The relation between starch digestion rate and amino acid level for broiler chickens

Abstract

Digestion coefficients of nutrients give information about the amount of nutrients available to the animal but not about the rate or site of absorption. Gradual digestion of starch may have an amino acid sparing effect and therefore enhance growth efficiency of broiler chickens. A growth trial was performed with 6,800 broiler chickens from 9 to 30 d of age to investigate interactions between starch digestion rate and amino acid level. Birds were fed either a pea-corn-based diet (slowly digestible starch) or a tapioca-corn-based diet (rapidly digestible starch). Both diets were formulated with five levels of digestible lysine, varying from 8.5 to 11.0 g/kg. The minimal levels of other amino acids varied accordingly. Starch source did not affect feed intake (2,213 g), but weight gain was consistently higher for birds on pea-corn diets than for those on tapioca-corn diets (1,426 vs. 1,400 g; P < 0.01). Feed conversion was better (P < 0.01) for birds on pea-corn diets (1.55) than for birds on tapioca-corn diets (1.58). The difference in feed conversion between birds on pea-corn and tapioca-corn diets was greater with lower amino acid levels (0.043) than with higher amino acid levels (0.019) in the diet (P = 0.11). This interaction was more pronounced during the first 9 d of the experiment (P < 0.05). It was concluded that feeding slowly digestible starch improved protein and energy utilization in broiler chickens.

Factors affecting the nutritional value of pea (<i>Pisum sativum</i>) for broilers

“…The performed trial revealed a positive Pearson's correlation between starch concentrations in pea seeds and ileal digestibility of nearly all amino acids (average r = 0.60; P ≤ 0.05). According to Weurding et al (2003), due to its structure, pea starch is characterized by very slow degradation in the gastrointestinal tract of birds compared with maize starch. The above authors speculated that diets with rapidly digestible starch may result in elevated plasma glucose levels when other nutrients are not yet absorbed, which may have consequences for protein utilization (Weurding et al, 2003).…”

“…According to Weurding et al (2003), due to its structure, pea starch is characterized by very slow degradation in the gastrointestinal tract of birds compared with maize starch. The above authors speculated that diets with rapidly digestible starch may result in elevated plasma glucose levels when other nutrients are not yet absorbed, which may have consequences for protein utilization (Weurding et al, 2003). The higher amino acid AID in the cultivars characterized by higher starch contents determined in the current study is difficult to explain and needs further studies.…”

“…In comparison with other leguminous plants, pea seeds have the highest starch content (over 40%). Additionally, pea starch is characterized by very slow degradation in the gastrointestinal tract of birds compared with maize starch, which may affect protein deposition (Weurding et al, 2003). Notwithstanding, pea seeds are known to contain antinutrients that may negatively impact the production results of broiler chickens.…”

Energy content and amino acid digestibility of extruded and dehulled-extruded corn by pigs and its effect on the performance of weaned pigs

“…The lower feed intake of diets containing extruded corn might explain the poorer weight gain observed (Johnston et al, 1999). Weurding et al (2003) and Van Kempen et al (2007) also reported that raw corn was preferred for animal feeding due to its slowly digestible starch resulting in a slow and steady release of glucose which did not strongly stimulate insulin, therefore raw corn could improve feed intake and performance. In addition, the reason for the lower feed intake in extruded corn may be due to the poorer palatability caused by higher levels of retrograded starch (Hongtrakul et al, 1998;Lv et al, 2006) compared with raw corn.…”

Grain Sorghum: A Conundrum for Chicken-Meat Production

“…Accumulating evidence suggests that the provision of some slowly digestible starch in broiler diets is beneficial for feed conversion efficiency [79][80][81]. One possibility is that retarded starch digestion rates provide a greater supply of glucose to the lower small intestine which spares amino acids from catabolism for energy to meet the gut mucosa's requirements thereby permitting the entry of amino acids into the systemic circulation to become available for protein deposition [22].…”