Utilization Of Dietary Protein Research Articles

The Modification of Dietary Protein with Ammonium Hydroxide Enhancement Improves Longevity and Metabolic Outcomes in a Sex-Dependent Manner.

(1) Background: Dietary protein is a key component of all dietary patterns. It has been demonstrated that there are subtle differences in health implications associated with the source of dietary protein consumed. This study examined dietary protein sources (DPSs) in a long-term study of diet-induced obesity ± ammonium hydroxide enhancement (AHE) and its role in improving long-term health outcomes. (2) Methods: Over 18 months, 272 C3H/HeJ mice (136 male and 136 female) were monitored on high-fat diets with varying DPSs ± AHE. Mice were monitored for weekly change in total mass, as well as 6-month assessments of lean and fat mass. At each assessment, a cohort (~8 mice per diet per sex) was censored for a cross-sectional examination of organ function. (3) Results: Longevity was improved in females fed AHE diets, regardless of DPSs. Females' measures of fat and lean mass were markedly elevated with casein protein diets compared to beef protein diets regardless of AHE. Females fed a beef protein diet + AHE demonstrated reduced fat mass and increased lean mass with aging. In males, AHE beef protein diet-fed mice showed marked improvement to longevity and increased lean mass at 6 months. (4) Conclusions: This study demonstrates that dietary protein modification by AHE attenuates the negative impacts of HF diets in both males and females in a sex-dependent manner. Furthermore, the results from this study emphasize the importance of identifying the differences in the utilization of dietary proteins in both a sex- and age-related manner and demonstrate the potential of DPS modification by AHE as a dietary intervention.

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.

The effect of feeding level on protein and energy utilization in young and mature Kacang goats

Abstract A study was conducted to evaluate the amount of feeding on nutrient utilization of Kacang goats. This study used 16 heads, consisting of 8 young Kacang goats (5-6 months old), weighing 12.75 kg (CV = 2.4%), and 8 mature Kacang goats (12-15 months old), weighing 17.34 kg (CV = 2.7%). The diet was in the form of pellets, consisting of 25% wheat straw, 32% soybean meal, 39% rice bran, 3% sugarcane molasses, and 1% minerals. This study used a completely randomized design (CRD) in a nested structure. The main factor (the nest) was the age of the goat, i.e. young and mature, while the second factor (the nested factor) was feeding level, i.e. low (maintenance level) and high (twice maintenance level). The parameters were dry matter intake (DMI), dry matter digestibility (DMD), protein and energy intake, protein and energy digestibility, protein and energy retention, body weight gain (BWG), and feed conversion. The results showed the goat of high feeding level had higher DMI (P&lt;0.05) than that of low feeding level, both in the young goat (243 g/d vs 466 g/d) and the mature goat (303g/d vs 657). There was no significant difference (P&gt;0.05) in DMD between feeding levels and between age of goats (averaged 73.67%). The goats of high level had higher (P&lt;0.01) nutrients retention in goats and the mature goats. The goats of high feeding level had significantly higher (P&lt;0.05) BWG than that of low feeding level (14.64 g/d vs 41.95 g/d in the young goat and 18.35 g/d vs 58.77 g/d in the mature goat). The high feeding level resulted in lower FCR (P&lt;0.01) than the lower feeding level, both in the young goats (16.40 vs 11.44) and in the mature goats (16.47 vs 11.47). It can be concluded that young and mature Kacang goats had similar abilities in feed digestion. The higher feeding level resulted in the better utilization of dietary protein and energy, and productivity of the goat.

The response of turkeys to dietary balanced protein during two periods of growth

ABSTRACT 1. Two experiments were conducted to measure the response of growing turkeys to dietary protein content. In the first, 960 sexed British United Turkey (BUT 6) poults were used to measure the response to balanced protein from 3 to 6 weeks of age. In the second, 1440 sexed BUT and Hybrid Converter poults were raised from 14 to 17 weeks. 2. In both experiments, six levels of dietary protein were fed, with feed intake, body and feather weight gain and changes in body composition measured. The levels of protein chosen ranged from 0.53 to 1.2 of the Aviagen requirements for growing turkeys. 3. In the first experiment, six poults were sampled from each sex at the start of the experiment for carcass analysis, and four were sampled from each strain and sex in the second. At the end of each experiment, eight poults from each treatment were sampled. Body composition analyses were made on individual defeathered birds. 4. Weight gain increased linearly with protein intake in the early period and exponentially in the later period. In both periods, feed intake decreased as protein content reduced. 5. In the early period, body lipid content increased from 20.2 to 41.5 g/kg body weight, as dietary protein content decreased, but there was no change in the later period. Efficiency of utilisation of dietary protein declined linearly with an increase in dietary protein content, from 0.87 to 0.46 g/g in the first, and from 0.43 to 0.27 g/g in the later period. 6. The inability of the growing turkey to increase feed intake on marginally limiting feeds may have been due to a genetic constraints to store excess energy consumed as body lipid, resulting in the observed decrease in feed intake as dietary protein content is reduced.

Current advances for in vitro protein digestibility.

Protein is an essential macronutrient in our diet, source of nitrogen and essential amino acids, but the biological utilization of dietary protein depends on its digestibility and the absorption of amino acids and peptides in the gastrointestinal tract. The methods to define the amount and the quality of protein to meet human nutritional needs, such as the Digestible Indispensable Amino Acid Score (DIAAS), require the use of animal models or human studies. These in vivo methods are the reference in protein quality evaluation, but they are expensive and long-lasting procedures with significant ethical restrictions. Therefore, the development of rapid, reproducible and in vitro digestion methods validated with in vivo data is an old demand. This review describes the challenges of the in vitro digestion methods in the evaluation of the protein nutritional quality. In addition to the technical difficulties to simulate the complex and adaptable processes of digestion and absorption, these methods are affected by similar limitations as the in vivo procedures, i.e., analytical techniques to accurately determine bioavailable amino acids and the contribution of the endogenous nitrogen. The in vitro methods used for the evaluation of protein digestibility, with special attention on those showing comparative data, are revised, emphasizing their pros and cons. The internationally harmonized digestion protocol proposed by the INFOGEST network is being adapted to evaluate protein and amino acid digestibility. The inter-laboratory reproducibility of this protocol was demonstrated for dairy products. The in vivo/in vitro comparability results obtained to date with this protocol for several plant and animal sources are promising, but it requires an extensive validation with a wider range of foods and substrates with known in vivo digestibility. These in vitro methods will probably not be applicable to all foods, and therefore, it is important to identify their limitations, not to elude their use, but to apply them within the limits, by using the appropriate standards and references, and always as a complementary tool to in vivo tests to reduce their number.

The Recent Advances to Increase Nutrient Utilization of Dietary Plant Proteins by Enzyme Supplementation and Fermentation in Rainbow Trout (Oncorhynchus mykiss): A Review

Aquaculture is the fastest growing animal production sector globally. However, its sustainability heavily relies on the development of nutritionally balanced cost-effective and environmentally friendly aqua feeds for fish and crustacean species that are already being farmed or the candidate species for intensive farming in the future around the world. Therefore, feeds produced for farmed aquatic species should be highly digestible in terms of nitrogen and phosphorous contents in order to avoid excessive release of these nutrients into the water column through solid and soluble discharge. Excessive nitrogen and phosphorous in the water are the main reason of eutrophication occurring causing severe depletion of oxygen and creating hypoxia for many aquatic organisms living inside water column. Strategies like formulating aqua feeds on required DP/DE (Digestible Protein/Digestible non-protein Energy) basis for farmed species and using synthetic enzymes as feed additives in order to make plant phosphorous bioavailable for fish are being utilized by the commercial aqua feed producers around the world. Fermenting plant protein ingredients with microorganisms and using prebiotics and probiotics as feed additives are also considered a viable option to reduce the nutrient load of aquafarms since these have been shown to increase the digestibility of feed ingredients via increased gut health maintaining the optimal composition and environmental conditions for gut microbiome. In this regard, this review is intended to emphasize the importance of the sustainability efforts of aquaculture production from the perspectives of environmentally friendly aqua feed formulations and improvements based on the recent knowledge gathered for the effects of dietary external enzyme supplementation and fermentation of plant ingredients on growth and wellbeing of rainbow trout (Oncorhynchus mykiss) throughout the world.

Optimal dietary supplementation of phytase for red drum (Sciaenops ocellatus) based on growth and mineral utilization

A 9-week feeding trial was conducted with juvenile red drum to evaluate the potential benefits of supplementing dietary phytase on growth performance and utilization of phosphorus (P) and various trace minerals. The negative control diet (0.9% of total P and 0.57% of available P) was formulated to have inadequate available P based on the established P requirement of red drum. The positive control diet contained extra monocalcium phosphate (MCP) to provide 0.73% available phosphorus to meet the red drum's minimum P requirement. Another four phytase-supplemented diets were made via adding Quantum Blue phytase (AB Vista, Plantation, Florida) at either 1000, 2000, 4000, or 8000 phytase units (FTU)/kg to the negative control diet. Each diet was fed to quadruplicate groups of 20 juvenile red drum (initial weight of 4.99 ± 0.09 g) in 110-L aquaria operated as a brackish water (7 ppt) recirculating aquaculture system for 9 weeks. The results showed that compared to red drum fed the negative control diet, fish fed the phytase-supplemented diets had significantly (P < 0.05) increased weight gain, feed efficiency, and protein retention. In addition, significantly increased apparent availability of P was observed in red drum fed the diets containing phytase compared to those fed the negative control diet. Red drum given the phytase-supplemented diets also had significantly enhanced utilization of various minerals, except for whole-body retention of Mn and bone deposition of Fe, compared to fish fed the negative control diet. According to the results based on the orthogonal polynomial contrasts, the optimal dietary phytase dosage was found to be 5520 FTU/kg of dry diet. Consequently, the supplementation of dietary phytase significantly improved growth performance of red drum and partly substituted for dietary MCP in diets containing 40% soybean meal and insufficient available P. In addition, dietary phytase supplementation significantly enhanced the utilization of dietary protein and various minerals by red drum.

Branched-chain amino acid supplementation does not enhance lean tissue accretion in low birth weight neonatal pigs, despite lower Sestrin2 expression in skeletal muscle.

Postnatal muscle growth is impaired in low birth weight (L) neonatal pigs. Leucine supplementation has been established as a dietary intervention to enhance muscle growth in growing animals. The aim of this study was to investigate the efficacy of supplementing L neonatal pig formulas with branched-chain amino acids (B) to enhance the rate of protein accretion. Twenty-four 3-day old pigs were divided into two groups low (L) and normal birth weight (N) based on weight at birth. Pigs were assigned to a control (C) or 1% branched-chain amino acids (B) formulas, and fed at 250mL·kg body weight -1·d-1 for 28 d. Body weight of pigs in the L group was less than those in the N group (P < 0.01). However, fractional body weight was greater for L pigs compared with their N siblings from day 24 to 28 of feeding regardless of formula (P < 0.01). In addition, feed efficiency (P < 0.0001) and efficiently of protein accretion (P < 0.0001) were greater for L than N pigs regardless of supplementation. Pigs fed the B formula had greater plasma leucine, isoleucine, and valine concentrations compared with those fed the C formula (P < 0.05). Longissimus dorsi Sestrin2 protein expression was less for pigs in the L group compared with those in the N group (P < 0.01), but did not result in a corresponding increase in translation initiation signaling. Longissimus dorsi mRNAexpression of BCAT2 was less for LB pigs compared with those in the LC group, and was intermediate for NC and NB pigs (P < 0.05). Hepatic mRNA expression of BCKDHA was greater for pigs in the L compared with those in the N groups (P < 0.05). However, plasma branched-chain keto-acid concentration was reduced for C compared with those in the B group (P < 0.05). These data suggest that branched-chain amino acid supplementation does not improve lean tissue accretion of low and normal birth weight pigs, despite a reduction in Sestrin2 expression in skeletal muscle of low birth weight pigs. The modest improvement in fractional growth rate of low birth weight pigs compared with their normal birth weight siblings was likely due to a more efficient dietary protein utilization.

Effect of a Baobab Powder Diet on Growth and Digestive Balance in Growing Rats

Introduction: The fight against malnutrition (over- and undernutrition) requires knowledge of the fruits we eat. Baobab is a fruit from the north of Côte d'Ivoire whose consumption can help improve nutrition. Aim: The aim of this study was to investigate the chemical composition of baobab pulp and evaluate its nutritional impact after consumption in growing rats. Methodology: To achieve this objective, the physicochemical parameters and macronutrient contents of baobab flour were determined. Then, 3 batches of 5 rats were fed separately with three diets: RFB (baobab pulp), RM (baobab pulp + cornstarch) and RFM (cornstarch). Regular weighing was carried out to determine growth and digestibility parameters. Results: At the end of the work, it was found that baobab pulp is an acidic food (pH = 3.2), composed mainly of carbohydrates (92.47), mainly energy. It has a high starch content (56.34), a high sugar content (21.37), hence its sweet taste; with a considerable fiber content (7.82), in terms of dry matter (DM). Baobab flour contains very low levels of protein (2.08) and lipids (0.37). From a nutritional point of view, the baobab pulp diet (RFB) does not promote rat growth, and therefore the utilization of dietary protein. In addition, the RFB diet results in negative digestibility of dietary proteins and very low digestibility of the dry matter in the food consumed. On the other hand, rat growth and the digestibility of dietary protein and dry matter increased with the reduction (RM) or elimination (RFM) of baobab flour from the diet. Conclusion: Ultimately, these results enable us to assess the nutritional quality of baobab flour. Its consumption, which does not promote weight gain despite its high carbohydrate content, can therefore be used in the fight against obesity.

Dietary supplementation of VA enhances growth, feed utilization, glucose and lipid metabolism, appetite, and antioxidant capacity of Chinese perch (Siniperca chuatsi).

The aim of this study was to investigate the effect of dietary vitamin A on juvenile Chinese perch (Siniperca chuatsi). Chinese perch were fed with five experimental diets containing 0, 20, 40, 60, and 80mg VA·kg-1 for 8weeks. Results showed that dietary vitamin A significantly influenced the fish's growth, feed utilization, glucose and lipid metabolism, appetite, and antioxidant capacity. Vitamin A-supplemented groups had higher weight gain rate (WGR) and specific growth rate (SGR) compared to the control group. Feed conversion ratio (FCR) was also lower in the vitamin A-supplemented groups. Dietary vitamin A had no significant effect on the survival rate (SR). Compared to the control group, fish fed with vitamin A had increased feed intake (FI), and the expression of appetite-promoting genes (npy and agrp) was significantly higher in the 40mg VA·kg-1 group. Vitamin A also enhanced the utilization of dietary protein by Chinese perch. The serum glucose content of the fish fed with 40mg VA·kg-1 diet was significantly higher than that of the control group and 20mg VA·kg-1 diet, indicating that the promoting effect of VA on gluconeogenesis was greater than that on glycolysis. Additionally, dietary vitamin A increased the expression of lipid metabolism-related genes (hl and fas) and antioxidant genes (nrf2 and gpx) in the fish. These results suggest that the optimal vitamin A requirement of juvenile Chinese perch bream was estimated to be 37.32mg VA·kg-1 based on broken-line regression analysis of WGR. In conclusion, this study provides valuable insights into the potential benefits of dietary vitamin A on the growth, metabolism, and antioxidant capacity of Chinese perch.

Dietary protein levels modulate the gut microbiome composition through fecal samples derived from lactating ewes.

In ruminants, the digestion and utilization of dietary proteins are closely linked to the bacterial populations that are present in the gastrointestinal tract. In the present study, 16S rDNA sequencing, together with a metagenomic strategy was used to characterize the fecal bacteria of ewes in the early lactation stage after feeding with three levels of dietary proteins 8.58%, 10.34%, and 13.93%, in three different groups (H_1), (H_m) and (H_h), respectively. A total of 376,278,516 clean data-points were obtained by metagenomic sequencing. Firmicutes and Bacteroidetes were the dominant phyla, regardless of the dietary protein levels. In the H_h group, the phyla Proteobacteria, Caldiserica, and Candidatus_Cryosericota were less abundant than those in the H_I group. In contrast, Lentisphaerae, Chlamydiae, and Planctomycetes were significantly more abundant in the H_h group. Some genera, such as Prevotella, Roseburia, and Firmicutes_unclassified, were less abundant in the H_h group than those in the H_I group. In contrast, Ruminococcus, Ruminococcaceae_noname, Anaerotruncus, Thermotalae, Lentisphaerae_noname, and Paraprevotella were enriched in the H_h group. The acquired microbial genes were mainly clustered into biological processes; molecular functions; cytosol; cellular components; cytoplasm; structural constituents of ribosomes; plasma membranes; translation; and catalytic activities. 205987 genes were significantly enriched in the H_h group. In contrast, 108129 genes were more abundant in the H_I group. Our findings reveal that dynamic changes in fecal bacteria and their genes are strongly influenced by the levels of dietary proteins. We discovered that differentially expressed genes mainly regulate metabolic activity and KEGG demonstrated the primary involvement of these genes in the metabolism of carbohydrates, amino acids, nucleotides, and vitamins. Additionally, genes responsible for metabolism were more abundant in the H_h group. Investigating fecal bacterial characteristics may help researchers develop a dietary formula for lactating ewes to optimize the growth and health of ewes and lambs.

132 Weight and Reproduction Response to a Peanut Skins Plus Corn Supplement Offered to Heifers Grazing Spring Wheat Pasture During Artificial Insemination Breeding

Abstract The objective was to assess heifer weight and reproduction response to a peanut skins plus corn supplement during spring wheat grazing. In spring of 2021 and 2022, 10 and 8 pastures (1.62 ha/pasture) of fall overseeded wheat were randomly assigned to supplement (SUP) or control (CONT) constrained to the same number of replications per treatment. Pastures were stocked with 6 heifers/pasture each year. The initial goal was to use peanut skins as a single ingredient; however, testing palatability in year 1, before spring grazing, demonstrated a need to create a mixed supplement for improved acceptance. Over 5 weeks from initiation of grazing to breeding, heifers were transitioned from a 33:67 to a 50:50 peanut skins:corn mix. Supplement was offered at 0.5% BW, as-fed, at the start of spring wheat grazing in early March. An additional 2.4% and 8.3% inclusion of dried molasses was incorporated to further enhance acceptance in year 1 and 2, respectively. Estrus synchronization (ES) began March 31 and April 5 for each year. Data were analyzed across year with year considered as a random effect and pasture the experimental unit. Initial weight was 12 ± 5.8kg greater (P = 0.05) for SUP. Weight at ES tended (P = 0.11) to be 9.4 ± 5.55kg greater for SUP. Reproduction tract score was similar (P = 0.55), averaging 4.2 ± 0.13, and heifers were of similar (P = 0.33) age (405 ± 4.1 days) at time of insemination. Average daily gain from initial wheat grazing until removal for natural service breeding did not differ between treatments (P = 0.92) and averaged 1.0 ± 0.21 kg. Body condition score was similar (P = 0.43) at ES and averaged 5.7 ± 0.7. The heavier initial BW of SUP heifers was sustained through wheat grazing (P = 0.05). Ultrasound determined pregnancies averaged 66.7 and 50.0 ± 6.6% for SUP and CONT, respectively, for an odds ratio of 2.1 ± 0.79 (P = 0.08) at 30 days after insemination. Overall pregnancy rates following natural service averaged 88.9 and 79.6 ± 4.88% for SUP and CONT, respectively with an odds ratio of 2.1±1.12 (P=0.19). High dietary protein has been associated with reduced reproductive performance. Using the peanut skins plus corn supplement was hypothesized to improve reproduction on a high protein diet due to the possible effect of peanut skins tannins on dietary protein utilization and corn altering the rumen degradable protein to organic matter ratio. While the fixed time artificial insemination pregnancy rates for CONT would not be considered poor, there was a tendency for SUP to secure more pregnancies among heifers of similar age, reproductive tract score, and body condition.

Effects of different levels of dietary crude protein on the physiological response, reproductive performance, blood profiles, milk composition and odor emission in gestating sows.

This study was conducted to evaluate the effects of crude protein (CP) levels on the physiological response, reproductive performance, blood profiles, milk composition and odor emission in gestating sows. Seventy-two multiparous sows (Yorkshire×Landrace) of average body weight (BW), backfat thickness, and parity were assigned to one of six treatments with 10 or 11 sows per treatment in a completely randomized design. Experimental diets with different CP levels were as follows: i) CP11, corn‒soybean-based diet containing 11% CP; ii) CP12, corn‒soybean-based diet containing 12% CP; iii) CP13, corn‒soybean-based diet containing 13% CP; iv) CP14, corn‒soybean-based diet containing 14% CP; v) CP15, corn‒soybean-based diet containing 15% CP; and vi) CP16: corn‒soybean-based diet containing 16% CP. There was no significant difference in the performance of sow or piglet growth when sows were fed different dietary protein levels. Milk fat (linear, p = 0.05) and total solids (linear, p = 0.04) decreased as dietary CP levels increased. Increasing dietary CP levels in the gestation diet caused a significant increase in creatinine at days 35 and 110 of gestation (linear, p = 0.01; linear, p = 0.01). The total protein in sows also increased as dietary CP levels increased during the gestation period and 24 hours postpartum (linear, p = 0.01; linear, p = 0.01). During the whole experimental period, an increase in urea in sows was observed when sows were fed increasing levels of dietary CP (linear, p = 0.01), and increasing blood urea nitrogen (BUN) concentrations were observed as well. In the blood parameters of piglets, there were linear improvements in creatinine (linear, p = 0.01), total protein (linear, p = 0.01), urea (linear, p = 0.01), and BUN (linear, p = 0.01) with increasing levels of dietary CP as measured 24 hours postpartum. At two measurement points (days 35 and 110) of gestation, the odor gas concentration, including amine, ammonia, and hydrogen sulfide, increased linearly when sows fed diets with increasing levels of dietary CP (linear, p = 0.01). Moreover, as dietary CP levels increased to 16%, the odor gas concentration was increased with a quadratic response (quadratic, p = 0.01). Reducing dietary CP levels from 16% to 11% in a gestating diet did not exert detrimental effects on sow body condition or piglet performance. Moreover, a low protein diet (11% CP) may improve dietary protein utilization and metabolism to reduce odor gas emissions in manure and urine in gestating sows.

Protein-Sparing Effect of α-Lipoic Acid in Diets with Different Protein/Carbohydrate Ratios for the Oriental River Prawn, Macrobrachium nipponense

Carbohydrates are commonly used in aquaculture feed because they are the cheapest energy source. Promoting carbohydrate catabolism for energy production can increase the dietary protein utilization efficiency (i.e., a protein-sparing effect). Alpha-lipoic acid (α-LA) is a cofactor of some rate-limiting key enzymes (pyruvate dehydrogenase complex and α-ketoglutarate dehydrogenase) in carbohydrate metabolism. To determine whether α-LA could promote carbohydrate catabolism to have a protein-sparing effect, we investigated the growth, activities of key enzymes involved in carbohydrate metabolism, transcript levels of genes encoding enzymes involved in energy metabolism, and the hepatopancreas structure of Macrobrachium nipponense fed with diets containing different protein/carbohydrate ratios (P/C) with and without α-LA. Six experimental diets for M. nipponense were formulated with casein and fish meal as the protein sources, fish oil and soybean oil as the lipid sources, and corn starch as the carbohydrate source. The six diets consisted of three different P/Cs ( P 41 / C 18 , P 37 / C 24 , and P 33 / C 30 ) without or with α-LA (at 1300 mg/kg). Each diet had six replicates and was fed to prawns (initial weight 0.110 ± 0.010 g) twice daily to apparent satiation. Dietary supplementation with α-LA significantly increased the survival rate of prawns, regardless of the P/C ratio. In the low-P/C group ( P 33 / C 30 ), the weight gain did not vary between those that consumed α-LA and those that did not. The P/C ratio and α-LA significantly affected the activities of key enzymes involved in glycolysis and the citric acid cycle. In the P 41 / C 18 group, the hexokinase (HK) and pyruvate dehydrogenase (PDH) activities were significantly higher in prawns that consumed α-LA than in those that did not. In both the P 37 / C 24 and P 33 / C 30 groups, the pyruvate kinase (PK) activity was significantly higher in prawns that consumed α-LA than in those that did not. Significant interactions between P/C and α-LA were found for the transcript levels of genes encoding adenine ribonucleotide-dependent protein kinase subunits (AMPK αand AMPK β), HK, glucose-6-phosphate dehydrogenase (G6PDH), acetyl-CoA carboxylase (ACC), and fatty acid binding protein 10 (FABP 10), all of which are involved in energy metabolism. In the low-P/C group, α-LA increased the transcript levels of genes encoding AMPK α, AMPK β, HK, phosphoenolpyruvate carboxykinase (PEPCK), G6PDH, and MDH, decreased the transcript level of the gene encoding ACC, and did not affect the transcript levels of genes encoding FABP10 and palmitoyl transferase 1 (CPT1). The P/C ratio and α-LA did not affect the overall morphology of the hepatopancreas, but at a low P/C, dietary supplementation of α-LA increased the number of hepatopancreatic B cells. In conclusion, supplementation with α-LA at 1300 mg/kg in a low-P/C diet of M. nipponense increased its carbohydrate utilization efficiency, energy metabolism, and the number of hepatopancreas B cells, thereby having a protein-sparing effect.

Insulin-like growth factor II, a marker gene for determining the optimum dietary protein level in clownfish Amphiprion ocellaris.

In vivo study was conducted to determine the role of insulin-like growth factors (IGF-II) related to dietary protein utilization. For this early juvenile stage of marine false clownfish Amphiprion ocellaris, 300 numbers of 20-day-old larvae (initial body weight of 18.2±0.027 mg/fish) were used as an experimental animal. Animals were fed for 12 weeks with different dietary protein levels (35, 40, 45, 50, and 55%), using Spirulina maxima as a major protein source. Proximate compositions and amino acid profile of the formulated diet were analyzed by the standard methods. Eventually, significant (P<0.05) mean, body weight gain, absolute growth rate, specific growth rate, and feed conversion ratio were obtained in the fishes fed with 50% of dietary protein, whereas, poor growth performance was noticed in 35% of the dietary protein level fed juveniles. The growth-responsible gene IGF-II expression studies showed the significant upregulation in the growth of the juveniles at 2.05±0.11 for 40%, 3.13±0.20 for 45%, 4.97±0.13 for 50%, and 4.33± 0.24 for 55%, which were higher than the control group 35%. The study concluded that 50% of dietary protein level is optimal for better growth indices in clownfish; A. ocellaris juveniles and IGF-II can be used as a potential marker gene to assess the growth indices in A. ocellaris.

Evaluation of tributyrin supplementation in milk replacer on diarrhoea occurrence in preweaning Holstein calves

Neonatal calf diarrhoea is one of the most important health challenges in cattle herds causing substantial economic losses and antimicrobial use. Due to the raising problem of antimicrobial resistance, effective alternatives are urgently required, in line with European policies. The aim of this study was to evaluate the effect of tributyrin supplementation in milk replacer on diarrhoea, performance and metabolic status in preweaning Holstein calves. Twelve newborn calves, after colostrum administration, were randomly allotted in two experimental groups for 42 days: control (CTRL) fed milk replacer, tributyrin (TRIB) fed milk replacer supplemented with 0.3% of liquid tributyrin on milk powder weight. Calves BW was recorded on a weekly basis from day 7 to day 42, and feed intake was recorded daily to calculate zootechnical performance. Faecal consistency was assessed daily through the faecal score (0–3 scale; considering diarrhoea moderate = 2 and severe = 3). Faecal samples were collected weekly from rectal ampulla for microbiological analysis by plate counting method evaluating the number of total bacteria, lactic acid bacteria and coliform bacteria. On day 0 and day 42, individual blood samples were collected from jugular vein for metabolic profile analysis. Serum samples of day 42 were also evaluated for the antioxidant barrier using a colorimetric test, while glucagon-like peptide 2 and diamine oxidase concentrations were measured through immunoenzymatic assays. Tributyrin supplementation did not influence the zootechnical performance of calves over 42 days of trial. Diarrhoea frequency was significantly lower in TRIB compared to CTRL group (27.91 and 38.37%; P < 0.01) considering the whole experimental period. In particular, the major effect was observed for moderate diarrhoea in TRIB group that showed a significantly reduced frequency compared to CTRL (P < 0.01) thus suggesting a preventive effect of tributyrin. Faecal total bacterial, lactic acid and coliform bacteria counts did not show differences between groups. Urea serum concentrations tended to be lower in TRIB compared to CTRL, indicating an efficient utilisation of dietary protein. Antioxidant barrier and glucagon-like peptide 2 were comparable between CTRL and TRIB on day 42. Diamine oxidase concentrations were significantly decreased in TRIB compared to CTRL group after 42 days of trial (P < 0.01), suggesting a higher gut epithelial integrity probably due to lower diarrhoea frequency and the nourish effect of tributyrin on enterocytes. In conclusion, tributyrin could be considered as a valuable bioactive feed additive to decrease the neonatal diarrhoea occurrence and support intestinal integrity in preweaning calves.

Inhibition of Starch Digestion by α-Amylase Inhibitor Reduces the Efficiency of Utilization of Dietary Proteins and Lipids and Retards the Growth of Rats

Digestion/absorption and nutritional utilization of starch, protein and lipids were studied in rats fed diets containing purified kidney bean α-amylase inhibitor at levels of 0, 1.6, 3.3 and 6.6 g/kg diet. At the two higher levels, the growth rate of rats and the apparent digestibilities and utilization of dietary starch and protein were significantly less than in control rats, and losses of nitrogen, lipids and carbohydrate resulted in a significant reduction in dry body weight. Some organs of the body were also affected: the relative dry weights of the intestines and the pancreas were higher, whereas liver and thymus weights were lower than in control rats. As starch digestion in the small intestine was negligible at higher inhibitor concentrations, the cecum was practically blocked by solidified digesta. This effect and the ensuing bacterial fermentation stimulated the growth of this tissue by hyperplasia and hypertrophy. However, as the distension was not always sufficient, the organ was occasionally ruptured and the rats had to be killed. Inhibitor doses in this work were comparable to those in clinical studies, implying that the use of the inhibitor is not without health risks. Moreover, diets rich in α-amylase inhibitor such as those containing transgenic plants with high levels of inhibitor gene expression cannot be recommended in intensive animal production.

Additive Tannins in Ruminant Nutrition: An Alternative to Achieve Sustainability in Animal Production

Sustainable intensification involves maintaining ecosystem balance and increasing productivity per animal per unit area. Phytogenic additives can be used as an alternative to achieve sustainable intensification. Tannins are phenolic compounds present in plants that are classified according to their chemical structure into hydrolyzable and condensed compounds. When added to ruminant diets, condensed tannins exert effects on rumen fermentation, such as a reduction in rumen protein degradation and enteric methane production per unit of dry matter ingested, and may also improve weight gain. The advantage of this mechanism is that it increases dietary protein utilization, reduces nitrogen excretion in urine, and reduces nitrous oxide emissions. However, the positive effects of these compounds as nutritional additives require further investigation. Therefore, the objective of this review is to demonstrate the results hitherto known of the use of condensed tannins in ruminant nutrition. The use of tannins can result in both positive and negative effects, depending on the sources and doses administered.

Meta-analysis of the relationship between dietary condensed tannins and methane emissions by cattle

Using condensed tannins (CT) in ruminant nutrition yields many benefits, especially regarding better dietary protein utilization and decreased methane (CH4) emission by altering ruminal fermentation kinetics. A meta-analysis was conducted to develop and analyze a database from published studies and verify the effects of CT inclusion on enteric CH4 emission by cattle, nutrient digestibility and ruminal parameters, and their interactions. The study aimed to develop regression equations based on the significant components and their interactions to target a specific ruminal CH4 mitigation when correctly associating CT inclusion level and diet composition. A database was developed from 40 published studies that measured cattle CH4 emission using in vitro or in vivo methods and reported the source and inclusion levels of CT as well as typical diet characteristics, including crude protein (CP), organic matter (OM), neutral detergent fiber (NDF), and ether extract (EE). Other related parameters were also included in the database when reported, such as dry matter intake (DMI) and digestibility, OM digestibility, NDF digestibility, and ruminal parameters, including pH, ruminal ammonia nitrogen, total volatile fatty acids (VFA), acetate, propionate, butyrate, and the acetate-to-propionate ratio. The meta-analysis was conducted by multiple linear regression, using the nlme package of R 4.2.1, in which studies were assumed as random variables affecting the intercept and slopes. The CH4 emission, expressed in L/kg of DMI, decreased with increasing levels of dietary CT when in vitro and in vivo were analyzed together (P < 0.001) or in vivo alone (P < 0.001). Total VFA concentration (P = 0.049), propionate (P = 0.042), and butyrate (P = 0.047) increased with increasing levels of dietary CT on in vitro + in vivo methods, suggesting improved fermentability. When analyzing all chemical components of the diet, OM (P = 0.043) and CP (P = 0.010) decreased CH4 production with in vitro methods, EE decreased CH4 production on in vivo method (P = 0.001), while dietary NDF increased CH4 production on in vitro + in vivo (P = 0.016), and also separately for in vivo (P = 0.058) and in vitro method (P = 0.022). There was an interaction between CT and CP for in vivo experiments (P = 0.010): CH4 = 35.64 – 6.87 ×CT – 0.49 ×CP + 0.33 ×CT*CP. Across many experiments, increasing the level of dietary CT led to a decrease in ruminal CH4 concentrations for in vitro and in vivo fermentation conditions and an increase in molar proportions of propionate, butyrate, and total VFA, indicating that it is an efficient natural alternative to reduce environmental impacts of ruminant production systems possibly. Our meta-analysis identified diet components that significantly affect enteric CH4 emissions by cattle and developed a prediction model based on these components, including OM, CP, NDF, and EE. The in vivo CH4 method showed that an interaction between CT and CP diet content affects CH4 emissions. Future research and meta-analysis must focus on CT biological activity along with percent content to dictate ideal diet inclusion to suppress CH4 emissions without depressing animal performance.

Effect of non-encapsulated and encapsulated mimosa (Acacia mearnsii) tannins on growth performance, nutrient digestibility, methane and rumen fermentation of South African mutton Merino ram lambs

The use of mimosa tannins as feed additives in contemporary ruminant nutrition studies has gained wider acceptance, because of their potential to reduce enteric methane and enhance dietary protein utilization. However, tannin’s astringency and quick dissolution decrease feed intake and digestibility. Microencapsulation technology could be adopted to neutralize the astringency and ensure controlled tannin solubility across ruminant digestive tract. The present study examined the influence of supplementing unencapsulated and encapsulated Mimosa (Acacia tannin) tannins on growth performance, digestibility, methane (CH4) and rumen fermentation in South African mutton Merino sheep. A total of 40 weaned Merino ram lambs of 96 days old (34 −35 kg body weight, BW) were randomly allocated to one of the four dietary treatments in a randomized complete block design as follows: total mixed ration, (T1, TMR alone); TMR + Monensin at 75 mg/kg feed dry matter, DM (T2, Monensin); TMR + unencapsulated Mimosa tannin at 20 g/kg DM (T3, UMT) and TMR + encapsulated Mimosa tannin in sunflower oil at 20 g/kg DM equivalent (T4, EMTS). The lambs were adapted to the diets over a period of 28 days thereafter, feed intake and weight changes were recorded for 77 days. The lambs were moved to metabolic crates and assessed for digestibility followed by methane measurement in open-circuit respiratory chambers. Finally, the animals were slaughtered, rumen fluids sampled and analysed for volatile fatty acids (VFAs) and ammonia nitrogen (NH3-N). Inclusion of UMT and EMTS did not affect (P > 0.05) feed intake and weight gain. Compared with the TMR alone, UMT and EMTS increased intake of DM (T1, 1328 g/day vs T3, 1578.1 and T4, 1569 g/day; P = 0.05), DM adjusted to BW (T1, 69.3 g/kg BW vs T3, 83.8 and T4, 83.7 g/kg BW; P = 0.04), organic matter, OM (T1, 1254 g/kg vs T3, 1494 and T4, 1490 g/day; P = 0.04), neutral detergent fibre, NDF (T1, 344 g/day vs T3, 434 and T4, 416 g/day; P = 0.01) and acid detergent fibre, ADF (T1, 174 and T3, 241 g/day vs T4, 218 g/day; P = 0.02), compared with the control. However, only UMT decreased (P = 0.01) digestibility of DM (T3, 640 g/kg vs T1, 746 g/kg), OM (T3, 655 g/kg vs T1, 761 g/kg) and CP (T3, 734 g/kg vs T1, 829 g/kg). Furthermore, UMT increased (P = 0.01) faecal nitrogen (N) excretion (T3, 13.7 g/head/day vs T1, 8.03 g/head/day and T3, 266 g/kg N-intake vs T1, 171 g/kg N-intake). UMT and EMTS reduced CH4 in g/kg DM-intake (T3, 15.3 and T4, 14.8; vs T1, 18.9; P = 0.04). However, NH3-N and total VFAs concentrations were not influenced (P > 0.05) by the inclusion of UMT and EMTS. It was concluded that UMT and EMTS could be utilized in mitigating enteric CH4 while enhancing nutrient intake when supplemented at 20 g/kg DM of feed. Among the two, however, EMTS reduced more CH4 without affecting digestibility compared to equivalent proportion of UMT. Further studies should be conducted on the total tannin concentration of the encapsulated mimosa tannin in sunflower oil.