Coefficient Of Total Tract Apparent Digestibility Of Dry Matter Research Articles

Effect of the increase of dietary starch and soluble fibre on digestive efficiency and growth performance of meat rabbits

Effect of increasing dietary starch and soluble fibre on performance and digestive efficiency was studied in 246 cross-bred rabbits from weaning (34 d of age) to slaughtering (75 d). A 3 × 2 factorial arrangement ( i.e. three levels of starch: 60, 103, and 147 g/kg diet; two levels of soluble fibre: 100 and 138 g/kg diet) was used. The rabbits were assigned to six groups and fed the six diets ad libitum. When dietary starch was increased, the coefficient of total tract apparent digestibility (CTTAD) of dry matter (on average, 0.547–0.629) and all nutrients linearly increased (P<0.001), but the CTTAD of soluble fibre did not vary. Weight gain, digestible energy intake, and feed conversion ratio linearly (P<0.01) improved (6.4%, 5.7% and 11.1%, respectively), and feed intake decreased (5.6%). In the caecum, ammonia-N production linearly decreased (7.21–4.93 mmol/L; P=0.01), acetate proportion tended to increase (84.2–85.8 mmol/100 mmol volatile fatty acids, VFA; P=0.06), and propionate value decreased (4.00–3.33 mmol/100 mmol VFA; P<0.01). As the starch level increased, the CTTAD of NDF and hemicelluloses improved slightly in the diets with 100 g/kg soluble fibre, while at a higher rate in the diets with 138 g/kg soluble fibre (significant interaction, P<0.01). The increase of dietary starch linearly increased slaughter weight (SW) and carcass weight; the proportion of the gastrointestinal tract linearly decreased (196–182 g/kg SW; P<0.001) and the dressing percentage increased (59.3–60.8% SW, P<0.001), as well as dissectible fat (P=0.03). The increase of dietary soluble fibre improved (P<0.001) the CTTAD of dry matter (0.540–0.639) and all nutrients, but the CTTAD of crude protein was not affected; it stimulated daily growth (5.3%; P=0.05) and reduced (P<0.001) feed intake (12.4%) and feed conversion ratio (15.0%). In the caecum, pH decreased (5.88–5.70; P=0.02), total VFA concentration tended to increase (73.8–82.8 mmol/L; P=0.10), and valerate concentration decreased (0.43–0.35 mmol/100 mmol VFA; P=0.01). Slaughter weight and reference carcass weight increased (0.03<P<0.07); the gastro-intestinal tract proportion tended to increase (185–190 g/kg SW; P=0.06) without affecting dressing percentage or carcass composition. In conclusion, the use of soluble fibre is recommended in association with (rather than in replacement of) starch to increase the energy value of diets and improve overall farm-feed efficiency and carcass quality.

Effects of corn distillers dried grains with solubles and xylanase on growth performance and digestibility of diet components in broilers

The objective of this study was to investigate the effect of corn distillers dried grains with solubles (cDDGS) and xylanase in corn-based diets on growth performance and digestibility of diet components in broiler chickens. The experiment was a 3×4 factorial design with diets containing 3 levels of cDDGS (0, 100 and 200g/kg) and 4 levels of xylanase (0, 1200, 2400 and 3600U/kg). The diets were fed to 720 Cobb 500 chicks for 42 days. Excreta was collected at 18–21 days to measure coefficients of total tract apparent digestibility (CTTAD) and ileal digesta was collected at 42 days to measure coefficients of ileal apparent digestibility (CIAD). Dietary cDDGS caused poor (P<0.05) feed conversion ratio (FCR) of broilers from 1 to 21 and 22 to 42 days, but increased (P<0.05) feed intake (FI) at 1–21 days. Inclusion of xylanase increased (P<0.05) FI by 4–5% at 1–21 days, and did not affect (P≥0.05) FCR in either period. In the two growing periods, cDDGS decreased (P<0.05) the CTTAD of dry matter (DM), and the CIAD of DM and hemicelluloses, whereas xylanase increased (P<0.05) the digestibility of DM and hemicellulose by 5% and 20%, respectively. There were significant interactions (P<0.05) between cDDGS and xylanase for BWG and energy digestibility. In comparison with the 100g/kg cDDGS diet, the inclusion of 200g/kg cDDGS led to poorer (P<0.05) FCR at 22–42 days, and lower (P<0.05) CTTAD of DM at 18–21 days. There were no differences (P≥0.05) in most growth parameters between the doses of xylanase at 1200, 2400 and 3600U/kg. Xylanase at 2400U/kg increased (P<0.05) CTTAD of DM compared with the lower dose, but 3600U/kg xylanase showed no further improvement (P≥0.05) on digestibility measurements. The results suggest that supplementing xylanase to diets containing cDDGS can improve growth performance and digestibility of diet components in broilers.

Nutritional value of mixed grass haylage in Icelandic horses

The influence of cutting time of mixed grass haylages on energy and nitrogen (N) metabolism, and the coefficients of total tract apparent digestibility (CTTAD) were studied in four mature Icelandic geldings by performing total collection of faeces and urine. The experiment was arranged as 4 × 4 balanced Latin square. The four haylages used were harvested at different times and were considered to be representative in botanical composition for mixed grass haylages in Iceland. The CTTAD of dry matter (DM), organic matter (OM), crude protein, neutral detergent fibre, acid detergent fibre (ADF) and energy were different ( p < 0.05) in the haylage batches. The CTTAD of all dietary components and energy decreased with time of cutting. The content of ADF (% in DM) accounted for a major part of the difference in CTTAD of OM ( r 2 = 0.95) between haylage batches. The urinary nitrogen losses decreased with date of cutting, while the energy losses in urine (as % of digestible energy intake) were unaffected ( p > 0.05). The digestible energy content of the haylages studied ranged from 13.4 to 10.8 MJ/kg DM.

Effect of feeding schedule on apparent energy and amino acid digestibility by growing pigs

An experiment was conducted to investigate the effects of feeding schedule on dry matter (DM), gross energy (GE), crude protein (CP), and amino acid (AA) digestibility by growing pigs. Six growing castrates (initial body weight: 40.5 ± 2.25 kg) were equipped with a T-cannula in the distal ileum and allotted to a repeated 3 × 3 Latin square design with three animals and three periods in each square. A maize–soybean meal based diet (181 g CP/kg) was formulated and fed to the pigs in three different feeding schedules; i.e., one meal per day, two meals per day, or free access to feed. Pigs fed one or two meals per day were allotted a daily amount of feed equivalent to three times the maintenance energy requirement. Fecal and ileal samples were collected from all pigs in each period. The coefficients of ileal apparent digestibility (CIAD) for DM, GE, CP, and AA were calculated as were the coefficients of total tract apparent digestibility (CTTAD) of DM and GE. Results of the experiment showed that there were no differences in the CIAD for DM, GE, or for any of the AA among the three feeding schedules. In contrast, pigs given free access to the diet had lower (P<0.002) CTTAD for DM and GE compared with pigs fed a restricted amount of feed either once or twice daily. Therefore, the concentration of digestible energy in the diet was lower if calculated from pigs given free access to the diet compared with pigs fed the diet once or twice daily (14.38 MJ/kg versus 14.83 MJ/kg and 15.13 MJ/kg). It is concluded that the feeding schedule does not influence the CIAD for DM, GE, CP, or AA by pigs. Therefore, any of the three feeding schedules that were used in the current experiment may be used in experiments aimed at measuring CIAD in pigs. However, if the CTTAD of DM and GE are measured, it is recommended that pigs are given free access to feed.

Digestibility of dried star grass ( Cynodon nlemfuensis) and consumption of fresh star grass in primiparous pregnant sows

Two experiments to evaluate the consumption and digestibility of star grass ( Cynodon nlemfuensis) in pregnant sows are reported. Experiment one: Six pregnant sows were used to evaluate the effect of dried star grass (DSG) on coefficient of total tract apparent digestibility (CTTAD) of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), gross energy (GE) and nitrogen balance (NB). The experimental diets included 0 g (0 DSG) and 250 g of DSG kg −1 (250 DSG). These diets were similar in crude protein, vitamins and minerals. The experiment was conducted in two periods: 15 days for adaptation and 7 days for total urine and faeces collection. The CTTAD of DM, OM, CP, NDF, ADF, and GE were lower (P<0.05) in sows fed with 250 DSG diet than in sows fed with 0 DSG diet. The digestible energy value obtained for DSG was 5.5 MJ kg −1 DM. Experiment two: Six pregnant sows were used to evaluate fresh star grass (FSG) consumption. The sows were fed three basal diets based on soya bean meal and sorghum. The diets were designed to supply 19 (L), 26 (M) and 33 (H) MJ of DE day −1. After the basal diets were consumed, the sows were offered chopped FSG ad libitum. Dry matter consumption of FSG decreased (P<0.05) as energy intake from basal diets increased (L: 231 g day −1, M: 180 g day −1 and H: 136 g day −1). However, the total DM consumption (basal diet + FSG) reduced linearly (P<0.05) as energy intake from experimental diets decreased (L: 1671 kg −1, M: 1980 kg −1 and H: 2296 kg −1). Results suggest that inclusion of DSG in sow diets reduced digestibility and FSG consumption increased as energy supply in the basal diet was reduced. However, the increased in FSG consumption did not compensate for the energy deficit in the basal diet.

Digestibility and digestive organ development in indigenous and improved chickens and ducks fed diets with increasing inclusion levels of cassava leaf meal

Growing indigenous Cambodian chickens and ducks, and broiler chickens and White Pekin ducks were fed diets containing 0%, 7%, 14% and 20% of cassava leaf meal (CLM) to study the effects of CLM level on diet digestibility and gastrointestinal tract (GIT) and organ development. The coefficient of total tract apparent digestibility (CTTAD) of dry matter (DM) and intake of digestible DM decreased with increased dietary CLM. DM and digestible DM intake was higher for local breeds than for the corresponding exotic breeds, and higher for ducks than for chickens (p < 0.001), although there were no species or breed effects on CTTAD of DM (p > 0.05). Weight of small intestine, caeca, gizzard and pancreas, expressed as per kg body weight, increased with increased CLM in the diet (p < 0.001). There was no consistent diet effect on liver weight. Length of small intestine and caeca, expressed on a mass-specific basis, increased with dietary CLM content (p < 0.001). When expressed as per kg body weight small intestine, proventriculus, gizzard, pancreas and liver weights, and small intestine length, were higher in ducks than in chickens (p < 0.001), and were higher in the indigenous than in the improved breeds (p < 0.01), except for small intestine weights, which were similar. However chickens had higher weight of caeca (p < 0.001) and colon (p < 0.01) in absolute units and per kg body weight.

O-21. A prospective investigation into venous changes and lymphoedema in breast cancer

A pig digestibility trial was conducted to investigate the effects of fermentation or extrusion of wheat bran included in a basal diet on coefficients of total tract apparent digestibility (CTTAD) regarding dry matter (DM), organic matter (OM), crude protein (CP), crude fiber (CF), ether extract (EE), starch, energy (GE), phosphorus (P) and calcium (Ca). In the experiment, 9 growing pigs were allocated to a 3 × 3 Latin square design to measure the CTTAD of the basal diet containing different modified wheat bran variants, and therefore to demonstrate relative differences in the CTTAD among the diets as a result of wheat bran modification. The wheat bran was used in native form (NWB), as fermented bran ensiled with Lactobacillus paracasei and Lactobacillus plantarum (FWB) and as extruded wheat bran (EWB). Wheat bran variants were included at 200 g kg−1 in a phosphorus deficient basal diet. The obtained results show that the CTTAD of DM was increased when feeding the diet with FWB (+2%, P<0.05) instead of NWB (0.87). Likewise the CTTAD of OM was also increased with FWB (+2%, P<0.05), compared to NWB (0.88). Also the CTTAD of CF was improved with FWB and EWB (+9%, P<0.05), related to NWB (0.58). The CTTAD of ash was improved with FWB (+14%, P<0.05) compared to NWB (0.60). Correspondingly, the CTTAD values of P and Ca were also elevated when feeding the FWB diet. P-digestibility was increased in the FWB feeding group compared to those groups fed with NWB (+35%, P<0.05) and EWB (+53%, P<0.05). Regarding the Ca digestibility, similar results were obtained (P<0.05). While the CTTAD of energy was increased in the FWB (+3%, P<0.05) and EWB (+2%, P<0.05) feeding groups compared to that of NWB (0.85), the N-balance and the CTTAD of starch were not affected by the treatments. Nevertheless, the CTTAD of EE was enhanced in the FWB treatment group (+40%, P<0.05), and was also improved by extrusion (+30%, P<0.05) compared to the NWB (0.50) treatment. In conclusion, fermented and extruded wheat bran exert some significant influence on the apparent total tact digestibility of several essential nutrients, minerals and energy when included in a basal diet, whereby fermentation seems to be the more potent strategy, as positive effects on the CTTAD of P and Ca could only be observed in the feeding group with FWB.

Effect of Leucaena leucocephala leaf meal treated with acetic acid or sodium hydroxide on apparent digestibility and nitrogen retention in pig diets

Forty male pigs (43.4±6.2 kg of liveweight) housed in metabolism crates were used to evaluate the effect of Leucaena leucocephala leaf meal (LLM) treated with acetic acid (AA) or sodium hydroxide (NaOH) in pig diets, on coefficient of total tract apparent digestibility (CTTAD) of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and nitrogen balance (NB). The experimental diets included 200 g LLM kg −1 which had been treated with four levels (0, 30, 60 and 90 g kg −1 DM) of AA or NaOH, respectively as chemical treatments. The experiment was conducted in two periods: 7 days for adaptation, and 7 days for total urine and faeces collection. There were no differences ( P>0.05) between treatments (AA and NaOH) on CTTAD of DM, OM and CP. However, CTTAD of NDF was higher ( P<0.05) in pigs fed diets with LLM treated with AA (0.49) than in pigs fed diets with LLM treated with NaOH (0.44). There were no differences ( P>0.05) on apparent digestibility between levels of treatments (0, 30, 60 and 90 g kg −1). Nitrogen retained was higher ( P<0.05) in pigs fed diets that included LLM treated with level 30 g kg −1 of AA or NaOH (11.2 g per day) in comparison to pigs fed diets with LLM treated with 0, 60 and 90 g kg −1 (4.6, 7.3 and 6.7 g per day, respectively) as seen from the quadratic response. The results obtained in the current work suggest that treating LLM with 30 g kg −1 of AA or NaOH increased nitrogen retention in growing pigs.