AA Diets Research Articles

Impacts of Dietary Supplementations of Orange Peel and Tomato Pomace Extracts as Natural Sources for Ascorbic Acid on Growth Performance, Carcass Characteristics, Plasma Biochemicals and Antioxidant Status of Growing Rabbits.

Simple SummaryThere has been growing interest in using natural feed additives in to enhance animal performance and meat quality for human consumption. Citrus fruit residues can act as potential natural resources of antioxidants, which comprise a considerable quantity of ascorbic acid. Tomato pomace powder has a good nutritional value because of its content of essential amino acids and fatty acids besides its high content of antioxidants. This work examined the impact of dietary orange peel and tomato pomace extract supplementations at level of 200 mg/kg on growth performance, plasma biochemicals, carcass characteristics and antioxidant status of growing male rabbits. Dietary supplementations of orange peel and tomato pomace extracts could effectively improve growth performance, antioxidative status, modulate ascorbic acid level in plasma and meat and lower the plasma total cholesterol.The effect of dietary orange peel (OPE) and tomato pomace extract (TPE) supplementations on growth performance, plasma biochemicals, carcass characteristics and antioxidant status of growing male rabbits were investigated. A total of 96 rabbits (5 weeks old) were distributed into four groups. The first group received untreated pelleted diet (control). The second group was fed a diet containing ascorbic acid (AA; 1.0 g/kg diet), while the third and fourth groups consumed diets supplemented with 200 gm of OPE or (TPE, respectively. Our results indicated that OPE and TPE contained 59, 14.03 mg ascorbic acid/100 g DM, respectively. Growth performance, except feed conversion ratio, and carcass weight were improved by dietary supplementations. Dietary supplementations decreased kidneys, abdominal, back fats and ether extract of meat. Plasma protein and globulin levels were high in rabbits fed AA and TPE-supplemented diets. Low plasma total cholesterol and LDL-cholesterol concentrations were observed in rabbits fed the supplemented diets. Plasma AA was increased in rabbits fed AA and OPE-supplemented diets. Rabbits fed OPE and TPE-supplemented diets had great SOD activity. The best economic efficiency was recorded by rabbits fed the supplemented diets. Dietary supplementations of OPE and TPE could effectively improve growth performance, antioxidative status, modulate AA level in plasma and meat and lower plasma total cholesterol and LDL.

Food Production in Space From CO <sub>2</sub> Using Microbial Electrosynthesis

Human space survival requires sustainable food production methods. The current food method in space is launching prepackaged food which is costly and unsustainable. Alternatives include growing crops and microalgae single cell protein (SCP) using artificial light photosynthesis, which are also costly and inefficient. Prepackaged food and SCP food growing solutions were compared to microbial electrosynthesis of acetic acid (MES-AA) using electroactive bacteria. The analysis employed an equivalent system mass (ESM) technique customarily used by the National Aeronautics and Space Administration to compare and select from alternative systems. Since the dominant cost of a space mission is the cost of launching mass, components of a system are converted to an equivalent mass, including power, heat rejection, and volume. Distinct three-year roundtrip manned missions were evaluated for the International Space Station, the Moon, and Mars. The average ESM of MES-AA is 1.38x and 2.84x lower than prepackaged food and microalgae SCP, respectively. The alternative food with the lowest average ESM in space, SCP from hydrogen-oxidizing bacteria (HOB), is 1.86x lower than MES-AA. The expected electricity-to-calorie energy conversion efficiency of MES is 19.8%; consuming 3.45 kW to fully feed five astronauts with AA (diets would realistically compose multiple foods). MES-AA has a higher energy efficiency than any currently investigated alternative food in space. The most promising food source is HOB, having the lowest ESM and highest nutritional quality. However, MES can provide diet diversity at a lower cost than customarily storing prepackaged food or growing crops in space.

Effects of the Pelleting Process on Diet Formulations with Varying Levels of Crystalline Amino Acids and Reducing Sugars on Nursery Pig Growth Performance

Pelleting swine feed and the use of crystalline amino acids and by-product ingredients can potentially create ideal conditions that further facilitate the Maillard browning reaction. The Maillard reaction combines an amino group of a free amino acid and a carbonyl group of a reducing sugar (RS), making the amino acid less available. The objective of this study was to determine the effects of pelleting swine diets containing free amino acids and reducing sugars at high temperatures on nursery pig growth performance. A total of 360 pigs (initially 25.0 lb; Line 200 × 400; DNA, Columbus, NE) were used in a study evaluating the effect of crystalline AA, reducing sugars, and feed form on growth performance of nursery pigs. Treatments were arranged in a 2 × 2 × 2 factorial with main effects of crystalline AA concentration (low vs. high), reducing sugars (RS; low vs. high), and diet form (mash vs. pellet). Diets were formulated with low or high crystalline AA and low or high reducing sugars provided by co-product ingredients, DDGS and bakery meal. Diets were pelleted to a conditioning temperature of 187.5°F. When pigs weighed approximately 25 lb, they were weighed, and pens were randomly assigned treatments. There were 9 replications per treatment and 5 pigs per pen. There were no 3-way or 2-way interactions. For the main effect of form, there was no evidence of difference in ADG, and ADFI increased (P = 0.001) in pigs fed mash diets compared to pellets. Feed efficiency and caloric efficiency improved (P = 0.001) in pigs fed pelleted diets compared to mash diets. For the main effect of crystalline AA, there was no evidence of difference in ADG or F/G; however, pigs fed high crystalline AA had increased (P = 0.024) ADFI compared to those fed low crystalline AA diets. For the main effect of RS inclusion, pigs fed low RS diets had increased (P < 0.041) ADG and ADFI compared to pigs fed high RS inclusion diets. There was an improvement (P = 0.019) in F/G and caloric efficiency for pigs fed high RS inclusion diets compared to those fed low RS diets. There was no evidence of difference in IOFC for form, crystalline AA, or RS. In conclusion, there was no evidence of interactions between diet types, indicating that increasing amounts of crystalline AA and RS did not increase the Maillard reaction or reduce growth performance when pelleting diets

Effects of dietary ascorbic acid on growth performance, hematological parameters, antioxidant and non-specific immune responses in starry flounder, Platichthys stellatus

A 4-week feeding trial was conducted to assess the effect of AA on growth performance, hematological parameters, antioxidant and non-specific immune response in starry flounder, Platichthys stellatus (mean weight, 139.47 ± 1.41 g; mean length, 19.87 ± 0.21 cm). AA diets were designed as 0, 50, 100, 200, 400, 600 and 800 mg/kg, supplied as l-ascorbyl-2-monophosphate (AMP). The results of present study indicated that body weight gain (BWG), feed efficiency ratio (FER) and specific growth rate (SGR) were significantly higher than control group fed AA-free diet. In addition, AA diet increased red blood cell (RBC) count, hematocrit (Ht), hemoglobin (Hb), plasma calcium and magnesium, whereas total protein, glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) were significantly decreased. The superoxide dismutase activity (SOD), catalase activity (CAT), glutathione (GSH) and glutathione-S-transferase (GST) activity were significantly decreased compared with control group. Lysozyme and phagocytosis were significantly enhanced by increasing dose of AA supplementation. These results indicated that AA diet had a positive effect on growth performance, hematological parameter, antioxidant and non-specific immunity in starry flounder.

Effect of adding the Limiting Amino Acids to Low – Crude Protein Diets on Performance of Broiler Chicks.

This study was conducted to study the effect of decreasing the dietary crude protein level while supplementing the essential amino acids on growth performance, carcass, some blood constitutes of broiler chicks. An experiment was done using 252 one day-old broiler chicks Arbor-acres, randomly allotted to seven dietary treatment groups; the first group positive control with optimum CP level (PC), the second group negative control (NC) low 3 points than requirements, and groups 3 up 7 were fed the NC diet but supplemented incrementally with the essential amino acids; lysine, lysine+ methionine, lysine+ methionine+ tryptophan, lysine+ methionine+ tryptophan +threonine and lysine+ methionine+ tryptophan+ threonine+ valine, respectively to cover the dietary requirements for each amino acid during starter, grower and finisher periods. Results show that there were no significant differences between treatments (P=0.242) on starter live weight. For grower period the control group with optimum CP % level, followed by low CP % diet supplemented with all amino acids had significantly the highest live body weight compared with the low CP group without supplemental amino acids (P= 0.006). The gains in body weight were found to be significant during grower and finisher phases the highest values were observed in the positive control and low CP supplemental with all AA diets. The same two treatments the best FCR for the overall experimental period compared to the other treatments. Carcass traits were not significantly affected by dietry treatments. Plasma total protein (P=0.034), albumin (P=0.002), and triglycerides (P=0.002), were significantly affected by dietary treatments. The lowest feed cost per kg live weight gain of chickens were found in the experimental group (T7) containing all amino acids supplemented to the low CP diets. It could be recommended to decrease the dietary CP level of broiler chicks by 3 points without affecting the growth performance up on supplementing the essential AA.

Nutrient digestibility of multi-enzyme supplemented low-energy and AA diets for grower pigs1.

A study was conducted to determine effects of supplementing multi-enzyme on apparent ileal digestibility (AID) of energy and AA; and apparent total tract digestibility (ATTD) of energy for pigs fed low-energy and AA diets. Eight ileal-cannulated barrows (initial BW: 38.7 ± 2.75 kg) were fed four diets in a replicated 4 × 4 Latin square design to give 8 replicates per diet. Diets were positive control (PC) diet, negative control (NC) diet without or with multi-enzyme at 0.5 or 1.0 g/kg. The PC diet was formulated to meet or exceed NRC (2012) nutrient recommendations for grower pigs (25 to 50 kg), except for Ca and digestible P, which were lower than NRC (2012) recommendations by 0.13 and 0.17 percentage points, respectively, due to phytase supplementation at 1,000 FTU/kg. The NC diet was formulated to be lower in NE by 75 kcal/kg and standardized ileal digestible AA content by a mean of 3%. These reductions were achieved by partial replacement of corn and soybean meal (SBM) and complete replacement of soybean oil and monocalcium phosphate in PC diet with 25% corn distillers dried grains with solubles (DDGS) and 3.6% soybean hulls. Multi-enzyme at 1.0 g/kg supplied 1,900 U of xylanase, 300 U of β-glucanase, 1,300 U of cellulase, 11,500 U of amylase, 120 U of mannanase, 850 U of pectinase, 6,000 U of protease, and 700 U of invertase per kilogram of diet. The AID of GE, N, most AA, most component sugars of nonstarch polysaccharides (NSP) and P; ATTD of GE for PC diet was greater (P < 0.05) than those for NC diets. An increase in dietary level of multi-enzyme from 0 to 1.0 g/kg resulted in a linear increase (P < 0.05) in AID of Ile by 4.3%, and tended to linearly increase (P < 0.10) AID of Leu, Met, Phe, and Val by a mean of 3.4%. Increasing dietary multi-enzyme from 0 to 1.0 g/kg linearly increased (P < 0.05) AID of total NSP and P by 53.7% and 19.2%, respectively; ATTD of GE by 8.4% and DE and NE values by 8.8% and 8.2%, respectively; tended to linearly increase (P < 0.10) AID of GE by 8.1%. The NE values for NC diet with multi-enzyme at 1.0 g/kg tended to be greater (P < 0.10) than that for PC diet (2,337 vs. 2,222 kcal/kg of DM). In conclusion, multi-enzyme supplementation improved energy and nutrient digestibilities of a corn-SBM-corn DDGS-based diet, implying that the multi-enzyme fed in the current study can be used to enhance energy and nutrient utilization of low-energy AA diets for grower pigs.

Effects of Increasing Crystalline Amino Acids in Sorghum- or Corn-based Diets on Finishing Pig Growth Performance and Carcass Composition

A study was conducted to determine the impact of increasing crystalline amino acids in either sorghum- or corn-based diets on finishing pig growth and carcass composition. A total of 288 pigs (PIC 327×1050; initially 101.1 lb) were used in a 90-d study with 8 pigs per pen and 6 pens per treatment. Treatments were arranged in a 2 × 3 factorial with main effects of grain source (sorghum vs. corn) and crystalline AA supplementation (low, medium, or high). Amino acids ratios to Lys as well as standardized ileal digestibility coefficients used were set by NRC (2012). All diets were formulated to the same Lys:NE ratio and at 95% of the pig’s estimated Lys requirement to ensure that AA were not above the pigs’ requirement. The grain sources and soybean meal were analyzed for AA profile and diets formulated from these concentrations. The low AA fortification contained L-lysine HCl and DL-methionine. The medium AA fortification contained L-lysine HCl, DL-methionine, and L-threonine. The high AA fortification contained L-lysine HCl, DL-methionine, L-threonine, and L-valine in sorghumor L-tryptophan in corn-based diets. Overall, there were no grain source × crystalline AA level interactions observed for any response criteria measured. Pigs fed corn-based diets tended to have greater ADG (P < 0.072) and had better F/G (P < 0.01) than those fed sorghum-based diets. As crystalline AA increased, ADG tended to increase then decrease (quadratic; P=0.057), and ADFI decreased (linear; P = 0.019) resulting in a tendency for improved F/G (quadratic; P=0.097). Pigs fed sorghum had decreased (P < 0.01) jowl fat iodine value in comparison to those fed corn-based diets. Crystalline AA level did not impact carcass characteristics. In conclusion, diets with high AA fortification had decreased ADG and ADFI with slightly improved F/G compared with low or medium AA fortification. Furthermore, grain sorghum had approximately 97% of the feeding value relative to corn based on F/G.

Nitrogen and Energy Partitioning in Two Genetic Groups of Pigs Fed Low-Protein Diets at 130 kg Body Weight

The aim was to evaluate the effect of low-protein (LP) or low-amino acid diets on digestibility, energy and nitrogen (N) utilisation in 2 genetic groups (GG) of pigs (129±11 kg BW). Duroc Large White (A) pigs were chosen to represent a traditional GG for ham production, and Danbred Duroc (D) pigs to represent a GG with fast growing rate and high carcass lean yield. Dietary treatments: a conventional diet (CONV) containing 13.2% C P, and two LP diets, one with LP (10.4%) and low essential AA (LP1), the second with LP (9.7%) and high essential AA (LP2). Compared to CONV, LP2 had the same essential AA content per unit feed, while LP1 the same essential AA content per unit CP. Feed was restricted (DMI=6.8% BW0.75). Four consecutive digestibility/balances periods were conducted with 24 barrows, 12 A and 12 D. Metabolic cages and respiration chambers were used. No significant difference between diets was registered for digestibility. Nitrogen excreted: 41.3, 33.4 and 29.0 g/d (P=0.009), for CONV, LP1 and LP2 diets, respectively. Nitrogen retention was similar between the diets. Heat production (HP) was the lowest for LP diets. There was a tendency (P=0.079) for a lower energy digestibility in D group. The D pigs also had a higher HP and hence a lower retained energy in comparison with the A pigs. In conclusion: it is possible to reduce N excretion using very LP diets and LP low AA diets; Danbred GG have a higher heat production and a lower energy retention than A pigs.

Evaluation of standardized ileal digestible valine:lysine, total lysine:crude protein, and replacing fish meal, meat and bone meal, and poultry byproduct meal with crystalline amino acids on growth performance of nursery pigs from seven to twelve kilograms

Five experiments were conducted to evaluate replacing fish meal, meat and bone meal, and poultry byproduct meal with crystalline AA for 7- to 12-kg pigs. In all experiments, pigs (PIC TR4 × 1050) were fed a common diet for 3 d postweaning, treatment diets for 14 d (d 0 to 14), and, again, a common diet for 14 d (d 14 to 28). Treatment diets were corn-soybean meal based and formulated to contain 1.30% standardized ileal digestible (SID) Lys. Experiment 1 evaluated replacing dietary fish meal with crystalline AA. For the 6 treatments, crystalline Lys, Met, Thr, Trp, Ile, Val, Gln, and Gly all increased to maintain minimum AA ratios as fish meal decreased (4.50, 3.60, 2.70, 1.80, and 0.90 to 0.00%). There was no difference in ADG, ADFI, or G:F among treatments, validating a low-CP, AA-fortified diet for subsequent experiments. Experiment 2 evaluated deleting crystalline AA from a low-CP, AA-fortified diet with 6 treatments: 1) a positive control similar to the diet validated in Exp. 1, 2) positive control with l-Ile deleted, 3) positive control with l-Trp deleted, 4) positive control with l-Val deleted, 5) positive control with l-Gln and l-Gly deleted, and 6) positive control with l-Ile, l-Trp, l-Val, l-Gln, and l-Gly deleted (NC). Pigs fed the positive control or Ile deleted diet had improved (P < 0.05) ADG and ADFI during d 0 to 14 compared with pigs fed diets with l-Trp or l-Val deleted or NC. Experiment 3 evaluated 6 treatments with total Lys:CP of 6.79, 6.92, 7.06, 7.20, 7.35, and 7.51%. Fish meal was adjusted as a source of dispensable N to achieve the target Lys:CP. There were no differences in growth performance among pigs fed different Lys:CP diets. Experiment 4 evaluated increasing SID Val:Lys with Val at 57.4, 59.9, 62.3, 64.7, 67.2, and 69.6% of Lys. Average daily gain and ADFI increased (quadratic, P < 0.01) and G:F improved (linear, P = 0.02) during d 0 to 14 as Val:Lys increased from 57.4 to 64.7%. Experiment 5 was a 2 × 3 factorial arrangement of treatments with main effects of low or high level of crystalline AA and 3 animal protein sources (fish meal, meat and bone meal, or poultry byproduct meal). Low- and high-crystalline AA diets contained 4.5 or 1% fish meal, 6 or 1.2% meat and bone meal, and 6 or 1% poultry byproduct meal, respectively. No AA × protein source interactions were observed. From d 0 to 14, no differences in growth performance among protein sources was found, whereas increasing crystalline AA improved (P = 0.04) ADG. In conclusion, crystalline AA can replace fish meal, meat and bone meal, and poultry byproduct meal when balanced for SID AA ratios of Met and Cys:Lys (58%), Thr:Lys (62%), Trp:Lys (16.5%), Val:Lys (65%), and Ile:Lys (52%).

Comparison of the metabolic effects of milk-derived α-lactalbumin and amino acids mixture with equal composition in diet-induced obese mice

The effects of milk-derived whey protein α-lactalbumin (α-lac) and amino acid mixture with equal amino acid profile (AA) on weight loss and weight regain in a model of diet-induced obesity were compared. Obesity was induced in C57BL/6J mice with a high-fat diet. Energy restriction was performed for 50 days on casein (calcium 0.8%) and two different high-calcium (1.8%) whey protein-based (α-lac + Ca and AA + Ca) diets, after which the animals were fed with the same diets ad libitum for additional 50 days. The mice on α-lac and AA lost significantly more weight and body fat than mice on casein diet ( P < 0.05). There was no difference between α-lac and AA diets. Ad libitum feeding after weight loss resulted in weight regain and fat accumulation in all groups. Our findings indicate that the anti-obesity effects of α-lac during energy restriction can be reproduced by amino acid mixture with equal amino acid profile.

The effect of peptide absorption on PepT1 gene expression and digestive system hormones in rainbow trout ( Oncorhynchus mykiss)

The present study evaluates the effect of protein source (dipeptides, free amino acids, and intact protein) on development and growth of Salmonid fish alevin. Specifically, we follow the expression of oligopeptide transporter protein PepT1 in the intestine of rainbow trout ( Oncorhynchus mykiss). Fish were fed exogenously one of four diets: three formulated (lysyl–glycine dipeptide supplemented diet — PP, free lysine and glycine supplemented diet — AA, control diet with no lysine — CON) or commercial starter (Aller Futura — AF). Fish increased mean body weight 8 fold with PP- and AA-supplemented diets resulting in significantly higher weight gain than fish fed CON. Statistical analysis revealed a significant increase in relative PepT1 expression of fish fed experimental diets. Immunohistochemical staining with PepT1 antibody showed the presence of the transporter protein in the brush border membrane of the proximal intestinal enterocytes of fish from all experimental groups. Leptin immunoreactivity occurred not only in the gastric glands but also in proximal intestine and pyloric caeca of fish fed PP, AA and AF diets. Leptin immunoreactivity was also observed in hepatocyte cytoplasm and pancreatic acinar cells. Gastrin/CCK immunoreactive cells were present in the proximal intestine and pyloric caeca.

The Legume Inflammation Feeding Experiment (LIFE): Effects of Gut Hormone Levels

The LIFE Study was designed to test the effects of a legume‐rich diet on biomarkers of insulin resistance (IR) and inflammation. A secondary objective was to test the effect of the diet on gut hormones: leptin, ghrelin (total), and cholecystokinin (CCK). Sixty‐four men (35‐75 yrs), who had undergone a screening colonoscopy within the past 2 years, were recruited in Central Pennsylvania to consume a legume diet (LG,1 1/2 cups of cooked dry beans) and an isocaloric average American diet (AA) in random order each for 4 weeks separated by a 3‐wk compliance break. Preliminary results show that fasting plasma leptin concentrations were reduced on both LG (‐0.118 ± 0.026 S.D. ng/mL, P&lt;0.0001) and AA diets (‐0.072 ± 0.019 ng/mL, P=0.0003) but the difference between diets was not statistically significant (P=0.1499). Fasting ghrelin levels slightly decreased on LG diet (‐15.289 ± 16.709 pg/mL) and increased on AA diet (19.129 ± 19.607 pg/mL); however, neither diet had an effect on ghrelin (P=0.3637 and P=0.3330, respectively). These results indicate that a legume‐rich diet may have favorable effects on lowering fasting leptin level with stable body weight. The measure and data analysis of CCK is ongoing. This study is supported by the National Cancer Institute and partial support provided by the GCRC, PSU.

Amino acid supplementation of hydrolyzed feather meal diets for finisher pigs1,2

The objective of this study was to determine the possibility of replacing soybean meal (SBM) in finisher pig diets completely with hydrolyzed feather meal (FM). Forty-five gilts and 45 castrated males (57.8+/-0.8 kg of BW; 3 gilts or 3 castrated males/pen) were randomly assigned to 5 finisher-1 diets with 6 pens per diet. At an average pen BW of 81.0+/-1.4 kg, pigs were offered finisher-2 diets. Corn-SBM, finisher-1 and finisher-2 positive control (PC) diets were formulated to contain 6.1 and 4.7 g of apparent ileal digestible (AID) Lys/kg, respectively. Corn-FM negative control (NC) diets were formulated to be iso-N to the PC diets. The NC diets were supplemented with Lys and Trp (NRC; NC + Lys and Trp) to alleviate apparent deficiencies based on AID AA in FM reported by the 1998 NRC. In addition, the NC diets were supplemented further with the third limiting AA, Thr (40+3AA; NC + Lys, Trp, and Thr), and fourth and fifth limiting AA, His and Ile (40+5AA; NC + Lys, Trp, Thr, His, and Ile), based on the assumption that the apparent ileal digestibility of all indispensable AA in FM is 40%. Pigs had ad libitum access to feed and water. At the end of the study (112.1+/-1.8 kg), blood samples were collected from all pigs before slaughter. As expected, overall ADFI, AID Lys (representing indispensable AA) intake (LysI), ADG, and G:F were greater and BW gain:LysI (G:LysI) was less in pigs fed the PC diet than those fed the NC diet (P<0.001). Pigs fed the NRC diet grew slower than those fed the PC diet (P=0.004), and their G:LysI tended to be less than those fed the PC (P=0.083) or the 40+3AA and 40+5AA diets (P=0.094). Greater fat-free lean percentage (P=0.005), fat-free lean gain (LG; P<0.001), and LG:F (P<0.001) were observed in pigs fed the PC diet compared with those fed the NC diet, but their LG:F or LG:LysI was similar to those fed the NRC diet. However, LG:F (P=0.030) and LG:LysI (P=0.028) were greater in pigs fed the 40+3AA and the 40+5AA diets than those fed the NRC diet. Pigs fed the 40+5AA diet tended to utilize AID Lys more efficiently for LG than those fed the 40+3AA diet (P=0.068). Subjective meat color (P<0.001), firmness (P=0.004), and marbling (P<0.001) scores were greater in pigs fed the 40+5AA diet than those fed the 40+3AA diet. Diets seemed to have no clear effect on the weight of liver, kidney, and heart or serum urea N and triacylglycerides. Pigs fed the PC diet had more serum albumin and total protein (P<0.001), but less glucose (P=0.031) and cholesterol (P<0.001) than those fed the NC diet. Serum total protein was greater (P=0.031) in pigs fed the 40+5AA diet than those fed the 40+3AA diet. The results indicated that the corn-FM diets were not as effective as the corn-SBM diet in supporting BW gain of finisher pigs. However, the results seemed to indicate that pigs fed the corn-FM diet supplemented with the necessary AA can utilize feed and AA for BW gain and lean gain as efficiently as those fed the corn-SBM diet. Further research is needed to explore fully the optimal AA supplementation strategy to effectively utilize FM for pig production.

The effect of ractopamine hydrochloride (Paylean ®) on lean carcass yields and pork quality characteristics of heavy pigs fed normal and amino acid fortified diets

Effects of ractopamine hydrochloride (RAC) on carcass parameters in heavy weight (133.24 ± 8.07 kg) finishing pigs ( n = 278) given amino acid fortified (AA) or 16% crude protein (CP) diets were evaluated. A total of seven experimental diets were formulated; RAC was added at 0, 5 and 20 ppm to the 16% CP diets (CP0, CP5 and CP20, respectively) and at 0, 5, 10 and 20 ppm to the AA fortified diets (AA0, AA5, AA10 and AA20, respectively). Carcass, tenderloin, and ham weights were heavier ( P < 0.05) for RAC AA diets vs. AA0. Loin weight was heavier ( P < 0.05) for AA20 vs. AA0 and CP20 vs. CP0. No differences ( P > 0.05) were observed for color or firmness scores. Carcass muscle score, ham weight and protein% were greater ( P < 0.05) for RAC diets. Moisture was greater ( P < 0.05) and fat was lower ( P < 0.05) for AA5 and AA20 vs. AA0 and CP5 and CP20 vs. CP0. Feeding RAC to late finishing swine increases carcass yields and protein% with lower fat% for pigs weighing up to 136 kg.

Effect of Season on Growth Performance of Finishing Pigs fed Low-Protein, Amino Acid Supplemented Diets

Myer, R.O., Brendemuhl, J.H. and Bucklin, R.A. 2008. Effect of season on growth performance of finishing pigs fed low-protein, amino acid supplemented diets. J. Appl. Anim. Res., 34: 1–8. A two year study was conducted to evaluate the effects of diet (low-protein diets supplemented with crystalline amino acids (aa) vs. high-protein, non aa supplemented control diets) and season/rearing environment (hot, humid summer vs. cool fall/winter) on growth performance and carcass lean content of finishing pigs (52 to 110 kg). For each year, two trials, each with 84 pigs, were conducted. Outside daily high and low temperatures (C) and RH (%), respectively, averaged 26, 21 and 81; 26, 20 and 83; 14, 7 and 80; and 10, 3 and77for yr 1 and 2 summer and y r 1 and 2 fall I winter, respectively. Diets were maize and soybean meal based (3.3 meal ME/kg). The low-protein (LP) diets were four percentage units lower in crude protein (CP) than the corresponding control diets; crystalline lysine, threonine, tryptophan and methionine were added to the LP diets to meet the pigs' requirements (NRC, 1998). For each trial, split sex Finisher I (52 to 82 kg), and Finisher II (82 to 110 kg), diets were fed. Each dietary treatment was fed to six pens of seven pigs for each trial. Water sprinklers were used during warm weather (>25C). Floor space was 0.7m2 per pig. Pigs reared during the summer grew 9% slower than pigs reared during the fall/winter (0.88 vs. 0.97 kg/d, P<0.001); average daily feed intake (ADF) and feed conversion efficiency (F/G) were also affected by season (P<0.001). Pigs fed the LP + aa diets averaged 3% lower ADG than pigs fed the control diets (0.91 vs. 0.94 kg; P<0.01); ADF and F/G were not affected (P>0.10). The decrease in ADG was more pronounced during the summer vs. fall/winter (6% vs. 1%; season × diet, p = 0.02). The decrease noted occurred only during Finisher II (0.91 vs. 0.84 kg/d; P<0.001; FI, 0.97 vs. 0.98). Estimated carcass lean was not affected by diet or season (mean = 51% fat free). The feeding of a LP + aa diet used appears to be of no particular benefit on improving pig growth performance from 52 to 110 kg under hot and humid conditions.

Induction of pancreatic trypsin by dietary amino acids in rats: Four trypsinogen isozymes and cholecystokinin messenger RNA

We previously demonstrated that feeding a diet containing a high level of amino acid mixture simulating casein (AA) induced an increase in pancreatic protease activities in rats. In the present study, this effect of dietary AA was further characterized with three separate experiments. These experiments (1) examined periodic changes in pancreatic and small intestinal trypsin activities after switching from a 20% (a normal nitrogen level) AA diet to a 60% AA (a high nitrogen level) diet; (2) measured the abundance of mRNA for four trypsinogen isozymes and for intestinal cholecystokinin (CCK) and secretin in rats fed 20% and 60% AA diets for 10 days compared with rats fed 20% and 60% casein diets; and (3) measured the abundance of mRNA for four trypsinogen isozymes after chronic administration of CCK. Trypsin activities were gradually increased in both the pancreas and the small intestinal lumen and reached maximum at 5 days after the switch to the 60% AA diet (Exp. 1). This result is evidence that the increase in the protease activity in the pancreas is due to enhancement of pancreatic trypsin production. In experiment 2, pancreatic trypsinogen isozymes I, II, III, and IV mRNA abundance were evaluated by the Northern blotting method using cDNA probes specific for each isozyme mRNA. Abundance of trypsinogen mRNA without trypsinogen I tended to increase in the rats fed the 60% casein diet but tended to decrease in the rats fed the 60% AA diet compared with the respective normal nitrogen level diet groups without significant difference. CCK mRNA abundance in the jejunal mucosa increased as a result of feeding the 60% casein diet, but not the 60% AA diet. Subcutaneous CCK injections (3.5 nmole/kg body weight/day, twice daily, at 8:30 am and 7:30 pm) for 10 days resulted in increased pancreatic trypsin activity, whereas the changes in mRNA of the four trypsinogen isozymes was similar between the 20% and 60% casein groups but differed between the 20% and 60% AA groups (Exp. 3). These results suggest that CCK is not involved in the induction of pancreatic trypsin that occurs with feeding of a high AA diet and that the mechanism of protease induction by dietary AA is different from that in the case of dietary protein.

Growth Is Compromised in Rats Fed Ozone-Treated Casein

Modified casein containing few phenylalanine residues and no other aromatic amino acid residues was obtained by ozonolysis of casein. Although 68% of phenylalanine was decomposed by ozonolysis of casein, ozonolysis caused alterations beyond the destruction of aromatic amino acid residues. Nearly the same degree of decomposition of amino acid residues was observed in casein ozonated after predigestion by pepsin. Rats were fed diets containing 8% casein supplemented with methionine and aspartic acid (8C-AA), 8% ozonated casein supplemented with methionine and free amino acids lost by ozonolysis (8OC-AA), 8% casein ozonated after predigestion by pepsin supplemented with methionine and free amino acids lost during preparation (8POC-AA) or 7.6% amino acid mixture. The growth of rats fed the 8OC-AA diet was significantly lower than that of those fed 8C-AA or 7.6AA diets. The growth of rats fed the 8POC-AA diet was comparable to growth of those fed 8OC-AA. The biological values of the 8OC-AA and 8POC-AA were comparable to that of 8C-AA, but true digestibility of 8OC-AA was significantly lower than that of 8C-AA. True digestibility 8POC-AA was significantly improved relative to 8OC-AA, but the growth of rats fed 8POC-AA was not improved relative to that of those fed 8OC-AA. Kidney and cecum weights of rats fed 8OC-AA and 8POC-AA were significantly heavier than those of the 8C-AA-fed group, although histopathological examination of kidneys showed no deterioration compared to that of the 8C-AA-fed group.(ABSTRACT TRUNCATED AT 250 WORDS)

Partial substitution of protein by a single amino acid or an organic acid in rainbow trout diets

Performances of rainbow trout ( Salmo gairdneri) fed on experimental diets in which fish meal (42%) was supplemented (12%) either with a purified protein (casein or corn (maize) gluten), with a single amino acid (AA: alanine, aspartic acid or glutamic acid) or with an organic acid (OA: succinic acid or citric acid) were analysed. The voluntary food intake of fish fed the AA and OA diets was lower than that of fish fed either on a control commercial diet or on a protein-supplemented diet, but without large alteration in the efficiencies of protein and energy utilization. The protein and energy content of the liver, digestive tract and carcass, and the plasma glucose and amino acids levels were analysed. It was concluded that a part of the protein in the diet could be replaced by a single amino acid such as aspartic acid. These results are discussed in the light of the control of food intake by energy density of the diet.