Ileal Digestibility Coefficients Research Articles

Nutritive value of plantain and chicory for pigs

Many feedstuffs used in pig diets are in direct competition with human food, the overall objective of the research is look at alternative ingredients, such as forages. The first step in feed evaluation is to determine the nutritive value of a potential ingredient. In the present study the effects of chicory (Cichorium intybus L.) and plantain (Plantago lanceolata L.) on (1) total tract energy digestibility, (2) ileal amino acid digestibility, and (3) morphology of distal ileum were investigated. Fifteen intact male pigs were blocked according to initial body weight (23 ± 2.89 kg) and allocated to three different diets: a wheat-based basal diet (basal diet), and two diets with inclusion of 250 g/kg chicory (chicory diet) or plantain (plantain diet). The experiment was conducted over a 10 day period, with 3–4 days of acclimatisation, followed by 5 days of adaptation and 5 days of faecal collection. Inclusion of chicory in the diet reduced the apparent ileal digestibility coefficient (AIDC) of crude protein (CP) and indispensable AA, including methionine + cysteine, threonine and tryptophan (P < 0.05); whereas, only the values of AIDC for CP and tryptophan were decreased by plantain inclusion (P < 0.05). The apparent total tract digestibility coefficient (ATTDC) of chicory and plantain diets were reduced for dry matter (DM), CP, starch, and energy (P < 0.05). A greater ATTDC for cellulose was observed in pigs fed chicory diet (P < 0.05). However, no difference in ATTDC for hemicellulose and lignin were observed (P > 0.05). Growth performance did not alter from inclusion of chicory and plantain after 10 days of feeding (P > 0.05). However, pigs fed the plantain diet had narrower distal ileum mucosal villus width (P = 0.02). Overall results show that inclusion of chicory and plantain forages at 250 g/kg in grower diets had a negative impact on digestibility of some nutrients, but had no impact on overall animal performance. To obtain a better understanding of the potential effects of chicory and plantain, adjustments in nutrient concentration and long-term on-farm experiments need to be performed.

Metabolizable energy and amino acid digestibility of soybean cake subjected to different dry extrusion temperatures for broilers

ABSTRACT Two experiments were conducted to evaluate the apparent metabolizable energy (AME), nitrogen-corrected apparent metabolizable energy (AMEn), and standardized ileal amino acid digestibility coefficient (SIDC) of extruded soybean cake (ESC) at four different extrusion temperatures: 90, 100, 110, and 120 °C. In experiment 1, 300 male broilers were randomly distributed into four treatments (600 g kg−1 reference diet + 400 g kg−1 of SBC at different extrusion temperatures) + reference diet, with six replicates of 10 birds. A metabolic assay [...]

Bacillus subtilis in broiler diets with different levels of energy and protein.

The present study evaluated the impacts of Bacillus subtilis (BAS) inclusion in broiler diets with standard nutrient content or nutrient deficiency (ND) on growth performance (GP) and nutrient digestibility. The 42 d experiment consisted of 6 experimental diets, a diet with standard nutrient content, and 2 diets with different levels of energy and protein deficiency, without or with BAS. At the end of experiment, apparent ileal digestibility coefficients (AIDC) of starch, crude protein (CP), and gross energy (GE) were determined. Furthermore, impacts of BAS supplementation in standard diets on gut histomorphology, bacterial metabolic activity, and composition were evaluated. Performance and AIDC data were subjected to ANOVA using GLM procedure with a 3 (nutrient levels) × 2 (BAS presence/absences) factorial arrangement of treatments. Gut histomorphology and microbiology data, obtained from broilers fed standard diets without (S) and with BAS (SB), were assessed by an independent Student's t-test. The ND in diets was effective enough to cause nutritional stress and negatively affect performance. Inclusion of BAS in both types of diet improved GP, which was due to the fact that adding BAS in these diets led to improvements in AIDC of CP, starch, and GE (P ≤ 0.05). Comparing only 2 experimental groups, S and SB, revealed no impact on bacterial composition and metabolism in the ileum and cecum, except a reduction in ileal lactobacilli number for SB group. Adding BAS to standard diet reduced crypt depth (CD) and increased villus length to CD ratio in the duodenum, whereas it had no impact on other histomorphological variables in the duodenum, jejunum, and ileum. In conclusion, supplementation of broiler diets with probiotic BAS can positively affect growth performance and nutrient digestibility and this positive impact might even be more pronounced in nutrient-deficient diets. However, the extent of the alleviating ability of BAS in nutrient-deficient diets as well as the biological mechanisms for such a phenomenon needs to be studied further.

Ileal digestibility of calcium and phosphorus in broilers fed diets with different phytases and Ca:available P ratios

Abstract: The objective of this work was to determine the apparent ileal digestibility of calcium and phosphorus in broilers fed diets with different phytases and calcium:available phosphorus (Ca:aP) ratios. Two experiments were carried out: one with broilers with 22 to 33 days of age, and the other with broilers with 35 to 42 days. The Ca:aP ratios used were 4.5:1.0, 6.0:1.0, and 7.5:1.0 in the first period, and 3.5:1.0, 5.0:1.0, and 6.5:1.0 in the second. All diets were supplemented with 1,500 units of phytase activity per kilogram of six different sources of microbial phytase. At the end of each experiment, two broilers per replicate were slaughtered to collect the ileal content. In the samples of digested food, the Ca and P contents were determined for later calculation of the apparent ileal digestibility coefficients of these minerals. The Ca:aP ratio influenced the activity of phytases, and the highest digestibility was observed with lower ratios, in both experiments. The phytases that provided greater digestibility coefficients were A, D, and E. In both ages evaluated, the inclusion of phytases in the feed improved the digestibility of Ca and P, which was also affected by the content of calcium and by the phytase source used.

Apparent metabolisable energy and amino acid digestibility of microalgae Spirulina platensis as an ingredient in broiler chicken diets

ABSTRACT1. This work investigates the apparent metabolisable energy (AME), its nitrogen-corrected form (AMEn) and amino acid (AA) digestibility coefficients of the microalgae Spirulina platensis as an ingredient in broiler chicken diets.2. One group of birds was fed with a basal control diet (BD), and another was fed with a test diet composed of the BD with the addition of the microalgae at a proportion of 200 g/kg. AME and AMEn were assessed by total excreta collection and indigestibility analysis using acid-insoluble ash (AIA) as a marker.3. The microalgae comprised 888.0 g/kg dry matter (DM), 18.42 MJ/kg gross energy, 514.7 g/kg crude protein, 9.9 g/kg ether extract, 10.6 g/kg crude fibre, 94.4 g/kg ash, 3.1 g/kg Ca and 11.0 g/kg P.4. The values obtained for AME (13.48 MJ/kg DM) and AMEn (11.72 MJ/kg DM) were higher (p < 0.01) than those obtained using the AIA method (9.39–8.29 MJ/kg DM). The microalgae ileal digestibility coefficients were 0.80 ± 0.04 and 0.78 ± 0.04 for essential and non-essential AA, respectively.5. Overall, the metabolisable energy content and digestibility of AA for S. platensis indicated that the microalgae are potentially an alternative nutrient source for broilers. The AIA method underestimated AME and AMEn in comparison to the total excreta collection method.

High levels of dietary phytase improves broiler performance

The objective of this study was to evaluate the effects of dietary phytase on broilers from 1 to 42 days of age. Five treatments were distributed in a completely randomized design, with eight replicates of 23 birds per experimental unit (per averages). The treatments consisted of a positive control diet (PC), a negative control diet (NC); and the NC diet + 1000, 2000 and 3000 FYT kg−1 phytase. The effects of dietary treatments on performance, bone quality and blood minerals were determined. From 1 to 21 days of age, WG, FI and FCR increased with increasing levels of phytase (P < 0.05), and from 1 to 42 days, body weight peaked with 2000 FTY kg−1 (P < 0.05). The best results for WG, FI and FCRC were obtained using 2051, 1992 and 2101 FTY kg−1, respectively. At 42 days of age, the Seedor Index (SI) and bone-dry matter (DM) were maximized at lower levels of phytase than for WG or FCR. The highest SI and DM values were obtained with 1553 and 1765 FTY kg−1, respectively. At 21 days of age, blood Ca content decreased with increasing phytase levels. Blood P exhibited quadratic behavior, with the maximum recorded at 1680 FYT kg−1 phytase. Tibia Ca increased with increasing phytase at 21 days of age (P < 0.05). Blood P at 42 days of age was lower than at 21 days, but did not vary between treatments. The apparent ileal digestibility coefficients of dry matter, mineral matter, crude protein and crude energy showed quadratic responses, with the highest coefficients obtained for the inclusion of 1164, 1592, 1085 and 1342 FYT kg−1 phytase, respectively. It is concluded that phytase improves broiler performance based on regression analyses. A high dose of 2973 FYT kg−1 had the best weight gain from 1 to 21 days of age. From 21 to 42 days, 2051 FYT kg−1 and 2101 FYT kg−1 showed the best weight gain and feed conversion ratio, respectively. These recommendations did not negatively affect the parameters evaluated.

Amino acid digestibility of larval meal (Musca domestica) for broiler chickens

Work was undertaken to investigate the potential use of housefly (Musca domestica) larvae reared on broiler manure as a source of nutrition for poultry production in the United Kingdom. Nutritional analysis showed that larvae have a high (>45% dry wt.) protein content and a favorable amino acid profile that is rich in key amino acids, such as lysine and methionine. A broiler digestibility trial was carried out to determine the apparent ileal digestibility coefficients (AIDC) and true ileal digestibility coefficients (TIDC) of amino acids (AA) from insect larval meal (ILM) from M. domestica and fishmeal (FM) in broiler chickens. This was calculated using multiple linear regression technique based upon 3 inclusions of each protein source in a semisynthetic diet. One-hundred-forty-four day-old male (Ross 308) broilers were fed from hatch on a commercial starter diet for 20 days. Experimental diets were fed from d 21 to 28, and feed intakes were measured daily. On d 28, the trial was terminated, ileal digesta were collected for the determination of AIDC and TIDC of AA, and inflammatory responses (gizzard erosion and eye discharge) were measured. No significant differences were observed in digestibilities between protein sources for any AA. Furthermore, ILM feeding did not induce gizzard erosion or eye discharge at any inclusion. These results provide strong evidence to suggest that ILM of the common housefly can provide a successful alternative protein source to FM in broiler diets.

Responses in digestibilities of macro-minerals, trace minerals and amino acids generated by exogenous phytase and xylanase in canola meal diets offered to broiler chickens

Atypical diets based on canola meal (584 g/kg) and dextrose, supplemented with phytase and xylanase individually and in combination, were offered to 120 male Ross 308 broiler chicks with six replicates for each of the four treatments. The objective was to determine the effects of phytase and xylanase on the apparent digestibility coefficients of macro-minerals, trace minerals and amino acids along the small intestine of broiler chickens. The combination increased phosphorus digestibility by a two-fold factor (0.694 versus 0.324), calcium digestibility by a three-fold factor (0.527 versus 0.178), increased zinc from -0.141 to 0.324 and increased sodium digestibility coefficients from -1.402 to -0.359 in comparison to the control diet. Similarly, phytase and xylanase in tandem generated better responses in the apparent ileal digestibility coefficients of amino acids. The enzyme combination significantly increased the digestibility of nine essential amino acids by from 5.47% (methionine) to 35.4% (threonine), and seven non-essential amino acids by from 13.9% (glutamic acid) to 32.9% (proline). The better responses in apparent ileal digestibilities of phosphorus, calcium, sodium, zinc and five other trace minerals in broiler chickens offered the combination diet was confounded by its higher enzyme recovery activities in comparison to the individual supplemented diets and the study may suggest that the inclusions of phytase and xylanase in tandem should be considered in diets containing canola meal for broiler chickens.

Impacts of age and calcium on Phytase efficacy in broiler chickens

A total of 648 straight-run hatchling Heritage 56M × fast feathering Cobb 500F broiler birds were used to determine the effects of Ca concentration and age on phytase efficacy. Corn and SBM based diets with 0.19% non-phytate P were prepared with three Ca (6.5, 8.0 and 9.5 g/kg) concentrations. A 6-phytase55Danisco Animal Nutrition, DuPont Industrial Biosciences, Marlborough, UK was added on-top at 0, 500 or 1000 FTU/kg at each Ca concentration, resulting in a total of 9 treatments. Broiler birds were fed the diets for 2 d either from 7 to 9 (6 birds/replicate) or 19 to 21 (3 birds/replicate) d of age, and ileal content was collected from every bird at the end of each feeding period to determine apparent ileal digestibility coefficient (AID). Age effect was determined by comparing responses between birds fed from 7 to 9 and 19 to 21 d of age. There was no interaction between Ca and phytase on AID P regardless of age. Increasing Ca from 6.5 to 9.5 g/kg resulted in 12 (0.58 vs. 0.51) and 11% (0.64 vs. 0.57) reduction in AID P, in 9-d-old and 21-d-old birds, respectively (P < .05). Compared to birds fed diets without phytase, AID P was 100 and 155% greater in 9 d old birds fed 500 and 1000 FTU phytase/kg diets, respectively (P < .05). Similar but lesser improvement in AID P was also seen in 21 d old birds, with 63 and 76% improvement as a result of 500 and 1000 FTU/kg phytase inclusion, respectively (P < .05). Despite similar pattern in response to Ca and phytase, the degree of dietary impact and efficacy of phytase was affected by age of birds. In the absence of phytase, detrimental effect of Ca was more apparent in 9 d old than 21 d old bird, where greater difference in AID P was seen when Ca increased from 6.5 to 9.5 g/kg. With phytase inclusion, differences in AID P between 9 and 21 d old birds were reduced, which was more apparent with higher phytase and Ca inclusion. Net improvement of digestible P for 500 and 1000 FTU phytase/kg was 1.55 and 2.42, 1.45 and 1.72 g/kg, respectively for 9 and 21 d old birds. It is clearly shown that, even though birds at different ages responded to Ca and phytase similarly, the detrimental impact of Ca and benefit of phytase inclusion was greater in younger than older birds.

Dietary starch influences growth performance, nutrient utilisation and digestive dynamics of protein and amino acids in broiler chickens offered low-protein diets

A total of 288 day-old, male Ross 308 chicks were offered six dietary treatments from 7 to 28 days post-hatch. A standard maize-soy diet was compared with five low protein diets containing high inclusions of maize starch and various combinations of supplemental amino acids. The assessed parameters included growth performance, nutrient utilisation, digestibility coefficients and disappearance rates of starch, protein and amino acids in four small intestinal segments. Also, the effects of three dietary treatments on free plasma amino acid concentrations in the anterior mesenteric vein or portal circulation were determined. The transition from standard to low protein diets elevated feed intakes and compromised FCR. Overall, tangible differences in responses were not observed in birds offered the five low protein diets which effectively precluded meaningful comparisons between the various combinations of crystalline amino acids. Maize starch inclusions in low protein diets enhanced starch digestibility coefficients and disappearance rates and parameters of nutrient utilisation. However, maize starch also depressed protein digestibility coefficients and disappearance rates. Moreover, amino acid digestibility coefficients were depressed in the three posterior segments of the small intestine. Instructively, proximal ileal starch digestibility coefficients were negatively correlated with digestibility coefficients of twelve amino acids in the proximal ileum to significant extents. Significant differences in concentrations of free amino acids in plasma from the anterior mesenteric vein were observed for histidine, lysine, methionine, threonine and valine in birds offered the standard and two low protein diets. The possibility that glucose and amino acids were effectively competing for intestinal uptakes, especially from the ileum, is discussed. Also, it appears that the metabolic fates of amino acids in enterocytes of the gut mucosa can be manipulated by dietary strategies and that crystalline amino acids may be less prone to undergo catabolism in the gut mucosa.

Metabolizable energy and amino acid digestibility of mash and pelleted diets for broilers determined under different methodologies

The objective of this study was to determine the interaction between feed processing and different methodologies for assessing apparent metabolizable energy corrected by nitrogen (AMEn) and standardized ileal digestibility coefficients (SIDC) of amino acids (AA) in broiler diets. A completely randomized design in a 4×2 factorial was used to evaluate AMEn by four methodologies and two physical forms of diet (mash and pelleted). The methodologies were total excreta collection and use of the markers: acid insoluble ash (AIA), titanium dioxide (TiO2) and chromium oxide (Cr2O3). After 5days of total excreta collection, all the birds were slaughtered and ileal content was assessed for AA. There was significant interaction (P<0.05) between the methodologies and physical form of the diets on AMEn values. Regardless of the physical form of the diet, the AIA marker provided similar AMEn values for total excreta collection on a DM basis. Pelleted diets had higher values (P<0.05) of AMEn (MJ/kg) on DM, except for Cr2O3. For AA, there was no interaction (P>0.05) between the markers and the physical form of the diets. There was no difference in SIDC between mash and pelleted diets (P>0.05). The AIA marker provided a higher SIDC compared to the TiO2 and Cr2O3 markers, except as regards methionine and lysine. Overall, pelleting increases dietary AMEn, but does not affect amino acid digestibility. Total collection and AIA lead to similar AMEn values, and AIA provides higher SIDC of the amino acids.

Standardized ileal digestibility of amino acids in European soya bean and rapeseed products fed to growing pigs.

This study was conducted to determine the chemical composition and standardized ileal digestibility coefficients (SID) of crude protein (CP) and amino acids (AA) of European soya bean and rapeseed products in pigs. Six soya bean and two rapeseed products were used as the sole dietary source of CP and AA, including raw (FFSB) and roasted full-fat soya beans (FFSBRoasted ), soya bean (SBC) and rapeseed cake (RSC), and rapeseed meal (RSM) from Bavaria (Germany), soya bean meal (SBM) from the Danube region (Austria; SBMAustria ), a commercially available standard SBM (SBMStd ) and an imported genetically modified organism-free SBM (SBMGMO-free ). Eight ileal- cannulated pigs with an initial body weight of 32±2kg were allotted to a row-column design with eight diets and six periods of seven days each. Trypsin inhibitor activity (TIA) ranged from 1.8 in SBMStd to 24.5mg/g DM in FFSB. The SID of CP and all AA in FFSBRoasted were greater than in FFSB, but lower when compared to SBC and SBMAustria (p<.05). The SID of CP and all AA (except glutamic acid) were not different between SBC and SBMAustria , but the SID of CP and all AA (except methionine) were greater (p<.05) in SBC than in SBMGMO-free . Furthermore, the SID of CP and most AA showed a quadratic response with decreasing TIA, and there exists a quadratic response in SID of CP and all AA with increasing lysine to CP ratio and neutral detergent insoluble nitrogen (p<.05). In conclusion, variation in chemical composition and SID of CP and AA was observed in different European soya bean and rapeseed products as influenced by differences in processing conditions. European SBC and SBMAustria can be used as alternative to imported SBMGMO-free and SBMStd in diets for growing pigs.

Effects of processing, particle size and moisturizing of sorghum-based feeds on pellet quality and broiler production.

ObjectiveThis study aimed to assess the effect of pelleted and expanded sorghum-based feeds prepared with different moisture levels and particle size of ingredients on metabolizable energy, ileal digestibility of amino acids and broiler performance.MethodsThe experiment was performed with 720 male broiler chicks of the Cobb strain, with treatments of six replications, with 15 birds each; they were arranged in a completely randomized design and 2×2×2 factorial scheme (pelleted or expanded feed processing, 0.8% or 1.6% moisture addition in the mixer, and particle size of 650 or 850 microns).ResultsHigher pellet quality (pellets, % and pellet durability index [PDI]) was obtained in expanded diets and inclusion of 1.6% moisture. The particle size of 850 microns increased the PDI of final diet. All studied treatments had no significant effect on weight gain and broiler carcass and cut yields. Lower feed conversion occurred for birds fed pelleted feed at 42 d. The highest apparent metabolizable energy (AME) and apparent metabolizable energy corrected to zero nitrogen balance (AMEn) values of feed in the initial rearing phase (10 to 13 days) were observed in birds fed pelleted feed or for feed prepared with 1.6% moisture. The highest ileal digestibility coefficients of amino acids were obtained with the consumption of pelleted feed prepared with a particle size of 650 microns and 1.6% moisture.ConclusionPelleted feed prepared with a milling particle size of 650 microns and 1.6% moisture provided increased ileal digestibility of amino acids and AMEn in the starter period. However, the expanded feed improved pellet quality and feed conversion of broilers at 42 days of age. We conclude that factors such as moisture, particle size and processing affect the pellet quality, and therefore should be considered when attempting to optimize broiler performance.

Concentration of metabolizable energy and digestibility of amino acids in Chinese produced dehulled double-low rapeseed expellers and non-dehulled double-low rapeseed co-products fed to growing-finishing pigs

Two experiments were conducted to determine and compare the digestible energy (DE), metabolizable energy (ME) and the coefficients of standardized ileal digestibility (CSID) of crude protein (CP) and amino acids (AA) in two sources of dehulled rapeseed expellers (RSE-DH1 and RSE-DH2), conventional rapeseed expellers (RSE-CV), cold-pressed rapeseed expellers (RSE-CP) and rapeseed meal (RSM) produced by Chinese double-low rapeseed fed to growing-finishing pigs. In experiment 1, 36 growing pigs [initial body weight (BW): 37.7±4.8kg] were randomly allotted to one of six diets (n=6) including a corn-soybean meal basal diet and five rapeseed co-product test diets. The test diets contained 194.8g/kg each of the five double-low rapeseed co-products added at the expense of corn and soybean meal in the basal diet. In experiment 2, six growing barrows (initial BW: 69.4±4.4kg) fitted with a T-cannula in the distal ileum were allotted to a 6×6 Latin square design with 6 periods and 6 diets. Diets included one N-free diet and five test diets which contained 400g/kg RSE or RSM as the only source of CP and AA. On an as fed basis, dehulled RSE samples (RSE-DH1 and RSE-DH2) contained the lowest neutral detergent fiber and acid detergent fiber among rapeseed co-product samples. Dehulled RSE samples had greater lysine concentration than non-dehulled RSE and RSM. The coefficient of apparent total tract ileal digestibility (CATTD) of gross energy (GE) in RSE-DH1 (0.822) was greater (P<0.05) than that in RSE-CV (0.700) and RSM (0.655), but the CATTD of GE did not differ among RSE-DH1, RSE-DH2 (0.782) and RSE-CP (0.722). On an as-fed basis, the ME value was greater (P<0.05) in dehulled RSE (14.5MJ/kg) than RSE-CV (12.2MJ/kg) and RSM (10.4MJ/kg). The RSE-DH1 (9.72MJ/kg) and RSE-DH2 (9.33MJ/kg) contained greater (P<0.05) calculated net energy value than RSE-CP (8.03MJ/kg), RSE-CV (7.84MJ/kg) and RSM (5.66MJ/kg). With the exception of phenylalanine and valine, the CSID of CP and all AA in dehulled RSE was greater (P<0.05) than that in RSE-CV and RSM. The CSID of CP and most of AA in RSE-DH1 was greater (P<0.05) than that in RSE-CP. In conclusion, compared with non-dehulled rapeseed co-products, dehulled double-low rapeseed expellers may be a better energy and protein source for pigs considering its greater ME value and CSID of AA.

Potential impact of the digestible indispensable amino acid score as a measure of protein quality on dietary regulations and health.

Regulatory frameworks for protein content claims in Canada and the United States are underpinned by the protein efficiency ratio and protein digestibility-corrected amino acid score (PDCAAS), respectively, which are used to assess the protein quality of a given food. The digestible indispensable amino acid score (DIAAS) is a novel approach to measuring the protein quality of foods and is supported by the Food and Agriculture Organization of the United Nations. Methodological concerns about the PDCAAS are addressed by the DIAAS through introduction of the use of ileal amino acid digestibility coefficients and untruncated protein scores. However, before the DIAAS is widely adopted within regulatory frameworks, a comprehensive assessment is required. Accordingly, this review addresses the potential impact of the DIAAS on regulation, communication, and public health, as well as knowledge gaps, analytical challenges, and cost of implementation. A pragmatic approach to addressing protein quality is advocated by suggesting the use of conservative coefficients of digestibility that are derived from in vitro methods. Before adopting the DIAAS as a framework for supporting protein content claims, updated food-related regulations and policies should also be evaluated through a lens that anticipates the impact on consumer-facing nutrition communication, the adoption of dietary patterns that are nutritionally adequate, and a food value chain that fosters a spirit of food and nutritional innovation.

Effect of inert fillers with changing energy-protein ratio on growth performance and energy digestibility in broilers

The purpose of this study was to examine the effects of using sand or diatomaceous earth (DIAE) as an inert filler while changing the energy-to-protein ratio in broilers, and therefore to evaluate if doing either will confound the results in energy enzyme efficacy studies by reducing the difference observed between the standard and low energy control diets. The dietary treatments consisted of one control treatment (3,050 ME kcal/kg, 220 CP g/kg) and a 2 × 2 factorial arrangements with 2 energy-to-protein levels (2,850 ME kcal/kg, 205 CP g/kg or 2,850 ME kcal/kg, 220 CP g/kg) and 2 inert fillers (sand or DIAE), each with 9 replicates. Each replicate pen included 5 straight-run broilers fed for a period of 21 d with weekly pen BW and feed intake measured. Ileal contents were collected on d 21 for ileal digestible energy (IDE), with 0.2% titanium dioxide as an indigestible marker. According to the main effect for inert filler, BW was significantly lower (P < 0.05) in treatments with reduced energy on d 21. Compared with the control group, no differences were observed among the reduced energy treatments for FCR and productivity index. Both IDE and ileal energy digestibility coefficient (IEDC) were decreased in the treatments formulated with reduced energy. Among reduced energy treatments, diets containing sand had significantly higher IDE and IEDC than the ones with DIAE. This study confirms that reduced dietary energy negatively influences broiler performance. Adding sand as the inert filler had an independently beneficial effect, and therefore DIAE may be a more appropriate source of inert filler to replace fat in a diet with a disrupted energy-to-protein ratio, which is the typical methodology in energy enzyme efficacy studies.

Nutritional value of a partially defatted and a highly defatted black soldier fly larvae (Hermetia illucens L.) meal for broiler chickens: apparent nutrient digestibility, apparent metabolizable energy and apparent ileal amino acid digestibility

BackgroundThe study aimed to determine the apparent total tract digestibility coefficients (ATTDC) of nutrients, the apparent metabolizable energy (AME and AMEn) and the amino acid (AA) apparent ileal digestibility coefficients (AIDC) of a partially defatted (BSFp) and a highly defatted (BSFh) black soldier fly larvae meal. The experimental diets were: a basal diet and two diets prepared by substituting 250 g/kg (w/w) of the basal diet with BSFp or BSFh, respectively.ResultsSignificant differences were found between BSFp and BSFh meals for ATTDC of the nutrients: BSFp resulted more digestible than BSFh, except for ATTDC of CP which did not differed between meals, while a statistical trend was observed for ATTDC of DM and EE. The AME and AMEn values were significantly (P < 0.05) different between the two BSF meals, with higher levels for BSFp (16.25 and 14.87 MJ/kg DM, respectively). The AIDC of the AA in BSFp ranged from 0.44 to 0.92, while in BSFh they ranged from 0.45 to 0.99. No significant differences were observed for the AA digestibility (0.77 and 0.80 for BSFp and BSFh, respectively), except for glutamic acid, proline and serine that were more digestible in the BSFh meal (P < 0.05).ConclusionsDefatted BSF meals can be considered as an excellent source of AME and digestible AA for broilers with a better efficient nutrient digestion. These considerations suggested the effective utilization of defatted BSF larvae meal in poultry feed formulation.

Assessing the effect of dietary inulin supplementation on gastrointestinal fermentation, digestibility and growth in pigs: A meta-analysis

Inulin has been reported to improve the homeostasis in the gastrointestinal tract (GIT) of pigs by modulating the intestinal microbiota and fermentation. The present study aimed to quantify the relationship between dietary inulin and microbial response variables in digesta from the GIT and feces of weaned, growing and finishing pigs using a meta-analytical approach. We further examined the effect of dietary inulin on the coefficients of ileal (CIAD) and total tract apparent digestibility (CTTAD) of nutrients and ADG. Pig’s starting body weight was considered the main inclusion criterion. Missing information about explanatory variables and few values available for response variables reduced the number of studies included. From the 33 included articles published between 2000 and 2016, individual sub-datasets for fermentation metabolites, bacterial abundances, CIAD, CTTAD and performance were built. Prediction models on the effect on inulin were computed accounting for inter- and intra-study variability. Dietary inulin levels ranged from 0.1 to 25.8%, whereby the median and mean inulin levels were 0.1–2% and 3–4%, respectively. Few of the investigated fermentation response variables were influenced by dietary inulin. Strong negative relationships were found between dietary inulin and gastric pH in weaned pigs (R2=0.81; P<0.001; n=12), colonic enterobacteria (R2=0.50; P<0.001; n=19) and fecal lactobacilli (R2=0.41; P<0.001; n=26) throughout all production phases, whereas observed negative relationships between inulin and colonic bifidobacteria and fecal enterobacteria and Escherichia coli were of minor physiological relevance (P<0.05). Moreover, increasing inulin levels negatively correlated with the CTTAD of crude protein (R2=0.83; P<0.001; n=15), but they did not influence average daily gain of pigs. Best-fit models indicated that dietary crude protein amplified the effect of inulin on CTTAD of crude protein and gastric pH, but counteracted the inulin effect on fecal E. coli (P<0.05). Accordingly, both pig’s body weight and inulin decreased gastric pH and fecal lactobacilli but counteracted the inulin effect on colonic bifidobacteria and fecal E. coli (P<0.05). In conclusion, this study supported a stimulatory effect of dietary inulin on gastric acid secretion, which may be favorable GIT health in weaned pigs. However, due to limiting information provided in the original studies, like dietary fructans or fibers, low numbers of observation and low inulin levels, relationships should be regarded as trends.

P and Ca digestibility is increased in broiler diets supplemented with the high-phytase HIGHPHY wheat

Around 70% of total seed phosphorus is represented by phytate which must be hydrolysed to be bioavailable in non-ruminant diets. The limited endogenous phytase activity in non-ruminant animals make it common practice to add an exogenous phytase source to most poultry and pig feeds. The mature grain phytase activity (MGPA) of cereal seeds provides a route for the seeds themselves to contribute to phytate digestion, but MGPA varies considerably between species and most varieties in current use make negligible contributions. Currently, all phytases used for feed supplementation and transgenic improvement of MGPA are derived from microbial enzymes belonging to the group of histidine acid phosphatases (HAP). Cereals contain HAP phytases, but the bulk of MGPA can be attributed to phytases belonging to a completely different group of phosphatases, the purple acid phosphatases (PAPhy). In recent years, increased MGPAs were achieved in cisgenic barley holding extra copies of barley PAPhy and in the wheat HIGHPHY mutant, where MGPA was increased to ~6200 FTU/kg. In the present study, the effect of replacing 33%, 66% and 100% of a standard wheat with HIGHPHY wheat was compared with a control diet with and without 500 FTU of supplemental phytase. Diets were compared by evaluating broiler performance, ileal Ca and P digestibility and tibia development, using nine replicate pens of four birds per diet over 3 weeks from hatch. There were no differences between treatments in any tibia or bird performance parameters, indicating the control diet did not contain sufficiently low levels of phosphorus to distinguish effect of phytase addition. However, in a comparison of the two wheats, the ileal Ca and P digestibility coefficients for the 100% HIGHPHY wheat diets are 22.9% and 35.6% higher, respectively, than for the control diet, indicating the wheat PAPhy is functional in the broiler digestive tract. Furthermore, 33% HIGHPHY replacement of conventional wheat, significantly improved Ca and P digestibility over the diet-supplemented exogenous phytase, probably due to the higher phytase activity in the HIGHPHY diet (1804 v. 1150 FTU). Full replacement by HIGHPHY gave 14.6% and 22.8% higher ileal digestibility coefficients for Ca and P, respectively, than for feed supplemented with exogenous HAP phytase at 500 FTU. This indicates that in planta wheat PAPhys has promising potential for improving P and mineral digestibility in animal feed.

Effect of calcium source and particle size on the true ileal digestibility and total tract retention of calcium in broiler chickens

The influence of calcium (Ca) source and particle size on true ileal digestibility coefficient (TIDC) of Ca and apparent total tract retention coefficient (ATTRC) of Ca in broilers was assessed. Four experimental diets containing limestone and oyster shell, each as fine (<0.5mm) and coarse (1–2mm) particles, were fed to broiler chickens from 21 to 24days of age. A Ca- and phosphorus-free diet was used to determine the ileal endogenous Ca losses. Limestone and oyster shell were obtained from commercial sources and ground to pass through a set of sieves to obtain the fine and coarse particles. Titanium dioxide was incorporated in all diets as an indigestible marker. Each experimental diet was randomly allotted to six replicate cages (eight birds per cage). Apparent ileal digestibility coefficient and ATTRC of Ca were calculated using the indicator method and the TIDC values were calculated by correcting for endogenous Ca losses. Ileal endogenous Ca losses were determined to be 115mg/kg of dry matter intake. The main effect of Ca source and the interaction between Ca source and particle size were not significant (P>0.05) for the TIDC and ATTRC of Ca. Both TIDC and ATTRC of Ca were influenced (P<0.05) by particle size, with coarser particles increasing the digestibility and retention values. Increased particle size increased the TIDC of Ca in limestone from 0.38 to 0.62 and that of oyster shell from 0.33 to 0.56. The corresponding increases in ATTRC of Ca were from 0.44 to 0.66 in limestone and from 0.40 to 0.60 in oyster shell. Calcium concentration in the gizzard contents of birds was higher (P<0.05) for limestone as compared to oyster shell and increased with increase in particle size. Calcium concentration in the gizzard contents was strongly correlated with the TIDC (r=0.81; P<0.01) and ATTRC (r=0.82; P<0.01) of Ca. A strong correlation (r=0.80, P<0.01) was also observed between TIDC and ATTRC of Ca.