Methionine sources at different dietary levels alters the growth and expression of genes related to homocysteine remethylation in the jejunum of broilers.

Sulfur amino acids are essential for the proper development of broilers and are required throughout the bird's life to perform important physiological functions. Studies that seek to understand the actions of sulfur amino acids in the body of birds are essential. The present study evaluated the influence of sulfur amino acid supplementation using DL-Methionine (DL-Met) and DL-Methionine hydroxy analogue (DL-HMTBA), on the performance and expression of genes related to methionine metabolism, in the jejunum of broilers. Four hundred and fifty male broilers (Cobb-700 slow feathering) were distributed in a completely randomized design, in a factorial scheme (2x3), with two sources of methionine (DL-Met and DL-HMTBA) and three levels of methionine (deficiency, requirement and excess). The mRNA expression of the MAT1, MTR, BHMT, MTRR, CBG and GSS genes, and performance data such as feed intake, weight gain, and feed conversion were evaluated. DL-HMTBA increased the expression of BHMT (p = 0.0072) and MTRR (p = 0.0003) in the jejunum of the birds. Methionine deficiency increased the expression of BHMT (p = 0.0805) and MTRR (p = 0.0018). Higher expression of GSS was observed in birds that were supplemented with DL-HMTBA (p = 0.0672). Analyzing our results, it is preferable to supplement sulfur amino acids with DL-Met at the requirement level. Birds fed with DL-HMTBA showed worse weight gain (p = 0.0117) and higher feed conversion (p = 0.0170); methionine deficiency resulted in higher feed intake (p = 0.0214), lower weight gain (p<0.0001) and consequently higher feed conversion (p<0.0001). Based on the information found in this work, it is recommended to supplement sulfur amino acids with DL-Met at the level of compliance with the requirement.

Addition of L-Glutamine + Glutamic Acid and L-Arginine to the diet of weaned piglets.

This study aimed to evaluate the supplementation of L-glutamine + glutamic acid and/or L-arginine on the productive performance, incidence of diarrhea, intestinal morphological of weaned piglets. Sixty-four 28-day-old weaned piglets were distributed in four treatments: DC - control diet; DG - glutamine diet (1% L-glutamine + glutamic acid); DA - arginine diet (1% L-arginine); and DGA - glutamine + arginine diet (0.5% L-glutamine + glutamic acid and 0.5% L-arginine) with eight replicates and two animals per experimental unit. The addition of 1% L-arginine to the piglet diet improved weight gain and feed conversion over 28 to 35 days of age. In the period of 28 to 49 days of age, supplementation with 1% L-glutamine + glutamic acid increased the animals' weight gain and reduced the incidence of diarrhea. Supplementation with amino acids in combination had a positive effect on the morphometric parameters of the intestinal mucosa compared to the control diet. Supplementation with 1% L-glutamine + glutamic acid increased the number of anti-PCNA+ cells and goblet cells. Taken together, our findings suggest that supplementation with L-glutamine + glutamic acid and L-arginine can improve the productive performance and enhance the integrity of the intestinal mucosa of weaned piglets.

Supplementation of L-glycine and L-glutamate to Japanese quails from 01 to 36 days of age using the ideal protein concept.

Experiment I: T1-1 =  basal diet with 25% crude protein (CP) + limiting amino acids (LA); T1-2  = 20% CP + LA; T1-3  = 20% CP + LA + L-glycine; T1-4  = 20% CP + LA + L-glutamate; T1-5  = 20% CP + LA + L-glycine + L-glutamate. Experiment II: T2-1  = basal diet with 22% CP + LA; T2-2  = 20% CP + LA; T2-3  = 17.6% CP + LA + L-glycine; T2-4  = 17.6% CP + LA + L-glutamate; T2-5  = 17.6% CP + LA + L-glycine + L-glutamate. The reduction of dietary protein based on the concept of ideal protein decreases nitrogen excretion in quails when L-glycine is added to the diets. Quails fed diets supplemented with L-glutamate as the non-specific nitrogen source equivalent to the nitrogen level of the control diet had increased nitrogen excretion. However, quails had reduced nitrogen excretion in both experiments when L-glycine was added to diets with L-glutamate. Carcass fat was increased by reducing dietary protein, but fat deposition was reduced by adding L-glutamate and L-glycine, or both. The dietary addition of L-glutamate and L-glycine in quails based on the ideal protein concept is not necessary (Exp. I). Although the total nitrogen, electrolytic balance and glycine level were adjusted in diets, quails had decreased performance. Therefore, other hypotheses besides protein reduction need to be studied (Exp. II). Protein reduction with supplementation of only limiting essential amino acids does not affect quail performance. Dietary addition of L-glycine reduces nitrogen excretion.