Influence of particle size and origin of field peas on apparent ileal digestibility of starch and amino acids and standardized ileal digestibility of amino acids when fed to growing pigs.

The objective was to test the hypothesis that particle size and origin of field peas influence the apparent ileal digestibility (AID) of starch, crude protein (CP), and amino acids (AA) and the standardized ileal digestibility (SID) of AA. Three sources of field peas were procured. One source was from the United States and two sources were from Canada. The U.S. source and one of the sources from Canada (i.e., Canada 1) were each divided into two batches and ground to achieve a target particle size of 250 or 450 µm, whereas the other source from Canada (i.e., Canada 2) was only ground to a target particle size of 250 µm. Each batch of field peas was included in one diet as the only source of AA. An N-free diet was used to determine the basal endogenous losses of CP and AA. Six barrows (initial weight: 50.5 kg; SD = 3.7) that had a T-cannula installed in the distal ileum were randomly allotted to a 6 × 6 Latin square design with six diets and six 7-d periods. Ileal digesta from pigs were collected for 2 d after 5 d of adaptation. Data were analyzed using a statistical model that included batch of field peas as the fixed effect and animal and period as the random effects. Contrast statements were used to analyze the effects of particle size, origin, and the interaction between particle size and origin. Results indicated that the AID of starch was increased by reducing the particle size in the U.S. source of field peas, but that was not the case for the Canada 1 source (interaction; P < 0.001). Particle size did not influence the AID of CP or AA, but the Canada 2 source of field peas had greater (P < 0.05) AID of Trp, Ala, Cys, Gly, and Tyr than the field peas from the United States. The SID of CP and AA was also not affected by the particle size of field peas. The SID of CP and Trp was greater (P < 0.05), and the SID of His, Ile, and Thr tended (P < 0.10) to be greater in the Canada 2 source compared with the U.S. source, but no differences between the two Canada sources were observed. In conclusion, a few differences in SID of AA between field peas produced in the United States and peas produced in Canada were observed, but there was no effect on SID of AA of reducing the particle size of field peas from 450 to 250 µm, whereas the AID of starch increased by reducing the particle size only in the field peas from the United States.

Standardized ileal digestibility of amino acids in canola meal fed to gestating and lactating sows1.

An experiment was conducted to determine the standardized ileal digestibility (SID) of CP and AA in solvent extracted canola meal (CM) fed to gestating and lactating sows without or with a multi-enzyme complex. Eight sows cannulated on day 40 of gestation were randomly assigned to 1 of 4 dietary treatments in a replicated 4 × 4 Latin square design. The 4 diets included 2 cornstarch-based diets with 31.3% CM as the only source of AA, without or with a multi-enzyme complex, a casein-cornstarch diet to determine ileal endogenous AA losses, and a phosphorus-free diet (phosphorus digestibility data reported elsewhere). All diets contained 0.3% titanium dioxide. Gestating sows were fed 3.0 kg/d of the respective experimental diets, whereas, during lactation, sows had ad libitum access to experimental diets. Ileal digesta samples were collected in midgestation, late gestation, and lactation. In each period, after 6-d acclimation to the experimental diets, on days 7 and 8, ileal digesta samples were collected continuously for 12 h. Results indicated that sows in lactation had greater apparent ileal digestibility (AID) of CP and all AA (P < 0.05) compared with sows in gestation. Enzyme supplementation improved (P < 0.05) the AID of histidine, lysine, methionine, valine, and alanine, and a tendency (P < 0.10) for improvement in AID was observed for arginine, isoleucine, tryptophan, and cysteine during lactation, but not during gestation. However, the SID of most AA was not affected by collection phase, but enzyme supplementation improved (P < 0.05) the SID of arginine, histidine, lysine, methionine, and valine during lactation. The SID of indispensable AA in CM fed to gestating and lactating sows were as follows: arginine, 89.2 and 91.3%; histidine, 93.1 and 94.0%; isoleucine, 85.9 and 87.0%; leucine, 89.2 and 89.2%; lysine, 87.0 and 87.7%; methionine, 92.2 and 93.2%; phenylalanine, 89.2 and 87.8%; threonine, 84.3 and 82.7%; tryptophan, 88.1 and 91.5%; valine, 85.9 and 84.3%. In conclusion, the SID of AA in CM fed to lactating sows may be improved if a mixture of carbohydrases is included in the diet, but under the conditions of this experiment, the carbohydrase mixture did not affect SID of AA in CM fed to gestating sows in midgestation or late gestation.

Distribution and localization of porcine calcium sensing receptor in different tissues of weaned piglets1.

Taste receptors including calcium sensing receptor (CaSR) are expressed in various animal tissues, and CaSR plays important roles in nutrient sensing and the physiology, growth, and development of animals. However, molecular distribution of porcine CaSR (pCaSR) in different tissues, especially along the longitudinal axis of the digestive tract in weaned piglets, is still unknown. In the present study, we investigated the distribution and localization of pCaSR in the different tissues including intestinal segments of weaned piglets. Six male pigs were anesthetized and euthanized. Different tissues such as intestinal segments were collected. The pCaSR mRNA abundance, protein abundance, and localization were measured by real-time PCR, Western blotting, and immunohistochemistry, respectively. The mRNA and protein of pCaSR were detected in the kidney, lung, liver, stomach, duodenum, jejunum, ileum, and colon. The pCaSR mRNA was much higher (five to 180 times) in the kidney when compared with other tissues (P < 0.05). The ileum had higher pCaSR mRNA and protein abundances than the stomach, duodenum, jejunum, and colon (P < 0.05). Immunohistochemical staining results indicated that the pCaSR protein was mostly located in the epithelia of the stomach, duodenum, jejunum, ileum, and colon. These results demonstrate that pCaSR is widely expressed in different tissues including intestinal segments in weaned piglets and the ileum has a higher expression level of pCaSR. Further research is needed to confirm the expression of CaSR in the different types of epithelial cells isolated from weaned piglets and characterize the functions of pCaSR, its potential ligands and cell signaling pathways related to CaSR activation in enteroendocrine cells and potentially in enterocytes.

Flaxseed meal and oat hulls supplementation: impact on dietary fiber digestibility, and flows of fatty acids and bile acids in growing pigs.

The present study was conducted to determine the effects of adding flaxseed meal (FM) or oat hulls (OHs) in pigs' diets on digestibility of dietary fiber (DF) and fatty acids (FAs), and gastrointestinal flows of FA and bile acids (BAs). Twelve Genesus [(Duroc ♂ × Yorkshire-Landrace ♀)] cannulated barrows (initial BW: 35.1 ± 0.44 kg) were individually housed and offered diets in a two-period cross-over design (n = 8). In each period, four pigs were assigned to one of the three corn-soybean meal-based diets without (control), or with FM or OHs. Soybean oil was added in each diet to give an FA content of 4.56%, 6.02%, and 6.05 % in the control, FM, and OH diets, respectively. Feces and ileal digesta contents were collected to determine apparent ileal (AID), total tract (ATTD) digestibility of dietary components and flows of FA and BA. Pigs fed the control diet had greater (P < 0.05) AID of SFA and insoluble DF and ATTD of SFA than pigs offered the OH and FM diets. The AID of total FA and MUFA in FM diet-fed pigs was lower (P = 0.02) compared to those fed the control and OH diets. The ATTD of CP, NDF, insoluble and total DF was lower (P < 0.05) in pigs fed the OH diet than in pigs that consumed the control and FM diets. In the terminal ileum, pigs fed OH and FM diets excreted more (P < 0.05) primary BA and all secondary BA (except lithocholic acid) compared to control diet-fed pigs. The intestinal flows of lithocholic acid in pigs fed the FM diet were higher (P < 0.05) than in pigs offered the control diet. Pigs fed FM and OH diets excreted more (P = 0.001) fecal ursodeoxycholic and total BAs compared to pigs that consumed the control diet. The ileal flows of eicosapentaenoic and erucic acids in pigs fed the FM and OH diets were greater (P < 0.05) than in pigs fed the control diet. The flow of all SFA, and palmitoleic, palmitelaidic, oleic, nervonic, linoleic, eicosapentaenoic, erucic, docosatetraenoic and docosapentaenoic acids in feces were greater (P < 0.05) in OH diet-fed pigs compared to pigs fed other diets. In conclusion, addition of FM and OHs in pig diets reduced FA digestibility, increased gastrointestinal flows of FA and excretion of BA. Dietary supplementation with FM and OHs induces variable effects on digestibility of DF fractions and fecal flows of unsaturated FA. Future studies are needed to quantify the contribution of endogenous FA losses from the host to gastrointestinal flows of FA.

Lipopolysaccharide immune stimulation but not ß-mannanase supplementation affects maintenance energy requirements in young weaned pigs.

BACKGROUND: Pathogen or diet-induced immune activation can partition energy and nutrients away from growth, but clear relationships between immune responses and the direction and magnitude of energy partitioning responses have yet to be elucidated. The objectives were to determine how ß-mannanase supplementation and lipopolysaccharide (LPS) immune stimulation affect maintenance energy requirements (MEm) and to characterize immune parameters, digestibility, growth performance, and energy balance. METHODS: In a randomized complete block design, 30 young weaned pigs were assigned to either the control treatment (CON; basal corn, soybean meal and soybean hulls diet), the enzyme treatment (ENZ; basal diet + 0.056% ß-mannanase), or the immune system stimulation treatment (ISS; basal diet + 0.056% ß-mannanase, challenged with repeated increasing doses of Escherichia coli LPS). The experiment consisted of a 10-d adaptation period, 5-d digestibility and nitrogen balance measurement, 22 h of heat production (HP) measurements, and 12 h of fasting HP measurements in indirect calorimetry chambers. The immune challenge consisted of 4 injections of either LPS (ISS) or sterile saline (CON and ENZ), one every 48 h beginning on d 10. Blood was collected pre- and post-challenge for complete blood counts with differential, haptoglobin and mannan binding lectin, 12 cytokines, and glucose and insulin concentrations. RESULTS: Beta-mannanase supplementation did not affect immune status, nutrient digestibility, growth performance, energy balance, or MEm. The ISS treatment induced fever, elevated proinflammatory cytokines and decreased leukocyte concentrations (P < 0.05). The ISS treatment did not impact nitrogen balance or nutrient digestibility (P > 0.10), but increased total HP (21%) and MEm (23%), resulting in decreased lipid deposition (-30%) and average daily gain (-18%) (P < 0.05). CONCLUSIONS: This experiment provides novel data on ß-mannanase supplementation effects on immune parameters and energy balance in pigs and is the first to directly relate decreased ADG to increased MEm independent of changes in feed intake in immune challenged pigs. Immune stimulation increased energy partitioning to the immune system by 23% which limited lipid deposition and weight gain. Understanding energy and nutrient partitioning in immune-stressed pigs may provide insight into more effective feeding and management strategies.

Tail-end dehulling of canola meal improves apparent and standardized total tract digestibility of phosphorus when fed to growing pigs.

Tail-end dehulling of canola meal (CM) has been shown to reduce dietary fiber and increase crude protein content in the dehulled meal. The application of this procedure also increased the total and non-phytate P content in the dehulled meal. However, it is unclear if dehulling affects P digestibility in the different fractions (i.e., the dehulled meal and the coarse fraction) and if it differs when fed to growing pigs at two different BW. Therefore, two experiments were conducted to determine the apparent (ATTD) and standardized (STTD) total tract digestibility of P in dehulled CM fed to growing pigs. Diets containing non-dehulled regular canola meal (RCM), and two fractions produced using sieve size of 355 µm: a low-fiber high-protein fraction (dehulled canola meal [DCM]) and a high-fiber low-protein fraction (coarse canola meal [CCM]) as the only source of P were fed to growing pigs at two different BW. A total of 48 pigs were used for the two experiments. In experiment 1, 24 barrows [(Yorkshire × Landrace) × Duroc] with initial BW of 24.5 ± 1.68 kg were individually housed in metabolism crates and fed the experimental diets for 10 d for total fecal collection. In experiment 2, 24 barrows with an average initial BW of 73.8 ± 4.93 kg were used; experimental diets and fecal collection procedures were the same as in experiment 1. Each experiment used six replicates per treatment. A P-free diet was used to determine basal endogenous losses of P (139.6 ± 10.7 and 150.89 ± 20.1 mg/kg of DMI for experiments 1 and 2, respectively). Data were analyzed as a completely randomized design. In experiment 1, the ATTD and STTD of P were greater (P < 0.05) for DCM (42.4% and 46.1%) than for the RCM (32.0% and 35.7%) and CCM (24.5% and 28.4%) diets. In experiment 2, the ATTD and STTD of P were greater (P < 0.05) for DCM (38.7% and 42.8%) than for the CCM diet (22.6% and 26.8%); whereas the values for RCM diet were intermediate (31.0% and 35.0%) and not different from the DCM and CCM. In conclusion, dehulling canola meal increased ATTD and STTD of P in growing pigs of different BW; however, there was no effect of BW.

Nutrient utilization and manure P excretion in growing pigs fed corn-barley-soybean based diets supplemented with microbial phytase.

The effect of high levels of microbial phytase supplementation in diets for growing pigs was studied in a 2-week performance and nutrient digestibility trial involving 28 growing pigs weighing 16.4 +/- 1.06 (mean +/- SD) kg. Seven corn-barley-soybean meal-based diets consisting of a positive control (PC) formulated to meet or exceed NRC nutrient requirements; a negative control (NC) with non-phytate P reduced by 0.1% unit from NRC requirement and fed without or with 500 or 1000 U/kg; a doubled negative control (DNC) with no added inorganic P and fed without or with 2000 or 4000 U/kg. Chromic oxide was added as an indigestible marker and all diets were fed as mash. Pigs fed the PC diet had a higher P digestibility compared with those fed the NC (P < 0.02) and the DNC (P < 0.001) diets. Supplementing the NC diet with pyhtase tended to improve P digestibility (P < 0.10). However, addition of phytase to the DNC diet resulted in linear (P < 0.001) and quadratic (P < 0.03) increases in P digestibility with an overall improvement of 8% and 121% at 4000 phytase U/kg of diet, respectively, compared with the PC and DNC diets. Apparent total tract digestibility of N, OM and DM were higher (P < 0.05) in the PC diet compared with the DNC diet, but not the NC diet (P < 0.10). No effect of phytase addition to NC was observed on Ca, N, DM and OM digestibility. Phytase addition to the DNC diet resulted in a linear increase (P < 0.05) in N, DM and OM digestibility but not Ca. Increasing the levels of phytase supplementation in the NC and the DNC diets linearly decreased fecal P (P < 0.05) content by 45 and 42%, respectively. Adding phytase at 1000 or 4000 U/kg increased P retention (P < 0.05) by 14.3 or 15.6% units, respectively, compared with the PC diet. Urinary P excretion was higher in the group fed the PC diet compared with those fed the NC and DNC diets (P < 0.05). The results of this study show that complete removal of inorganic P from growing pig diets coupled with phytase supplementation improves digestibility and retention of P and N, thus reducing manure P excretion without any negative effect on pig performance.

Reduction of deoxynivalenol in barley by treatment with aqueous sodium carbonate and heat.

Naturally contaminated lots of Canadian barley containing either 18.4 or 4.3 microg/g deoxynivalenol (DON) were heated at 80 degrees C, with small amounts of water or 1 M sodium carbonate solution to study the rate of DON reduction. Samples were heated in sealed polypropylene containers for periods of up to 8 days. In the 18.4 microg/g DON barley, rapid reductions were observed: with no solutions added, DON declined to 14.7 microg/g after 1 day, and to 4.9 microg/g after 8 days solely due to heat; with water at 10 mL/100 g barley, DON levels reached 3.7 microg/g after 8 days; with 1 M sodium carbonate solution added at 10 mL/100 g barley, DON declined to 4.7 microg/g after 1 day, and to 0.4 microg/g after 8 days; with 20 mL/100 g barley, DON declined to 1.4 microg/g after 1 day and to near-zero levels after 8 days. In the 4.3 microg/g DON barley, more gradual reductions were evident: with no solutions added, DON declined to 2.9 microg/g after 8 days solely due to heat; with water at 10 mL/100 g barley, DON levels reached 2.3 microg/g after 8 days; with 1 M sodium carbonate solution added at 10 mL/100 g barley, DON declined to 2.7 microg/g after 1 day, and to near-zero levels after 8 days; with 20 mL/100 g barley, DON declined to 1.4 microg/g after 1 day and to near-zero levels after 3, 5 and 8 days.