Digestibility In Pigs Research Articles

Effects of montmorillonite clay on growth performance, nutrient digestibility, vulva size, faecal microflora, and oxidative stress in weaning gilts challenged with zearalenone

Two experiments were conducted to evaluate the effects of montmorillonite clay (MC) on performance and nutrient digestibility of pigs challenged with zearalenone (ZEA). In experiment 1, 144 gilts (10.07±0.87kg) were assigned to 1 of 8 treatments in 2×4 factorial randomized complete block design for a 28d trial (6 pigs/pen, 3 pens/treatment). Factors included (1) ZEA levels (0, 0.2, 0.4, or 0.8mg ZEA/kg) and (2) MC addition [Clay to ZEA ratio maintained at 2500:1 (w:w)]. These diets included: (1) control, (2) control+2g MC/kg, (3) control+0.2mg ZEA/kg, (4) control+0.2mg ZEA/kg+0.5g MC/kg, (5) control+0.4mg ZEA/kg, (6) control+0.4mg ZEA/kg+1g MC/kg, (7) control+0.8mg ZEA/kg, and (8) control+0.8mg ZEA/kg+2g MC/kg. The ZEA challenges were shown to linearly depress (P=0.03) average daily gain (ADG) and feed efficiency, but the addition of MC improved (P=0.03) feed efficiency in the overall phase. Coefficient of apparent total tract digestibility of dry matter and nitrogen decreased (linear effect, P<0.05) as the ZEA levels increased and nitrogen digestibility were improved (P<0.01) by MC supplementation. Zearalenone linearly increased (P<0.05) vulva size (width, length, and area). Addition of MC reduced (P<0.05) average vulva width and area. Faecal Lactobacillus counts were increased (P=0.01) and Escherichia coli were reduced (P=0.01) in the MC supplemented treatments at 2 and 4wk regardless of the level of the MC. Serum malondialdehyde (MDA) concentration increased (linear effect at 2 and 4wk, P<0.05) and total superoxide dismutase (SOD) and aspartate amino transferase (AST) activities decreased (linear effect at 4wk, P<0.05) as dietary ZEA dosage increased; MC supplementation reversed (P<0.05) these effects. In experiment 2, 64 pigs (27.13±1.39kg) that were pre-fed ZEA treatments (0, 0.2, 0.4, or 0.8mg ZEA/kg) for 28d in experiment 1, were randomly divided into two halves and fed either control diet or control+2g MC/kg for 18d (2 gilts/pen, 4 pens/treatment). Adding 2g MC/kg increased (P<0.05) ADG, and decrease the vulva size and serum MAD concentration in pigs pre-fed ZEA diets throughout the 18d period. Serum SOD concentration increased (P<0.05) in those pigs fed MC on d 9. The results suggest that feeding low levels of ZEA reduced nutrient digestibility, increased oxidative stress, and negatively affected pigs’ growth, and montmorillonite clay was beneficial for detoxification of ZEA in pigs under and after ZEA challenge.

Method of using increasing levels of substitution of the basal diet by test feedstuffs in pig digestibility trials

Two experiments were carried out to study the methodology of using increasing levels of substitution of the basal diet with fibrous test feedstuffs (sticky coffee hull - SCH) in digestibility trials with pigs. In Experiment 1, a digestibility trial was conducted using 30 crossbred barrows, allotted in a randomized block design. In Experiment 2, 42 growing and 42 finishing pigs were used, allotted in a completely randomized design, with six diets and seven replicates, with one animal per experimental unit. The six diets consisted of: a control diet, four diets using SCH ME values as obtained in Experiment 1 plus a diet using SCH ME value estimated by linear regression equation for 15% substitution. The digestibility study indicated that the use of increasing levels of substitution (7, 14, 21 and 28%) reduced SCH digestibility. ME values, as-fed basis, were 2,456, 2,377, 2,247 and 1,945kcal/kg. The overall results indicate that higher levels of substitution overestimate the energy value and that the method of increasing levels of substitution of the basal diet with feedstuffs test can be used to more accurately estimate the energy values of fibrous feedstuffs for pigs. For growing and finishing pigs respectively, up to 28% and 15% of sticky coffee hull can be used without impairing pig performance and economic feasibility.

The effect of level of wheat inclusion in diets for growing and finishing pigs on performance, nutrient digestibility and gastric ulceration.

Four experimental diets were formulated to contain 700 g/kg cereal with decreasing levels of wheat:barley inclusion. Diet 1 contained 700 g/kg wheat, diet 2 contained 600 g/kg wheat and 100 g/kg barley, diet 3 contained 500 g/kg wheat and 200 g/kg barley and diet 4 contained 400 g/kg wheat and 300 g/kg barley. The diets were offered to pigs on three trials to investigate effects on the performance of individually (n = 72) and group housed (n = 480) pigs and on nutrient digestibility in pigs housed in metabolizm crates (n = 24). Performance was assessed from 10 wks of age until slaughter and carcass characteristics were measured. For the group performance study, one pig from each pen (in total 24) at 10, 15 wks and at finish were slaughtered to ascertain scores for stomach ulceration, stomach weights and intestinal length. Level of wheat inclusion did not significantly (p>0.05) affect liveweight gain (LWG) or feed conversion ratio (FCR). Feed intake was lowest (p<0.05) for individually housed pigs offered diets containing 700 g/kg wheat during the 10–15 wk period, which indicated that individually housed pigs attempted to eat to a constant energy intake. There was little evidence of stomach ulceration across treatments and increasing wheat inclusion had no detrimental effect. Higher levels of wheat inclusion tended to increase backfat depth at the P2 position which could lead to increasing grading penalties in a commercial situation although more research is required in this area. Increasing level of wheat inclusion increased digestible energy (DE) content but the lack of effect on FCR and killing out percentage indicated that utilization of energy from barley and wheat was similar. Digestibility coefficients increased linearly with increasing wheat content, which can be attributed to the lower level of fibre and higher level of starch in wheat compared with barley.

Bioavailability of Trace Elements in Beans and Zinc-Biofortified Wheat in Pigs

The objectives of this experiment were to study bioavailability of trace elements in beans and wheat containing different levels of zinc and to study how the water solubility of trace elements was related to the bioavailability in pigs. Three wheat and two bean types were used: wheat of Danish origin as a control (CtrlW), two Turkish wheat types low (LZnW) and high (HZnW) in zinc, a common bean (Com), and a faba bean (Faba). Two diets were composed by combining 81 % CtrlW and 19 % Com or Faba beans. Solubility was measured as the trace element concentration in the supernatant of feedstuffs, and diets incubated in distilled water at pH 4 and 38°C for 3 h. The bioavailability of zinc and copper of the three wheat types and the two bean-containing diets were evaluated in the pigs by collection of urine and feces for 7 days. The solubility of zinc was 34–63 %, copper 18–42 %, and iron 3–11 %. The zinc apparent digestibility in pigs was similar in the three wheat groups (11–14 %), but was significantly higher in the CtrlW+Faba group (23 %) and negative in the CtrlW+Com group (−30 %). The apparent digestibility of copper was higher in the HZnW (27 %) and CtrlW+Faba (33 %) groups than in the CtrlW (17 %) and LZnW (18 %) groups. The apparent copper digestibility of the CtrlW+Com diet was negative (−7 %). The solubility and digestibility results did not reflect the concentration in feedstuffs. The in vitro results of water solubility showed no relationship to the results of trace mineral bioavailability in pigs.

True and standardized ileal digestibilities and specific ileal endogenous recoveries of crude protein and amino acid in soybean meal, rapeseed meal and peas fed to growing pigs

A digestibility study was conducted to investigate true (TID) and standardized (SID) ileal digestibilities and specific ileal endogenous recoveries of crude protein (CP) and amino acids (AA) in pigs fed cornstarch-based assay diets with soybean meal, rapeseed meal or peas. The TID and total ileal endogenous CP and AA recoveries were determined using the homoarginine (Harg) method. Six barrows (German Landrace×Pietrain) with an initial body weight of 19±1.8kg, and fitted with ileal T-cannulas were fed the assay diets according to a double 3×3 Latin Square design. The assay diets were formulated to contain 180g CP/kg (as fed basis). Ileal digesta were collected continuously for 24h to determine SID values on days 6 to 8 and for 12 h to determine TID values on days 9 to 10 of each experimental period. The TID and total ileal endogenous recoveries were determined by feeding assay diets with 50% of the dietary protein source guanidinated to convert Lys to Harg for direct determination of TID of Lys. Total ileal endogenous Lys and CP recoveries (g/kg DMI) were highest (P<0.05) in ileal digesta of pigs fed the pea compared to the rapeseed meal or soybean meal assay diets. By contrast, recoveries of specific ileal endogenous CP and most AA (g/kg DMI) in the assay feed ingredients were higher in soybean meal compared to rapeseed meal (P<0.05) and intermediate for peas (P>0.05). The TID of CP and AA were the lowest (P<0.05) in rapeseed meal compared to soybean meal or peas. The lowest SID of CP and indispensable AA were observed in rapeseed meal, with intermediate values for peas, and highest values in soybean meal (P<0.05). As specific ileal endogenous recoveries differ among feed ingredients, these losses should be considered explicitly in addition to SID values to account for the metabolic costs associated with the intestinal synthesis and recycling of endogenous CP and AA.

Effect of an herb extract mixture on growth performance, nutrient digestibility, blood characteristics, and fecal microbial shedding in weanling pigs

A 6-week experiment was conducted to evaluate the effect of a dietary herb extracts mixture (HEM) on growth performance, nutrient digestibility, blood characteristics, and fecal microbial shedding in weanling pigs. A total of 144 pigs [(Landrace×Yorkshire)×Duroc] (BW=7.6±0.6kg; weaned at d 21) were randomly allocated to 4 treatments according to their BW and sex (9 replicates of 4 pigs per treatment). Treatments followed a 2×2 factorial design with 2 levels of HEM (0 or 250mgkg−1 diet) and apramycin (0 or 30mgkg−1 diet). During the first week, pigs fed HEM supplemented diets led to a lower (P<0.05) average daily feed intake (ADFI) but greater gain to feed ration (G:F) than those fed diets without HEM supplementation. Dietary HEM supplementation increased (P<0.05) average daily gain (ADG) and G:F during 4 to 6 weeks. Antibiotics treatments showed greater (P<0.05) ADG and G:F than those in non-antibiotics treatments from 0 to 1 week, 4 to 6 weeks, and the overall period. A decreased ADFI was observed (P<0.05) when pigs were fed antibiotics supplement from 4 to 6 weeks. Pigs fed diets supplemented with HEM or antibiotic led to a higher (P<0.05) DM and N digestibility at d 7. Dietary antibiotic increased (P<0.05) N and energy digestibility at d 21. Antibiotic supplemented diets led to a higher (P<0.05) DM digestibility in pigs at d 42. The coefficient of apparent total tract digestibility (CATTD) of DM and N was increased (P<0.05) by HEM treatments at d 42 compared with non-HEM treatments. The blood lymphocyte concentration in HEM groups was greater (P<0.05) than the non-HEM treatments at d 42. Pigs fed HEM supplemented diets had decreased fecal Escherichia coli concentration (P<0.05) at the end of the current study. In conclusion, administration of HEM in weaning pigs diet had no effect on the growth performance during the whole experiment. However, the beneficial effect on nutrient digestibilities, lymphocyte and fecal E. coli concentration suggested that those kind of HEM have a positive role in weaning pigs.

Effects of dietary lysine levels on apparent nutrient digestibility and cationic amino acid transporter mRNA abundance in the small intestine of finishing pigs, Sus scrofa

One hundred and twenty pigs were used to evaluate the effects of different dietary lysine levels on the growth performance, apparent nutrient digestibility, and abundance of cationic amino acid transporter messenger RNA (mRNA) in the small intestine of finishing pigs. Pigs received a low lysine diet (LL, 0.60% lysine), moderate lysine diet (ML, 0.80% lysine) or a high lysine diet (HL, 1.00% lysine) for 28 days. A digestion test was carried out during the third week. Although the apparent nutrient digestibility in pigs fed experimental diets were different (P < 0.05) and the highest when pigs were fed ML diet, diets did not change the growth performance. In the duodenum, mRNA abundance of PepT-1, as detected by real-time RT-PCR, was reduced in the LL diet (P < 0.05). A greater abundance of b(0,+) AT and PepT-1 mRNA was associated with the ML diet (P < 0.05) in the jejunum and ileum, respectively. In the ileum, the HL diet had a lower abundance of CAT-1 mRNA compared with other diets. These results showed that the finishing pigs would gain better nutrient digestibility when the dietary lysine content was 0.80%, and dietary lysine levels influenced the expression of cationic amino acid transporter mRNA in the small intestine of finishing pigs.

The presence of inositol phosphates in gastric pig digesta is affected by time after feeding a nonfermented or fermented liquid wheat- and barley-based diet1

The objective was to quantify the retention of digesta and evaluate the degradation of phytate or inositol hexakisphosphate (InsP(6)) and lower inositol phosphates (InsP₅, InsP₄, InsP₃, and InsP₂) in the stomach at different times after feeding pigs a fermented liquid diet with microbial phytase or a nonfermented diet with or without microbial phytase. Six barrows fitted with gastric cannulas were used. The experiment was a 3 × 3 Latin square with 3 pigs fed 3 diets during 3 wk in 2 replicates. Each experimental period lasted for 7 d, comprising 3 d of adaptation and 4 d of total collection of gastric digesta. For each pig, the digesta was collected once daily at 1, 2, 3, or 5 h after feeding the morning meal. A basal wheat- and barley-based diet was steam-pelleted at 90°C. The dietary treatments were a nonfermented basal diet (NF-BD), the NF-BD with microbial phytase (750 phytase units of phytase/kg, as-fed basis; NF-BD + phytase), and the NF-BD + phytase fermented for 17.5 h (F-BD + phytase). Gastric InsP₆-P was not detected at all in pigs fed F-BD + phytase because of complete InsP₆ degradation during fermentation of the feed before feeding. Gastric InsP₆-P decreased over time (P < 0.05) in pigs fed NF-BD and NF-BD + phytase. The decreases were 45, 54, 56, and 61 percentage points greater at 1, 2, 3, and 5 h, respectively, in pigs fed NF-BD + phytase compared with NF-BD. However, substantial amounts of InsP₆ still passed into the small intestine in pigs fed NF-BD + phytase, especially within the first hour (estimated to 17% of InsP₆-P intake). The accumulation of lower inositol phosphates in gastric digesta was very small for all treatments and at all times because of a rapid and almost complete degradation. In conclusion, phytase addition to the nonfermented diet increased the degradation of gastric InsP₆. However, considerable amounts of intact InsP₆ still passed into the small intestine because of a shortage of time for InsP₆ degradation in the stomach. Therefore, to increase the apparent digestibility of plant P in dry wheat- and barley-based diets, the development of phytases that can degrade InsP₆ effectively immediately after ingestion of the feed at an initial gastric pH from 6.5 to 5.0 is needed. Feeding F-BD + phytase compensated for the shortage of time because the InsP₆ degradation was completed during fermentation before feeding. The degradation of InsP₆ to InsP₅ is the bottleneck for plant P utilization in pigs because the degradation of the lower inositol phosphates is rapid and almost complete.

Effect of ensiling triticale, barley and wheat grains at different moisture content and addition of Lactobacillus plantarum (DSMZ 8866 and 8862) on fermentation characteristics and nutrient digestibility in pigs

The ensiling characteristics of barley, triticale and wheat grains at two different moisture levels, with and without the addition of lactic acid bacteria (LAB, Lactobacillus plantarum DSMZ 8862 and 8866) were determined after a 50-day storage period. In addition, the impact of the different ensiling techniques on the nutritional value was determined in pigs. In Experiment (Exp.) 1, mature grains were ground and water was added to adjust the moisture to 250 g kg −1 (low moisture content, LMC) or 350 g kg −1 (high moisture content, HMC). Grains were ensiled in laboratory scale silos for 3, 10 and 50 days. In the HMC silos, pH declined within 3 days irrespective of LAB treatment. In the LAB treated LMC, pH declined after 10 days of storage, whereas pH of untreated grains remained unchanged. Lactic acid production was higher (P<0.05) in HMC than in LMC grains, with almost no acid production with the untreated LMC grains. Denaturing gradient gel electrophoresis analysis revealed that the composition of the bacterial communities changed when LAB was added. Nutrient digestibility of HMC and LMC grains ensiled for 50 days with addition of LAB and untreated dry grains was determined separately for each grain in pigs. Digestibility was increased in LMC (crude fibre, crude protein, phosphorus) and HMC (ether extract) wheat grains, whereas only ether extract digestibility was improved in HMC triticale and no differences were observed for barley. A higher (P<0.05) phosphorus digestibility was observed in LMC triticale and wheat as compared to the dry grains, likely due to reduced phytate-P after ensiling. The results show that cereals with a moisture content of 250 g kg −1 can be ensiled successfully provided that LAB is added, and that under these conditions phosphorus availability is increased.

Evaluation of different microbial phytases on phosphorus digestibility in pigs fed a wheat and barley based diet

Phytase increases the availability of phytate phosphorus (P) in plant feedstuffs resulting in a reduced need for inorganic P addition and therefore minimized P excretion. Thus, the majority of pig feed is supplemented with microbial phytases. The present study aimed to examine three commercial phytases: one fungal 3-phytase from Aspergillus ficuum and two formulations of a bacterial 6-phytase from E. coli. The basal diet was composed of wheat, barley, soybean and rapeseed meal supplemented with vitamins and minerals without any added inorganic phosphate. Calcium was adjusted to 6.3 g/kg in the basal diet which was heat-treated at 90 °C. Phytase was then added at 250, 500 and 750 FTU/kg diet. A negative control without added phytase was included (plant phytase < 100 FTU/kg DM). The experiment comprised 10 treatments of 6 pigs (45 kg) kept in metabolism crates and fed one of the 10 diets for 12 days, 5 days for adaptation and 7 days for total collection of faeces. The P digestibility of the negative control was 31%, which increased significantly to 45, 50 and 53% when phytases were added at 250, 500 or 750 FTU/kg, respectively. The study showed the same efficacy for the fungal 3-phytase and the two bacterial 6-phytases on P digestibility at all three tested levels. The increase in P digestibility was greatest in the dosage range from 0 to 250 FTU/kg, while the increase was linear in the range between 250 and 750 FTU/kg.

Microbial phytase and liquid feeding increase phytate degradation in the gastrointestinal tract of growing pigs

The quantitative degradation of inositol phosphates (InsP 6 to InsP 2) in the stomach and small intestine as influenced by microbial phytase and fermented liquid feeding was compared by combining the results from two experiments. Six pigs (49 kg) were fitted with gastric cannulas ( Exp. 1) and 3 pigs (42 kg) were fitted with special ileal cannulas ( Exp. 2) for total collection of digesta. The pigs were castrated males, and both experiments were 3 × 3 Latin squares. A basal wheat/barley diet was pelleted at 90 °C (P 4 and Ca 7 g/kg DM). Diet 1, basal diet fed dry; diet 2, diet 1 with microbial phytase (750 FTU/kg) fed dry; diet 3, diet 2 fed in liquid form (fermented 17.5 h, 20 °C, 50% residual in the tank). InsP 6-P was not present in gastric or ileal digesta in pigs fed diet 3 due to complete InsP 6 degradation before feeding. In pigs fed diet 2 the amount of gastric InsP 6-P was considerably smaller compared with pigs fed diet 1 due to phytase addition (P ≤ 0.001). On the other hand, the amount of ileal InsP 6-P was only slightly less in pigs fed diet 2 compared with diet 1 indicating that InsP 6 is greatly degraded in the small intestine. Furthermore, the amounts of gastric or ileal InsP 5–InsP 2-P were very small for all diets showing that degradation of these compounds is rapid and nearly complete.

A comparison of two methods to assess nutrient digestibility in pigs

The noninvasive estimation of nutrient digestibility (DIG) is usually done by total collection (TC) of feces in balance crates or by the indicator method (IM) using an indigestible marker such as chromic oxide (CO). TC is precise but involves much labor. These methods were compared using pigs fed corn–soybean meal diets. In Trial 1, 10 pigs (68.1 kg) were individually housed in metabolism crates for a 5-day (d) TC. The IM phase immediately followed by adding CO to the feed for 2 consecutive d, and collecting a single grab fecal sample. In Trial 2, 24 pigs (66.2 kg) were used and Cr was fed for 7 consecutive d with single samples collected for 5 d starting when the stool color appeared bright green (which usually occurred on d3 after Cr was fed). Samples were composited into 5 final samples (d1, d1 + 2, d1 + 2 + 3, d1 + 2 + 3 + 4, d1 + 2 + 3 + 4 + 5) labeled D1, D2, D3, D4, and D5, respectively. In Trial 1, DIG values of DM, energy, and N were 2–3 percentage points lower for IM vs TC; DIG of Ca and P was 10–20 percentage points lower for IM. Differences related to dietary treatments were observed for 4 of these nutrients with TC but none of the nutrients with IM. In Trial 2, DIG by IM increased from D1 through D5, coinciding with increasing Cr excretion. For the macronutrients evaluated, all reached their DIG plateaus by D5 and similar values were observed between TC and IM. Dietary treatment differences were observed for Ca and P by TC and were also detected by IM. It is concluded that a multiday sample works better than a single grab sample for IM and that several days of marker observance are required before the marker content stabilizes in feces.

Nutritional evaluation of genetically modified rice expressing human lactoferrin gene

The nutritional quality of a new strain of genetically modified rice ( Oryza sativa L.) expressing human lactoferrin gene (hLF rice) was evaluated on the basis of components, nutrient digestibility in pigs, protein availability in rats and protein digestibility corrected amino acid scores (PDCAAS), and compared to its parental rice variety (PR rice). Although exogenous human lactoferrin gene was introduced, it did not interfere with the digestibility of protein, carbohydrates, fat and crude fiber. The revised protein efficiency ratio of hLF rice was increased to 2.50, which was significantly higher than that of PR rice. The PDCAAS of PR rice was 52.66 and its first limiting amino acid was lysine, while the PDCAAS of hLF rice was improved to 54.06 and its first limiting amino acid was tryptophan. Thus, it can be concluded that the nutritional quality of hLF rice is superior to PR rice according to the results of availability experiments and PDCAAS, and the hLF rice would be a superior strain of rice based on protein composition of the grain.

A preliminary study on the length of incubation needed to maximize guanidination of lysine in distillers dried grains with solubles (DDGS) and in pig ileal digesta

In heat-processed feed ingredients, the concentration of bioavailable lysine (Lys) may be estimated by measuring the amount of ileal digestible Lys that has a free ɛ–NH 2 ( i.e., not bound to reducing sugars). This Lys, called ileal digestible reactive Lys, is determined by measuring the reactive Lys in the feed ingredient and in ileal digesta of pigs fed the feed ingredient. A procedure used to measure reactive Lys in feed ingredients and in ileal digesta samples is the homoarginine procedure, which consists of a guanidination to convert the Lys that has a free ɛ–NH 2 group into homoarginine. However, the incubation time needed to maximize the guanidination can vary among types of protein and there is no information on the time needed to maximize guanidination in ileal digesta from pigs. Thus, an experiment was conducted to determine the optimum time of incubation needed to guanidinate Lys in maize distillers dried grains with solubles (DDGS) and in ileal digesta from a pig fed a diet containing maize DDGS as the sole source of Lys and other amino acids. A DDGS sample was guanidinated in 0.6 M O-methylisourea reagent at pH 11.4 for 1, 3, 6, or 9 days. Ileal digesta from a pig fed a diet containing DDGS was also incubated in 0.6 M O-methylisourea for 1, 3 or 6 days. The incubation time that resulted in maximal amount of Lys that had been converted to homoarginine was then determined. Results showed that in DDGS, the optimum incubation time in DDGS was 3.2 days (P<0.05). For ileal digesta, breakpoint analysis showed that the optimum incubation time was 3.7 days (P<0.05). In conclusion, the optimum conversion of Lys to homoarginine in DDGS and in ileal digesta requires an incubation time of 3.2 and 3.7 days, respectively, if 0.6 M O-methylisourea is used for incubation at a pH of 11.4.

The Effects of Different Copper (Inorganic and Organic) and Energy (Tallow and Glycerol) Sources on Growth Performance, Nutrient Digestibility, and Fecal Excretion Profiles in Growing Pigs

This study was conducted to determine the effects of different copper (inorganic and organic) and energy (tallow and glycerol) sources on growth performance, nutrient digestibility, gas emission, diarrhea incidence, and fecal copper concentration in growing pigs by using a 2x2 factorial design. In this trial, 96 pigs (63 d of age) were employed, with an average initial weight of 28.36±1.14 kg. The dietary treatments were i) basal diet with 134 ppm copper (Korea recommendation) as CuSO 4 +tallow; ii) basal diet with 134 ppm Cu as CuSO 4 +glycerol; iii) basal diet with 134 ppm copper as CuMet+tallow; and iv) basal diet with 134 ppm copper as CuMet+ glycerol. Throughout the entire experimental period, no differences were noted among treatment groups with regard to the magnitude of improvement in ADG (average daily gain), ADFI (average daily feed intake) and G/F (gain:feed) ratios. The nitrogen (N) digestibility of pigs fed on diets containing organic copper was improved as compared with that observed in pigs fed on diets containing inorganic copper (p<0.05). An interaction of copperxenergy was observed in the context of both nitrogen (p<0.05) and energy (p<0.01) digestibility. Ammonia emissions were significantly lower in the organic copper-added treatment groups than in the inorganic copper-added treatment groups (p<0.05). Mercaptan and hydrogen sulfide emissions were reduced via the addition of glycerol (p<0.05). No significant effects of copper or energy source, or their interaction, were observed in reference to diarrhea appearance and incidence throughout the entirety of the experimental period. The copper concentration in the feces was significantly lower in the organic copper source treatment group than was observed in the inorganic copper source treatment group (p<0.05). The results of this experiment show that organic copper substituted for inorganic copper in the diet results in a decreased fecal copper excretion, but exerts no effect on performance. The different energy (tallow and glycerol) sources interact with different copper sources and thus influence nutrient digestibility. Glycerol supplementation may reduce the concentrations of odorous sulfuric compounds with different Cu sources.

In-vitro assessment of the effects of dietary fibers on microbial fermentation and communities from large intestinal digesta of pigs

Dietary fibers (oat β-glucan, flaxseed gum, and fenugreek gum) can be fermented to short chain fatty acids (SCFAs) in batch cultures by pig intestinal digesta. Lactate in the β-glucan-grown cultures had the highest level among SCFAs produced, whereas flaxseed or fenugreek gum-containing cultures generated a significant amount of acetate, propionate and butyrate over three subcultures tested ( p < 0.05). Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA genes in the initial and subcultures revealed that types of fibers impacted pronouncedly on the bacterial community structure. Identified DGGE DNA bands were mainly affiliated with Bacteroidetes, and Firmicutes, in which numbers of butyrate-producing species were widely distributed. The fermentability of dietary fibers to SCFAs and their selection towards the bacterial communities suggest their potential application in promoting animal/human health.

Heat-treatment, phytase and fermented liquid feeding affect the presence of inositol phosphates in ileal digesta and phosphorus digestibility in pigs fed a wheat and barley diet

The aim was to evaluate the effect of heat-treatment, microbial phytase addition and feeding strategy (dry feeding v. fermented liquid feeding) on degradation of phytate (myo-inositol hexakisphosphate, InsP6) and formation and further degradation of lower inositol phosphates (myo-inositol pentakisphosphate–myo-inositol bisphosphate, InsP5–InsP2) at the distal ileum of pigs. Furthermore, the apparent ileal digestibility/degradability (AID) of phosphorus (P), InsP6–P and calcium (Ca) and the apparent total tract digestibility (ATTD) of P and Ca were studied. Pigs were fitted with a T-shaped ileal cannula for total collection of digesta at 2 h intervals during an 8 h sampling period after feeding the morning meal. Each period lasted for 2 weeks: 8 days of adaptation followed by 3 days of total collection of faeces and 3 days of total collection of ileal digesta. The experiment was designed as a 4 × 4 Latin square with four pigs fed four diets. A basal wheat/barley-based diet was fed either as non-heat-treated or heat-treated (steam-pelleted at 90°C). The heat-treatment resulted in an inactivation of plant phytase below detectable level. Diet 1 (non-heat-treated basal diet fed dry); diet 2 (heat-treated basal diet fed dry); diet 3 (as diet 2 but with microbial phytase (750 FTU/kg as fed) fed dry); diet 4 (as diet 3 fed liquid (fermented for 17.5 h nighttime and 6.5 h daytime at 20°C with 50% residue in the tank)). Chromic oxide (Cr2O3) was included as marker and ATTD was determined both by total collection of faeces (ATTDTotal) and Cr2O3 (ATTDCr). InsP6 was completely degraded in diet 4 before feeding resulting in no InsP6–P being present in ileal digesta. InsP6–P concentration in ileal digesta decreased with increasing dietary levels of plant or microbial phytase in pigs fed the dry diets. Consequently, AID and ATTD of P and Ca were greatest for pigs fed diet 4 followed by diets 3, 1 and 2. The ATTD of P depended on the used method as ATTDTotal of P was 72%, 61%, 44% and 34%, whereas ATTDCr of P was 65%, 52%, 38% and 23% for diets 4, 3, 1 and 2, respectively. In all pigs the ileal concentration of InsP5–InsP2–P was extremely small, and thus unimportant for maximisation of ATTD of plant P. In conclusion, fermented liquid feeding with microbial phytase seems to be an efficient approach to improve ATTD of plant P compared with dry feeding. This opens up for further reductions in P excretion.

Effects of Different Sources of Dietary Chromium on Growth, Blood Profiles and Carcass Traits in Growing-finishing Pigs

This study was carried out to evaluate the effects of dietary supplementation of different sources of chromium on growth performance, blood profile and carcass trait in growing-finishing pigs. A total of 200 growing pigs (LandraceYorkshire)Duroc, average initial weight 8.5 kg) were allotted to 5 treatments with 4 replicates per treatment and 10 pigs per replicate. Five treatments were designated as follows according to the source of chromium. i) Control (No chromium): corn-soybean meal based basal diet, ii) : control diet+200 ppb Cr as , iii) CrPic: control diet+200 ppb Cr as Cr picolinate, iv) CrMet-1: control diet+100 ppb Cr as Cr methionine, and v) CrMet-2: control diet+200 ppb Cr as Cr methionine. After the feeding trial, three pigs per replicate (12 pigs per treatment) were slaughtered for the evaluation of carcass traits. Average daily gain (ADG), average daily feed intake (ADFI), and feed: gain ratio (F/G) were not different (p>0.05) among dietary Cr sources. However, whole-period ADG of pigs fed CrPic, CrMet-1 and CrMet-2 diets was higher (p0.05) among dietary Cr sources, but the nutrient digestibility of pigs fed CrPic, CrMet-1 and CrMet-2 diets was higher (p and CrPic treatments than in the control only during the 90-110 kg phase. Backfat thickness was thinner (p0.05) among treatments. In conclusion, dietary supplementation of 200 ppb Cr, via either CrPic or CrMet, improved pig growth performance and nutrient digestibility. Moreover, dietary CrMet supplementation for the growing-finishing pig is evidently remarkable for improving both lean percentage of the carcass and backfat thickness.

Effects of nanocopper on copper availability and nutrients digestibility, growth performance and serum traits of piglets

Copper is a microelement routinely added to facilitate the normal growth of pigs. Copper fed at 30 to 250 mg/kg is recognized for its growth enhancement effect, particularly in weaned pigs. Past studies have proved its effect in improving the growth performance of pigs due to its antibacterial properties. However, studies also showed that the addition of high levels of copper results in low digestibility and absorption, which causes increased excretion of this mineral in feces and poses an environmental problem. This study aimed to enhance the copper digestibility in pigs when it is used as a growth promotant by modifying the copper size into nanometer. It is hoped that by improving the absorption of copper in pigs, the fecal excretion levels could be reduced and minimize environmental pollution. Two experiments were performed to explore the effects of nanocopper supplementation on the serum traits of weanling pigs. Using crossover design, eight LYD growing pigs were randomly assigned to three treatment groups, which are control, nanoCu and CuSO 4, to investigate the effect of nanoCu supplementation on the availability of copper and digestibility of nutrients in pigs. Each treatment was replicated thrice. Another trial was conducted on thirty-six LYD weanling pigs to determine the effect of supplementing nanoCu on their growth performance and serum traits. For both trials, copper levels in nanoCu and CuSO 4 groups were supplemented at a ratio of 50 mg/kg. Experimental results indicated statistically significant improvements in growth performance of the piglets when copper was supplemented at nanosize. Copper availability was significantly improved and feces copper level was reduced in the nanoCu supplemented group, as compared to the CuSO 4 group. Significant differences were observed in the improvement of the digestibility of crude fat and energy in pigs under nanoCu diet. The serum copper level and serum cholesterol concentrations, as well as hematology traits— RBC, WBC, MCV, HGB, HCT, PLT and RDW, were not affected by nanoCu supplementation. However, statistically significant improvements were observed in the IgG, γ-globulin and total globulin protein levels, and in the SOD activity of the nanoCu group. In conclusion, nanosize copper supplementation was proven to reduce copper excretion level in piglets, improve the digestible energy and absorption of fat, and enhance the SOD activity in blood serum and the immunity level of piglets.

Effect of dietary protein level on growth performance, indicators of enteric health, and gastrointestinal microbial ecology of weaned pigs induced with postweaning colibacillosis1,2

The effect of dietary CP level on performance, enteric health, and gastrointestinal microbial ecology of weaned pigs challenged with enterotoxigenic Escherichia coli (ETEC) K88 was investigated in a 14-d study. Forty weaned pigs (BW = 5.32 +/- 0.24 kg, mean +/- SD), housed 4 per pen, were randomly assigned to 2 diets (5 pens/diet): 1) 22.5% CP or 2) 17.6% CP supplemented with AA. Diets contained the same amount of ME and standardized ileal digestible Lys, Met + Cys, Thr, and Trp based on the ideal protein ratio. Isoleucine and Val were added to the 17.6% CP diet up to the level in the 22.5% CP diet. On d 8 postweaning, pigs were challenged with 6 mL of ETEC suspension (10(10) cfu/mL) by gavage. Feed disappearance and BW were measured on d 7, 9, 10, 12, and 14 for determination of ADG, ADFI, and G:F. One pig from each pen was serially slaughtered on -1, 3, and 7 d postchallenge (10 pigs/d of slaughter) to evaluate gut morphology, and gut microbial ecology and metabolites. Pigs fed the 22.5% CP diet had greater (P < 0.05) ADG and G:F than those fed the 17.6% CP diet before infection, but performance was similar between the 2 diets after ETEC challenge and overall. On d 3 after challenge, ETEC was not detected in the ileal digesta of pigs fed the 17.6% CP diet but was detected in the ileal digesta of 80% of pigs fed the 22.5% CP diet (5.22 +/- 1.07 cfu/g, mean +/- SD). Pigs fed the 17.6% CP diet had a greater (P < 0.01) prevalence of order Clostridiales (73 vs. 50%), family Lachnospiraceae (43 vs. 18%), and genus Roseburia (13 vs. 3%) in the colon digesta 7 d after challenge compared with those fed the 22.5% CP diet. The richness and diversity of bacteria in the colon digesta were less (P < 0.05) in pigs fed the 17.6% CP diet than in those fed the 22.5% CP diet at -1, 3, and 7 d postchallenge. Pigs fed the 22.5% CP diet had greater (P < 0.05) ammonia N concentration in the colon digesta on -1 and 7 d after challenge compared with those fed the 17.6% CP diet. Pigs fed the 22.5% CP diet had deeper (P < 0.05) crypts 1 d before challenge, shorter villi 3 d after challenge, and reduced villus height:crypt depth 1 d before and 3 d after challenge compared with those fed the 17.6% CP diet. In conclusion, a reduction in the dietary CP level of weaned pigs from 22.5 to 17.6% with AA supplementation impaired growth performance before, but not after, the ETEC challenge and increased the relative composition of butyrate producing bacteria in the colon digesta after ETEC challenge.