Effect of source of starch on net portal flux of glucose, lactate, volatile fatty acids and amino acids in the pig

Abstract

The ileal digestibilities of maize starch and native pea starch do not differ. However maize starch is digested faster than pea starch and the ileal amino acid digestibility of a diet containing pea starch is lower. In the present study, the net portal fluxes of glucose, lactate, volatile fatty acids (VFA) and amino acids were measured for diets including 650 g maize starch or pea starchhcg. The diets were fed at a level 870 kJ digestible energykg'"' twice daily (06.00 and 18.00 hours) to four female pigs in a crossover design. Portal vein blood flow did not differ between maize and pea starches (1620 and 1484 mumin respectively; SED 100; P = 0.23). For maize starch portal glucose flux was significantly higher during the first 6 h after feeding, was not different 8 h after feeding and was significantly lower thereafter. Net portal glucose flux was higher for maize starch than for pea starch (1759 and 1265 mmoV12 h respectively; SED 182; P = 0.054). Net portal lactate flux was not significantly different between maize and pea starches (36.5 and 67.2 mmoUl2 h respectively; SED 24.1; P = 0.27) and net portal VFA flux was lower for maize starch than for pea starch (169 and 218 mmoUl2 h respectively; SED 18; P = 0.054). Net portal fluxes of valine, isoleucine, phenylalanine, tryptophan, arginine, serine, cystine, tyrosine, lysine, histidine and the sum of essential amino acids tended to be or were higher (Pc0.1 or P<O.O5) and net portal flux of aspartic acid tended to be lower for pea starch (RO.1). It can be concluded that, although ileal digestibility of both starches is equal, the rate of appearance of glucose in the portal vein was higher for maize starch, influencing the net portal flux of amino acids.Starch: Net portal flux: Amino acids

Dietary starch sources affect net portal appearance of amino acids and glucose in growing pigs

“…However, consistent with previous studies (Rerat et al, 1984;Leclere et al, 1993;Vaugelade et al, 1994;Van der Meulen et al, 1997), we found that about 35% to 50% of dietary starch did not enter the portal vein as the glucose moiety in growing pigs (Table 6). The amounts of glucose entering the portal vein were higher in pigs fed the maize, sticky rice and brown rice diets than in pigs fed the RS diet (Table 6), possibly due to reduced catabolism of glucose in the gastrointestinal wall.…”

“…Although much attention has been directed towards defining the effect of dietary factors on glucose absorption into the portal vein of growing pigs (Rerat et al, 1984;Leclere et al, 1993;van der Meulen et al, 1997), little is known about the effect of various sources of dietary starch on intestinal amino acid metabolism. One study reported that the absorption of several amino acids into the portal vein differed between pigs fed the maize and pea starch (van der Meulen et al, 1997). The present study is the first to determine the effect of rice starch on the entry of dietary amino acids and glucose into the portal vein of pigs.…”

“…Extensive studies have shown that the digestibility of dietary carbohydrates in swine is largely affected by their source, structure and composition as well as by the activities of digestive enzymes (Cone and Vlot, 1990;Franco et al, 1992;Leclere et al, 1993;Weurding et al, 2001). Much evidence also showed that the rate of glucose absorption was tested from the portal vein of pigs (Rerat, 1985;Vaugelade et al, 1994;van der Meulen et al, 1997).…”

“…Research over the past 15 years has established that the small intestine of pigs also plays an important role in the metabolism of both essential and nonessential amino acids (Stoll et al, 1998;Burrin et al, 2000;Wu et al, 2005). van der Meulen et al (1997) showed an effect of source of starch (maize v. peas) on amino acid appearance in portal blood. At present, little is known about the effect of various sources of dietary starch, particularly rice starch, on the metabolism of amino acids in the PDV or their appearance in the portal circulation of pigs.…”

Evaluation of in situ valine production by Bacillus subtilis in young pigs

“…The blood samples taken in Experiment 2 on day 18 were obtained 3 h after feeding to assure a steady Val absorption. This time point was set up based on our own data obtained in Experiment 1 and on measurements on absorption kinetics in pigs showing a maximum absorption of nutrients from 0.5 to 2 h after feeding whereafter it decreases until~6 h post-feeding (Rerat et al, 1993;van der Meulen et al, 1997;Kristensen et al, 2009). Although the AA in focus was Val, other AA and metabolites were also measured.…”