Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DIGESTION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMed2001

The ratio of insoluble to soluble fiber components in soybean hulls affects ileal and total-tract nutrient digestibilities and fecal characteristics of dogs.

An experiment was conducted to evaluate the effects of soybean hulls (SH) containing varying ratios of insoluble:soluble fiber (I:S) on nutrient digestibilities and fecal characteristics of dogs. Ileally cannulated dogs (n = 6) were fed seven diets in a 6 x 7 Youden square arrangement of treatments. The seven diets included five SH-containing diets with I:S of 1.9, 2.7, 3.2, 5.2 or 7.2 and two diets containing either beet pulp (BP) or no supplemental fiber (control). Ileal digestibilities of DM, OM, CP, total dietary fiber (TDF), fat and gross energy (GE) were lower (P < 0.05) for dogs fed diets containing supplemental fiber compared with dogs fed the control diet. Fiber inclusion had a modest negative effect (P < 0.05) on total-tract DM, OM, fat and GE digestibilities compared with the control diet. Ileal digestibilities of DM and OM by dogs fed the SH treatments responded quadratically (P < 0.05) to I:S, with digestibility coefficients decreasing as the I:S approached 3.2. Highest ileal digestibilities were observed for diets with an I:S of 1.9 and 7.2. Similarly, a quadratic response (P < 0.05) was observed for digestibility of total amino acids at the ileum. Fecal outputs were lower (P < 0.001) when dogs consumed the control diet vs. fiber-containing diets. Among the SH-containing diets, there was a linear increase in fecal output as I:S increased (P = 0.031). The I:S in the diet affects DM and OM digestibilities at the ileum and affects fecal output, indicating that optimization of this ratio is desirable.

Amino Acids↗
PubMed2004

A combined 13CO2/H2 breath test can be used to assess starch digestion and fermentation in humans.

Ingestion of starch from corn (naturally enriched with (13)C) should produce (13)CO(2) after small intestinal digestion and (13)CO(2) and H(2) from colonic fermentation. This study used a combined (13)CO(2)/H(2) breath test to assess the digestion and fermentation of resistant starch and to show that the test could detect changes in digestibility due to cooking. Volunteers consumed 40 g digestible cornstarch with water (n = 8), or 40 g resistant cornstarch in liquid (n = 12) or cooked into a pancake (n = 4). Interval breath sampling was performed and analyzed for (13)CO(2) and H(2). Ingestion of resistant starch produced a double-peaked (13)CO(2) excretion curve. The first increase in (13)CO(2) occurred at the same time as excretion from digestible starch (55 +/- 9 and 68 +/- 9 min, respectively), which was due to small intestinal digestion. The second increase in (13)CO(2) was accompanied by an increase in H(2) excretion (432 +/- 15 and 428 +/- 48 min, respectively), which was indicative of colonic bacterial fermentation. Cooking resistant starch increased its degree of digestion from 36 to 72%. The (13)CO(2)/H(2) breath test can be used to estimate digestion and fermentation of starches in different physiologic and pathologic conditions.

Adult↗
PubMed1998

Dietary formulation with meat and bone meal on a total versus a digestible or bioavailable amino acid basis.

The digestibility and bioavailability of amino acids (AA) in meat and bone meals (MBM) may vary greatly due to different processing conditions. In the present study, two experiments were conducted to evaluate formulation of diets containing high or low quality MBM on a total AA basis vs a digestible or bioavailable AA basis compared to a corn-soybean meal control diet. Lysine, methionine, and cystine digestibilities (precision-fed cecectomized rooster assay) were 92, 91, and 71%, respectively, for high quality MBM and were 71, 83, and 31%, respectively, for the low quality MBM. Bioavailability values (slope-ratio chick growth assay) for TSAA in the two MBM were approximately 15 percentage units lower than the digestibility values. Male crossbred chicks were fed a 20% CP corn-SBM diet or corn-SBM diets containing 10 or 20% high or low quality MBM that were formulated to be equal in total, digestible, or bioavailable AA to the corn-SBM diet. All diets contained 3,200 kcal of TMEn/kg, 1.4% Ca, and 0.7% nonphytate P and were fed to chicks from 8 to 22 d posthatching. Growth performance of chicks fed 10 or 20% high or low quality MBM on a total AA basis was lower (P < 0.05) than that of chicks fed the corn-SBM diet. Growth of chicks fed 10% low quality MBM or 10 or 20% high quality MBM on a digestible or bioavailable basis was equivalent to that of chicks fed the corn-SBM diet; however, dietary inclusion of 20% low quality MBM depressed growth (P < 0.05) even on a digestible or bioavailable AA basis. Further supplementation of the latter diet with additional AA yielded growth that was similar to the corn-SBM control diet. The results indicated that formulation of diets containing MBM on a digestible or bioavailable AA basis is superior to formulation on a total AA basis. However, feeding high levels of a low quality MBM may require additional AA supplementation to obtain maximum chick growth.

Amino Acids↗
PubMed2007

Growth performance and ileal and total tract amino acid digestibility in broiler chickens fed diets containing bacterial protein produced on natural gas.

A total of 180 broiler chickens were fed 1 of 3 diets from day-old to slaughter at 35 d: a control diet with 35% soybean meal (SOY) or diets in which either 6% basic bacterial protein meal (BBP) or 6% autolysed bacterial protein meal (AUT) partially replaced soybean meal protein. Ileal and total tract apparent amino acid digestibility were examined in 5 chickens per diet using TiO(2) as an inert marker. Chickens fed the diets with bacterial protein had higher weight gain and feed consumption than control chicks during the first 3 wk, but there were no differences in growth or feed intake during the last 2 wk or during the total experimental period. The birds fed the BBP diet showed more efficient feed conversion compared with chickens fed the SOY and AUT diets. Litter quality at 5 wk was poorer in pens where the chickens were fed the AUT diet compared with the other 2 treatments. There were no differences among diets in the dressing percentage. Ileal amino acid digestibility at 5 wk of age revealed only minor differences between diets. There was a tendency toward lower ileal digestibility (0.12 > P > 0.07) of Arg, Lys, Met, and Phe in the AUT diet compared with the SOY diet, whereas there were no differences between the SOY and BBP diets. Total tract amino acid digestibilities at 5 wk were similar or slightly lower than the ileal digestibilities within diets. Total tract amino acid digestibility at 2 wk was similar to the total tract amino acid digestibility at 5 wk. The diets containing bacterial protein showed lower total tract digestibility of most amino acids compared with the SOY diet. It was concluded that 6% of either basic or autolysed bacterial protein can replace soybean meal in diets for broiler chickens without impairing growth performance, and the basic bacterial protein seemed to be a slightly better substitute than the autolysed bacterial protein.

Amino Acids↗
PubMed1992

Selective decontamination of the digestive tract prevents secondary infection of the abdominal cavity, and endotoxemia and mortality in sterile peritonitis in laboratory rats.

BACKGROUND AND METHODS: This study was undertaken to find out whether translocation of bacteria to the abdominal cavity and endotoxemia in rats with sterile peritonitis could be prevented by selective decontamination of the digestive tract. Sterile peritonitis was caused by the intraperitoneal injection of either 100, 150, 200, or 300 mg of zymosan suspended in paraffin. RESULTS: The frequency of infection of the abdominal cavity depended on the dose of zymosan given, ranging from 20% in rats receiving 100 mg to 89% in rats receiving 300 mg of zymosan. In rats not receiving antibiotics for selective decontamination of the digestive tract (the control group). Gram-negative bacilli were isolated from the digestive tract in all rats, and Gram-negative bacilli were isolated from the abdominal cavity in ten of 19 rats. In rats receiving antibiotics for selective decontamination of the digestive tract, Gram-negative bacilli were isolated from the digestive tract in none of the 14 rats, and likewise, Gram-negative bacilli were isolated from the abdominal cavity in none of the 14 rats (p < .005). Moreover, in rats receiving antibiotics for selective decontamination of the digestive tract, endotoxin levels in feces and plasma were significantly lower, as compared with rats not receiving antibiotics for selective decontamination of the digestive tract. CONCLUSION: Selective decontamination of the digestive tract prevents translocation of Gram-negative bacilli to the abdominal cavity, and endotoxemia and mortality in rats with sterile peritonitis.

Animals↗
PubMed2002

Incidence of digestive cancers and occupational exposure to asbestos.

While the role of exposure to asbestos in the development of several cancers such as mesotheliomas and bronchopulmonary cancers is now well established, the possible relationship between digestive cancers, other than peritoneal mesotheliomas, and occupational exposure to asbestos is still controversial. The great majority of the studies are based on mortality data. The aim of the study was to analyse the relationship between digestive cancer incidence and occupational exposure to asbestos in a population of subjects for whom precise occupational exposure data and precise incidence data were available. The population consisted of salaried and retired workers from a company using asbestos to manufacture fireproof textiles and friction materials. There were 1454 men (79.9%) and 366 women (20.1%). A cumulative exposure index and a mean exposure concentration in fibres/ml for each subject were calculated with the aid of an in-house job-exposure matrix. The number of cases of digestive cancer observed was compared with the expected and Standardized Incidence Ratio (SIR) was estimated. Precise occupational exposure data allowed us to study the dose-response relationship between asbestos exposure and risk of digestive cancer using Cox model. Fifty-six digestive cancers occurred in the study population over the 18-year follow-up period for 48.4 expected (SIR = 1.16 [0.87-1.50]). Comparing with incidence in the county, SIR was not significant for any of the digestive localization, but for peritoneum. However, even after taking into account the potential confounders via the Cox model, there was a significant dose-response relationship between the occurrence of digestive cancers and the mean exposure concentration, even after exclusion of peritoneum cancers. Our study provides initial evidence suggesting a relationship between occupational exposure to asbestos and the risk of digestive cancer: first, it is a study of incidence although the risk evidenced is not significant; secondly, a dose-effect relationship is demonstrated in the whole population. However, these preliminary results require confirmation by more powerful studies focusing on larger series.

Adult↗
PubMed2006

The effect of gastric digestion on food allergy.

PURPOSE OF REVIEW: The role of the stomach as the primary location of protein digestion is very well recognized, leading to classification of proteins as digestion-resistant or digestion-labile. This review analyses the role of gastric digestion in food allergy. RECENT FINDINGS: Hindrance of gastric digestion by elevation of the gastric pH, the therapeutic goal of anti-ulcer medication, was recently shown to trigger food allergy via oral sensitization in a murine food allergy model. The relevance in humans was assessed in an observational study of 152 gastroenterological patients who were medicated with anti-ulcer drugs due to dyspeptic disorders. Twenty-five percent of all patients developed a boost or de-novo IgE formation towards regular constituents of the daily diet. The clinical relevance of the induced antibodies was confirmed by positive skin and oral-provocation tests. Moreover, the importance of gastric digestion was also proven for food-allergic patients, as the allergenicity of allergens were reduced up to a 10,000-fold by gastric digestion. SUMMARY: These recent studies indicate for the first time the important gate-keeping function of gastric digestion, both in the sensitization and the effector phases of food allergy.

Allergens↗
PubMed2004

The influence of calcium intake on phosphorus digestibility in mature ponies.

Literature data show conflicting results on the effect of feeding high calcium (Ca) levels on phosphorus (P) digestibility in ponies. None of the studies reported involved a dose response as to the effect of Ca intake on apparent P digestibility while keeping P intake constant. Thus, the influence of high dietary Ca level on apparent P digestibility was studied in balance trials by feeding six mature ponies three different Ca levels against a constant P intake. The ponies received 148, 316 and 535 mg Ca/kg BW/day with the low, intermediate and high Ca diet. Phosphorus intake was approximately 125 mg P/kg BW and magnesium (Mg) intake was approximately 35 mg Mg/kg BW/day. The intermediate and high Ca level decreased apparent digestibility, renal excretion and retention of P when compared with the low Ca level. However, apparent digestibility and renal excretion of P were not different between the intermediate and high Ca level. The high Ca level resulted in a retention of 66 mg Ca/kg BW/day. The percentage apparent digestibility of Ca was lower for the intermediate and high Ca level compared with the low Ca level. Magnesium digestibility was not affected by high dietary Ca level. In practice, high absolute amounts of Ca should be prevented especially when low amounts of P are fed; P digestibility will be depressed and a negative P balance may occur.

Animal Feed↗
PubMed2004

Kinetic analysis of pepsin digestion of chicken egg white ovomucoid and allergenic potential of pepsin fragments.

BACKGROUND: The allergenic potential of chicken egg white ovomucoid (OVM) is thought to depend on its stability to heat treatment and digestion. Pepsin-digested fragments have been speculated to continue to exert an allergenic potential. OVM was digested in simulated gastric fluid (SGF) to examine the reactivity of the resulting fragments to IgE in sera from allergic patients. METHODS: OVM was digested in SGF and subjected to SDS-PAGE. The detected fragments were then subjected to N-terminal sequencing and liquid chromatography/mass spectrometry/mass spectrometry analysis to confirm the cleavage sites and partial amino acid sequences. The reactivity of the fragments to IgE antibodies in serum samples from patients allergic to egg white was then determined using Western blotting (n=24). RESULTS: The rate of OVM digestion depended on the pepsin/OVM ratio in the SGF. OVM was first cleaved near the end of the first domain, and the resulting fragments were then further digested into smaller fragments. In the Western blot analysis, 93% of the OVM-reactive sera also bound to the 23.5- to 28.5-kDa fragments, and 21% reacted with the smaller 7- and 4.5-kDa fragments. CONCLUSION: When the digestion of OVM in SGF was kinetically analyzed, 21% of the examined patients retained their IgE-binding capacity to the small 4.5-kDa fragment. Patients with a positive reaction to this small peptide fragment were thought to be unlikely to outgrow their egg white allergy. The combination of SGF-digestibility studies and human IgE-binding experiments seems to be useful for the elucidation and diagnosis of the allergenic potential of OVM.

Allergens↗
PubMed1984

Comparative freeze-fracture study of perialgal and digestive vacuoles in Paramecium bursaria.

In the endosymbiotic unit of Paramecium bursaria (Ciliata) and Chlorella sp. (Chlorophyceae) algae are enclosed individually in perialgal vacuoles, which do not show acid phosphatase activity and thus differ from digestive vacuoles. Both types of vacuoles have been studied by freeze-fracture. Perialgal vacuoles are nearly spherical; their membrane always fits tightly to the algal surface. The vacuole size and shape do not vary much. During division of the algal cell into four autospores the vacuole diameter only doubles. After autospore formation the vacuole invaginates around the algal daughter cells and divides. Newly formed perialgal vacuoles remain in intimate contact and exhibit characteristic attachment zones before final separation. The two fracture faces of perialgal vacuole membranes are homogeneously covered with intramembranous particles (IMPs) but rarely show signs of vesicles pinching off or fusing with the membrane, except during vacuole division. The P-faces bear more IMPs (3164 +/- 625 IMP/micron 2) than the E-faces (654 +/- 208 IMP/micron 2). The range of IMP density on both faces is enormous, suggesting that the membrane is not static. Membrane changes are supposed to occur simultaneously with the enlargement of the vacuole and to be caused by fusion with cytoplasmic vesicles, as the fractured necks on vacuole membranes may indicate. Digestive vacuoles in P. bursaria show significant variations in size, shape, membrane topography and IMP density, as well as signs of endocytic activity. Different vacuole populations are present in P. bursaria according to different feeding conditions: ciliates fed for a long time have small vacuoles with few IMPs (322 +/- 198 IMP/micron 2 on the E-faces, 1438 +/- 458 IMP/micron 2 on the P-faces), which are probably condensed digestive vacuoles, whereas organisms fed for a short time have larger vacuoles with highly particulate faces (680 +/- 282 IMP/micron 2 on the E-faces, 2701 +/- 503 IMP/micron 2 on the P-faces) and thus are supposed to be older vacuoles. The digestive vacuole membrane changes continuously. Compared to digestive vacuoles perialgal vacuoles are characterized by small size combined with high IMP density on the two fracture faces. Their IMP densities resemble those of old digestive vacuole membranes. However, it would be premature to conclude that membranes of perialgal and old digestive vacuoles are identical. Membranes of old digestive vacuoles are mainly derived from lysosomal material, which presumably does not contribute to the formation of perialgal vacuole membranes as is indicated by the small vacuole diameter; fusion with lysosomes would considerably enlarge it.(ABSTRACT TRUNCATED AT 400 WORDS)

Chlorella↗
PubMed1984

Effects of fibre on digestibility and passage time in callithricidae.

The effects of fibre in a pelleted diet on food intake, digestibility of crude fibre, dry matter and energy, on passage time and consistency of faeces were studied in 2 species of Callithricidae, Callithrix jacchus and Saguinus fuscicollis. Coarse cellulose, microcellulose, wheat bran and shrimp meal (chitin = crude fibre) were tested in diets containing 2,4 and 6% total crude fibre, respectively. Digestibility and passage time were determined by inclusion of 0.5% Cr2O3 in the diet. Both celluloses had little influence on the digestibility of energy and dry matter. Digestibility of crude fibre was very low. Wheat bran led to evident depression of energy and dry matter digestibility. High digestibility of crude fibre occurred at the higher levels of inclusion in the diet. Shrimp meal was highly digested with little influence on digestibility of energy and dry matter, indicating considerable degradation of chitin. Wheat bran showed a marked effect, while microcellulose had no effect on passage time, consistency and volume of faeces.

Animal Feed↗
PubMed1991

[Study on digestibility and energy availability of daily food intake (Part 4. Shiitake mushroom)].

The digestibilities of nutrients and energy in Shiitke mushrooms (Lentinus edodes) was measured in healthy adult males. A test diet was given for 5 days after 5 days on a basal diet which supplied 40g/day of protein and 45kcal/kg/day of energy. The test diet was identical with the basal diet except that shiitake was incorporated. Digestibility was calculated by the difference of fecal output between the test period and the basal period. The results obtained were follows: 1. Shiitake 60g/day intake level Digestibility of protein was 69.3 +/- 11.2%. Digestibility of fat was 66.6 +/- 24.9%. Digestibility of carbohydrate was 55.7 +/- 10.5%. The ratio of the total available energy to intake energy (Net Energy Availability) was 55.4 +/- 15.4%. 2. Shiitake 40g/day intake level Digestibility of protein was 85.5 +/- 23.8%. Digestibility of fat was 70.0 +/- 90.1%. Digestibility of carbohydrate was 65.8 +/- 13.1%. The ratio of the total available energy to intake energy (Net Energy Availability) was 67.4 +/- 25.9%.

Adult↗
PubMed2005

Dietary preference and digestive enzyme activities as indicators of trophic resource utilization by six species of crab.

The digestive physiology and stomach contents of six crab species from a variety of habitats were investigated to provide an indication of their digestive capability and dietary preferences. Stomach contents varied between species, but the key enzymes present were generally consistent with the types of dietary material being ingested. Nectocarcinus integrifons (red rock crab) consumed large quantities of seagrass and had high cellulase activity (0.02+/-0.004 units mg-1) to digest the constituent cellulose. Petrolisthes elongatus (porcelain crab) ingested brown and green phytoplankton and algae and had considerable laminarinase (0.35+/-0.08 units mg-1) and beta-glucosidase (0.025+/-0.005 units mg-1) activities to digest the laminarin in its diet. Leptograpsus variegatus (omnivorous swift-footed shore crab) had high activities of protease (1.2+/-0.02 units mg-1), alpha-glucosidase, and alpha-amylase and appeared well equipped to utilize both dietary protein and carbohydrate. Stomach contents in Nectocarcinus tuberculosus (velvet crab) and Carcinus maenas (green crab) also suggest that these species are omnivorous. N. tuberculosus had high cellulase and chitinase for digesting the cellulose in plants and the chitin in invertebrate shells respectively. C. maenas had intermediate digestive enzyme levels and may employ more of a generalist feeding strategy than other species. Plagusia chabrus (speedy crab) is carnivorous, consuming encrusting bryozoans, hydroids, crustaceans, and fish. It has high protease activity, particularly trypsin (0.73+/-0.12 units mg-1), to digest the protein in its animal prey. Each species of crab studied had a complex suite of digestive enzymes, the relative activities of which reflected individual and very different species-specific dietary niches.

Animals↗
PubMed2006

In vivo measurement of flatulence and nutrient digestibility in dogs fed poultry by-product meal, conventional soybean meal, and low-oligosaccharide low-phytate soybean meal.

OBJECTIVE: To determine an optimal window for determining peak flatulence and evaluate the effects of oligosaccharides and supplemental beta-mannanase in soybean meal-based diets on nutrient availability and flatulence. ANIMALS: 6 dogs. PROCEDURES: Dogs were used in a 2 x 3 factorial arrangement of treatments in a 6 x 6 Latin square experiment to evaluate the digestibility, flatulence, and fecal odor metabolites of low-oligosaccharide low-phytate soybean meal (LLM), conventional soybean meal (SBM), and poultry by-product (PBP) meal diets with or without supplemental beta-mannanase (5 g/kg). RESULTS: Enzyme supplementation had no effect on total tract dry matter (DM), nitrogen digestibility, or digestible energy; however, differences between protein sources did exist for total tract DM digestibility and digestible energy. The PBP meal had higher DM digestibility and digestible energy (mean, 0.913 and 4,255 cal/g), compared with soy-based diets (mean, 0.870 and 4,049 cal/g). No differences were detected for any treatment regardless of protein source or addition of supplemental enzyme for any flatulence components analyzed. No differences were detected for all fecal odor metabolites regardless of addition of supplemental enzyme; however, differences between protein sources were detected. The PBP meal had lower concentrations of carboxylic acids and esters and higher concentrations of heterocycles, phenols, thio and sulfides, ketones, alcohols, and indoles than LLM and SBM. CONCLUSIONS AND CLINICAL RELEVANCE: Diets containing < 22.4 g of stachyose/kg and < 2 g of raffinose/kg did not alter digestibility or increase flatulence in dogs.

Animal Feed↗
PubMed1990

Intake and digestibility by wethers as influenced by forage morphology at three levels of forage offering.

Animals on pasture do not always have the opportunity for ad libitum consumption. Our objectives were to determine effects of intake level on digestibility of 12 grass hays, and to relate differences in intake and digestibility to proportions of leaf blade, leaf sheath and stem. In each of two periods, 24 wethers were offered one of 12 hays at three consecutive levels of feeding: (L1) ad libitum, allowing 15% refusal; (L2) restricted to 100% of hay consumed ad libitum by individual wether during L1; and (L3) 1.8% of BW on a DM basis. Hays offered included two sorghum-sudan, four barley, four oat and two pearl millet. Hays were similar in NDF concentration but differed in morphological composition Organic matter intake averaged 1.99 +/- .04, 1.79 +/- .04 and 1.52 +/- .01% of BW for L1, L2 and L3, respectively. Organic matter digestibilities averaged 71.8 +/- .55 72.4 +/- .60 and 72.3 +/- .65% for L1, L2 and L3, respectively. Intake SEM within hays were lower with restricted intakes (L3), whereas the opposite was observed for the SEM for digestibility. Forage morphological composition within feeding level influenced intake and digestibility by altering diet selection capabilities of wethers. Wethers did not consume equal NDF amounts, ranging form .95 to 1.47% of BW, because hays differed in morphological composition. Ash-free ADF and 72% sulfuric acid lignin were higher (P less than .01) in stem than in blade or sheath. In vivo digestibilities measured under restricted feeding conditions were related more closely (P less than .05) to in vitro estimates of digestibility than were digestibilities measured under ad libitum conditions (r = .72, .79 and .85 for L1, L2 and L3, respectively). This study demonstrates that variation in morphological characteristics of forages may account for part of the difference in voluntary intake of forages of similar chemical composition. New knowledge in this area will be valuable in developing improved forage quality prediction procedures.

Animal Feed↗
PubMed1991

Effects of feeding alkaline hydrogen peroxide-treated wheat straw-based diets on intake, digestion, ruminal fermentation, and production responses by mid-lactation dairy cows.

The objective of this experiment was to determine the effects of feeding different levels of alkaline hydrogen peroxide-treated wheat straw (AHP-WS) in the diet on feed intake, nutrient digestion, ruminal fermentation, and production responses in mid-lactation dairy cows. Eight Holstein cows, averaging 147 d postpartum, were used in two replications of a 4 x 4 Latin square design. Complete mixed diets consisted of 70% forage and 30% concentrate (DM basis) with various levels of AHP-WS, alfalfa haylage, and corn silage as forage sources. Treatments contained 0 (control), 20.0, 40.1, or 60.0% AHP-WS in the diet. A quadratic effect (P = .08) of AHP-WS level on DMI was noted, with values of 2.16, 22.3, 20.8, and 18.9 kg/d for the control, 20.0, 40.1, and 60.0% AHP-WS treatments, respectively. Apparent digestibilities of DM, OM, CP, and ADF were not affected (P greater than .10) by replacing haylage and corn silage with increasing amounts of AHP-WS in the diet, but there was a linear increase (P = .03) in NDF digestibility (44% for control vs 59% for the 60.0% AHP-WS diet) and a parallel decrease (P less than .05) in cell content digestibility (82 vs 70% for these two diets). Yields of milk and 4% fat-corrected milk (FCM) were decreased (quadratic; P = .0001) as the level of AHP-WS increased in the diet. The addition of AHP-WS to the diet decreased the milk fat percentage from 3.72 to 3.60% (quadratic; P = .05) and decreased milk protein percentage from 3.27 to 3.13% (linear; P = .0001). Cows fed the higher levels of AHP-WS had linear increases (P = .0001) in ruminal concentrations of total VFA (128.0 mM for control vs 136.0 mM for the 60.0% AHP-WS treatment) and molar proportion of acetate, resulting in a quadratic effect (P less than .0001) on the acetate:propionate ratio. These data indicate that feeding the 40.1 and 60.0% AHP-WS diets lowered digestible DM and OM intakes, which resulted in reduced 4% FCM yield as nutrient intakes were decreased compared with cows fed the 20.0% AHP-WS diet or the control diet containing alfalfa haylage and corn silage. Although substituting AHP-WS for haylage and corn silage increased NDF digestibility and tended to increase digestible NDF intake, milk production was depressed because digestible DMI decreased.

Animal Feed↗
PubMed1993

Prediction of digestibility of nutrients and energy values of pig diets from chemical analysis.

The DE and ME values and digestible nutrient contents of 114 diets were measured in 45-kg growing pigs (four to five animals per diet) fed approximately 500 kcal of ME/kg BW.60. Diets differed widely with regard to their chemical characteristics and their ingredients. Chemical composition of each diet was measured by at least four laboratories. The results were used to establish prediction equations of DE or ME values, digestible nutrient contents, and digestibility coefficients of energy and nutrients from chemical characteristics. Digestibility coefficients of energy (range: 65 to 95%) and CP (range: 64 to 94%) were highly dependent on dietary fiber and mineral contents. The digestibility coefficient of ether extract increased curvilinearly (from 2 to 84%) with the dietary fat content. The digestibility of fiber was lower (45% for NDF) than for the other chemical constituents. The ME:DE ratio averaged 96.3% and was negatively correlated to the dietary protein content. The DE and ME values could be accurately predicted (R2 > .90 and CV < 2%) from chemical characteristics; the best equations were obtained when the following predictors were combined in a linear model: ash, ether extract, crude protein, and an estimate of dietary fiber. The accuracy of the prediction was higher with NDF than with ADF or Weende crude fiber. The results suggest that even a rather large proportion of dietary fiber (approximately 50%) is degraded in the digestive tract, the amount of available energy from fiber digestion is negligible in connection with increased endogenous protein and fat losses. The equations obtained in the present study represent a basis for the prediction of the energy values of mixed diets with a composition of unknown ingredients.

Animal Feed↗
PubMed1994

Determination of apparent ileal amino acid digestibility in pigs: effect of dietary amino acid level.

Studies were carried out to investigate the effect of dietary amino acid level on apparent ileal amino acid digestibility. Six barrows, average initial BW 35 kg, were fitted with a simple T-cannula at the distal ileum and fed six diets according to a 6 x 6 Latin square design. Six cornstarch-based diets containing six levels of CP from SBM (4, 8, 12, 16, 20, and 24% CP, respectively) were formulated. Chronic oxide was included as a digestibility marker. Each experimental period consisted of 8 d. After a 6-d adaptation period, ileal digesta were collected for 24 h during d 7 and 9 at 2-h intervals. The pigs were fed twice daily, equal amounts, at 0800 and 2000. The dietary allowance was 1,600 g/d during the first period and increased by 100 g each following period. There was a quadratic increase (P < .05) in apparent ileal amino acid digestibility as the dietary CP content was increased from 4 to 24%. Initially, the apparent ileal amino acid digestibilities increased sharply then gradually reached their plateaus, after which there were no further increases and the digestibility values became independent of the dietary amino acid levels. The lower end points of 95% confidence intervals of the plateau ileal digestibility values were defined to be the initial plateau digestibilities. The dietary CP and amino acid contents, corresponding to the initial plateau digestibility values, represent the dietary threshold levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗