Different dietary starch patterns in lowprotein diets: effect on nitrogen efficiency,nutrient metabolism, and intestinal flora in growing pigs
发布于: 2023-08-28 来源: 国家饲料工程技术研究中心
关键词：Intestinal flora, Low-protein diet, Nitrogen efficiency, Nutrient metabolism, Starch patterns
摘要：Background: Protein releases amino acids faster than starch releases glucose in digestive tract of pigs fed lowprotein (LP) diets. Poor synchronization of dietary glucose and amino acids supply leads to compromised nitrogen
efficiency. Dietary starch patterns modulation may improve this situation.
Methods: Growing barrows (29.7 ± 2.0 kg) were randomly allotted into 5 dietary treatments with LP diets consisting
of different purified starches. Treatments included: waxy corn starch (W LP), corn starch + waxy corn starch (C + W
LP), corn starch (C LP), pea starch + waxy corn starch (P + W LP) and pea starch (P LP). In the experiment, growth
performance, protein deposition, nutrient metabolism, and fecal microbial community of pigs were investigated. In
vitro starch digestion was used for predicting the in vivo glucose response.
Results: Dietary starch in vitro glucose release profile was determined by starch source and the ratio of
amylopectin and amylose. C + W LP treatment showed decreased total nitrogen excretion and plasma citrulline
concentration and improved plasma leptin concentration among treatments (P < 0.05). Besides, the highest
nitrogen apparent biological value, whole-body protein deposition and growth performance and lowest urinary
nitrogen excretion were also observed in C + W LP treatment. Compared with the other groups, C + W LP and C LP
showed increased plasma pyruvate, IGF-1, and lipase concentrations (P < 0.05). The W LP group presented
dramatically increased plasma alanine and urea nitrogen concentration and decreased aldolase and leptin
concentrations (P < 0.05). Dietary starch patterns did not make an impact on bacterial richness and diversity, but
changed the taxonomic and functional structures of the microbial communities. Microbial protein fermentation
product (isobutyrate and isovalerate) presented increased in P LP treatments compared with the other treatments
(P < 0.05).
Conclusions: Dietary starch patterns modulation can regulate dietary glucose release profile, nutrient metabolism,
protein turnover, and fecal microbial fermentation in pigs. The optimal dietary glucose release profile effectively
strengthened whole-body protein deposition and improve nitrogen efficiency and growth performance in growing
pigs fed LP diets.