Dietary Protein Energy Research Articles

Effect of Dietary Crude Protein and Apparent Metabolizable Energy Levels on Growth Performance, Nitrogen Utilization, Serum Parameter, Protein Synthesis, and Amino Acid Metabolism of 1- to 10-Day-Old Male Broilers.

This research compared how different levels of dietary crude protein (CP) and apparent metabolizable energy (AME) affect the growth performance, nitrogen utilization, serum parameters, protein synthesis, and amino acid (AA) metabolism in broilers aged 1 to 10 days. In a 4 × 3 factorial experimental design, the broilers were fed four levels of dietary CP (20%, 21%, 22%, and 23%) and three levels of dietary AME (2800 kcal/kg, 2900 kcal/kg, and 3000 kcal/kg). A total of 936 one-day-old male Arbor Acres broilers were randomly allocated to 12 treatments with 6 replications each. Growth performance, nitrogen utilization, serum parameter, gene expression of protein synthesis, and AA metabolism were evaluated at 10 d. The results revealed no interaction between dietary CP and AME levels on growth performance (p > 0.05). However, 22% and 23% CP enhanced body weight gain (BWG), the feed conversion ratio (FCR), total CP intake, and body protein deposition but had a detrimental effect on the protein efficiency ratio (PER) compared to 20% or 21% CP (p < 0.05). Broilers fed diets with 2800 kcal/kg AME showed increased feed intake (FI) and inferior PER (p < 0.05). Broilers fed diets with 3000 kcal/kg AME showed decreased muscle mRNA expression of mammalian target of the rapamycin (mTOR) and Atrogin-1 compared to those fed diets with 2800 kcal/kg and 2900 kcal/kg AME (p < 0.05). Increasing dietary CP level from 20% to 23% decreased muscle mTOR and increased S6K1 mRNA expression, respectively (p < 0.05). The muscle mRNA expression of Atrogin-1 was highest for broilers fed 23% CP diets (p < 0.05). The mRNA expression of betaine homocysteine methyltransferase (BHMT) and Liver alanine aminotransferase of the 22% and 23% CP groups were higher than those of 20% CP (p < 0.05). Significant interactions between dietary CP and AME levels were observed for muscle AMPK and liver lysine-ketoglutarate reductase (LKR) and branched-chain alpha-keto acid dehydrogenase (BCKDH) mRNA expression (p < 0.05). Dietary AME level had no effect on muscle AMPK mRNA expression for broilers fed 21% and 22% CP diets (p > 0.05), whereas increasing dietary AME levels decreased AMPK mRNA expression for broilers fed 23% CP diets (p < 0.05). The mRNA expression of LKR and BCKDH was highest for broilers fed the diet with 2800 kcal/kg AME and 22% CP, while it was lowest for broilers fed the diet with 3000 kcal/kg AME and 20% CP. The findings suggest that inadequate energy density hindered AA utilization for protein synthesis, leading to increased AA catabolism for broilers aged 1 to 10 days, and a dietary CP level of 22% and an AME level of 2900 to 3000 kcal/kg may be recommended based on performance and dietary protein utilization.

Cross-sectional relationship between dietary protein intake, energy intake and protein energy wasting in chronic kidney disease patients.

The potential threshold for dietary energy intake (DEI) that might prevent protein-energy wasting (PEW) in chronic kidney disease (CKD) is uncertain. The subjects were non-dialysis CKD patients aged ≥ 14 years who were hospitalised from September 2019 to July 2022. PEW was measured by subjective global assessment. DEI and dietary protein intake (DPI) were obtained by 3-d diet recalls. Patients were divided into adequate DEI group and inadequate DEI group according to DEI ≥ 30 or < 30 kcal/kg/d. Logistic regression analysis and restricted cubic spline were used in this study. We enrolled 409 patients, with 53·8 % had hypertension and 18·6 % had diabetes. The DEI and DPI were 27·63 (sd 5·79) kcal/kg/d and 1·00 (0·90, 1·20) g/kg/d, respectively. 69·2 % of participants are in the inadequate DEI group. Malnutrition occurred in 18·6 % of patients. Comparing with patients in the adequate DEI group, those in the inadequate DEI group had significantly lower total lymphocyte count, serum cholesterol and LDL-cholesterol and a higher prevalence of PEW. For every 1 kcal/kg/d increase in DEI, the incidence of PEW was reduced by 12·0 % (OR: 0·880, 95 % CI: 0·830, 0·933, P < 0·001). There was a nonlinear curve relationship between DEI and PEW (overall P < 0·001), and DEI ≥ 27·6 kcal/kg/d may have a preventive effect on PEW in CKD. Low DPI was also significantly associated with malnutrition, but not when DEI was adequate. Decreased energy intake may be a more important factor of PEW in CKD than protein intake.

Environmental Indicators of Vegan and Vegetarian Diets: A Pilot Study in a Group of Young Adult Female Consumers in Poland

It has been broadly reported that the production of animal-derived foods significantly contributes to the environmental footprint of the agri-food sector, considering, among others, such indicators as land use, greenhouse gas emissions, and the water footprint. However, the environmental sustainability aspects of whole diets (i.e., more plant-based vs. meat-containing) have been studied so far to a limited extent, in many cases not taking into consideration various regional settings, which to a great extent determine meat- and other animal-derived foods’ substitutes consumed by vegetarians and vegans. The aim of this study was therefore to assess the environmental indicators of vegetarian, vegan, and meat-containing diets of a selected group of Polish consumers. Based on three-day food records of 24 respondents and the published data on the environmental footprint of a range of foodstuffs, the three dietary environmental indicators were calculated. In addition, the results were standardized in terms of dietary protein intake and energy value. The study showed the elimination of meat and other animal-derived foods from the respondents’ diet was predominantly motivated by their concerns related to animal welfare issues, which appeared to be a stronger factor than the willingness to reduce the diets’ environmental footprint. Following the results standardization, the studied vegetarian and vegan diets were characterized by 47.0% and 64.4% lower carbon footprint, 32.2% and 60.9% lower land use indicators, and 37.1% and 62.9% lower water footprints, respectively, compared to the meat-containing diet. Animal-derived foods, including milk and dairy, appeared to be the main contributors to all three environmental footprint indicators of both the meat-containing and the vegetarian diets. In the vegan group, the environmental footprint was found to be mainly influenced by the consumption of legumes and legume-based foods, cereal products, potatoes, sugar, products containing cocoa and vegetables, with nuts showing especially significant contribution to the fresh water consumption. The study confirms moving towards more plant-based diet has a potential to significantly reduce the diet’s environmental footprint. It also contributes to creating a ‘roadmap’ for consumers, to encourage them to plan their diets responsibly, taking into consideration both the health and the environmental sustainability aspects.

Effects of the use of tannins on the ruminal fermentation of cattle: A meta-analysis and meta-regression

This systematic review-meta-analysis (MA) estimates the impact of including tannins in beef and dairy cattle diets on short-chain fatty acids (SCFA), ammonia nitrogen (N-NH3), dry matter digestibility (DMD), and methane (CH4) production. The effects are described according to the sources (natural or extract), type of tannin (condensed, CT, or hydrolyzed HT or blend), total tannin concentration in the source, and doses. The bibliographic search was performed in five electronic databases: CAB-Abstracts, PubMed, Scopus, Science Direct, and Web of Science. Predefined protocols were used at all stages of the systematic review process. An MA for random effects was performed for each indicator separately with the mean difference between the control (without tannin) and treated (with tannin) groups. Twenty-seven articles were included for this study, of which 20 were for SCFA, 20 for N-NH3, 14 for DMD, and 10 for CH4. The inclusion of HT reduced the total SCFA concentration (p = 0.005). Within a dose range of 10–40 g/kg of a CT extract, the total SCFA concentration was reduced by 0.804 mM in the rumen fluid (p < 0.016). The effects of tannins on reducing the N-NH3 concentration are evident, either extracted or naturally in the plant, and regardless of the type of tannin (p < 0.05). DMD was reduced with the use of a tannin blend (p = 0.041) and the inclusion of tannins reduced CH4 production (p = 0.005), with moderate heterogeneity (I2 = 44.5 %). Through the 27 studies included, we concluded that tannins affect the concentration of N-NH3, SCFA, DMD, and CH4. Tannins associated with balanced protein-energy diets can reduce ruminal protein degradability and CH4 production, which can benefit animal metabolism and the environment.

Effect of varying dietary crude protein and metabolizable energy levels on leg abnormalities and performance in broiler chickens

Background: Nutrient restriction is a common strategy to prevent metabolic disorders in fast growing broiler chickens, but limited information is available regarding the impact of diets with low protein and energy on leg abnormalities. Objective: Two experiments were conducted to evaluate the effect of varying crude protein (CP) and metabolizable energy (ME) levels on gastrocnemius tendon (GTeBS) and tibia breaking strength (TiBS), gait score (GS) and valgus/varus angulation (VAng). Methods: In Experiment 1, eight-d-old Ross 308 broilers (n=90) were randomly assigned into three treatments: 13/2,900 (13% CP and 2,900 kcal ME kg-1 of diet), 17/3,000 (17% CP and 3,000 kcal ME kg-1 of diet), and 21/3,025 or control (21% CP and 3,025 kcal ME kg-1 of diet). In Experiment 2, six-d-old Ross 308 chickens (n=192) were randomly distributed into two treatments: 16/3,000; 16% CP and 3,000 kcal ME kg-1 of diet and 21/3,000 or control; 21% CP and 3,000 kcal ME kg-1 of diet. In both experiments data were analyzed as one-way ANOVA. Results: In Experiment 1, broilers in the 17/3,000 and control treatments had similar (p&gt;0.05) GTeBS (202 and 224 N, respectively), and TiBS (338 and 332 N, respectively). Birds in the 13/2,900 treatment showed higher GS (lower walking ability; 80% of birds with score &gt;3), and greater VAng (53% of birds with score &gt;2) than broilers in the control treatment (0% of birds with GS score &gt;3 and 0% of birds with VAng score &gt;2). Experiment 2, broilers in the 16/3,000 showed similar VAng, GS and TiBS than birds in the control treatment. However, birds in the 16/3,000 treatment showed lower (-26%) GTeBS than birds in the control treatment (p&lt;0.05). Conclusions: Feeding broilers with 16% CP and 3,000 kcal ME kg-1 of diet did not affect tibia breaking strength, gait score and valgus/varus angulation. A diet containing 16% CP or less and 2,900-3,000 kcal ME kg-1 reduces tendon and tibia breaking strength.

PSVI-16 Performance Response of Nursery Pigs Fed Increasing Levels of Fermentable and Structural Fiber

Abstract Dietary fiber can provide functional benefits to nursery pigs, thereby improving gut health and growth performance. However, effects vary depending on the type and amount of fiber supplemented. The objective of this experiment was to determine the effects of dietary fermentable fiber (FRM), structural fiber (STR), and their interaction on growth performance of nursery pigs. In total, 3,014 weanling pigs (body weight = 5.71 ± 0.11 kg, 15 replicate pens/treatment, 21 – 23 pigs/pen) were allotted by pen in a randomized complete block design to treatments in a 3 × 3 factorial arrangement with 2 factors: FRM (12, 13, or 14%) and STR (3, 4, or 5%). Diets were formulated to maintain similar dietary protein and metabolizable energy, and rice hulls or beet pulp were added to achieve different levels of STR and FRM, respectively. Fiber concentrations were estimated using in vitro fermentation methods. Phase 1 and 2 diets were fed from day 0 – 11 and 11 – 21 post-weaning, respectively. A common diet was fed from d 21 – 43. Data were analyzed by general linear model in R with random effect of location block. Orthogonal contrasts tested for linear and quadratic effects of STR and FRM, and their interaction. Overall (d 0 – 43), increasing FRM increased average daily gain (ADG; linear, P &amp;lt; 0.05). As STR increased, overall ADG increased and then decreased (quadratic, P &amp;lt; 0.05), with 4% STR resulting in the greatest ADG. Interactions between fiber type were observed (P &amp;lt; 0.05) for final body weight, overall average daily feed intake, and overall gain:feed. Pigs fed 14% FRM and 5% STR had the numerically greatest final body weight and ADG. In summary, increasing STR up to 4% improved performance, and greater levels of FRM can further improve performance when higher levels of STR are provided in the diet.

High performance of growing lambs grazing Paspalum notatum INIA Sepé with energy-protein supplement including sorghum-DDGS

Sorghum dried distillers’ grain with soluble (S-DDGS) has not been utilized as supplement in lamb growing and finishing diets under grazing conditions in summer. The hypothesis was that the performance of post-weaning lambs grazing Paspalum notatum (PN) INIA Sepé supplemented with an energy-protein diet (whole sorghum grain [SG], and soybean meal [SM]) is not reduced by the inclusion of 40% S-DDGS. During 82 days, in summer, 42 Merino Dohne male lambs (130 ± 7.6 days of age, 32 ± 2.4 kg of body weight [BW], and 2.2 ± 0.2 body condition score [BCS]) were evaluated, in a completely random experimental design with three treatments and two replicates each (n = 14 each one). All lambs grazed PN INIA Sepé and in two treatments they were daily supplemented (1.7% BW) with different components. The treatments were: PN (control group, no supplementation), SGSM (70% SG, 30% SM) and DDGS (45% SG, 40% S-DDGS, and 15% SM). Supplemented lambs had higher (P&lt;0.0001) body weight gain (BWG), final BW and wool growth (140 and 126 g/a/d, 43.5 and 42.4 kg; 1814 and 1892 µg/cm2/d for DDGS and SGSM, respectively) than control lambs (40 g/a/d; 35.5 kg; 1353 µg/cm2/d) (P&lt;0.0001), without differences between supplemented groups. Gastrointestinal nematodes infestation (GIN) was affected by the treatments on day 69, where supplemented animals showed lower infestation levels than control lambs (P=0.0024). The inclusion of S-DDGS in the supplement did not reduce the productive performance of the lambs when the concentration of crude protein and energy remained constant.

Effects of feeding varying dietary crude protein and digestible energy concentrations on performance of pigs raised in a humid tropical environment

This paper aims at investigating relationships and effects of varying protein and energy levels on growth performance, efficiency of feed conversion and efficiency of nutrient utilization of weanling pigs fed from of 9 to 60kg. A total of one hundred and twenty weanling pigs weighing ± 9kg were allotted randomly to sixteen groups of eight pigs each. for females and four castrated males in a 4x 4factorial design. The sixteen diets consist of four digestible energy levels (3,000: 3300: 3,600 and 3,900 kcal/kg) and four crude protein levels (18; 21: 24 and 27%). The pigs were fed these experimental diets until they attained a predetermined liveweight of 60 +1.5 kg. The effects of the varying crude protein and digestible energy were studied on growth and performance parameters Neither protein nor energy levels significantly affected daily feed intake, but significantly decreased daily feed intake at 27protein level. Daily protein intake was influenced by protein intake and digestible energy intake was also significantly influenced by digestible energy intake. There were no significant interactions between protein and energy levels with respect to feed intake and intake of protein and energy Energy but no protein levels significantly influenced rate of live weight gain. Feed conversion efficiency (FEC) was highly (P 0.001) influenced by energy but not protein levels. In both sexes, females and castrated males, increasing dietary levels of protein and energy resulted in improved efficiency of feed utilization within protein levels but there were significant differences between the two highest energy levels for castrated males and within the diets with 3.300, 3.600 and 3.900 kcal/DE/kg for the females. When high protein levels were combined with high energy levels feed intakes were depressed only on the 279% protein level. Feed conversion efficiency was maximized on the diet with 21 and 249% protein levels with appreciable sex diferences, with female pigs requiring more protein than males. Digestible Energy range of 3,300 and 3,600 kcalkg would be adequate for maximum gain and efficiency of feed utilization in pigs under the humid tropical environment tropical. Feed to gain ratio, a very important economic index should be an important index of the quality of any diet for promoting growth.

Effect of feeding varying levels of dietary crude protein and digestible energy levels on nitrogen retention, urinary and blood plasma constituents in pigs fed from 9 to 60kg

This study was designed to investigate the effects and possible interactions of varying crude protein (CP) and digestible energy levels (DE) on Nitrogen Retention, (NR), Urinary and blood plasma constituents in pigs reared from 6 to 60 kg liveweight. One hundred and twenty eight Large White x Landrace pigs weighing 9+1.5kg were assigned to sixteen groups of eight pigs, comprising four females and four castrated males in a 4x4 factorial design, the factors were four crude protein levels: (18, 21, 24 and 27%) and four digestible energy levels: (3,000; 3,300: 3,600 and 3,900 kcal/kg) nitrogen retention studies were conducted during the 4 week after the animals were 4 weeks on test diets. There were 6 pigs (3 females and 3 males) in the nitrogen balance trials. Apparent protein digestibility was calculated from the faecal collection. Urinary urea, citrulline and allocation were also determined. Six out of the eight experimental pigs per diet were selected for bleeding and the plasma urea concentrations were determined. There was a significant ( 0.05) Protein x Energy, Energy X Sex and Protein x Energy x Sex interactions. Females retained significantly higher proportions of their nitrogen intake than the castrated males, the lowest nitrogen retention was obtained on the lowest protein and lowest energy combination. The best nitrogen retention in males was obtained on the 21% protein diet with 3,600 kcal DE/kg, while in females; the best was obtained on the diet containing 24% Protein. Total urinary urea concentration was significantly (p 0.01) influenced by both protein and energy levels and significant Protein x Energy interactions also occurred. Dietary protein, expectedly, significantly influenced plasma urea concentrations tending to be lowest on the two intermediate energy levels; 3,300 and 3,600 kcal DE /kg. Nitrogen retention was optimum between 18 and 21% protein levels and castrated males tended to show optimum nitrogen economy on lower protein levels than female pigs. Total urea concentration paralleled nitrogen retention profile. The Kiriyama Index(A/U x IP) may be a precise method to determine protein requirement for pigs in the humid tropical environment. Digestible energy levels of between 3,300 and 3,600 kcal/kg would be adequate for maximum nitrogen economy.

OPTIMUM PROTEIN AND ENERGY LEVELS FOR FINISHING BROILER CHICKENS IN A TROPICAL ENVIRONMENT

Three experiments were conducted to determine the optimum protein and energy levels for finishing broiler chickens in a tropical environment. Dietary protein levels (20, 23 and 26 percent) and energy levels (2800, 3000 and 3200 Kcal/kg diet) tested had no significant effects on performance of finishing chickens fed fishmeal-containing rations. Rations based on cereals and groundnut meal, without fishmeal, did not support maximum liveweight gain and feed efficiency at dietary protein levels below 26 percent. Dietary treatments had no significant effects on carcass dressing percentages. Based on the present results, a protein level of 20 percent(for fishmeal containing rations) and 23 or 26 percent (for rations based on groundnut meal without fishmeal) and energy levels of 2800 to 3000 Kcal/Kg diet are tentatively recommended for finishing broiler chickens raised in a tropical country like Nigeria.

Maternal determinants of low birth weight among Indian children: Evidence from the National Family Health Survey-4, 2015-16.

ObjectiveLow birth weight (LBW) is a serious public health problem in low- and middle-income countries and a leading cause of death in the first month of life. In India, about 18% of children are born with LBW (<2500 grams) in 2015–16. In this study, we aim to examine the influence of maternal factors and socio-demographic covariates on LBW in Indian children.MethodsData were drawn from the fourth round of the National Family Health Survey (NFHS-4), conducted in 2015–16. A cross-sectional study was designed using a stratified two-stage sampling technique. Cross-tabulation, Pearson’s chi-squared test, and multivariate logistic regression analyses were employed to assess the impact of maternal factors and other covariates on children’s LBW.ResultsOf total participants (n = 147,762), 17.5% of children were found to be born with LBW. The study revealed that women who had prior experience of stillbirth (Adjusted odds ratio [AOR]: 1.20, 95% CI: 1.04–1.38) and any sign of pregnancy complications (AOR: 1.08, 95% CI: 1.05–1.11) were more likely to have LBW children, even after adjusting for a range of covariates. Maternal food diversity was found to a protective factor against children’s LBW. Women with underweight and anemic condition were associated with an increased likelihood of LBW children. Regarding maternity care, women who attended ≥4 ANC visits (AOR: 0.84, 95% CI: 0.80–0.88), took iron tablets/syrup during pregnancy (AOR: 0.94, 95% CI: 0.90–0.98), and delivered in a public health facility (AOR: 0.84, 95% CI: 0.79–0.88) were less likely to have LBW babies. Besides, various socio-demographic factors such as place of residence, caste, religion, education, wealth quintile, and geographical region were significantly associated with LBW of children.ConclusionInterventions are needed for adequate ANC utilization, improvement in public facility-based delivery, providing iron supplementation, and uptake of balanced energy-protein diet among pregnant mothers. Besides, special attention should be given to the socio-economically disadvantaged women to address adverse pregnancy and birth outcomes including LBW.

Consequences of varying dietary crude protein and metabolizable energy levels on growth performance, carcass characteristics and biochemical parameters of growing geese

This research aimed to investigate the effect of varying dietary crude protein (CP) and metabolizable energy (ME) quantity on growth, carcass characteristics, biochemical blood parameters and molecular aspects of growing geese. Overall, a total of 180 Egyptian goslings were used in a 2 × 3 factorial design. Two levels of CP (18% and 16%) and three levels of ME (3000, 2900 and 2800 kcal/kg diet) were employed. Growth traits showed no significant differences as a result of different CP or ME levels. Birds fed the higher CP level consumed more feed than the lower. Carcass, dressing, heart, spleen, abdominal fat and thigh percentages within the group fed 18% CP were higher than the other group. Compared with the other ME-based diet, geese fed a low-ME based diet had the highest heart percentage. Feeding growing geese on a 2900 Kcal/kg ME-based diet increased the serum content of total protein and globulin. Geese fed the high-ME diet showed the highest levels of ALP and C4 as compared with other ME levels. Regarding Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), different protein and energy levels did not affect the molecular weight of blood proteins of Egyptian geese during the growing phase. It could be concluded the levels of 16% CP and 2800 kcal/kg ME are enough to maintain the growth performance and the other physiological indices as well as molecular aspects.

Nutrition of Genetically Improved Farmed Tilapia (GIFT) in biofloc technology system: Optimization of digestible protein and digestible energy levels during nursery phase

The objective of the present work was to investigate different dietary digestible protein (22%, 26% and 30% of DP) and digestible energy (3000, 3150 and 3300 kcal DE kg−1) levels on growth performance and hematological parameters of Genetically Improved Farmed Tilapia (GIFT) fingerlings (0.99 ± 0.1 g of mean initial weight) over 42 days. In addition, proximate analysis of carcass and biofloc biomass, as well as planktonic community characterization were performed. A factorial design (digestible protein and digestible energy as factors) was applied totaling nine treatments with four replicates each. The FCR (~1.17) and survival (>98%) were similar between all treatments (P > .05). When assessing the final weight of the fish, in terms of weight gain and specific growth rate, the 22% and 26% DP treatments were not affected by the energy level (P > .05); however, the 30% DP level were affected by energy levels (P < .05) with best results using 3150 kcal DE kg−1. In regard to somatic parameters, carcass yield and condition factor of the fish were similar between all treatments (P > .05). Standard length presented an interaction effect (P < .05); while total length and the hepatosomatic index were affected by protein levels. Hematological parameters showed variability according to different dietary protein levels while carcass proximate composition was affected by both protein and energy levels (P < .05). The monitoring of planktonic communitities indicated some variation over the duration of the experiment, specifically on the number of dinoflagellates, rotifers and protozoa groups. These results suggest that the optimal digestible protein and digestible energy levels for tilapia fingerlings raised in freshwater biofloc systems are 26% DP and 3000 kcal DE kg−1.

Proper dietary crude protein and metabolizable energy levels on growth performance, carcass characteristics and meat quality of Royal Project Bresse capon

Proper dietary crude protein and metabolizable energy levels on growth performance, carcass characteristics and meat quality of Royal Project Bresse capon

Microbial biomass, marine invertebrate meals and feed restriction influence the biological and gut microbiota response of shrimp Penaeus monodon

P. monodon juveniles were fed krill meal (KM), krill hydrolysate (KH), whole squid (SQ), and the microbial biomass, Novacq™ (NQ), at 10% inclusion, in practical fishmeal and soybean meal based diets. Diets were fed to apparent satiation as well as restrictively pair-fed (~60% of control diet satiation) for 6 weeks to examine the effects of the test ingredients and feed restriction on shrimp growth, feed efficiency, digestive enzyme activity, nutritional condition, and gut microbiota.All diets when fed to satiety significantly outperformed the control diet, with shrimp fed NQ 87%, SQ 73%, KH 41% and KM 38% larger than shrimp fed the control diet. NQ fed shrimp had the best feed conversion ratio (FCR) and significantly improved retention efficiency (RE) of dietary lipid (RETL), protein (RECP) and gross energy (REGE). SQ significantly promoted feed intake over control and KM fed shrimp, but neither KM, KH nor SQ improved RETL, RECP or REGE. While there was little change in the apparent digestibility (AD) of each diet, the apparent biological value (ABV) of lipid (ABVTL), protein (ABVCP) and gross energy (ABVGE) were significantly improved by inclusion of NQ; and ABVTL and ABVGE were significantly improved by addition of SQ. Feed restriction had a stronger effect on hepatopancreas digestive enzymes and gut microbiota than addition of any feed ingredient. Total protease activity was positively correlated with feed efficiency, including FCR, RETL and REGE. Shrimp fed to satiety tended to have high levels of Vibrio whereas those on the restricted ration tended to have higher levels of bacteria in Rhodobacteracaea, Flavobacteriales and Bacteroidales.We conclude that shrimp are more efficient in using digested dietary macronutrients for growth when whole squid and Novacq™ are provided, due to improvements in feed intake and post-absorptive processes. Feeding restriction was shown to be a useful strategy to improve P. monodon feeding efficiency, digestive capacity and modulate gut microbiota, however it reduced the scope for shrimp growth especially on high performing diets. Novacq™ was more effective than some of the known invertebrate meals and a more environmentally sustainable growth and nutrient utilisation promoter for shrimp.

Biofloc technology (BFT): Adjusting the levels of digestible protein and digestible energy in diets of Nile tilapia juveniles raised in brackish water

Several studies have been performed adjusting the levels of dietary digestible protein and digestible energy for tilapia, but none of them was performed in biofloc technology (BFT) system, especially in brackish (10) water. In this sense, three levels of digestible protein (22, 26 and 30% DP) and three levels of digestible energy (3000, 3150 and 3300 kcal DE / kg) were evaluated on growth performance, body composition, hematological parameters and planktonic community in juveniles of Nile tilapia (O. niloticus) raised under BFT conditions. A total of 540 tilapia fingerlings (GIFT strain with 1.25 ± 0.15 g initial weight) were reared during 42 days in thirty-six plastic tanks (75 L), fed three times a day. No interaction was detected in the parameters evaluated. The fish fed with feed containing 26% and 30% of DP obtained higher final weight, specific growth rate and condition factor as compared to those fed with 22% of DP (P < 0.05). Body protein on tilapia carcass increased proportionally according to dietary protein. The higher dietary energy level promoted a higher body lipid deposition. According to hematological parameters fish from all treatments presented a satisfactory immunological status. The monitoring of planktonic community indicated a variation over time, specially on the number of dinoflagellates, rotifers and microalgae. The results indicated that diets containing 26% of DP and 3150 kcal / kg of DE for Nile tilapia juveniles promoted suitable growth performance and health conditions when reared in biofloc brackish water, and enabled savings in regards to dietary protein once the energy levels were adjusted.

Effects of dietary protein level and energy intake from 50 to 120 kg on body weight, back fat thickness and body composition in gilts

Body composition and body weight at mating plays an important role in reproductive performance and longevity of the sows, and therefore the dietary supply of protein and energy during rearing of the gilts are manipulated to obtain a more optimal body weight and composition at mating. The objective of the present study was to design a smaller but fatter gilt through different levels of dietary protein and different feeding strategies. It was hypothesized that gilts fed a low dietary protein concentration and had a high energy intake would have a lower BW and higher body fatness compared with gilts fed higher dietary protein levels with low energy intake. A total of 44 gilts entered the experiment at a BW of 47.6 ± 2.6 kg and were randomly allotted to one of six treatments in a 3 × 2 factorial experiment. The six dietary treatments consisted of three dietary protein levels (low (LP), medium (MP), high (HP)) and two energy levels (high (HE) and low (LE)). The BW of the gilts was recorded weekly for 84 days and back fat (BF) thickness was measured at day 1, 42 and 84. The body composition of the gilts was measured at day 1 and 84 by dual-energy x-ray absorptiometry (DXA) scans. At day 84 gilts fed HP and HE had the greatest BW (136 kg) and gilts fed LP and MP at LE had the least BW (107–109 kg; P < 0.001). The greatest BF thickness at day 84 was observed in gilts fed LP and HE (12.5 mm), and these gilts had a BW of 123 kg. Gilts fed LP and HE had the greatest body fat content (29.3%; P < 0.001) and the least body lean content (68.3%; P < 0.001). In conclusion, it was possible to design lighter gilts with an increased fat percentage by feeding a low protein diet and high energy from 50 to 120 kg.

Digestive enzymes and parasitology of Nile tilapia juveniles raised in brackish biofloc water and fed with different digestible protein and digestible energy levels

Biofloc technology (BFT) system is increasing around the world and Nile tilapia is suggested as the major fish species for such technology. The objective of this study was to evaluate diets with different levels of digestible protein (22, 26 and 30% DP) and digestible energy (3000, 3150 and 3300 kcal kg−1) for Nile tilapia juveniles raised in brackish biofloc system water (10 ppt) and its effects on the activity of digestive enzymes and the presence of ectoparasites in the gills. Tilapia juveniles (1.25 ± 0.15 g of initial weight) were stocked in thirty-two experimental units (100 L tanks) with 15 fish per tank. After 42 days fish were harvested, sampled and analyzed. The pepsine (stomach) and trypsine (intestine) activities significantly increased according to the increase of dietary levels. For both cases the higher activity was observed in 30% DP treatment (P < 0.05), with (pepsine) and without interaction (trypsine) with digestible energy levels. The opposite trend was observed for chymotripsine activity (intestine), in which 22% DP presented the higher activity, with significant interaction with energy levels. The higher activity for intestinal lipase activity was observed in 3150 kcal kg−1. No difference was found for ectoparasite analyses in gills between the treatments. Although in all treatments monogea type was found (70–90% of prevalence), the number of parasites per fish was low in all treatments (<1.6 parasites fish−1). The results suggested that differences in dietary digestible protein and digestible energy affected the activity of digestive enzymes in Nile tilapia juveniles raised in biofloc with 10 ppt of salinity. On the other hand, biofloc system did not promote ectoparasite spread even with low dietary levels of digestible protein and digestible energy.

Effects of protease supplementation of low protein and/or energy diets on growth performance and blood parameters in broiler chickens under heat stress condition

The effects of feeding low dietary crude protein (CP) and/or metabolisable energy (ME) with or without supplemental protease on growth performance, carcase characteristics and physiological responses in broiler chickens were investigated under cyclic heat stress condition. A total of 350 day-old male broiler chicks were fed with one of the following seven experimental diets: (1) recommended-CP and recommended-ME (RPE, served as control); (2) recommended-CP and low-ME (RPLE); (3) recommended-CP and low-ME with protease (RPLEP); (4) low-CP and recommended-ME (LPRE); (5) low-CP and recommended-ME with protease (LPREP); (6) low-CP and low-ME (LPE) and (7) low-CP and low-ME with protease (LPEP). From 22 to 42 d of age, half of the chickens from each dietary group were exposed to 34 ± 1 °C for 7 h daily (heat stress), whereas the other half were raised at constant 23 ± 2 °C (normal temperature). Supplementation of protease to RPLE, LPRE and LPE diets had no significant effects on feed intake (FI), weight gain (WG) or feed conversion ratio (FCR). Diet had no effect on serum glucose, total protein, certain acute phase proteins (APPs), corticosterone or breast yield. Regardless of protease supplementation, heat stressed birds had significantly lower FI, WG and breast yield, and higher FCR, APPs and corticosterone compared to birds raised in normal temperature. In conclusion, dietary supplementation of protease to low CP and/or ME diets showed negligible effects on growth performance, carcase characteristic and physiological responses in broiler chickens under heat stress condition. The inclusion of microbial protease in broiler diets could be considered by poultry industry as an effective nutritional tool for reducing ME or CP, in order to decrease abdominal fat deposition, improve feed efficiency and increase the profit margin.HighlightsProtease supplementation has no specific help for broilers under heat stress.Feeding low CP and/or ME diet is not stressful for broiler chickens.

Effects of varying levels of dietary protein and net energy on growth performance, nitrogen balance and faecal characteristics of growing-finishing pigs

This experiment was conducted to evaluate the effects of dietary protein and net energy (NE) levels on growth performance, nutrient digestibility, nitrogen metabolism, and faecal microbiota of growing-finishing pigs. Eighteen crossed barrows were randomly allocated into one of three dietary treatments: high protein + high NE diet, low protein + high NE diet, and low protein + low NE diet. The whole experiment lasted 90 days and was divided into three phases (phase I: 25-50 kg; phase II: 50-75 kg; phase III: 75-105 kg). All pigs were individually housed in a metabolism cage and subjected to four-day total faeces and urine collection period at the end of each phase. There was no significant difference in growth performance, nutrient digestibility, serum total protein, and albumin concentrations of pigs among the dietary treatments. Compared with the high protein + high NE diet, pigs fed low protein + high NE and low protein + low NE diets had lower N intake, urine N, and total N excretion in each phase. At the end of the experiment, pigs fed the low protein + high NE and low protein + low NE diets had lower blood urea nitrogen, serum NH3-N concentrations, faecal pH value, faecal NH3-N concentration, and faecal Escherichia coli count than those fed the high protein + high NE diet. However, there was no significant difference in all of the above indexes between low protein + high NE and low protein + low NE diets. Decreasing the dietary protein content by 3.5 percentage units has no adverse effects on growth performance and nutrient digestibility of pigs while significantly reduces N excretion and faecal Escherichia coli count. Moreover, further decreasing dietary NE level in the low-protein diet by 0.35-0.5 MJ/kg does not affect growth performance, nutrient digestibility, N excretion, blood profiles, and faecal Escherichia coli count of pigs.