Apparent Ileal Digestibility Of Starch Research Articles

Comparative digestibility of energy and nutrients and fermentability of dietary fiber in eight cereal grains fed to pigs

Cereal grains provide a large portion of caloric intake in diets for humans, but not all cereal grains provide the same amount of energy. Therefore, an experiment was conducted to determine and compare the metabolizable energy (ME), the apparent ileal digestibility (AID), and the apparent total tract digestibility (ATTD) of gross energy (GE) and nutrients in eight cereal grains when fed to pigs. Rice had greater (P < 0.05) AID of GE than other cereal grains, greater (P < 0.05) AID of starch than yellow dent corn, dehulled barley, rye, and wheat, and greater (P < 0.05) ATTD of GE than yellow dent corn, rye, sorghum, and wheat. Dehulled barley, rye, and sorghum had less (P < 0.05) AID of starch than other cereal grains. Dehulled barley had greater (P < 0.05) ATTD of GE than rye. Dehulled oats had the greatest (P < 0.05) ME compared with other cereal grains, whereas rye had the least (P < 0.05) ME. Dehulled oats provide more energy to diets and should be used if the goal is to increase caloric intake. In contrast, sorghum and rye may be more suitable to control diabetes and manage body weight of humans.

Influence of cereal type and the inclusion of sunflower meal as a source of additional dietary fibre on nutrient retention, growth performance and digestive organ size in broilers from one to twenty-one days of age

Two experiments (Exp.) involving male Ross 308 broiler chicks were conducted to study the influence of type of cereal (sorghum or wheat) and the inclusion of sunflower meal (SFM) as a dietary fibre source on nutrient retention and growth performance. The experiment involved two feeding periods, starter (1–10 d of age) and finisher (11–21 d of age) and four experimental diets per period. Diets were organized factorially with two levels of sorghum in substitution of wheat (0 vs. 200 or 250 g sorghum/kg for the starter and finisher feeds, respectively) and two levels of SFM (0 vs. 40 or 25 g SFM/kg for each period). In Exp. 1, diet did not affect total tract apparent retention of nutrients. At 21 d of age, the coefficient of ileal apparent digestibility of starch was higher (P<0.001) for the wheat than for the sorghum diets. At 10 and 21 d of age, birds fed the sorghum diets had larger digestive tracts than chicks fed the wheat diets (P<0.01). In Exp. 2, the inclusion of SFM impaired (P<0.05) average daily gain (ADG) of birds from 1 to 10 days of age. From 11 to 21 d of age, birds fed the wheat diets had higher ADG than chicks fed the sorghum diets (P<0.05). However, no differences in growth performance were observed for the entire experimental period. In conclusion, the inclusion of 200 g sorghum/kg did not affect nutrient retention or growth performance during the first 10 d of life. However, the inclusion of SFM reduced growth performance at this stage. The inclusion of 250 g sorghum/kg reduced apparent ileal digestibility of starch and growth performance from 11 to 21 d of age. The cereal type and the inclusion of SFM as a source of additional dietary fibre might affect digestive traits and growth performance of young broilers.

Processing of barley and enzyme supplementation in diets for young pigs

Two trials were conducted to study the influence of heat processing (HP) of barley and enzyme supplementation (ES) to diets for young pigs. In trial one, six treatments arranged factorially with two types of barley processing (raw or cooked-flaked) and three levels of ES (0, 600 and 1200 mg/kg) were used. Each treatment was replicated four times and five piglets caged together formed the experimental unit. The enzyme complex contained 3100 U α-amylase/g, 400 U xylanase/g and 225 U β-glucanase/g. Growth rate, feed intake and feed conversion were measured at 14 and 28 days. Coefficient of total tract apparent digestibility (CTTAD) of organic matter (OM), energy, crude protein (CP), ether extract (EE), crude fibre and starch were assessed at 14 days. In trial two, 16 piglets were used to measure ileal viscosity (VISC), apparent ileal digestibility of starch, pH at the stomach, caecum and colon and volatile fatty acid (VFA) concentration in the caecum. Only diets containing 0 or 600 mg ES/kg were used. From 0 to 14 days after weaning, piglets fed HP barley grew faster than piglets fed raw barley (0.213 kg per day versus 0.184 kg per day, P=0.050) but the effect disappeared thereafter. Barley processing increased coefficient of apparent ileal digestibility (CIAD) of starch (0.993 versus 0.984 for HP and raw barley diets; P=0.017) but VISC, digestive pH or VFA concentration of the caecum were not affected. None of the total tract digestibility coefficients studied was affected by dietary treatment. It is concluded that HP of barley improved piglet growth during the first 14 day post-weaning and increased apparent ileal digestibility of starch, but that ES had no effect on performance of piglets.

Dietary Carboxymethylcellulose with High Instead of Low Viscosity Reduces Macronutrient Digestion in Broiler Chickens

The question addressed was whether the viscosity per se of dietary non-starch polysaccharides influences macronutrient digestion in broiler chickens. Water-soluble carboxymethylcellulose preparations of low (LCMC) or high viscosity (HCMC) were fed to broiler chickens (n = 10/group) from 21 to 35 d of age. The HCMC preparations reduced weight gain and raised water intake compared with LCMC. After the HCMC diet was fed, viscosity of the supernatant of small intestinal contents was significantly raised. The HCMC preparations raised the group mean ATP concentration in the digesta of duodenum plus jejunum, indicating that bacterial activity was increased. Consumption of HCMC depressed apparent fecal digestibility of lipids and nitrogen and also apparent ileal digestibility of starch. The dietary HCMC tended (P = 0.077) to reduce plasma triglyceride concentrations. After HCMC consumption, the weights of the small intestine and colon, without or with contents, were elevated. The data indicate that high viscosity of digesta in broiler chickens is associated with a reduced macronutrient digestion and impaired growth performance. Because the carboxymethylcellulose preparations were nonfermentable by fresh feces, we suggest that HCMC reduces macronutrient digestion by raising the viscosity of small intestinal contents, which is associated with enhanced bacterial fermentation due to accumulation of undigested material.

Ileal and faecal digestibility in piglets of field beans ( Vicia faba L.) varying in tannin content

The ileal and faecal digestibility of nutrients of four varieties of field beans was determined in piglets (15–30 kg) fitted with a post-valvular T caecum cannula. The varieties differed in their content of condensed tannins. Beans of a white flowering variety (cultivar ‘Blandine’) had a low content of condensed tannins (< 0.1%). The other beans originated from coloured flowering varieties and had a medium (0.4%) (cultivar ‘Herz Freya’) or high tannin content (1.0%) (cultivars ‘Mythos’ and ‘Alfred’). The low-tannin beans were evaluated as such and after autoclave treatment (30 min, 105°C). Beans were included in the diets at a level of 300 g kg −1. Diets were tested in 18 piglets in two experimental periods ( n = 6). The ileal N digestibility (%) was higher ( P < 0.05) for the low-tannin beans (85.7) than for the medium- and high-tannin varieties (73.7, 72.4, 71.5 for ‘Herz Freya’, ‘Mythos’ and ‘Alfred’, respectively). Faecal N digestibility values were 89.3, 85.7, 82.4 and 79.4 for ‘Blandine’, ‘Herz Freya’, ‘Mythos’ and ‘Alfred’ beans, respectively. The values for ‘Blandine’ and ‘Alfred’ beans differed significantly ( P < 0.05). For individual amino acids differences in digestibility between ‘Blandine’ beans and the average value for beans of the three tannin-containing varieties ranged from 8 units for aspartic acid to 18 units for cystine. Autoclaving the low-tannin field beans ‘Blandine’ did not improve their N digestibility at the ileal (85.7 (raw) versus 82.3 (autoclaved)) and the faecal level (89.3 versus 88.9). Apparent ileal digestibility of starch was similar for all raw and the autoclaved beans. The absence of condensed tannins in field beans seems to have a positive effect on ileal and faecal digestibility of particularly crude protein and amino acids of faba beans in pigs. Autoclaving low-tannin faba beans did not improve the nutritional value for pigs.