Dietary glutamine, glutamic acid and nucleotides increase the carbon turnover (δ13C) on the intestinal mucosa of weaned piglets

Abstract

This study aimed at evaluating the influence of dietary glutamine, glutamic acid and nucleotides on duodenal and jejunal carbon turnover, and on mucosa morphometry of piglets weaned at an age of 21 days. The diets were: additive-free diet - control (C); 1% of glutamine (G); 1% of glutamic acid (GA); and 1% of nucleotides (N). In intestinal mucosa morphometry trial, 65 animals were used. At day 0 (baseline), five animals were slaughtered to determine the villus height (VH), crypt depth (CD), VH : CD ratio and villi density (VD). The remaining 60 animals were allocated into a randomized block design with 4×3 factorial arrangement (four diets: C - control, G - glutamine, GA - glutamic acid and N - nucleotides; three slaughter ages: 7, 14 and 21 days post-weaning) with five piglets slaughtered per treatment. In carbon turnover trial, 123 animals were used. At day 0 (baseline), three animals were slaughtered to quantify the δ 13C half-life (T50%) and the 99% carbon substitution (T99%) on intestinal mucosa. The remaining 120 animals were blocked by three weight categories (light, medium and heavy) and, randomly assigned to pen with the same four diets from the previous trial with one piglet slaughtered per weight category per treatment at days 1, 2, 4, 5, 7, 9, 13, 20, 27 and 49 after weaning. Morphometric analyses have yielded no consistent results regarding the action of the evaluated additives, and few reproducible age-related effects. The N diets determined lower T50% values (5.18 days) and T99% (17.21 days) than G and C diets (T50%=7.29, 7.58 days and T99%=24.22, 25.17 days, respectively) in the duodenal mucosa. In jejunum, the N, GA and G diets determined the lowest T50% means (4.9, 6.2 and 6.7 days, respectively) and T99% means (15.34, 21.10 and 21.84 days, respectively) in comparison with C diets (T50%=7.44 and T99%=24.72 days). The inclusion of the additives in the diets of piglets accelerated the carbon turnover in piglets during the post-weaning period. The stable isotopes technique (δ 13C) is an important methodology in studies of additives with trophic effects on the intestinal mucosa of the piglets.

IRMS as a tool to obtain the carbon turnover (δ13C) in organs of weaned piglets fed glutamic acid and nucleotides

“…Caldara et al. () obtained a liver‐T 50% of 9.2 days for animals fed C‐diet in a 46‐day experiment, value lower than the obtained in this study for the liver‐T 50% of piglets fed C‐diet (11.43 days) in a 49‐day trial that in turns it was greater than values found for liver of piglets fed C‐diet by Amorim (; 8 days), Miassi (; 10.4 days) and Augusto (; 9.9 days). However in this study, the obtained liver‐T 50% of piglets fed GA‐diet (11.57 days) was greater compared to the reported by Amorim () (7.1 days), working with weaned piglets fed the same GA‐source and level in diet over 49 days.…”

“…() obtained a liver‐T 50% of 9.2 days for animals fed C‐diet in a 46‐day experiment, value lower than the obtained in this study for the liver‐T 50% of piglets fed C‐diet (11.43 days) in a 49‐day trial that in turns it was greater than values found for liver of piglets fed C‐diet by Amorim (; 8 days), Miassi (; 10.4 days) and Augusto (; 9.9 days). However in this study, the obtained liver‐T 50% of piglets fed GA‐diet (11.57 days) was greater compared to the reported by Amorim () (7.1 days), working with weaned piglets fed the same GA‐source and level in diet over 49 days. The liver‐T 50% of piglets fed Nu‐diet observed in this study (11.95 days) was greater than value found by Amorim () for liver of weanling pigs fed 1% Nu‐diet (9.9 days, and t 95% = 44 days) and by Miassi () for liver of weaned pigs fed 0.2% Nu‐diet (10.1 days) during 49 days.…”

“…The kidneys‐T 50% of piglets fed C‐diet in the present study was 2 days lower than the kidneys‐T 50% reported by Amorim () (15.3 days), while for piglets fed 1% GA‐diet (13.1 days) in the present study, it was 3 days lower. The same trend was observed for kidneys‐T 50% of piglets fed 1% Nu‐diet (12.6 days), which had a 4 days faster isotopic incorporation compared to the value observed in present study.…”

“…The T 50% of C‐diet found in the present study was greater than T 50% reported by Lo Tierzo () (14.1 days) and Amorim () (14 days) for pancreas of piglets at 70‐day‐old fed C‐diet, as well as for pancreas‐T 50% of piglets fed GA‐diet (14.5 days) or fed Nu‐diet (16.6 days) in comparison with values obtained by Amorim () (1% Glu‐diet with T 50% = 12 days) or (1% Nu‐diet with T 50% = 10.5 days) for the same evaluation period (49‐day trial). On the other hand, Miassi () observed pancreas‐T 50% of 17.2 days; 14.6 days; 13.8 days and 15.4 days for 0%, 0.2%, 0.4% and 0.6% Nu levels, respectively, were greater than values obtained in present study for pancreas‐T 50% of piglets fed C‐diet (15.6 days) and those fed 0.1% Nu (16.6 days).…”

“…However in this study, the obtained liver‐T 50% of piglets fed GA‐diet (11.57 days) was greater compared to the reported by Amorim () (7.1 days), working with weaned piglets fed the same GA‐source and level in diet over 49 days. The liver‐T 50% of piglets fed Nu‐diet observed in this study (11.95 days) was greater than value found by Amorim () for liver of weanling pigs fed 1% Nu‐diet (9.9 days, and t 95% = 44 days) and by Miassi () for liver of weaned pigs fed 0.2% Nu‐diet (10.1 days) during 49 days.…”