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Sixty growing male pigs were used to test the hypothesis that high dietary Ca content reduces P absorption to a greater extent in microbial phytase-supplemented diets via reducing inositol phosphate (IP) degradation and enhancing P precipitation. Pigs were equally allotted over diets with three Ca contents 2·0, 5·8 and 9·6 g/kg with or without microbial phytase (0 v. 500 FTU/kg) in a 2 × 3 factorial arrangement. Faeces and urine were collected at the end of the 21-d experimental period. Subsequently, pigs were euthanised and digesta quantitatively collected from different gastrointestinal tract (GIT) segments. Increasing dietary Ca content reduced apparent P digestibility in all GIT segments posterior to the stomach (P < 0·001), with greater effect in phytase-supplemented diets in the distal small intestine (Pinteraction = 0·007) and total tract (Pinteraction = 0·023). Nonetheless, increasing dietary Ca to 5·8 g/kg enhanced P retention, but only in phytase-supplemented diets. Ileal IP6 degradation increased with phytase (P < 0·001) but decreased with increasing dietary Ca content (P = 0·014). Proportion of IP esters in total IP (∑IP) indicated that IP6/∑IP was increased while IP4/∑IP and IP3/∑IP were reduced with increasing dietary Ca content and also with a greater impact in phytase-supplemented diets (Pinteraction = 0·025, 0·018 and 0·009, respectively). In all GIT segments, P solubility was increased with phytase (P < 0·001) and tended to be reduced with dietary Ca content (P < 0·096). Measurements in GIT segments showed that increasing dietary Ca content reduced apparent P digestibility via reducing IP degradation and enhancing P precipitation, with a greater impact in phytase-supplemented diets due to reduced IP degradation.

Expression levels of genes (RT-qPCR) related to Ca and P homeostasis (transporters and claudins (CLDN)) were determined in porcine jejunal and colonic mucosa. Forty growing pigs (BW 30·4 (sem 1·3) kg) received a low and high Ca content (2·0 and 9·6 g/kg, respectively) diet with or without microbial phytase (500 FTU/kg) for 21 d. Dietary Ca intake enhanced serum Ca and alkaline phosphatase concentration and reduced P, 1,25(OH)2D3, and parathyroid hormone concentration. Jejunal transient receptor potential vanilloid 5 (TRPV5) mRNA expression was decreased (32%) with phytase inclusion only, while colonic TRPV5 mRNA was reduced by dietary Ca (34%) and phytase (44%). Both jejunal and colonic TRPV6 mRNA expression was reduced (30%) with microbial phytase. Calbindin-D9k mRNA expression was lower in colonic but not jejunal mucosa with high dietary Ca (59%) and microbial phytase (37%). None of the mRNAs encoding the Na–P cotransporters (NaPi-IIc, PiT-1, PiT-2) were affected. Jejunal, but not colonic expression of the phosphate transporter XPR1, was slightly downregulated with dietary Ca. Dietary Ca downregulated colonic CLDN-4 (20%) and CLDN-10 (40%) expression while CLDN-7 was reduced by phytase inclusion in pigs fed low dietary Ca. Expression of colonic CLDN-12 tended to be increased by phytase. In jejunal mucosa, dietary Ca increased CLDN-2 expression (48%) and decreased CLDN-10 (49%) expression, while phytase slightly upregulated CLDN-12 expression. In conclusion, compared with a Ca-deficient phytase-free diet, high dietary Ca and phytase intake in pigs downregulate jejunal and colonic genes related to transcellular Ca absorption and upregulate Ca pore-forming claudins.

The novel chelator, L-glutamic acid, N,N-diacetic acid (GLDA) can be used as a dietary ingredient to safely reduce Zn supplementation in complete feed, without compromising the Zn status of farm animals. The objective of this study was to study dietary tolerance, bioaccumulation, and evaluate the safety of GLDA when supplemented in broiler diets at 0, 100, 300, 1000, 3,000, and 10,000 mg/kg. A total of 480 one-day-old Ross 308 male broilers were randomly allocated to 48 pens and fed one of the 6 experimental diets. Production performance was used to assess tolerance to the additive. At trial end, toxicity was evaluated using hematology, plasma biochemistry (n = 144) and gross necropsy (n = 48). Residue levels of GLDA were assessed in liver, kidney and breast tissue of birds used for necropsy. Performance showed an increase (P < 0.05) in body weight for GLDA inclusion at 300 mg/kg. A decrease on the measured performance parameters was found for the 10,000 mg/kg GLDA inclusion level (P < 0.05). The additive was added as a tetra-sodium salt, leading to sodium levels being 2.5 times higher in the latter treatment compared to the control diet which may have led to impaired intestinal barrier function. Mortality was not different between treatments. Residue levels for GLDA at the highest inclusion indicate that 0.0005% of total GLDA consumption is accumulated in breast tissue. Higher values of GLDA were found in kidney and liver at the highest inclusion level, potentially confirming that the small fraction of GLDA absorbed was readily excreted by the animal. At 100 and 300 mg/kg GLDA inclusion there were negligible amounts of GLDA present in all tissues measured. The present experiment demonstrated a high dietary tolerance to GLDA in broilers and indicated that GLDA does not pose a significant risk to food safety when supplemented below 3,000 mg/kg.

The hypothesis that dietary inclusion of microbial phytase improves apparent calcium (Ca) digestibility thereby allowing a lower dietary Ca inclusion without compromising growth performance was tested. One-day-old male Ross 308 broilers (25 birds/pen, 9 pens/treatment) were assigned to 8 experimental diets containing one of 4 dietary Ca to retainable P (rP) ratios (1.3, 1.8, 2.3, and 2.8) with (1,000 FTU/kg) or without microbial phytase. On d 21 to 23, digesta from different intestinal segments of 8 birds per pen were collected to determine apparent Ca and P digestibility. Mid duodenal mucosa was collected for expression of Ca (CaBP-D28k, PMCA1) and P (NaPi-IIb, PiT-1, PiT-2, and XPR1) transporters by RT-qPCR. Dietary phytase inclusion in low Ca/rP diets increased Ca digestibility in the distal ileum (Pinteraction = 0.023) but not the proximal or distal jejunum. Broilers receiving the lowest Ca/rP displayed the lowest body weight gain, highest feed conversion ratio (P < 0.001), and lowest tibia strength, irrespective of dietary phytase inclusion. Incremental dietary Ca/rP linearly reduced P digestibility to a greater extent in the absence of phytase in the distal jejunum and ileum (Pinteraction = 0.021 and 0.001, respectively). Incremental dietary Ca/rP linearly reduced serum P more in phytase-free diets (Pinteraction < 0.001), and lowered duodenal expression of P transporters NaPi-IIb, PiT-2, and XPR1 (P = 0.052, 0.071 and 0.028, respectively). Incremental dietary Ca/rP linearly increased (P < 0.001) serum Ca irrespective of phytase inclusion, accompanied by a lower (P < 0.001) duodenal expression of Ca transporters CaSR, CaBP-D28k and PMCA1 and Ca-pore forming claudins CLDN-2 and CLDN-12. Dietary phytase increased (P = 0.026) NaPi-IIb but reduced (P = 0.029) CLDN-2 expression. Incremental Ca/rP reduced Ca and P digestibility, increased serum Ca, lowered serum P and inhibited mRNA levels of Ca and P-related transporters, indicating that these transporters and CLDN contribute to the observed effect of dietary Ca and phytase on Ca and P absorption. Despite the improvement in Ca digestibility, dietary phytase did not restore the compromised growth performance and tibia strength of broilers fed a Ca-deficient diet, leading to rejection of the hypothesis.

Chelating agents can be used to improve the nutritional availability of trace minerals within the gastrointestinal tract. This study was conducted to determine the effect of a novel chelating agents, L-glutamic acid N,N-diacetic acid (GLDA), a biodegradable alternative to ethylenediaminetetraacetic acid on the nutritional bioavailability of zinc in broilers. Twelve dietary treatments were allocated to 96 pens in a randomized block design. Pens contained 10 Ross 308 male broilers in a factorial design with 6 incremental zinc levels (40, 45, 50, 60, 80, and 120 ppm of total Zn), with and without inclusion of GLDA (0 and 100 ppm) as respective factors. Experimental diets were supplied from day 7 to 21/22 and serum, liver and tibia Zn content were determined in 3 birds per pen. Growth performance and liver characteristics were not affected by dietary treatments, but both supplemental Zn and GLDA enhanced tibia and serum zinc concentration. The positive effect of GLDA was observed at all levels of the dietary Zn addition. The amount of zinc needed to reach 95% of the asymptotic Zn response was determined using nonlinear regression. When GLDA was included in the diet, based on tibia Zn, the same Zn status was achieved with a 19 ppm smaller Zn dose while based on serum Zn this was 27 ppm less Zn. Dietary GLDA reduces supplemental Zn needs to fulfill nutritional demands as defined by tibia Zn and serum Zn response. Considering the positive effect on the nutritional availability of Zn in broilers, GLDA presents an opportunity as biodegradable additive, to reduce Zn supplementation to livestock and thereby reducing Zn excretion into the environment, while fulfilling the nutrition Zn needs of farmed animals.

The use of seaweed as feed ingredient is gaining interest but the high ash content, low nutrient digestibility, short shelf life and poor economic feasibility hamper practical application. This study investigates the effect of washing, ensiling and extraction processes on the nutritional value of seaweed products for broilers, based on nutrient content and in vitro and in vivo digestibility. The effects of ensiling, washing and extraction processes were evaluated using Saccharina latissima, Laminaria digitata and Ulva lactuca, with 2, 4, and 6 h incubations in an in vitro simulated digestibility model, to obtain insight into the kinetics of digestibility. In an in vivo study, 160 Ross 308 male broilers were fed (day 14–22) a basal grower diet, or the basal grower diet with 100 g/kg of S. latissima silage or silage residue. Performance and ileal and total tract nutrient digestibility were determined. Washing and ensiling reduced the ash content, but also the in vitro organic matter digestibility (both P < 0.001). Washing also reduced nitrogen digestibility (P < 0.001). Extraction of seaweed decreased in vitro organic matter and nitrogen digestibility. Feeding seaweed diets to broilers resulted in a higher feed conversion ratio (1.62 versus 1.86 and 1.77 for broilers fed the basal, silage and silage residue diets respectively, P < 0.001) without increase in final body weight. Feeding S. latissima silage residue compared to silage resulted in a slightly better broiler performance and a higher amino acid digestibility. In conclusion, washing, ensiling and extraction processes reduce the nutritional value of the seaweed products, and do not make seaweed suitable for inclusion in broiler diets. To create suitable seaweed products for inclusion in broiler diets, a further reduction in the ash content and increase in digestibility is needed.

An experiment was conducted to determine the effects of diet composition, feeding level (FL), and BW on endogenous phosphorous losses (EPL) using growing-finishing (GF) pigs and sows. After an adaptation period, 48 GF pigs (initial BW 90.5 kg) and 48 just-weaned sows (initial BW 195 kg), both individually housed, were allotted to 12 dietary treatments in a 2 × 3 × 2 factorial arrangement. Treatments were animal type (GF pigs or sows), diet composition (a semipurified starch (STA), inulin (INU), or lignocellulose (CEL) based low-P diet), and FL (2.0 or 3.0 kg/d). Digestibility of DM, OM, CP, crude fat, and carbohydrates (COH), and fecal P excretion (in g/d, mg/kg DMI, and g/(kg BW·d)) were determined using TiO as indigestible marker. Digestibility of OM and COH differed among diets ( < 0.001) and was greatest in both types of pigs fed the STA diet and lowest in those fed the CEL diet. While digestibility of OM and COH was similar in sows and GF pigs that were fed the STA diet and the CEL diet, on the INU diet, sows had, compared with GF pigs, a greater digestibility of OM (92.2 vs. 87.2%) and COH (92.5 vs. 88.4%), respectively. Both BW and FL increased fecal P excretion (g/d). When expressed in mg/kg DMI, P excretion was higher in sows than in GF pigs on the STA diet (498 versus 236 mg/kg DMI), the INU diet (526 vs. 316 mg/kg DMI), and the CEL diet (928 vs. 342 mg/kg DMI). When expressed in mg/(kg BW·d), however, P excretion was similar in GF pigs and sows that were fed the STA diet and in those that were fed the INU diet, whereas it was greater in sows than in GF pigs that were fed the CEL diet (11.6 vs. 7.3 mg/(kg BW·d)). The results of this study indicate that EPL (mg/kg DMI) in pigs substantially increase with increasing BW. Application of EPL (mg/kg DMI) determined in GF pigs may underestimate EPL and therefore P requirements in gestating sows. Moreover, EPL is diet dependent and increases with an increasing content of dietary nonstarch polysaccharides (NSP). The degree of this increase may differ between sows and GF pigs and seems to depend on properties of dietary fiber.

Purpose: Feed production is responsible for the majority of the environmental impact of livestock production, especially for monogastric animals, such as pigs. Some feeding strategies demonstrated that replacing one ingredient with a high impact, e.g. soybean meal (SBM), with an alternative protein source, e.g. locally produced peas or rapeseed meal, has potential to reduce the environmental impact. These studies, however, used an attributional life cycle assessment (ALCA), which solely addresses the direct environmental impact of a product. A replacement of SBM with alternative protein sources, however, can also have indirect environmental consequences, which might change environmental benefits of using alternative protein sources. This study aims to explore differences in results when performing an ALCA and a CLCA to reduce the environmental impact of pig production. We illustrated this for two case studies: replacing SBM with rapeseed meal (RSM), and replacing SBM with waste-fed larvae meal in diets of finishing-pigs. Methods: We used an ALCA and CLCA to assess global warming potential (GWP), energy use (EU) and land use (LU) of replacing SBM with RSM and waste-fed larvae meal, for finishing-pigs. The functional unit was 1 kg of body weight gain. Results and discussion: Based on an ALCA, replacing SBM with RSM showed that GWP (3%) and EU (1%) were not changed, but LU was decreased (14%). ALCA results for replacing SBM with waste-fed larvae meal showed that EU did not change (1%), but GWP (10%) and LU (56%) were decreased. Based on a CLCA, replacing SBM with RSM showed an increased GWP (15%), EU (12%) and LU (10%). Replacing SBM with waste-fed larvae meal showed an increased GWP (60%) and EU (89%), but LU (70%) was decreased. Furthermore, the results of the sensitivity analysis showed that assumptions required to perform a CLCA, such as definition of the marginal product, have a large impact on final results but did not affect the final conclusions. Conclusions: The CLCA results seem to contradict the ALCA results. CLCA results for both case studies showed that using co-products and waste-fed larvae meal currently not reduces the net environmental impact of pork production. This would have been overlooked when results were only based on ALCA. To gain insight into the environmental impact of feed, animal nutritionists can use an ALCA. If policy makers or the feed industry, however, want to assess the net environmental impact of a potential feeding strategy, it is recommended to perform a CLCA. Feed and food markets are, however, highly dynamic. Pig feed optimization is based on least cost optimization and a wide range of ingredients are available; diet compositions can, therefore, change easily, resulting in different environmental impacts. Ideally, therefore, a CLCA should include a sensitivity analysis (e.g. different feed prices or different marginal products) to provide a range of possible outcomes to make the results more robust.

The hypothesis was tested that an increased digestion of coarse compared with fine limestone can alleviate the negative effects of a low dietary Ca/P ratio on the growth performance and characteristics of tibia strength (CTS) in broilers. A total of 1,152 Ross 308 broiler chickens received a standard commercial starter feed from day 0 to 13. From day 14 onward, birds received 1 of 12 diets containing 1 of 6 Ca/P ratios (0.50, 0.75, 1.00, 1.25, 1.50, and 1.75) and 1 of 2 limestone particle sizes (

The increasing demand for animal protein by the growing world population intensifies the exploration of novel feed sources. This study evaluated the nutritional value of six intact seaweed species (i.e. the brown species Saccharina latissima, Laminaria digitata, and Ascophyllum nodossum, the red species Palmaria palmata, and Chondrus crispus and green species Ulva lactuca), collected from the coast of Ireland, Scotland and France as an ingredient for animal feed. The nutrient composition, in vitro digestibility, and in vitro gas production simulating rumen fermentation, were determined. The nutrient contents (g/kg dry matter), both between and within species, were highly variable, ranging from 45–248 for crude protein, 351–691 for non-starch polysaccharides, and 173–445 for ash. Overall, the brown seaweeds had the highest non-starch polysaccharides content, whereas samples of the red and green seaweeds had an amino acid content up to 265 g/kg dry matter. All samples had a substantial non-protein nitrogen fraction, varying from 0.12–0.29 of nitrogen. The fibre fractions of brown seaweeds showed different properties than land-based plants, as illustrated by a lower analysed neutral detergent fibre than acid detergent fibre content. The ileal organic matter and nitrogen digestibility, as well as the total tract organic matter digestibility (mean digestibility coefficients: 0.81, 0.89 and 0.88, respectively) were lower for all seaweeds compared to soybean meal (digestibility coefficients: 0.84, 0.98 and 0.97, respectively). S. latissima, L digitata, P. palmata and U. lactuca had a higher maximum gas production than alfalfa, but lower than sugar beet pulp. Based on the protein content and amino acid-pattern, intact P. palmata and U. lactuca would be a valuable protein source for farm animals, with the high non-starch polysaccharides and non-protein nitrogen contents and a low in vitro digestibility potentially limiting their use as a feed ingredient for monogastric species. The fermentability of L. digitata, S. latissima and P. palmata indicate that these intact seaweeds may have a higher nutritional value in ruminants. The high ash content in all seaweed species hampers the use of intact seaweed for both ruminants and monogastrics. Extraction of protein and other favourable components, while reducing the ash content, seems an important step towards seaweed inclusion in animal diets. Further identification and characterisation of seaweed polysaccharides is required to understand and improve the digestibility of seaweed fractions.

The objective of this ring test was to investigate the prececal phosphorus (P) digestibility of soybean meal (SBM) in broiler chickens using the trial protocol proposed by the World's Poultry Science Association. It was hypothesized that prececal P digestibility of SBM determined in the collaborating stations is similar. Three diets with different inclusion levels of SBM were mixed in a feed mill specialized in experimental diets and transported to 17 collaborating stations. Broiler chicks were raised on commercial starter diets according to station-specific management routine. Then they were fed the experimental diets for a minimum of 5 d before content of the posterior half of the ileum was collected. A minimum of 6 experimental replicates per diet was used in each station. All diets and digesta samples were analyzed in the same laboratory. Diet, station, and their interaction significantly affected (P < 0.05) the prececal digestibility values of P and calcium of the diets. The prececal P digestibility of SBM was determined by linear regression and varied among stations from 19 to 51%, with significant differences among stations. In a subset of 4 stations, the prececal disappearance of myo- inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate)-P; InsP6-P) also was studied. The prececal InsP6-P disappearance correlated well with the prececal P digestibility. We hypothesized that factors influencing InsP6 hydrolysis were main contributors to the variation in prececal P digestibility among stations. These factors were probably related to the feeding and housing conditions (floor pens or cages) of the birds in the pre-experimental phase. Therefore, we suggest that the World's Poultry Science Association protocol for the determination of digestible P be should extended to the standardization of the pre-experimental period. We also suggest that comparisons of P digestibility measurements among studies are made only with great caution until the protocol is more refined. info:eu-repo/semantics/publishedVersion

The specificity of O-methylisourea (OMIU) to bind to the ε-amino group of Lys, an important supposition for the OMIU-reactive Lys analysis of foods, feeds, ingredients, and digesta, was investigated. Crystalline l-Lys incubated under standard conditions with OMIU resulted in low homoarginine recoveries. The reaction of OMIU with the α-amino group of Lys was confirmed by MS analysis, with double derivatized Lys being identified. None of the changes in reaction conditions (OMIU pH, OMIU to Lys ratio, and reaction time) with crystalline l-Lys resulted in 100% recovery of homoarginine. The average free Lys content in ileal digesta of growing pigs and broilers was found to be 13% of total Lys, which could result in a significant underestimation of the reactive Lys content. The reaction of OMIU with α-amino groups may necessitate analysis of free Lys to accurately quantify reactive lysine in samples containing a large proportion of Lys with a free α-amino group.

Feed ingredients used in swine diets are often processed to improve nutritional value. However, (over-)processing may result in chemical reactions with amino acids (AAs) that decrease their ileal digestibility. This study aimed to determine effects of (over-)processing of soybean meal (SBM) and rapeseed meal (RSM) on post-absorptive utilization of ileal digestible AAs for retention and on body AA composition of growing pigs. Soybean meal and RSM were processed by secondary toasting in the presence of lignosulfonate to obtain processed soybean meal (pSBM) and processed rapeseed meal (pRSM). Four diets contained SBM, pSBM, RSM or pRSM as sole protein source. Two additional diets contained pSBM or pRSM and were supplemented with crystalline AA to similar standardized ileal digestible (SID) AA level as the SBM or RSM diet. These diets were used to verify that processing affected AA retention by affecting ileal AA digestibility rather than post-absorptive AA utilization. The SID AA levels of the protein sources were determined in a previous study. In total, 59 pigs were used (initial BW of 15.6±0.7 kg) of which five were used to determine initial body composition at the start of the experiment. In total, 54 pigs were fed one of six experimental diets and were slaughtered at a BW of 40 kg. The organ fraction (i.e. empty organs plus blood) and carcass were analyzed separately for N and AA content. Post-absorptive AA utilization was calculated from AA retention and SID AA intake. An interaction between diet type, comprising effects of processing and supplementing crystalline AA, and protein source was observed for CP content in the organ fraction, carcass and empty body and for nutrient retention. Processing reduced CP content and nutrient retention more for SBM than for RSM. Moreover, processing reduced (P

Two similar experiments were conducted to determine the separate effects of feeding level (FL) and BW on basal endogenous phospho-rous losses (EPL) from the digestive tract and minimal urinary P content in growing-finishing (GF) pigs and sows. After an adaptation period, 16 GF pigs (initial BW 85 kg) and 16 gestating sows (initial BW 201 kg), both individually housed and divided in 2 groups of 8, received the same semipurified low-P diet at a feeding level (FL) of 2 or 3 kg/d during a 22-d period. Grab samples of feces and spot samples of urine were collected 2 times per day on d 6-8, 13-15, and 20-22 of feeding the low-P diet in GF pigs and on d 20-22 in sows. Phosphorus content was determined and excretion in the feces (in g/d, g/kg DMI, and g/(kg BW·d)) was calculated using titanium dioxide as indigestible marker. In GF pigs, the fecal P excretion (g/d) decreased over time from the first to the third collection period (P

Pharmacological levels of dietary copper (150–250 mg/kg) improve growth performance in pigs, but the majority of Cu is excreted in the manure and may contribute to accumulation in the soil. This experiment with 4 levels of dietary Cu supplementation (15, 80, 120, and 160 mg/kg) from weaning to d 56 after weaning was conducted to determine the dose-dependent effects of dietary Cu on growth performance and fecal consistency in pigs. From d 56 to slaughter, all pigs received the same grower and finisher diets supplemented with 15 mg/kg Cu. Each treatment comprised 10 pens with 8 pigs each, mixed males and females, as experimental units. The pigs were housed in a nursery unit until d 40 after weaning and in a grow–finish unit thereafter. Growth performance and fecal consistency were determined in 2-wk intervals until d 56; thereafter, growth performance was monitored between d 56 and slaughter. The Cu supplementation linearly increased ADFI and ADG (P Pharmacological levels of dietary copper (150–250 mg/kg) improve growth performance in pigs, but the majority of Cu is excreted in the manure and may contribute to accumulation in the soil. This experiment with 4 levels of dietary Cu supplementation (15, 80, 120, and 160 mg/kg) from weaning to d 56 after weaning was conducted to determine the dose-dependent effects of dietary Cu on growth performance and fecal consistency in pigs. From d 56 to slaughter, all pigs received the same grower and finisher diets supplemented with 15 mg/kg Cu. Each treatment comprised 10 pens with 8 pigs each, mixed males and females, as experimental units. The pigs were housed in a nursery unit until d 40 after weaning and in a grow–finish unit thereafter. Growth performance and fecal consistency were determined in 2-wk intervals until d 56; thereafter, growth performance was monitored between d 56 and slaughter. The Cu supplementation linearly increased ADFI and ADG (P

A study was conducted to compare protein digestibility of processed ingredients using 2 in vitro methods with known standardized ileal digestibility of CP (SIDCP) measured in growing pigs. The SIDCP in soybean meal (SBM), rapeseed meal (RSM), and both ingredients retoasted in the presence of lignosulfonate, resulting in processed SBM (pSBM) and processed RSM (pRSM), was determined in a trial with growing pigs surgically fitted with a steered ileocecal valve cannula. Toasting in the presence of lignosulfonate was performed to induce protein damage. Initial pH and degree of hydrolysis after 10 min (DH10) and 120 min (DH120) were determined using the pH-STAT method. Hydrolysis was performed using trypsin, chymotrypsin, and peptidase at pH 8. Size-exclusion profiles of the resulting peptides after hydrolysis were also determined. Crude protein digestibility was determined using a 2-step enzymatic method, with pepsin at pH 2 and pancreatin at pH 6.8. The SIDCP in SBM, pSBM, RSM, and pRSM were 83.9, 71.6, 74.9, and 64.6%, respectively. Initial pH of ingredient solutions measured at constant N concentration was 6.9, 5.9, 6.1, and 5.5, respectively, and was highly positively correlated to SIDCP (r = 0.99, P A study was conducted to compare protein digestibility of processed ingredients using 2 in vitro methods with known standardized ileal digestibility of CP (SIDCP) measured in growing pigs. The SIDCP in soybean meal (SBM), rapeseed meal (RSM), and both ingredients retoasted in the presence of lignosulfonate, resulting in processed SBM (pSBM) and processed RSM (pRSM), was determined in a trial with growing pigs surgically fitted with a steered ileocecal valve cannula. Toasting in the presence of lignosulfonate was performed to induce protein damage. Initial pH and degree of hydrolysis after 10 min (DH10) and 120 min (DH120) were determined using the pH-STAT method. Hydrolysis was performed using trypsin, chymotrypsin, and peptidase at pH 8. Size-exclusion profiles of the resulting peptides after hydrolysis were also determined. Crude protein digestibility was determined using a 2-step enzymatic method, with pepsin at pH 2 and pancreatin at pH 6.8. The SIDCP in SBM, pSBM, RSM, and pRSM were 83.9, 71.6, 74.9, and 64.6%, respectively. Initial pH of ingredient solutions measured at constant N concentration was 6.9, 5.9, 6.1, and 5.5, respectively, and was highly positively correlated to SIDCP (r = 0.99, P

An experiment was conducted to determine the effects of processing of soybean meal (SBM) and 00-rapeseed meal (RSM) on N solubilization in chyme, CP digestibility along the small intestine, metabolic load as determined by organ weight, body composition, and growth performance in growing pigs. The SBM and RSM were processed by secondary toasting (at 95°C for 30 min) in the presence of lignosulfonate, resulting in processed SBM (pSBM) and processed RSM (pRSM) as a model for overprocessed protein sources. Fifty-four growing pigs were each fed 1 of the 6 experimental diets. Four of the diets contained SBM, pSBM, RSM, or pRSM as the sole protein source. The remaining 2 experimental diets contained pSBM or pRSM and were supplemented with crystalline AA to the same standardized ileal digestible AA levels as the SBM or RSM diet. Pigs were slaughtered at 40 kg, and organ weights were recorded. The organs plus blood and empty carcass were analyzed for CP content. The small intestine was divided into 3 segments, and chyme samples were taken from the last meter of each segment. Chyme of the SBM, pSBM, RSM, and pRSM diets was centrifuged to separate the soluble and insoluble fractions, and N content was determined in the latter. The amount of insoluble N as a fraction of N in chyme at each small intestinal segment was not affected by processing. Diet type, comprising effects of processing and supplementing crystalline AA, affected ( < 0.05) the G:F and standardized ileal digestibility (SID) of CP. Processing reduced G:F from 0.56 to 0.38 for SBM and 0.49 to 0.40 for RSM, whereas supplementing crystalline AA increased G:F to the level of the SBM and RSM diets. Processing reduced the SID of CP from 87.2% to 69.2% for SBM and 71.0% to 52.2% for RSM. Diet type affected ( < 0.05) the CP content in the empty body, with processing reducing this content from 170 to 144 g/kg empty BW for SBM and 157 to 149 g/kg empty BW for RSM and supplementing crystalline AA restoring this content. Processing reduced ( < 0.05) the weight of several organs, and supplementing crystalline AA restored organ weight. In conclusion, processing increased the amount of N in the chyme, reduced organ weight, body CP content, and G:F. These effects were caused by a reduction in available AA as supplementing crystalline AA restored organ weight, body CP content, and G:F.

The growing world population demands an increase in animal protein production. Seaweed may be a valuable source of protein for animal feed. However, a biorefinery approach aimed at cascading valorisation of both protein and non-protein seaweed constituents is required to realise an economically feasible value chain. In this study, such a biorefinery approach is presented for the green seaweed Ulva lactuca containing 225 g protein (N × 4.6) kg−1 dry matter (DM). The sugars in the biomass were solubilised by hot water treatment followed by enzymatic hydrolysis and centrifugation resulting in a sugar-rich hydrolysate (38.8 g L−1 sugars) containing glucose, rhamnose and xylose, and a protein-enriched (343 g kg−1 in DM) extracted fraction. This extracted fraction was characterised for use in animal feed, as compared to U. lactuca biomass. Based on the content of essential amino acids and the in vitro N (85 %) and organic matter (90 %) digestibility, the extracted fraction seems a promising protein source in diets for monogastric animals with improved characteristics as compared to the intact U. lactuca. The gas production test indicated a moderate rumen fermentation of U. lactuca and the extracted fraction, about similar to that of alfalfa. Reduction of the high content of minerals and trace elements may be required to allow a high inclusion level of U. lactuca products in animal diets. The hydrolysate was used successfully for the production of acetone, butanol, ethanol and 1,2-propanediol by clostridial fermentation, and the rhamnose fermentation pattern was studied. Electronic supplementary material The online version of this article (doi:10.1007/s10811-016-0842-3) contains supplementary material, which is available to authorized users.

An experiment was conducted to determine protein quality in processed protein sources using the content of AA, -methylisourea (OMIU)-reactive Lys, Maillard reaction products (MRP), and cross-link products; the standardized ileal digestibility (SID) of CP and AA; and growth performance in growing pigs as criteria. Differences in protein quality were created by secondary toasting (at 95°C for 30 min) of soybean meal (SBM) and rapeseed meal (RSM) in the presence of lignosulfonate resulting in processed SBM (pSBM) and processed RSM (pRSM). The processing treatment was used as a model for overprocessed protein sources. Ten growing pigs were each fed 1 of the 4 diets containing SBM, pSBM, RSM, or pRSM in each of 3 periods. Ileal chyme was collected at the end of each period and analyzed for CP, AA, and OMIU-reactive Lys. Diets were analyzed for furosine and carboxymethyllysine (CML) as an indicator for MRP and lysinoalanine (LAL), which is a cross-link product. The SBM and RSM diets contained furosine, CML, and LAL, indicating that the Maillard reaction and cross-linking had taken place in SBM and RSM, presumably during the oil extraction/desolventizing process. The amounts of furosine, CML, and LAL were elevated in pSBM and pRSM due to further processing. Processing resulted in a reduction in total and OMIU-reactive Lys contents and a decrease in G:F from 0.52 to 0.42 for SBM and 0.46 to 0.39 for RSM ( = 0.006), SID of CP from 83.9 to 71.6% for SBM and 74.9 to 64.6% for RSM ( < 0.001), and SID of AA ( < 0.001), with the largest effects for total and OMIU-reactive Lys. The effects of processing could be substantial and should be taken into account when using processed protein sources in diets for growing pigs. The extent of protein damage may be assessed by additional analyses of MRP and cross-link products.

Om de uitscheiding van stikstof en fosfaat in dierlijke mest te berekenen, kunnen veehouders gebruik maken van de zogenoemde forfaitaire productienormen of excretieforfaits in de Uitvoeringsregeling van de Meststoffenwet. Deze forfaitaire productie geeft weer hoeveel stikstof en fosfaat in mest per dier en per diercategorie op jaarbasis wordt geproduceerd. Op verzoek van het Ministerie van Landbouw, Natuur en Voedselkwaliteit heeft een werkgroep van de Commissie Deskundigen Meststoffenwet (CDM) in dit rapport een voorstel gemaakt om de excretieforfaits van de Uitvoeringsregeling Meststoffenwet te actualiseren. Bij de excretieforfaits wordt onderscheid gemaakt tussen gangbare en biologische dierhouderijsystemen. De bruto excretie van stikstof en fosfaat voor dieren in gangbare dierhouderijsystemen is gebaseerd op de resultaten van de Werkgroep Uniformering berekening Mest- en mineralencijfers (WUM) voor de jaren 2015, 2016 en 2017. De WUM berekent per jaar de gemiddelde excreties per diercategorie op basis van statistische gegevens van voedergebruik en dierlijke productie. De bruto stikstof- en fosfaatexcretie voor dieren in biologische dierhouderijsystemen is gebaseerd op die van gangbare dierhouderijsystemen en een diercategorie-specifieke correctiefactor. De bruto stikstofexcretie is vervolgens gecorrigeerd voor gasvormige stikstofverliezen op basis van de afname in de verhouding tussen stikstof en fosfaat bij excretie en bij afvoer van de dierlijke mest.

Processed Animal Proteins (PAPs) have long been banned from farm animal diets in the EU. In this period, raw material selection and processes to prepare PAPs have been improved and diversified allowing for a range of products available for inclusion in animal diets. As a consequence, the products and their respective specifications in present feedstuff tables do not cover the composition and quality of presently available PAPs. This report presents the methods and results of a study, conducted by Wageningen Livestock Research at the request of European Fat Processors and Renderers Association (EFPRA), in which the total tract digestibility of proximate components and ileal phosphorus, calcium and amino acid digestibility of 2 PAPs of pig origin in broiler chickens were evaluated. The results from this study showed that the chemical composition of the new PAPs are broadly similar to the 'former' PAPs, but that the AME and the digestibility of crude fat, crude protein and amino acids of the new PAPs was lower. Therefore it is recommended, once the ban on the use of animal proteins in broiler diets ends, to update the present PAP table figures for broilers.

Purpose The expected increase in demand for food raises concerns about the expansion of agricultural land worldwide. To avoid expansion, we need to focus on increasing land productivity, reducing waste, and shifting human diets. Studies exploring diet shifts so far have ignored competition for land between humans and animals. Our objective was to study the relation between land use, the share of animal protein in the human diet, population size, and land availability and quality. Methods We used linear programming to determine minimum land required to feed a population a diet with 0–80 % of the protein derived from terrestrial domestic animals. Populations ranged from 15 million to the maximum number of people that could be supported by the system. The agricultural system in the Netherlands was used as illustration, assuming no import and export of feed and food. Daily energy and protein requirements of humans were fulfilled by a diet potentially consisting of grain (wheat), root and tuber crops (potato, sugar beet), oil crops (rapeseed), legumes (brown bean), and animal protein from ruminants (milk and meat) and monogastrics (pork). Results and discussion Land is used most efficiently if people would derive 12 % of dietary protein from animals (% PA), especially milk. The role of animals in such a diet is to convert co-products from crop production and the human food industry into protein-rich milk and meat. Below 12 % PA, human-inedible products were wasted (i.e., not used for food production), whereas above 12 % PA, additional crops had to be cultivated to feed livestock. Large populations (40 million or more) could be sustained only if animal protein was consumed. This results from the fact that at high population sizes, land unsuitable for crop production was necessary to meet dietary requirements of the population, and contributed to food production by providing animal protein without competing for land with crops. Conclusions A land use optimization model including crop and animal production enables identification of the optimal % PA in the diet. Land use per capita was lowest at 12 % PA. At this level, animals optimally consume co-products from food production. Larger populations, furthermore, can be sustained only with diets relatively high in % PA, as land unsuitable for crop production is needed to fulfil their food demand. The optimal % PA in the human diet depended on population size and the relative share of land unsuitable for crop production.

This report presents the methods and results of a study, conducted by Wageningen Livestock Research at the request of EFPRA, in which the effect of partially replacement of soybean meal by two different processed animal proteins (PAPs) of pig origin on performance results, intestinal health, litter quality, footpad lesions and bone quality in broilers chickens from 0 – 42 days was evaluated. The two PAPs differ from each other in processing method. From this study it was concluded that it is possible to replace a part of the dietary soybean meal by processed proteins from pig origin, while maintaining performance results, litter quality, footpad health, gait, intestinal health and bone quality.

The major impact of the livestock sector on the environment may be reduced by feeding agricultural co-products to animals. Since the last decade, co-products from biodiesel production, such as rapeseed meal (RSM), became increasingly available in Europe. Consequently, an increase in RSM content in livestock diets was observed at the expense of soybean meal (SBM) content. Cultivation of SBM is associated with high environmental impacts, especially when emissions related to land use change (LUC) are included. This study aims to assess the environmental impact of replacing SBM with RSM in finishing pig diets. As RSM has a lower nutritional value, we assessed the environmental impact of replacing SBM with RSM using scenarios that differed in handling changes in nutritional level. Scenario 1 (S1) was the basic scenario containing SBM. In scenario 2 (S2), RSM replaced SBM based on CP content, resulting in reduced energy and amino acid content, and hence an increased feed intake to realize the same growth rate. The diet of scenario 3 (S3) was identical to S2; however, we assumed that pigs were not able to increase their feed intake, leading to reduced growth performance. In scenario 4 (S4), the energy and amino acid content were increased to the same level of S1. Pig performances were simulated using a growth model. We analyzed the environmental impact of each scenario using life-cycle assessment, including processes of feed production, manure management, piglet production, enteric fermentation and housing. Results show that, expressed as per kg of BW, replacing SBM with RSM in finishing pig diets marginally decreased global warming potential (GWP) and energy use (EU) but decreased land use (LU) up to 12%. Between scenarios, S3 had the maximum potential to reduce the environmental impact, due to a lower impact per kg of feed and an increased body protein-to-lipid ratio of the pigs, resulting in a better feed conversion ratio. Optimization of the body protein-to-lipid ratio, therefore, might result in a reduced environmental impact of pig production. Furthermore, the impact of replacing SBM with RSM changed only marginally when emissions related to direct (up to 2.9%) and indirect LUC (up to 2.5%) were included. When we evaluated environmental impacts of feed production only, which implies excluding other processes along the chain as is generally found in the literature, GWP decreased up to 10%, including LUC, EU up to 5% and LU up to 16%.

Transparency document related to this article can be found online at http://dx.doi.org/10.1016/j.fct.2017.08.033. Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.fct.2017.08.033.; International audience; Within the frame of the EU-funded MARLON project, background data were reviewed to explore the possibility of measuring health indicators during post-market monitoring for potential effects of feeds, particularly genetically modified (GM) feeds, on livestock animal health, if applicable. Four case studies (CSs) of potential health effects on livestock were framed and the current knowledge of a possible effect of GM feed was reviewed. Concerning allergenicity (CS-1), there are no case-reports of allergic reactions or immunotoxic effects resulting from GM feed consumption as compared with non-GM feed. The likelihood of horizontal gene transfer (HGT; CS-2) of GMO-related DNA to different species is not different from that for other DNA and is unlikely to raise health concerns. Concerning mycotoxins (CS-3), insect-resistant GM maize may reduce fumonisins contamination as a health benefit, yet other Fusarium toxins and aflatoxins show inconclusive results. For nutritionally altered crops (CS-4), the genetic modifications applied lead to compositional changes which require special considerations of their nutritional impacts. No health indicators were thus identified except for possible beneficial impacts of reduced mycotoxins and nutritional enhancement. More generally, veterinary health data should ideally be linked with animal exposure information so as to be able to establish cause-effect relationships.

Three in vitro experiments were carried out to determine the effect of temperature, moisture content, duration of incubation, Ca level, soaking with water or citric acid onphytate degradation in a wheat–barley–rye–soybean meal-based broiler diet. In experiment 1, phytase activity of individual feed ingredients and 4 low-P broiler diets, containing 2, 4, 8, and 12 g Ca per kg diet, respectively, were measured in the presence or absence of sodium phytate or soybean meal. By using sodium phytate as substrate, phytase activity of rye, wheat, barley and soybean meal was 3350, 1170, 580 and 30 FTU/kg, respectively (P 0.05). In experiment 2, the effect of 2 moisture levels (0.25 and 50%), 3 temperatures (70, 75 and 80 C) and 3 durations of incubation (2, 4, and 8 min) on the residual phytase activity of diet 1 (basal diet) were evaluated as a 2 × 3 × 3 factorial arrangement with 3 replicates per treatment. The loss of activity of intrinsic phytase increased from 0.25 at 70 C to 0.61 at 80 C (P In conclusion, soaking of a broiler diet, especially in a citric acid solution one day before feeding, may increase available P and decrease the need of supplemental inorganic P to these diets, thus improving the sustainable use of P resources.

This report describes design of and management in animal housings common in 2013 for the main livestock categories. These serve as reference to quantify the effect of measures to reduce ammonia emissions within the framework of the Dutch national program PAS (Programmatische Aanpak Stikstof) to reduce nitrogen deposition in The Netherlands Dit rapport beschrijft uitvoering van- en management in stallen zoals dat in 2013 gangbaar was voor de belangrijkste categorieën landbouwhuisdieren. Deze dienen als referentie om het effect van maatregelen om ammoniakemissie te reduceren te kunnen kwantificeren in het kader van de Programmatische Aanpak Stikstof (PAS)

This is the accepted manuscript of the paper "Surveying selected European feed and livestock production chains for features enabling the case-specific post-market monitoring of livestock for intake and potential health impacts of animal feeds derived from genetically modified crops", published as final paper in "Food and Chemical ToxicologyVolume 117, 2018, Pages 66-78http://dx.doi.org/10.1016/j.fct.2017.10.004”. Abstract:This review, which has been prepared within the frame of the European Union (EU)-funded project MARLON, surveys the organisation and characteristics of specific livestock and feed production chains (conventional, organic, GM-free) within the EU, with an emphasis on controls, regulations, traceability, and common production practices. Furthermore, an overview of the origin of animal feed used in the EU as well as an examination of the use of genetically modified organisms (GMOs) in feed is provided. From the data, it shows that livestock is traceable at the herd or individual level, depending on the species. Husbandry practices can vary widely according to geography and animal species, whilst controls and checks are in place for notifiable diseases and general health symptoms (such as mortality, disease, productive performance). For feeds, it would be possible only to make coarse estimates, at best, for the amount of GM feed ingredients that an animal is exposed to. Labeling requirements are apparently correctly followed. Provided that confounding factors are taken into account, practices such as organic agriculture that explicitly involve the use of non-GM feeds could be used for comparison to those involving the use of GM feed.

In many Natura 2000 area’s, the nitrogen deposition is higher than wished for. This led to a deadlock in economic development of, among others, livestock husbandry. The interdepartmental program ‘Programma Aanpak Stikstof’ (PAS), is meant to overcome the standstill of grants of permits to produce, while in term preservation goals of nature area’s can be achieved. For the three sector groups Traffic and Transportation, Industry and Energy, and Agriculture source measures are inventoried to deal with the bottlenecks. By order of the Ministry of Economic Affairs this report presents the inventory of measures for agriculture. De stikstofdepositie in veel Natura 2000-gebieden in Nederland is hoger dan gewenst. Dit heeft geleid tot een impasse in economische ontwikkeling van onder meer de veehouderij. Het interdepartementale Programma Aanpak Stikstof (PAS) heeft tot doel de vastgelopen vergunningverlening weer vlot te trekken en ervoor te zorgen dat op termijn de instandhoudingsdoelstellingen van de natuurgebieden kunnen worden gehaald. Voor de drie sectorclusters Verkeer en Vervoer, Industrie en Energie en de Landbouw worden daarom bronmaatregelen geïnventariseerd om knelpunten op te vangen. In opdracht van het Ministerie van Economische Zaken is dit de inventarisatie van maatregelen voor de landbouwsector.

Dit rapport beschrijft een praktijkstudie naar de mogelijkheden om het verteerbaar fosfor (vP) gehalte in het rantsoen van biologisch gehouden vleesvarkens te verlagen. De verlaging van het berekend vP-gehalte met 0,4 g/kg (15% in startvoer, 20% in vleesvarkensvoer) had geen negatieve invloed op de gezondheid en groei van de varkens. Deze verlaging ten opzichte van het controlevoer draagt bij aan een hogere fosforbenutting. De gerealiseerde vP-gehalten, gebaseerd op analyse van voer en feces, waren echter aanzienlijk hoger dan vooraf berekend op basis van tabelwaarden. Hierdoor kan niet vastgesteld worden of een verlaging van het vP-gehalte ten opzichte van de norm voor regulier gehouden varkens mogelijk is zonder invloed op de dierprestaties.

De studie beschreven in dit rapport had tot doel voor een aantal specifieke onderdelen van de berekening van de stalbalans na te gaan of de berekening van de stikstofexcretie voor varkens en pluimvee aansluit bij de biologische productie van varkens en leghennen in de praktijk. Hiervoor is in een deskstudie aandacht besteed aan de stikstof- en fosforgehalten in eigen geteelde biologische voedermiddelen, de berekening van het levend eindgewicht van biologische vleesvarkens en de invloed van biologische huisvesting op gasvormige verliezen bij pluimvee en varkens. Daarnaast zijn stalbalansen verzameld van biologische bedrijven met leghennen, vleesvarkens en zeugen. Hiermee zijn de bruto excretie van N en P en de gasvormige N-verliezen berekend. Op basis van de resultaten worden aanbevelingen gedaan voor praktische toepassing.

In this study, the usefulness of intrinsic phytase of plant ingredients for degrading phytate was investigated. The enzymatic conversion from phytate to soluble inorganic phosphate was determined in vitro with and without addition of microbial phytase. Phytate degradation was measured in mixtures in which ingredients with a high intrinsic phytase activity and ingredients with a high phytate content were combined. In deze studie is de bruikbaarheid van intrinsiek fytase vanuit grondstoffen voor de afbraak van fytinezuur in grondstoffen onderzocht. De enzymatische omzetbaarheid van fytinezuur naar oplosbaar anorganische fosfaat werd in vitro bepaald met en zonder toevoeging microbieel fytase. De afbraak van fytinezuur is gemeten in combinaties van grondstoffen met een hoge intrinsieke fytase activiteit en grondstoffen met een hoog fytinezuurgehalte.

Alternative feed sources are required to improve the environmental and economic sustainability of current pig production systems and to reduce the competition for cropland between the feed and food sectors. The objective of this study was to assess the environmental and economic impacts of utilizing existing and new co-products in the diets of pigs in Brazil. Three diet scenarios were designed: a reference scenario with a standard corn-soybean meal based finishing diet, a macauba kernel cake based scenario and a co-product based scenario. The diets were equal in nutritional density. Inclusion of co-products in the diet of pigs has the potential to reduce the environmental impacts of pork production, particularly land use and the global warming potential when land use change is included. Compared with the reference scenario, land use per finished pig is 10% lower for the alternative scenarios. Global warming potential per kg live weight is 3.4–7% lower for the alternative scenarios when direct land use change is included whereas it is about 6–7% lower when indirect land use change is included. The land use ratio results (4.84 for the reference scenario and 4.35 for the alternative scenarios) imply that the production of pork using co-products can make available cropland for food crops production for direct human consumption. Compared with the reference finishing diet, the cost prices are 14% lower for the macauba kernel cake and 5% lower for the co-product based finishing diets. The inclusion of co-products in the diets of pigs is, therefore, an important strategy to improve the environmental and economic sustainability of pig production.

Low birth weight piglets have a reduced viability because of a low colostrum immunoglobulin (Ig) and energy intake. Additional supply of energy and Ig may improve their survival and immuno-competence. This study was conducted to determine the absorption of IgG from oral supplements containing IgG from porcine plasma and an additional energy substrate, as compared to IgG absorption from sow colostrum. Sixty newborn piglets (mean body weight (BW) 1183 g) from eight sows were removed from the dam prior to suckling and allocated to five treatments. Piglets received either 28 g of standardised sows colostrum per kg of BW (control) or one out of four products containing porcine IgG and fats, glycerine, dextrose or a combination of these as additional energy source. After 12 h of fasting in which only drinking water was supplied, plasma IgG content was determined and efficiency of IgG absorption calculated as total plasma IgG divided by ingested IgG. Treatment means of plasma IgG varied from 1.8 to 7.3 mg/mL (P

The aim of this study, comprising two experiments, was (1) to determine in Experiment 1 the relationship of incremental dietary P (phosphorus) content on precaecal digestible P in male broilers and (2) to determine in Experiment 2 the precaecal P digestibility of various inorganic P sources at marginal levels of P supply.In Experiment 1, a total of 260 male Ross 308 broilers were divided into groups of 10 birds per pen resulting in 8 replicates for treatment 1 and 6 replicates for treatments 2–4. Experimental diets were formulated to contain 4 incremental concentrations of digestible P by means of increasing concentrations of monocalcium phosphate (MCP). In the second experiment, 480-d-old male Ross 308 broilers were divided in groups of 12 birds per pen resulting in 16 replicates for the basal diet and 6 replicates for each test diet. A total of 4 inorganic P sources, MCP, monodicalcium phosphate (MDCP), dicalcium phosphate (DCP) and defluorinated phosphate (DFP) were added to the basal diet to determine the precaecal P digestibility. Three of the 4 inorganic P sources (MCP, MDCP and DCP) represented a mix of batches from different producers. At the end of both experiments, the chyme of the posterior part of the small intestine was collected. Digestibility of P and Ca was determined using titanium dioxide as indigestible marker.In Experiment 1, a reduction in precaecal digestibility of P was observed above an estimated precaecal digestible dietary P concentration of 4.8 g/kg.The precaecal P digestibility of the tested inorganic P sources in Experiment 2 was 78.3% for MCP, 59.0% for DCP, 70.7% for MDCP and 31.5% for DFP.

Ileal indigestible protein may be an important factor for the occurrence of post weaning diarrhoea in piglets. Depending on the quantity of indigested protein, an imbalance in the microbial community can occur, resulting in an overgrowth of pathogens. Diet viscosity may influence nutrient digestibility and substrate availability for microbial growth. Therefore, we examined the effect of dietary viscosity in piglet nutrition. Carboxymethylcellulose (CMC) was added as a model substance in order to increase diet viscosity. The effect of 1% supplemented CMC on nutrient digestibility, morphological and physiological parameters was measured in piglets 3 weeks post weaning at 26 days of age. The main effects of inclusion of CMC were: – A 10% slower gastric emptying rate ( P = 0.18). – An increased protein hydrolysis in the gastric fraction, measured as increased nitrogen concentration in the liquid phase of gastric contents (26% in control vs. 34% in experimental group; P = 0.13). – An increased production of the protein hydrolysing enzyme amino-peptidase from 359 U/g protein for the control diet to 516 U/g protein for the experimental diet ( P – A numerical increase in apparent ileal protein digestibility by 6% from 75.2% to 79.5% ( P = 0.22) and a significant increase in faecal protein digestibility by 5% ( P = 0.044). These results indicate that an optimized diet viscosity might be one factor exerting a beneficial influence on protein digestibility. We hypothesize that the effect of diet viscosity on gastric emptying rate is the major factor.

Anti-nutritional factors such as PHA-lectins (phytohaemagglutinin) in piglet diets can compromise piglet's performance and health by gut damage, which is especially important at weaning. Two trials were conducted to investigate the effect of PHA and fermentable carbohydrates on performance, gut morphology, physiology and microbiology in piglets weaned at 26 days. We studied dietary PHA as a model to standardize gut damage and its effect on intestinal morphology and microbiology in piglets until 2 weeks post weaning. In general, significant lower values were observed on day 7 compared to day 14 post weaning (d7 vs. d14: 358 vs. 442 μm villus height; 42.1 vs. 108.7 U/g protein sucrase-isomaltase), indicating gut maturation. We observed very few changes between day of weaning to day 7 post weaning, lactobacilli counts being most affected (8.9, 6.9, 7.4 cfu/g for d0, d7, d14). Apart from these marked time effects the effect of PHA was negligible and thus a less suitable model to standardize gut damage in this setup. Furthermore we studied the effect of PHA in combination with rapid or slow fermentable carbohydrates (CHO) on performance and physiological parameters. We observed a dramatic effect on performance (ADG g/d: 245 no PHA + low CHO, 111 PHA + low CHO, 132 PHA + rapid CHO, 105 PHA + slow CHO), which was less clearly reflected in the physiological parameters.

Reducing the CP content and increasing the fermentable carbohydrates (FC) content of the diet may counteract the negative effects of protein fermentation in newly weaned piglets fed high-CP diets. To study the synergistic effects of CP and FC on gut health and its consequences for growth performance, 272 newly weaned piglets (26 d of age, 8.7 kg of BW) were allotted to 1 of 4 dietary treatments in a 2 x 2 factorial arrangement, with low and high CP and low and high FC content as the factors. Eight piglets from each dietary treatment were killed on d 7 postweaning. Feces and digesta from ileum and colon were collected to determine nutrient digestibility, fermentation products, and microbial counts. In addition, jejunum tissues samples were collected for intestinal morphology and enzyme activity determination. During the entire 4-wk period, interactions between the dietary CP and FC contents were found for ADFI (P = 0.022), ADG (P = 0.001), and G:F (P = 0.033). The high-FC content reduced ADFI, ADG, and G:F in the low-CP diet, whereas the FC content did not affect growth performance in the high-CP diet. Lowering the CP content of the low-FC diet improved ADFI and ADG, whereas lowering the CP content of the high-FC diet did not influence growth performance. The low-CP diets resulted in a lower concentration of ammonia in the small intestine (P = 0.003), indicating reduced protein fermentation. In the small intestine, the high FC content increased the number of lactobacilli (P = 0.047), tended to decrease the number of coliforms (P = 0.063), tended to increase the lactic acid content (P = 0.080), and reduced the concentration of ammonia (P = 0.049). In the colon, the high-FC diets increased the concentration of total VFA (P = 0.009), acetic acid (P = 0.003), and butyric acid (P = 0.018), and tended to decrease the ammonia concentration (P = 0.076). Intestinal morphology and activity of brush border enzymes were not affected by the diet, although maltase activity tended to decrease with increasing dietary FC (P = 0.061). We concluded that an increase in the dietary FC content, and to a lesser extent a decrease in the CP content, reduced ammonia concentrations and altered the microflora and fermentation patterns in the gastrointestinal tract of weaned piglets. However, these effects were not necessarily reflected by an increased growth performance of the piglets.