) and fed to shrimp (1.59 ± 0.03 g) reared at two water temperatures (28 °C and 20 °C) for 8 weeks. The results showed that compared with 28 °C, shrimp reared at 20 °C showed lower growth performance, feed utilization, apparent digestibility and total hemocyte count (THC) (P < 0.05), but higher content of serum glucose, intracellular reactive oxygen species (ROS) and Ca2+, malonaldehyde (MDA) and apoptosis rate (P < 0.05), indicating a higher risk of oxidative damage during low temperature stress. Interestingly, shrimp could cope with cold stress by changing hemocyte composition, increasing antioxidant enzyme activity and genes expression of apoptosis and autophagy. The effect of taurine was different at different temperatures. At 28 °C, taurine supplementation improved growth rate of shrimp by increasing digestive enzyme activities, digestion absorption rate and nutrient utilization. Based on the quadratic model of weight gain rate, feed efficiency, protein retention efficiency and the broken line model of apparent digestibility coefficients of protein, the amount of taurine required for shrimp reared at 28 °C was 0.57–0.60% of dry diet. At 20 °C, taurine increased the number of THC, granulocytes, semi-granulocytes, the activities of antioxidant enzymes such as superoxide dismutase and catalase, and decreased the content of ROS in the cells, which may enhance cold resistance of shrimp. Moreover, taurine supplementation down-regulated mRNA expression of cell apoptosis genes (cyt-c, caspase-9 and caspase-3) and up-regulated mRNA expression of cell autophagy genes (atg1, atg13, atg7 and lc3) (P < 0.05), which may help to maintain cell stability at 20 °C. The optimal requirement of taurine in shrimp reared at 20 °C was 0.56–0.66% of dry diet in this experiment based on THC and MDA content. In conclusion, our study suggests that appropriate taurine promotes growth and feed utilization at optimal temperature and enhances the stability of hemocyte at low temperature in white shrimp.

Dried crickets (Gryllus sigillatus) or black soldier fly (Hermetia illucens) larvae meal for broiler chickens: nutrient composition and digestibility

Abstract This study explores the potential of cricket meal and black soldier fly larvae meal (BSFLM) as alternative protein sources in broiler chicken diets. With the use of the substitution method, using diatomaceous earth as an external marker, we investigated the nutrient availability and apparent metabilizeable energy content of oven-dried full-fat cricket meal (OD-CM), freeze-dried full-fat cricket meal (FD-CM), and defatted BSFLM in a feeding trial involving 320 Ross 308 broilers housed in 32 pens (8 replicates / treatment; 8 birds / pen). Feed intake, daily weight gain, and feed conversion ratio were measured between days 15 and 21. Excreta collected on days 19, 20, and 21 were analyzed for nutrient content. Both cricket treatments were high in crude protein. Additionally, FD-CM demonstrated the highest fat content, surpassing OD-CM. OD-CM displayed a significantly higher apparent digestibility coefficient for crude protein compared to BSFLM (). FD-CM had the highest apparent digestibility coefficient for gross energy (). The nitrogen-corrected apparent metabolizable energy of OD-CM and FD-CM were significantly higher than that of BSFLM (). Furthermore, OD-CM exhibited a significantly higher available crude protein content compared to BSFLM and FD-CM (). This research sheds light on the potential of OD-CM and FD-CM as valuable alternative protein sources for broiler chickens, providing critical insights for the poultry industry’s sustainable future. This research is important as the apparent digestibility coefficients, as well as available nutrients calculated for the three ingredients may be used to accurately formulate poultry diets on an available nutrient basis.

Solid-state fermentation converts rice bran into a high-protein feed ingredient for Penaeus monodon

Fermented rice bran (FRB) was evaluated as an alternative protein source to soybean meal (SM) in practical diets for juvenile black tiger shrimp, Penaeus monodon. This feed ingredient was tested in a feeding trial to replace soybean meal in P. monodon diets at 0% (T0), 12.5% (T12.5), 25% (T25), 37.5% (T37.5), and 50% (T50). Five iso-nitrogenous and iso-caloric experimental diets containing 44% crude protein were fed to groups of juvenile shrimp (0.47 ± 0.002 g) randomly assigned to twenty 60-l rectangular tanks equipped with a recirculating seawater system. Each dietary treatment was run in 4 replicates, and the feeding trial lasted 50 days. Results show significant improvement in weight gain, specific growth rate, and protein efficiency ratio in treatment T12.5 and T25. Treatments with higher levels of SM replacement with FRB exhibited similar growth indices to those of the control group. Polynomial regression analysis indicates that the optimum replacement of soybean meal with FRB for optimum growth is 21.08%. The apparent dry matter and protein digestibility coefficients of FRB are 83.05 ± 0.02% and 87.20 ± 0.30%, respectively. There were no significant differences in the whole-body composition (dry matter, protein, lipid, ash) among treatments of shrimp fed with FRB replacement. The data suggest that FRB replacement of dietary soybean meal is feasible at 50% without affecting the growth performance but may promote growth at 21.08% replacement of P. monodon.

Influence of Jerusalem artichoke tuber as a prebiotic on the nutrient utilization, weaning stress indicators and immunocompetence of crossbred calves during the pre- and post-weaning phases

This study explored the potential prebiotic properties of pulverized Jerusalem artichoke tuber (JAP) in pre- and post-weaned calves. Accordingly, 24 fifteen-day-old calves were randomly assigned to four groups (n = 6). The groups received JAP supplementation at levels of 0 (CON), 1 (JAP1), 2 (JAP2), and 3 (JAP3) percent of dry matter intake (DMI) during the first 60 days of the 120-day experiment. Two 6-days digestion trials were conducted: one during the 4th week of the experiment (pre-wean), and the second during the tenth week (post-wean). Additionally, serum concentrations of cortisol and epinephrine were measured in both the pre- and post-weaning phases to assess the stress levels. Immunocompetence of the calves during both the stages was evaluated through lymphocyte proliferation response. In the pre-weaning phase, the calves supplemented with JAP had better (P < 0.05) protein intake and digestion compared to the control group. In the post-weaning phase, the JAP supplemented groups exhibited significantly (P < 0.05) improved digestibility coefficients for dry matter, organic matter, crude protein, ether extract, and neutral detergent fibre. Although cortisol levels didn't show significant differences (P > 0.05) between the groups during both pre-weaning and post-weaning stages, the post-weaning stage did reveal a significant reduction (P < 0.05) in epinephrine levels in JAP1 compared to the other groups. Additionally, JAP supplementation enhanced (P < 0.05) the calves' response to lymphocyte proliferation during the post-weaning phase. Considering the improved nutrient digestibility, enhanced systemic immunity, and reduced epinephrine levels observed in the JAP supplemented groups, our findings suggest that JAP may have promising potential as a prebiotic for calves.

Nutrient Digestibility of Non-conventional Protein Sources Blend in African Catfish, Clarias gariepinus (Burchell, 1822) Post Juveniles Using Novel Aquafeed Formulation Software

In this study, the growth performance, carcass composition, and apparent digestibility coefficient of African catfish, Clarias gariepinus, were evaluated in relation to different non-conventional protein sources blends diets that were formulated using a novel feed formulation software (FUTA AQUAFEED). Diet 1 served as the control diet, and the other four experimental diets (Diets 2 through 5) included non-conventional protein sources such blood meal, water hyacinth, palm kernel cake, palm beetle meal, blackfly meal, water fern, and Moringa. The gross composition of the experimental feeds exhibited notable variations in nutrient content. The crude protein content in the diets were iso-nitrogenous. Analysis of the composition of the carcass showed that diets varied significantly. Diet 5 had the highest fat content (10.66%), while Diet 3 had the highest crude protein amount (61.57%). Growth performance parameters such as initial and final weights, weight increase, feed conversion ratio (FCR), specific growth rate (SGR), and protein efficiency ratio (PER) exhibited diverse patterns. Diet 5 produced the greatest final weight (324.00 ± 122.94 g) and weight gain (173.32 ± 96.06 g), suggesting that the varied protein blend may have advantages. Dietary differences were seen in the apparent digestibility coefficients of crude protein and lipids. The crude protein digestibility coefficient (90.68%) was best in Diet 3, while the crude lipid digestibility coefficient (92.00%) was highest in Diet 1. In conclusion, the inclusion of unconventional protein sources in the diets of C. gariepinus affects both their growth performance and nutritional makeup. Through the incorporation of alternate protein sources into fish diets, the findings offer insights for improving aquaculture techniques and advancing sustainability.

Maintenance requirement and growth utilization efficiency of digestible methionine and cysteine determined for striped catfish (Pangasianodon hypophthalmus) using ration level technique

Knowledge of the amino acid (AA) requirements for striped catfish (Pangasianodon hypophthalmus) is very limited. The main objective of the study was to determine maintenance requirements and utilization of digestible methonine (Met) and other essential amino acids (EAA) for growth in juvenile striped catfish. To evaluate the objective, a series of three different trials were carried out. Initially, a 28-d feed deprivation study showed an allometric relationship between energy, protein, or AA losses (y) and geometric body weight (BW), where the relationship was expressed as a power function (y = aBWb) with the exponent values (b) being 0.84 for energy, 0.83 for protein, and 0.81–0.90 for various EAAs. Next, a digestibility trial was carried out to determine apparent digestibility coefficients of energy, protein and AA from the ingredients, including: fish meal, soybean meal, wheat bran, regular and defatted rice bran. These values were then used in the final trial to formulate two diets on a digestible AA basis with similar crude protein (31%), energy (17.1 kJ g−1) and AA composition - except for digestible Met and Met+Cys, which were 0.47% and 0.90% for Diet A, and 0.61% and 1.05% for Diet B. The diets were fed to quadruplicate groups of fish (∼10 g initial weight; 20 fish per tank) at increasing ration levels (∼ 35%, 55%, 77%, 93% and 100% apparent satiation) for 64 days. One group was deprived of feed for 28 days. The results showed that feeding catfish at increasing ration levels significantly improves the growth performance in both dietary treatments. Additionally, the group fed Diet B showed significantly better weight gain than the corresponding group fed Diet A at 93% and 100% satiation. The maintenance requirement was determined to be 21.77 mg digestible (dig) Met kg−0.83 d−1 and 35.3 mg dig Met+Cys kg−0.83 d−1 based on a linear model and to be 18.8 mg digestible (dig) Met kg−0.83 d−1 and 30.7 mg dig Met+Cys kg−0.83 d−1 based on an exponential fit to the data. The efficiency of digestible Met utilization (kDMetassessed based on Diet B) for growth above maintenance was found to be 63% (including data of all ration levels) or 71% (excluding data of 100% satiation), while that for the Met+Cys (kDM+C) was found to be 46% (including data of all ration levels) or 51% (excluding data of 100% satiation). The efficiency of digestible protein utilization for weight gain with Diet B was found to be higher (66%) than that with Diet A (57%), indicating the importance of balancing striped catfish diets for dietary Met. The study also determined maintenance requirements and utilization efficiency of other EAAs which need to be further improved. These data can be used to derive AA requirements for striped catfish based on a factorial modelling approach which relies on maintenance requirements, growth utilization of AA, and targeted growth or protein deposition.

Transgenic, high-protein sorghums display promise in poultry diets in an initial comparison

This study aimed to compare the inclusion of transgenic sorghums against commercially available sorghums on growth performance in broiler chickens. Isonitrogenous and isoenergetic diets were offered to a total 288 male Ross 308 broiler chickens from 14 to 35 d posthatch. Three dietary treatments were diets based on transgenic sorghums with a mean protein content of 154.7 g/kg and 5 treatments were based on commercially available sorghum hybrids with a mean protein content of 90.6 g/kg. Soybean meal inclusions in the commercial sorghum diets averaged 215 g/kg, which was reduced to 171 g/kg in the transgenic sorghum diets because of the higher protein contents. Overall growth performance was highly satisfactory, and commercial sorghums supported 2.55% (2,330 vs. 2,272 g/bird; P = 0.010) more weight gains and 2.74% (2,929 vs. 2,851 g/bird; P = 0.012) higher feed intakes; however, the transgenic sorghums supported a fractionally better FCR (1.255 vs 1.257; P = 0.826). There were no statistical differences in apparent jejunal and ileal starch and protein (N) digestibility coefficients between treatments. The transgenic sorghum diets generated slightly, but significantly, higher AME:GE ratios and AMEn, but the commercial sorghum diets generated 6.33% (235 vs. 221 g/kg; P < 0.001) greater breast meat yields. Apparent ileal digestibility coefficients of 16 amino acids averaged 0.839 and 0.832 for transgenic and commercial sorghum-based diets, respectively, without any significant differences in individual amino acids. This outcome suggests amino acid digestibilities of the transgenic sorghums may be inherently higher than commercial hybrid sorghums as the 25.7% higher average soybean meal inclusions would have advantaged amino acid digestibilities in commercial sorghum diets. The possibility that the digestibilities of amino acids in the kafirin component of transgenic sorghums was enhanced by modifications to the structure of kafirin protein bodies is discussed. In conclusion, transgenic sorghums with higher protein concentrations led to 20.5% reduction of soybean meal inclusions in broiler diets, and this change did not compromise feed conversion efficiency compared to standard commercial hybrid sorghums.

Digestibility of feed nutrients when the NAA feed additive is included in the diet of geese

The purpose of the research was to study the digestibility of feed nutrients when different doses of the NAA feed additive were included in the diet of meat geese and to analyze the gain in live weight of the experimental poultry. The geese received the feed additive throughout the entire rearing cycle (from 1 to 60 days). A physiological experiment to study the digestibility of feed nutrients was carried out when the geese were 50 days old. On 6 geese from each group, the digestibility coefficients of dry matter, protein, fiber, fat, nitrogen-free extractive substances and ash were determined. During the experiment the amount of compound feed eaten, the amount of excreted litter and the live weight of the geese were taken into account. The results obtained indicate that of the three tested dosages (0,5 ml, 1,0 and 2,0 ml per 1 kg of compound feed), the dose of 1,0 ml per 1 kg of compound feed turned out to be optimal. Nutrient digestibility coefficients were higher in geese of the 3rd experimental group, whose diet was supplemented with 1,0 ml of feed additive per 1 kg of compound feed. The digestibility coefficients of dry matter, protein, fi ber and nitrogen-free extractive substances were higher in the 3rd experimental group compared to the values of herdmates in the 1st control group by 3,03 abs.%, 2,28 abs.%, 3,34 abs.% and 5,24 abs.%, respectively. In the 2nd and 4th experimental groups the coeffi cients of digestibility of dry matter of protein, fi ber, nitrogen-free extractive substances and ash were almost at the same level as the results of the 1st control group. The fat digestibility coeffi cient in the 1st control group was 84,49 %, and in the 2nd, 3rd and 4th experimental groups it was 82,44 %, 81,49 and 82,94 %, respectively. The feed additive at the dose of 1,0 ml per 1 kg of compound feed, which the geese of the 3rd experimental group received, had the significant impact on the dynamics of the live weight of the poultry. Already at 10 days of age geese from the 3rd experimental group were 10,2 g (p ≤ 0,05) heavier than their herdmates from the 1st control group; at 30 and 60 days of age, this difference was significantly higher than in 1st control group by 7,48 and 5,38 % (p ≤ 0,05), respectively.

Exploring the nutritional value of corn fermented protein as a replacement for soybean meal in diets for juvenile channel catfish (Ictalurus punctatus): Impacts on production performance, intestinal health, and disease resistance

The use of corn fermented protein (CFP) can be a promising alternative ingredient to replace soybean meal (SBM) in aquafeeds, because of its attractive price and constant supply. In this study, the apparent digestibility of CFP was evaluated with channel catfish (Ictalurus punctatus), followed by a comparative feeding trial in which dehulled, solvent extracted SBM in the control diet was incrementally replaced with graded levels of CFP. A slight but significantly higher apparent protein digestibility coefficient was observed for SBM (91%) compared to CFP (89%). However, phosphorus and lipid were twice as available from CFP than SBM. A 60-day feeding trial was conducted, testing the gradual replacement of SBM by CFP on an equalnitrogen basis at 0, 25, 50, 75, and 100%. Channel catfish juveniles (∼11.6 g) were stocked in 30 aquaria (30 fish/ 110-L tank; n = 6) operating as a recirculating system and offered the experimental diets to apparent satiation twice daily. No differences were observed for hepatosomatic index, survival, or serum superoxide dismutase and lysozyme activities. Also, no treatment effects were observed for whole-body protein, ash, and protein conversion efficiency. However, weight gain, feed efficiency, intraperitoneal fat, and whole-body lipid were significantly affected by the dietary treatments with CFP able to replace up to 40 to 58% of the SBM in the diet while providing similar fish performance and body composition as fish fed the control diet. Digesta samples from the posterior segment of the intestine were subjected to DNA extraction, followed by 16S rRNA gene (V3-V4 region) sequencing to profile the intestinal microbiota. A higher relative abundance of Aeromonas spp. was observed for fish fed the control diet. The remaining fish from the feeding trial were challenged with Edwardsiella ictaluri, and cumulative survival was monitored for 21 days. Survival after the bacterial challenge gradually increased as the inclusion levels of CFP increased in the diets, with the 100% replacement treatment being significantly different from the control diet. In conclusion, CFP is a promising alternative plant protein ingredient with high protein and phosphorus digestibility, and it can replace up to 40 to 58% of the SBM in feed formulations for juvenile channel catfish based on weight gain and feed efficiency while potentially increasing disease resistance against E. ictaluri.

Effect of Dietary Seaweed Supplementation on Growth, Feed Utilization, Digestibility Co-efficient, Digestive Enzyme Activity and Challenge Study against Aeromonas hydrophila of Nile Tilapia Oreochromis niloticus

Background: The present study aimed to determine the growth, digestibility co-efficient, digestive enzyme activity and disease resistance of juvenile GIFT tilapia fed with Ulva seaweed meal supplemented diet. Methods: The study was undertaken with different inclusion levels of Ulva seaweed meal (USM) such as raw (UR) and fermented (UF) Ulva meal (UR-5, UR-10, UR-15, UF-5, UF-10 and UF-15% of diet) and control feed (C) for a period of 60 days. Result: GIFT fed with fermented Ulva meal at a 10% inclusion level in their diet exhibited the highest growth performance (41.43 g) followed by UF5 (41.07±0.43 g), UR5 (39.65±0.36 g), control (39.09±0.20 g), UF15 (38.67±0.26 g), UR10 (38.47±1.47 g) and UR15 (35.77±0.35 g) diet. The Highest Apparent Digestibility Coefficient (ADC) for Crude Protein (85.14±0.91%) was observed in fishes fed with fermented Ulva meal at a 10% inclusion rate than other treatments and the control groups for Dry Matter, Ether Extract, and Gross Energy. The enzymatic activities of digestive enzymes, namely Amylase activity (0.029±0.00 units/mg protein/min), Protease activity (0.147±0.0 units/mgprotein/min) and Lipase activity (0.273±0.05 units/mg protein/min), showed higher levels in the group of fishes fed with a diet containing 10% fermented Ulva meal, as compared to the other treatment groups and the control. Increased survival rate (86.66%) was observed when the fishes were challenged with Aeromonas hydrophila at the end of the trial for Ulva based diets. The results obtained on histopathology showed the presence of lower degree levels of infection in 10% fermented Ulva meal supplementation.The present study concluded that dietary Ulva meal requirement for juvenile GIFT tilapia can be at 10% of Ulva Fermented (UF) and UF-5, Ulva Raw (UR) 5%, control (C), UF-15, UR-10 and UR-15 diet respectively.

Effects of yeast extract supplemented in diet on growth performance, digestibility, intestinal histology, and the antioxidant capacity of the juvenile turbot (Scophthalmus maximus).

An 8-week feeding experiment was conducted on the juvenile turbot (Scophthalmus maximus) to evaluate the influence of yeast extract (YE) supplementation in the diet on growth performance, feed utilization, body composition, nutrient digestibility, intestinal histology, and antioxidant capacity. Four experimental diets were formulated with graded levels of yeast extract 0 (YE0), 1% (YE1), 3% (YE3), and 5% (YE5) and fed to turbots (initial body weight: 4.2 ± 0.1g) with three replicates per diet and 200 fish in each replicate, respectively. The results showed that turbots fed with diets YE1 and YE3 displayed a significantly higher specific growth rate and protein efficiency rate than those fed with diets YE0 and YE5, while the feed conversion ratios in YE1 and YE3 groups were lower than those in YE0 and YE5. Fish fed with diets YE3 and YE5 showed higher body crude protein contents than those in groups YE0 and YE1. The highest apparent digestibility coefficients for dry matter and crude protein, digestive enzyme activities (trypsin, lipase, and amylase), and the height of the intestinal fold were observed in the YE3 group. YE3 treatment displayed a significantly higher superoxide dismutase (SOD) activity than the YE0 group, while the malondialdehyde (MDA) content in YE1 was significantly lower than those in YE0 and YE5. No significant difference was observed in serum physiological and biochemical parameters among all treatments. Overall, appropriate dietary supplementation of the yeast extract could improve the growth performance, digestibility, and antioxidant capacity of the juvenile turbot, and the recommended yeast extract level in the feed is 2.47%.

Evaluation of in vitro and in vivo digestibility of potential feed ingredients for juvenile Yellowtail Snapper

AbstractObjectiveThe carnivorous Yellowtail Snapper Ocyurus chrysurus has the potential for production in aquaculture. However, there is a lack of studies investigating the digestibility of ingredients needed to formulate balanced diets for this species.MethodsThe in vitro protein digestibility of fish meal (FM), poultry by‐product meal (PBM), poultry meal (PM), protiblend, canola meal (CM), soybean meal, and wheat gluten was evaluated using the pH‐stat technique. The in vivo digestibility was determined by formulating test diets with a 70:30 ratio of the reference diet and the test ingredients.ResultIn terms of in vitro digestibility, FM, PBM, and PM exhibited the highest degree of hydrolysis (DH). Conversely, PBM displayed the lowest apparent digestibility coefficient of protein (ADCprotein) in the in vivo digestibility test. Meanwhile, FM, PM, and CM demonstrated higher values of protein digestibility. Beta regression between ADCprotein and the DH and ash content of the ingredients resulted in a high correlation (R2 = 0.94).ConclusionThe results of the present study indicate that Yellowtail Snapper efficiently digested and absorbed FM, PM, and CM ingredients, which contain a lower content of ash.

Evaluation of andean lupin (Lupinus mutabilis) seed meal as a dietary component on growth performance, feed utilization, nutrient digestibility, and liver histology of rainbow trout (Oncorhynchus mykiss) Juveniles

This study aimed to investigate the effects of dietary inclusion of Andean lupin (Lupinus mutabilis) on the growth performance, carcass composition, liver histology, and nutrient digestibility in rainbow trout (Oncorhynchus mykiss) juveniles. The experiment involved triplicate groups of fish (initial body weight 32.10 ± 0.79 g) fed four extruded experimental diets with varying levels of Andean lupin (0, 50, 100, and 200 g kg−1) twice a day to apparent satiety over a period of 40 days. Faecal samples were collected daily for nutrient digestibility analysis. No significant correlations were observed between the dietary inclusion of Andean lupin and final weight, survival, weight gain, protein efficiency retention, thermal growth rate, feed conversion rate, and feed intake (P > 0.05). Similarly, there were no significant relationships between increasing dietary inclusion of Andean lupin and apparent digestibility coefficients for dry matter, crude protein, carbohydrate, and energy. However, the inclusion of Andean lupin led to a decrease in apparent digestibility coefficients for ash (R2 =0.6, P < 0.05). Furthermore, the digestibility of Mg and Zn decreased in a quadratic manner (P < 0.01) with increasing levels of Andean lupin inclusion. The dietary treatments did not significantly affect whole-body composition, spleen-somatic index, and intestine-somatic index (P > 0.05). However, the hepatosomatic index decreased quadratically with increasing inclusion of Andean lupin (R2 =0.51, P < 0.05), likely due to a slight reduction in cytoplasmic vacuolization of hepatocytes. In conclusion, this study demonstrates that Andean lupin is a promising plant protein ingredient for rainbow trout diets. It can be included at levels up to 200 g kg−1 without adversely affecting growth performance and nutrient digestibility. These findings contribute to the expanding knowledge on alternative protein sources in aquaculture feed formulation.

Effect of different levels of whole corn germ on energy values and ileal digestibility in broilers.

This study evaluated the effects of broiler age (A) and levels of replacement (L) of control diet (CD) on the utilization of energy and nutrients of whole corn germ. 720 one-day-old broilers (b) were allocated at completely randomized design to six treatments and six replicates, in three assays: pre-starter (1-8 days, 10 b/cage), starter (15-22 days, 6 b/cage), and grower (28-35 days, 4 b/cage) phases. The treatments were: CD and four test diets (L): 100, 150, 200, 250, or 300 g kg-1 of the CD replaced by WCG levels. The data were adjusted to the response surface model. The stationary points for apparent energy metabolizable (AME) and AME corrected for nitrogen balance (AMEn) were: 4173 and 3591 kcal kg-1, respectively, and coefficients of gross energy (AMCGE), crude protein (AMCCP), dry matter (AMCDM), and ether extract (AMCEE) were: 49.3, 40.4, 72.6, and 61.3%, respectively; and Ileal digestibility coefficient of crude protein (IDCCP), dry matter (IDCDM), digestibility crude protein values (DCP), and digestibility dry matter value (DDM) were: 78.0, 57.96, 8.50, and 56.17%, respectively. The EP for AMEn was at 18 days of age, 28 g kg-1 WCG. There was a correlation between A and L on digestibility and metabolisability of nutrient's WCG.

Effects of Substituting Fish Meal by Chlorella Meal in Practical Diet on Growth, Feed Utilization, and Flesh Quality of Pacific White Shrimp (Penaeus vannamei)

This study investigated the effects of substituting fish meal (FM) in practical diet by chlorella meal on the growth, feed utilization, and flesh quality of Pacific white shrimp (Penaeus vannamei). First, a basal diet was prepared with 200 g/kg FM inclusion (FM‐20), and then chlorella meal was used to reduce FM inclusion to 150 g/kg (FM‐15), 100 g/kg (FM‐10), 50 g/kg (FM‐5), and 0 g/kg (FM‐0), corresponding to the replacement levels of 25%, 50%, 75%, and 100% of dietary FM, respectively. Shrimp (1.37 ± 0.10 g) were fed with the five isonitrogenous and isolipidic diets for 56 days. No significant difference was observed in feed conversion ratio (FCR) and weight gain (WG) between FM‐20 and FM‐15 group (P &gt; 0.05), but when chlorella meal substituted 50% of dietary FM, WG, protein and lipid retention, and n‐3/n‐6 PUFAs in flesh were significantly reduced with significant increase in FCR (P &lt; 0.05). Survival, feed intake, meat yield, apparent digestibility coefficient of crude protein, dry matter, and flesh shear force showed no significant difference between FM‐20 and substituted groups (P &gt; 0.05). When dietary FM was totally substituted by chlorella meal, the body yellowness and redness and essential amino acid content in flesh, including Lys and Met, were significantly reduced (P &lt; 0.05). No significant differences were found in flesh total collagen, crude lipid, crude protein, serum biochemical indexes, flesh texture profiles (hardness, springiness, etc.), water holding capacity, antioxidant capacity, fatty acid, free amino acid composition, and muscle fiber density among the five treatments (P &gt; 0.05). To sum up, in a practical diet with 200 g/kg FM inclusion, chlorella meal successfully replaced 25% of dietary FM without adverse impacts on the growth and feed utilization, and the substitution of 75% of dietary FM did not negatively affect the flesh quality of Pacific white shrimp.

Establishment of hydrolysates from enzymatic plant and fish protein by-products into fish nutrition

The aim of this research was to scientifically prove the technology for producing plant-fish hydrolysates from sunflower meal and fish waste (carp processing) and to develop scientifically based recipes for protein hydrolysates and feed using it for carp of different ages. Compositions from fish waste and different amounts of sunflower meal have been developed, the chemical composition of the compositions and the digestibility of protein by carp have been studied. It was distinguished that the best characteristics when studing the nutritional value and digestibility of crude protein have the protein hydrolysates of fish waste and sunflower meal, taken in a ratio of 1 to 2. Accordingly, in this case, a high content of dry matter was noted 65.57 ± 0.18%), crude protein 41.92±0.72%, crude fat 2.74±0.12% and low crude fiber 14.34±0.10%, and the apparent protein digestibility coefficient was 78.8%. The compiled enzyme compositions for enzymatic hydrolysis are optimal at a temperature of 50°C and the proportion of the enzyme composition for fermentation in an amount of 5%, containing enzyme preparations: Protozyme - 40%, Cellulase - 35%, Lipase - 10% and Amylorizin - 15%.

Intestinal microbiota differences associated with physiological health, meat quality, and regulating mineral interactions of Penaeus vannamei fed organic manganese

The objective of this study was to investigate the effects of organic manganese (Mn) on the health status of white shrimp (Penaeus vannamei) and the potential correlations between intestinal microbiota and host health, meat quality, and mineral interactions. An 8-week experiment was designed with 7 dietary treatments: C0, no Mn supplementation; S20, 20 mg/kg Mn from MnSO4·H2O (inorganic); SO, 10 mg/kg inorganic Mn and 5 mg/kg Mn from Mn-proteinate (organic); O10, O20, O30 and O40, 10, 20, 30 and 40 mg/kg organic Mn, respectively. The 840 shrimp (approximately 5.30 g) were randomly allocated into 21 tanks, with each diet group containing 3 tanks and each tank accommodating 40 shrimp. The results showed that 10 mg/kg organic Mn supplementation is optimal to replace 20 mg/kg inorganic Mn. Compared with inorganic Mn, organic Mn shaped healthier intestinal microbiota communities and enhanced the competitive advantage of shrimp for Mn uptake, which resulted in promoting nutrition metabolism (higher apparent digestibility coefficient (ADC) of crude protein (P = 0.031) and concentrations of glucose (P = 0.013), triglyceride (P < 0.01) and total cholesterol (P < 0.001)), enhancing antioxidant capacity and immune response (P < 0.05), improving meat quality (P < 0.05), and regulating iron content in whole body and muscle, zinc content in muscle and ADC of copper and zinc (P < 0.01). Pearson's correlations were observed between gene expression analysis of the immune response and antioxidant capacity, Crude proteinADC, meat texture, and dietary organic Mn, between ADC of copper and zinc, muscle content of iron and zinc (r = 0.55, 0.79, 0.93, −0.91, −0.90, respectively, P < 0.001). In conclusion, organic Mn affects shrimp health status, meat quality and mineral interactions which correlate with changes of the intestinal microbiota.

HEMPSEED CAKE IN RABBIT NUTRITION: LIVESTOCK PERFORMANCES, QUALITY OF MEAT, DIGESTIBILITY OF NUTRIENTS AND ANIMAL HEALTH STATUS

The objective of this study was to evaluate the effect of dried hempseed cake (by-product of oil production) supplementation (5 % − EG1 and 10 % − EG2) to rabbit feed mixture on livestock performances, quality of meat, digestibility of nutrients and animal health status. The chemical composition of the Longissimus thoracis and lumborum muscle including the content of fatty acids and amino acids, and the biochemical parameters in caecum and blood of growing rabbits were investigated. No significant differences among the experimental groups in feed intake, body weight and carcass parameters were found. The digestibility trial was performed using the balance method. Feed mixtures differed in digestible energy content i.e., crude protein, crude fibre and fat. The resulting digestibility coefficients for protein fell within the range of 66.72 − 74.18 %, fat digestibility was in the interval from 88.73 to 89.34 % and crude fibre digestibility was in the range from 27.56 to 34.59 %. Fatty acid profile in intramuscular lipids represents the highest content of monounsaturated fatty acids (MUFA; 47.72 − 48.51 %), followed by the content of saturated acids (SFA; 33.75 − 33.87 %) and a low content of polyunsaturated fatty acids (PUFA; 11.23 − 12.08 %). Hempseed oil cake could be included in rabbits' diet with beneficial effect on carcass quality and can enhance the nutritional quality of rabbit meat with the focus on essential amino acids. The tested blood serum parameters were within the range of the physiological reference values with no statistical differences between experimental groups, except for glucose and cholesterol content. The data on volatile fatty acids (VFA) show that most intensive process was in the caecum of rabbits in the experimental groups EG1 and EG2. All obtained data let us to recommend the inclusion of hempseed cake up to 10 % in rabbit diet without any negative effect on animal welfare, livestock performance and quality of meat.

Nutritional value of torula yeast as an alternative protein feedstuff for hybrid Striped Bass (White Bass × Striped Bass)

AbstractObjectiveTwo separate trials were conducted to evaluate the digestibility of a novel alternative ingredient, enhanced torula yeast (TY) Cyberlindnera jadinii, in diets for hybrid Striped Bass (HSB; White Bass Morone chrysops × Striped Bass M. saxatilis) and to evaluate graded inclusion levels of this product when replacing soybean products.MethodsIn trial 1, the digestibility of TY was determined by testing a reference diet and a TY diet (reference and TY ingredient at an 80:20 ratio). A total of 90 fish were fed the experimental digestibility diets for 21 days, and fecal samples were collected using the stripping technique. In trial 2, a comparative feeding trial evaluated the replacement of soybean meal by TY on a crude protein basis at 50, 100, 200, and 300 g of TY/kg of experimental diet. A total of 150 HSB (18.6 ± 0.21 g/fish [mean + SE]) were distributed among fifteen 110‐L glass aquaria. Each diet was fed to triplicate groups of fish for 9 weeks.ResultIn trial 1, apparent digestibility coefficients for protein, lipid, organic matter, and energy of TY were 0.97, 0.98, 0.75, and 0.75, respectively. The availability of essential amino acids also was generally high, ranging from 0.74 to 0.99. For trial 2, a second‐order polynomial regression indicated that the optimal inclusion levels of TY in diets were 102, 112, and 109 g/kg for weight gain, feed efficiency, and protein conversion efficiency, respectively. However, the muscle yield linearly decreased with the graded inclusion levels of TY. Linear increases in intraperitoneal fat, hepatosomatic index, and whole‐body lipid were observed as the inclusion of TY increased in the diet.ConclusionIn conclusion, nutrients from TY were well utilized by HSB, and it can replace soybean products without affecting growth performance, with the optimal TY inclusion level being 102–112 g/kg of diet.