Multi-criteria assessment of pea protein quality in rats: a comparison between casein, gluten and pea protein alone or supplemented with methionine.

The objective of this study was to assess the nutritional quality of pea protein isolate in rats and to evaluate the impact of methionine (Met) supplementation. Several protein diets were studied: pea protein, casein, gluten, pea protein-gluten combination and pea protein supplemented with Met. Study 1: Young male Wistar rats (n 8/group) were fed the test diets ad libitum for 28 d. The protein efficiency ratio (PER) was measured. Study 2: Adult male Wistar rats (n 9/group) were fed the test diets for 10 d. A protein-free diet group was used to determine endogenous losses of N. The rats were placed in metabolism cages for 3 d to assess N balance, true faecal N digestibility and to calculate the Protein Digestible-Corrected Amino Acid Score (PDCAAS). They were then given a calibrated meal and euthanised 6 h later for collection of digestive contents. The true caecal amino acid (AA) digestibility was determined, and the Digestible Indispensable Amino Acid Score (DIAAS) was calculated. Met supplementation increased the PER of pea protein (2·52 v. 1·14, P < 0·001) up to the PER of casein (2·55). Mean true caecal AA digestibility was 94 % for pea protein. The DIAAS was 0·88 for pea protein and 1·10 with Met supplementation, 1·29 for casein and 0·25 for gluten. Pea protein was highly digestible in rats under our experimental conditions, and Met supplementation enabled generation of a mixture that had a protein quality that was not different from that of casein.

Differential Diagnosis between Low-Grade and High-Grade Astrocytoma Using System A Amino Acid Transport PET Imaging with C-11-MeAIB: A Comparison Study with C-11-Methionine PET Imaging.

Introductions: [N-methyl-C-11]α-Methylaminoisobutyric acid (MeAIB) is an artificial amino acid radiotracer used for PET study, which is metabolically stable in vivo. In addition, MeAIB is transported by system A neutral amino acid transport, which is observed ubiquitously in all types of mammalian cells. It has already been shown that MeAIB-PET is useful for malignant lymphoma, head and neck cancers, and lung tumors. However, there have been no reports evaluating the usefulness of MeAIB-PET in the diagnosis of brain tumors. The purpose of this study is to investigate the efficacy of system A amino acid transport PET imaging, MeAIB-PET, in clinical brain tumor diagnosis compared to [S-methyl-C-11]-L-methionine (MET)-PET. Methods: Thirty-one consecutive patients (male: 16, female: 15), who were suspected of having brain tumors, received both MeAIB-PET and MET-PET within a 2-week interval. All patients were classified into two groups: Group A as a benign group, which included patients who were diagnosed as low-grade astrocytoma, grade II or less, or other low-grade astrocytoma (n=12) and Group B as a malignant group, which included patients who were diagnosed as anaplastic astrocytoma, glioblastoma multiforme (GBM), or recurrent GBM despite prior surgery or chemoradiotherapy (n=19). PET imaging was performed 20 min after the IV injection of MeAIB and MET, respectively. Semiquantitative analyses of MeAIB and MET uptake using SUVmax and tumor-to-contralateral normal brain tissue (T/N) ratio were evaluated to compare these PET images. ROC analyses for the diagnostic accuracy of MeAIB-PET and MET-PET were also calculated. Results: In MeAIB-PET imaging, the SUVmax was 1.20 ± 1.29 for the benign group and 2.94 ± 1.22 for the malignant group (p < 0.005), and the T/N ratio was 3.77 ± 2.39 for the benign group and 16.83 ± 2.39 for the malignant group (p < 0.001). In MET-PET, the SUVmax was 3.01 ± 0.94 for the benign group and 4.72 ± 1.61 for the malignant group (p < 0.005), and the T/N ratio was 2.64 ± 1.40 for the benign group and 3.21 ± 1.14 for the malignant group (n.s.). For the analysis using the T/N ratio, there was a significant difference between the benign and malignant groups with MeAIB-PET with p < 0.001. The result of ROC analysis using the T/N ratio indicated a better diagnosis accuracy for MeAIB-PET for brain tumors than MET-PET (p < 0.01). Conclusions: MeAIB, a system A amino acid transport-specific radiolabeled agents, could provide better assessments for detecting malignant type brain tumors. In a differential diagnosis between low-grade and high-grade astrocytoma, MeAIB-PET is a useful diagnostic imaging tool, especially in evaluations using the T/N ratio. Clinical trial registration: This trial was registered with UMIN000032498.

Digestible sulfur amino acid requirement of starting turkeys.

Three experiments (a total of 1,020 poults) were conducted to determine the digestible sulfur amino acid (SAA) requirement for female turkey poults during the starter period. Poults were fed a standard corn-soybean meal diet (PC) that met or exceeded NRC recommendations (28% CP, 3,172 kcal MEn/kg) for 1 wk and were then randomly assigned to treatments until 22 d (Experiment 2 and 3) or 23 d (Experiment 1) of age. Dietary treatments included the PC diet and seven or nine titrated levels of methionine added to a basal corn-soybean meal diet, for a total of 0.50 to 1.33% total digestible SAA. The basal diet contained 18.4% intact crude protein. All diets contained 3,171 kcal MEn/kg. The true digestible SAA content of the basal diet without methionine additions was 0.50% based on digestibility assays of the corn and soybeans with cecectomized turkeys. Diets were formulated to contain 1.40% digestible lysine. Other amino acids were maintained at levels in relation to lysine based on previous research with turkeys and the Illinois Ideal Chick Protein. Broken-line analysis suggests that the digestible SAA requirement for female turkeys during the starter period is 0.76% for optimum body weight gain and 0.75% for optimal feed:gain at the energy levels used in these studies.

Influence of activity and dietary energy on broiler performance, carcase yield and sensory quality.

1. A total of 2560 male and female Ross broilers were raised to 42 days of age in a 2 X 2 treatment factorial arrangement experiment to investigate the influence of different degrees of physical activity and dietary energy on broiler performance, abdominal fat content, carcase yield and sensory quality. 2. Vertical fans were used to force the treatment birds to walk 3 to 4 times as far as the normal activity birds: birds were fed a normal and a high energy diet (12.55 compared with 13.81 MJ ME/kg) with the same energy/protein, energy/lysine and energy/methionine + cystine ratios. 3. High activity birds had greater body weight (+4.1%), food intake (+5.1%) and ME intake (+5.1%) than normal activity birds. Birds receiving high energy diet had a lower food conversion and food intake than birds receiving normal energy diet. There were no significant differences in body weight or ME intake between birds with different diets. 4. Slaughter yields, both absolute and relative to live body weight, were affected by activity or dietary energy to varying degrees. Breast meat was increased with more activity. The absolute weight of abdominal fat was independent of activity and in males the relative weight of abdominal fat was decreased in high activity birds. 5. Different degrees of activity and dietary energy had only minor influences on broilers sensory quality.

Protein requirements of growing steers limit-fed corn-based diets.

In Exp. 1, six steers (254 kg) were used in a 6 x 4 incomplete Latin square to determine the effects of solvent-extracted soybean meal alone or in combination with rumen-protected methionine and lysine on N balance in steers limit-fed a high-corn diet to gain 1.1 kg/d. The basal diet contained (DM basis) 80% rolled corn, 15% alfalfa, and .9% urea (13.9% CP), and 2 or 4% soybean meal replaced corn to give CP concentrations of 14.8 and 15.6%, respectively. Each diet was fed with and without 5 g/d of Smartamine-ML (.75 and 2.0 g of rumen-protected methionine and lysine, respectively). Nitrogen retention increased linearly (P = .09) with level of soybean meal. Rumen-protected methionine and lysine had no effect on N balance. In Exp. 2, seven steers (233 kg) were used in a 7 x 4 incomplete Latin square experiment to investigate optimal levels and sources of CP for steers limit-fed to gain 1 kg/d. Treatments included a negative-control diet (urea; 11.7% CP) and six diets containing either 13.5, 15.4, or 17.2% CP with either solvent-extracted or expeller-processed soybean meal. Diets provided 75, 87.5, 100, or 112.5% of estimated CP requirement for a gain of 1 kg/d. The basal diet contained 83% rolled corn, 15% alfalfa, and .2% urea. Nitrogen retention increased linearly (P = .006) with soybean meal addition, and no differences were observed between CP sources. The CP system underpredicted the protein requirements of limit-fed steers under our conditions.

Examination of the dietary methionine requirements of breeding northern bobwhite, Colinus virginianus.

Adult Northern bobwhite were used to test the hypothesis that dietary methionine levels recommended by the NRC for breeding quail are excessive for wild bobwhite. We tested the hypothesis by comparing immunocompetence, reproductive performance, and chick viability of Northern bobwhite hens fed diets containing low (0.31%), moderate (0.39%), or high (0.47%) concentrations of methionine. Chick viability was determined by assessing immunocompetence, including evaluating the ability of hens to passively transfer immunity to their chicks. Hens were fed the experimental diets for 6 wk on an ad libitum basis. After 6 wk, methionine treatment had no measurable effect (P > or = 0.20) on hen phytohemagglutinin wing web indices, organ weights, or serum anti-Pasteurella multocida titer indices. Mean egg weight, percentage egg production, total cumulative egg production, yolk weight, yolk volume, and percentage fertile and percentage hatch of fertile eggs did not differ (P > or = 0.12) among diet treatments. Amount of albumen in eggs produced by hens fed the high methionine diet averaged 0.27 g more (P = 0.003) than eggs of hens fed the low methionine diet. Anti-P. multocida titer of yolks from eggs in Week 6 were not different (P = 0.36) between birds fed the high and the low methionine diets. The mortality rate of chicks after challenge with 23 cfu of P. multocida was not different (P > or = 0.05) among diets. Chicks hatched from eggs laid by vaccinated hens during Weeks 2 and 3, however, had lower (P < 0.05) mortality than chicks of unvaccinated hens. It appears a dietary methionine concentration of 0.3% may be sufficient for wild Northern bobwhite to produce viable chicks.

Sorghum amino acid-supplemented diets for the 50- to 100-kilogram pig.

Three experiments were conducted to evaluate lysine (Lys), threonine (Thr), methionine (Met), tryptophan (Trp), and nonessential N (+N) supplementation of all sorghum grain (S) diets on growth and carcass characteristics of 50- to 100-kg pigs. In Exp. 1, four replicate pens of four pigs each were fed: 1) sorghum-soybean meal positive control (S-SBM); 2) S + Lys + Thr + Met + Trp to equal the amino acid concentrations in S-SBM (LTMT); 3) Diet 2 + N (LTMT+N); and 4) S negative control. Compared with pigs fed S-SBM, pigs fed LTMT or LTMT+N had reduced (P < .05) ADG, ADFI, serum urea N (SUN), pancreas weight, LMA, and percentage of muscling (PM) but higher dressing percentage (DP) and similar 10th rib fat thickness (TRF). Apparent N digestibility was lower (P < .05) in pigs fed LTMT than in pigs fed LTMT+N or S-SBM. In Exp. 2, two replicate pens of four pigs each were fed: 1) S-SBM; 2) S + Lys + Thr (LT); 3) S + Lys + Thr + Met (LTM); 4) S + Lys + Thr + Trp (LTT); 5) LTMT; 6 to 9) as 2 to 5 +N; and 10) S negative control. Compared with pigs fed S-SBM, pigs fed S, LT, LT+N, and LTM+N had lower (P < .05) ADG. Daily gain of pigs fed LTM, LTT, LTMT, LTT+N, or LTMT+N was not different (P > .10) from pigs fed S-SBM.(ABSTRACT TRUNCATED AT 250 WORDS)