Lowering the dietary protein levels by the use of synthetic amino acids and the use of a mono component protease

Effects of low protein diets on acid-base balance, electrolyte balance, intestinal structure, and amino acid transport in piglets

Reducing the dietary crude protein (CP) could effectively reduce pressure on protein ingredient supplies. However, few data have been reported about the extent to which CP can be reduced and whether limiting the use of soybean meal leads to electrolyte imbalance. In this experiment, using the low protein (LP) diet [2% lower than NRC (2012)], seventy-two piglets (35 days old) were randomly divided into 2 groups with 6 replicates of 6 piglets each: CON group (CP = 18.5%) and LP group (CP = 16.5%), to investigate the effect of the LP diet on electrolyte balance, acid-base balance, intestinal structure and amino acid transport in piglets. The results revealed that the LP diet decreased the average daily gain and dietary CP digestibility, and damaged the villi structure of the small intestine. Compared with the CON diet, the potassium content decreased and the chlorine content increased in the LP diet, and similar trends were shown in piglet serum. The arterial pH, pCO2, HCO3 -, and base excess of piglets in the LP group were lower than those in the CON group, while pO2 was higher than those in the CON group. Interestingly, the LP diet significantly increased the lysine content in piglet serum and significantly decreased the levels of arginine, leucine, and glutamic acid. Furthermore, the LP diet significantly affected the expression of some amino acid transport vectors (B0AT1, EAAC1, and y+LAT1). In summary, these findings suggested that the LP diet leads to acid-base imbalance, amino acid transport disorder and amino acids imbalance in piglets, and the dietary electrolyte may be a key factor in the impact of the LP diet on piglet growth performance and intestinal health.

Aspartic protease supplementation enhancing the performance, carcass characteristics, nutrient digestibility and economic viability, without changing blood parameters and salivary cortisol of pigs

Aiming to study the performance, carcass characteristics, nutrient digestibility, blood parameters, salivary cortisol levels, and economic viability of pigs administered aspartic protease, a total of 135 pigs were housed in pens in a randomized block design, divided into five treatments with nine replications. The experimental diets were positive control (PC), basic diet with a 5.0% reduction in protein and amino acid requirements; negative control (NC) with a 7.5% reduction in protein and amino acid requirements; NC + 100 g/mT of aspartic protease (NC100); NC + 150 g/mT of aspartic protease (NC150); and NC + 200 g/mT of neutral serine protease (NC200). The inclusion of protease, independently of the source and amount, increased the average daily weight gain (P < 0.05) of animals compared with the control treatments (PC and NC), improved feed conversion (P < 0.05) in early stages, and improved diet digestibility (P < 0.05) compared with the PC. Treatment with NC150 and NC200 resulted in greater carcass weights (P < 0.05) than treatment with the PC. NC100 led to a greater carcass yield than PC (P < 0.05), and NC150 resulted in a greater loin eye area than PC (P < 0.05). No differences (P > 0.05) in the blood parameters or salivary cortisol levels were found. Regarding economic viability, proteases increased the profitability, with NC150 leading to the best results. Thus, the use of aspartic proteases is recommended to improve performance and further facilitate pork production.

Multiprotease improves amino acid release in vitro, energy, and nutrient utilization in broilers fed diets varying in crude protein levels

Low crude protein (CP) diets can reduce nitrogen (N) excretion and costs by increasing N utilization efficiency. Exogenous proteases may further improve protein digestibility in low CP diets. This study first evaluated in vitro the efficacy of a multiprotease on amino acid (AA) release from feedstuffs and broiler feed. Later, a broiler study evaluated the effect of feeding corn-soybean meal diets containing 3 CP levels (17, 19, and 21% CP) with supplementation on top of 0 or 2,400 U/kg multiprotease on chicken growth performance, total tract CP, and ileal AA digestibilities, and energy utilization. Ross 708 male chickens were placed in 42 cages and assigned to 6 treatments resulting from a 3 × 2 factorial arrangement. Three isocaloric basal diets were formulated to reduce CP, but all diets maintained digestible Lys:CP in 5.47% and the same ideal protein profile. Data were analyzed in a completely randomized design. On average, the multiprotease increased (P < 0.05) in vitro free AA release by 27.81% in most feedstuffs evaluated compared to the control. For broiler feed, 1,200 U/g multiprotease addition improved (P < 0.001) in vitro free AA release by 18.90%. This multiprotease showed interaction effects (P < 0.05) on chicken FCR, energy, and CP digestibility. As expected, BW at 24 d, BW gain, and FCR (8-24 d) worsened (P < 0.001) as dietary CP reduced from 21 to 17%, and multiprotease addition did not improve (P > 0.05) these parameters. BW gain decreased by 12.9% when N intake was reduced from 49.32 to 38.49 g/bird. Multiprotease supplementation improved (P < 0.01) AMEn by 71 kcal/kg, CP digestibility from 59.45 to 63.51%, ileal AA digestibility, and DM digestibility from 67.08 to 73.49%, but only in the 21% CP diet. No differences in ileal AA digestibility due to CP level (P > 0.05) were detected, except for Cys digestibility (P < 0.01). In conclusion, low CP diets reduced growth performance and improved N utilization but negatively affected energy utilization efficiency. Exogenous multiprotease supplementation improved AME, AMEn, protein, ileal AA, and DM digestibility in the 21% CP diet without significantly affecting growth performance.

Rosa D, Teixeira L, B. Sorbara JO, J. Cowieson A, Faruk MU. Effects of dietary digestible amino acids and a novel exogenous sfericase protease on growth performance of broilers

Two experiments (Exp.) were conducted to evaluate the effects of a novel exogenous sfericase protease on growth performance and ileal digestibility of broiler chickens until day 35 of age. In Exp. 1, 1350 one-day-old male chicks (Cobb 500) were allocated in 54 floor pens and fed one of the three dietary treatments, with 18 replicates of 25 birds each in a completely randomized design. Diets consisted of positive control [PC; commercially relevant ME and balanced amino acids (AA)]; negative control (NC; with reduction of 6% dig. Lys and proportional reductions for adjacent AA compared to the PC), and NC supplemented with sfericase protease [30,000 New Feed Protease units (NFP)/kg]. On day 35, ileal digesta was collected to determine apparent ileal digestibility of dry matter and nitrogen (N). In Exp. 2, 1620 one-day-old male chicks (Cobb 500) were allocated in 54 floor pens having three treatments and 18 replicates of 30 birds each in a completely randomized design from day 1-35. Broilers were fed a control basal diet (Control); Control supplemented with sfericase at 30,000 NFP/kg and at 60,000 NFP/kg. In Exp. 1, from day 1-35, body weight gain (BW gain) and feed conversion ratio (FCR) of broilers improved 3.4 and 2.5% when diets were supplemented with sfericase, respectively, whereas the digestibility of N increased by 2.7% compared to the NC. In Exp. 2, diets with usual protein and AA levels and supplemented with 30,000 NFP/kg had 2.3 and 1.75% improved BW gain and FCR from day 1-35, respectively. When diets were supplemented with 60,000 NFP/kg, BW gain and FCR were enhanced by 3.9 and 3.2%, respectively compared to the Control. In conclusion, these results demonstrate that the novel sfericase protease could be successfully used in corn-soy diets with protein and AA reductions or in feed formulations with usual digestible AA levels to enhance growth performance of broilers.

Land application of industrial wastes: impacts on soil quality, biota, and human health

Globally, waste disposal options such as landfill, incineration, and discharge to water, are not preferred long-term solutions due to their social, environmental, political, and economic implications. However, there is potential for increasing the sustainability of industrial processes by considering land application of industrial wastes. Applying waste to land can have beneficial outcomes including reducing waste sent to landfill and providing alternative nutrient sources for agriculture and other primary production. However, there are also potential hazards, including environmental contamination. This article reviewed the literature on industrial waste applications to soils and assessed the associated hazards and benefits. The review investigated wastes in relation to soil characteristics, dynamics between soils and waste constituents, and possible impacts on plants, animals, and humans. The current body of literature demonstrates the potential for the application of industrial waste into agricultural soils. The main challenge for applying industrial wastes to land is the presence of contaminants in some wastes and managing these to enhance positive effects and reduce negative outcomes to within acceptable limits. Examination of the literature also revealed several gaps in the research and opportunities for further investigation: specifically, a lack of long-term experiments and mass balance assessments, variable waste composition, and negative public opinion.

Amino acid digestibility coefficient values of animal protein meals with dietary protease for broiler chickens

A digestibility experiment was conducted to evaluate the effects of dietary exogenous monocomponent protease on the coefficient of apparent total tract digestibility (ATTD) and coefficient apparent ileal digestibility (AID) of amino acids in meat and bones meal (MBM), poultry byproducts meal (PBPM), and feather meal (FM). A total of 512 Cobb-500 male broiler chickens (aged 14 d) were randomly placed into 64 metabolism cages (8 birds per pen) and were allocated to eight treatments with eight replicates in a semi-controlled environmental room. The experimental diets consisted of the basal diet (corn/SBM) and the replacement of 300 g/kg on a weight basis with MBM, PBPM, or FM. The excreta were collected during 3 d (19 to 21 d), and the ileal digesta (using Celite as an indigestible marker) only 1 d (21 d). The protease contained 75,000 PROT units/g. The use of the enzyme increased (P < 0.05) ATTD for alanine, cysteine, glycine, and threonine in the basal diet and AID for the amino acids alanine, cysteine, glycine, lysine, threonine, and valine for the basal diet (vegetable). Regarding meals, there was an increase (P < 0.05) in the amino acid digestibility in large part due to the amino acids of MBM (14) and PBPM (9), with only five amino acids for FM. The amino acids glycine and threonine showed increases (P < 0.05) in both total and ileal digestibility for all animal meals and for the diet based on corn and soybean meal, which indicates a high specificity of the enzyme for these amino acids. The overall results obtained in this study found satisfactory effectiveness of this exogenous protease. The total collection method was lower by 1.83% of amino acids digestibility than the ileal method.

Comparison of formulation costs for poultry feeds based on crude protein versus the digestible lysine to protein ratio

Abstract The objective of this study was to determine the influence of using dLys:TP instead of crude protein recommendations of commercial poultry breeding companies to meet the chicken’s need for dietary essential and non-essential amino acids. The ingredient composition matrix used in the feed formulation was compiled from Feedstuffs Magazine. The rations were formulated using a linear feed formulation program to meet the minimum cost, with crude protein or dLys: TP of 5.58%. Using the dLys to TP ratio versus CP minimums for the model diets chosen, formula costs were changed from +$10.96 to -$4.26 per ton of feed. The magnitude of the changes was dependent on the imbalance present in the feeds from using the breeder management guide recommendations and ingredient prices. Through the use of dLys: TP, it is possible to improve the feed formulation process, assuring the birds get adequate EAA and NEAA without being wasteful and reducing environmental pollution.

Broilers fed a low protein diet supplemented with synthetic amino acids maintained growth performance and retained intestinal integrity while reducing nitrogen excretion when raised under poor sanitary conditions

The present study investigated the effects of supplementing a low protein (LP) diet supplemented with key essential amino acids (AA) to broilers on growth performance, intestinal tract function, blood metabolites, and nitrogen excretion when the animals were maintained under various sanitary conditions for 35 D after hatching. Three hundred eighty-four one-day-old male broilers (Ross 308) were randomly allotted to groups that received one of 6 dietary treatments in a 2 × 3 factorial arrangement (i.e., 2 environmental conditions and 3 dietary treatments) to give 8 replicates per treatment. Broilers were challenged with 2 environmental conditions (sanitary vs. poor sanitary). The dietary treatments were (1) high protein (HP) diet, (2) LP diet, and (3) LP diet with synthetic key essential AA (LPA): the LP diet was supplemented with synthetic AA up to the required levels for broilers. On day 14, birds consumed the LP diet impaired growth performance compared with those fed the HP diet, while the average daily weight gain-to-feed conversion ratio of birds fed the LPA diet improved to the level of birds fed the HP diet under poor sanitary conditions (P < 0.05). Broilers raised under poor sanitary conditions and fed the LP diet displayed higher (P < 0.05) zonula occludens (ZO-1) expression on day 14 than broilers fed either the HP or LPA diet. Under sanitary conditions, birds fed HP and LPA diets showed higher villus height and crypt depth compared with those of broilers fed the LP diet on day 35. Moreover, broilers raised in the poor sanitary environment had higher (P < 0.05) serum endotoxins than those raised in the sanitary environment. Broilers fed the LPA diet showed reduced (P < 0.05) nitrogen excretion on days 14 and 35 compared with those fed the LP and HP diets independent of the environment. In conclusion, the LPA diet did not impair growth performance under poor sanitary conditions for 14 D after hatch while resulting in lower nitrogen excretion in any environment conditions throughout the experiment.

Meta-analysis: explicit value of mono-component proteases in monogastric diets

A meta-analysis was conducted to investigate the effect of mono-component proteases on performance and apparent ileal amino acid digestibility (AIAAD, %) in monogastrics. A total of 67 experimental trials were included in the meta-analysis from published and internal reports, contributing 467 lines of data. Poultry and swine data accounted for 81 and 19% of the dataset, respectively. Forty-four different proteases were included in the meta-analysis, accounting for commercial and non-commercial products. Mixed Model analysis was used to assess protease effect and the influence of inherent characteristics of the control on protease response. The mean performance response to protease was a reduction in feed conversion ratio (FCR) for poultry (1%, P < 0.05) and swine (4%, P > 0.05). The mean relative effect of protease on AIAAD over the control was 1.6 ± 0.3%, ranging from 1.2% for Arg, Phe and Trp to 2.6% for Cys. For the majority of amino acids, inherent AIAAD of control diets influenced (P < 0.05) the magnitude of the protease response such that, as inherent digestibility increased, the effect of protease on amino acid digestibility decreased. The dataset was subsequently divided into 2 subgroups: diets with and without other enzymes, namely non-starch polysaccharide degrading enzymes (NSPase) and phytase. Addition of protease in diets containing no other enzymes significantly (P < 0.05) increased AIAAD for the majority of amino acids and tended (P < 0.10) to improve Met, Trp, Pro, Gly, and Tyr. However, when other enzymes were included in the experiment, the beneficial effect of protease on AIAAD was lost (P > 0.05). These findings suggest that when other enzymes are already included in the diet, addition of protease requires further justification for use in monogastric diets.

The Effect of Low Protein Energy-Rich Diets on Plasma Hepatic Markers, Hepatic Damage, and Discrimination Reversal Learning in Young Female Chicks

Consumption of low protein energy-rich (LPER) diets increases susceptibility to metabolic disease in mammals, such as hepatic damage, and can have an adverse effect on cognition. However, the effects of these diets on both physical and mental welfare have not been investigated in domestic meat chickens. Female chicks received a low protein energy-rich or a standard control diet from 21 to 51 days of age. The effects of these dietary manipulations on plasma hepatic markers for liver damage, liver necropsy, and learning a visual discrimination reversal task were assessed. Birds given access to LPER diets weighed less than chicks that had access to the control diets. All chicks had post-mortem signs of hepatic hemorrhage/increased liver color scores and aspartate aminotransferase (AST) levels above 230 U/L indicative of hepatic damage in birds. The LPER diet had no impact on the performance of female chicks when learning to distinguish colors in a reversal visual discrimination task. The present study suggests that liver damage does not become worse when feeding LPER or impact visual reversal learning in female meat-type chickens. However, the high incidence of liver cell damage/liver hemorrhage, and “abnormal” AST activities are of concern in female broiler chicks across both diets, and suggests that the health of modern meat-type genotypes needs to be improved.

CYSTATHIONINE GAMMA-SYNTHASE activity in rice is developmentally regulated and strongly correlated with sulfate

An important goal of rice cultivar development is improvement of protein quality, especially with respect to essential amino acids such as methionine. With the goal of increasing seed methionine content, we generated Oryza sativa ssp. japonica cv. Taipei 309 transgenic lines expressing a feedback-desensitized CYSTATHIONINE GAMMA-SYNTHASE from Arabidopsis thaliana (AtD-CGS) under the control of the maize ubiquitin promoter. Despite persistently elevated cystathionine gamma-synthase (CGS) activity in the AtD-CGS transgenic lines relative to untransformed Taipei, sulfate was the only sulfur-containing compound found to be elevated throughout vegetative development. Accumulation of methionine and other sulfur-containing metabolites was limited to the leaves of young plants. Sulfate concentration was found to strongly and positively correlate with CGS activity across vegetative development, irrespective of whether the activity was provided by the endogenous rice CGS or by a combination of endogenous and AtD-CGS. Conversely, the concentrations of glutathione, valine, and leucine were clearly negatively correlated with CGS activity in the same tissues. We also observed a strong decrease in CGS activity in both untransformed Taipei and the AtD-CGS transgenic lines as the plants approached heading stage. The mechanism for this downregulation is currently unknown and of potential importance for efforts to increase methionine content in rice.