Nutrient digestibilities,microbial populations,and protein catabolites as affected by fructan supplementation of dog diets

Fructans are fermentable carbohydrates and include short-chain fructooligosaccharides (scFOS), inulin, and hydrolyzed inulin (oligofructose, OF). Two studies with dogs were designed to examine the effects of low concentrations of fructans on nutrient digestibilities, fecal microbial populations, and endproducts of protein fermentation, and fecal characteristics. In Exp. 1, 11 adult male beagles were fed corn-based, kibbled diets supplemented with or without OF to provide 1.9 +/- 0.6 g/d. Dietary inclusion of OF decreased (P < 0.05) nutrient digestibilities, but did not affect fecal characteristics. Increasing OF concentration tended (P < 0.06) to linearly decrease fecal ammonia concentrations, but not those of branched-chain fatty acids (BCFA), amines, indole, or phenols. Fecal concentrations of total short-chain fatty acids (SCFA) and butyrate tended to be higher in OF-supplemented dogs (P < 0.10), as was the ratio of bifidobacteria to total anaerobes (P = 0.15). In Exp. 2, ileally cannulated adult female hounds were fed a meat-based kibbled diet and were assigned to four scFOS treatments (0, 1, 2, or 3 g/d) in a 4 x 4 Latin square design. Ileal nutrient digestibilities tended to increase (P < 0.15) with increasing concentrations of scFOS. On a DMI basis, fecal output tended to decrease linearly (P < 0.10) in response to increasing scFOS supplementation, whereas fecal score tended to exhibit a quadratic response (P = 0.12). In general, fecal concentrations of SCFA, BCFA, ammonia, phenols, and indoles were not altered by supplemental scFOS. Supplementation of scFOS increased fecal concentrations of total aerobes (P < 0.05) and decreased concentrations of Clostridium perfringens (P < 0.05). From these data, it seems that low levels of supplemental fructans have divergent effects on nutrient digestibility and fermentative endproducts, but do not adversely affect nutrient digestibility or fecal characteristics and may improve colonic microbial ecology in dogs.     

Quantifying differences in total tract nutrient digestibilities between goats and sheep

Conclusions from narrative qualitative reviews on differences in total tract digestibilities between goats and sheep did not account for variability among studies. Therefore meta‐analytic techniques were used to describe the magnitude of these differences with numerical values. A unitless effect size (Hedges’ g) was applied within studies to measure differences in digestibilities of dry matter (DM; 104 comparisons), organic matter (OM; 93 comparisons), crude protein (CP; 85 comparisons), neutral detergent fibre (NDF; 74 comparisons), acid detergent fibre (ADF; 59 comparisons), cellulose (24 comparisons), hemicellulose (18 comparisons) and gross energy (GE; 29 comparisons). The absence and inability to describe independent factors which contributed to variation among studies necessitated the use of frequentist random effects and hierarchical Bayesian models in the calculation of summary statistics across studies. Digestibilities of DM, OM, CP, NDF, ADF and hemicellulose were higher (p < 0.05) in goats than sheep when all‐forage diets were fed. When concentrates were included in the diets, there were no such differences. Differences between goats and sheep in DM intake were found to be non‐significant. Differences in nutrient digestibilities of forages as sole feed implies that species‐specific values have to be used in feed formulation and feeding strategies. However, caution is needed when extrapolating results from stall‐feeding, which is how digestibility data are usually measured, to grazing conditions.     

Selected gelling agents in canned dog food affect nutrient digestibilities and fecal characteristics of ileal cannulated dogs.

Little is known about the effects of gelling agents in canned dog food on nutrient digestibilities and fecal characteristics. Dogs were fed canned diets with either no gelling agent (control) or one of three gelling agents, wheat starch, a guar gum/carrageenan mixture (50:50), and a locust bean meal (LBM)/carrageenan mixture (50:50) incorporated at two levels (0.2 and 0.5% of the diet on a wet weight basis). Six dogs were fed each diet in a 6 x 7 Youden square design. Dogs fed diets containing gelling agents had higher ileal digestibilities of OM (P = 0.05), fat (P < 0.01), GE (P = 0.02), and total amino acids (P = 0.04) and lower (P < 0.01) total tract DM digestibilities when compared to dogs fed the control diet. Fecal output by dogs fed the control diet, expressed on both an as-is (73.4 g/d) and DM (45.6 g/d) basis, was lower (P < 0.01) than for dogs fed gelling agent-containing diets (mean 102.3 g/d as-is and 57.6 g/d DM). Dogs fed the control diet also had lower (P < 0.01) fecal DM percentages and higher (P = 0.02) fecal scores than dogs fed gelling agent-containing diets.     

Apparent total tract energy and macronutrient digestibility and fecal fermentative end-product concentrations of domestic cats fed extruded, raw beef-based, and cooked beef-based diets

The objectives of this study were to determine differences in apparent total tract energy and macronutrient digestibility, fecal and urine characteristics, and serum chemistry of domestic cats fed raw and cooked meat-based diets and extruded diet. Nine adult female domestic shorthair cats were utilized in a replicated 3 × 3 Latin square design. Dietary treatments included a high-protein extruded diet (EX; 57% CP), a raw beef-based diet (RB; 53% CP), and a cooked beef-based diet (CB; 52% CP). Cats were housed individually in metabolic cages and fed to maintain BW. The study consisted of three 21-d periods. Each period included diet adaptation during d 0 to 16; fecal and urine sample collections during d 17 to 20; and blood sample collection at d 21. Food intake was measured daily. Total feces and urine were collected for determination of nutrient digestibility. In addition, a fresh urine sample was collected from each cat for urinalysis, and a fresh fecal sample was collected from each cat for determination of DM percentage and ammonia, short-chain fatty acid (SCFA), and branched-chain fatty acid (BCFA) concentrations. All feces were scored after collection using a scale ranging from 1 (hard, dry pellets) to 5 (watery, liquid that can be poured). Blood was analyzed for serum metabolites. Apparent total tract DM, OM, CP, fat, and GE digestibilities were greater (P ≤ 0.05) in cats fed RB and CB than those fed EX. Total fecal SCFA concentrations did not differ among dietary treatments; however, molar ratios of SCFA were modified by diet, with cats fed RB and CB having an increased (P ≤ 0.05) proportion of fecal propionate and decreased (P ≤ 0.05) proportion of fecal butyrate compared with cats fed EX. Fecal concentrations of ammonia, isobutyrate, valerate, isovalerate, and total BCFA were greater (P ≤ 0.05) in cats fed EX compared with cats fed RB and CB. Our results indicated that cooking a raw meat diet does not alter apparent total tract energy and macronutrient digestibility and may also minimize risk of microbial contamination. Given the increasing popularity of feeding raw diets and the metabolic differences noted in this experiment, further research focused on the adequacy and safety of raw beef-based diets in domestic cats is justified.     

膨化全脂大豆对仔猪生产性能和养分消化率的影响

根据遗传、性别、体质量等相一致的原则,将30头35日龄断奶的杜洛克仔猪随机分为3组,每组设2个重复,研究膨化全脂大豆对仔猪生产性能和饲粮养分消化率的影响。对照组以玉米豆粕等配制饲粮,试验1组以膨化全脂大豆替代50%的豆粕,试验2组以膨化全脂大豆替代全部豆粕,其他饲粮组成保持不变,进行40d的饲养试验。在试验第20天开始,连续收集粪便3d,测定饲粮养分消化率。结果表明,试验1组日增重比对照组提高了17.6%,差异显著(P<0.05),试验2组比对照组提高了7.4%(P>0.05);试验1组和试验2组饲料利用率分别比对照组提高11.7%和7.6%。试验2组干物质消化率显著高于对照组(P<0.05),蛋白质的消化率3组基本接近,但含有膨化大豆的试验1组和试验2组的粗脂肪和粗灰分的消化率均比对照组有提高趋势。     

Evaluation of stabilized rice bran as an ingredient in dry extruded dog diets

The objectives of this research were to examine the palatability of stabilized rice bran (SRB) when included in a dry canine diet, and to determine the effects of SRB on food intake, digestion, fecal characteristics, blood lipid characteristics, and selected immune mediators. Experiment 1 tested the palatability of SRB. Diets contained poultry fat in Test 1 and soybean oil in Test 2, in conjunction with either 12% SRB or 12% defatted rice bran (DRB, as-fed basis), and were fed to 20 dogs. Diets contained approximately 32% protein and 22% fat (DM basis). Food intake data were collected and intake ratios calculated (grams of SRB diet consumed divided by total consumed of both diets). Intake ratios were 0.73 for Test 1 (P < 0.01) and 0.61 for Test 2 (P < 0.14) for SRB diets. Diets in Exp. 2 contained 12% SRB or DRB (as-fed basis), and poultry fat, beef tallow, or poultry fat:soybean oil (50:50) as the main fat sources, and were fed to 36 beagles. Diets contained approximately 32% protein and 22% fat (DM basis). The effects of SRB and DRB were determined on food intake, digestibility, fecal characteristics, and blood fatty acid, phospholipid, and eicosanoid concentrations. No differences were noted in food intake, digestibility, or fecal characteristics. Fat sources contributed much more to dietary fat than rice bran source; therefore, fat source profiles overwhelmed the rice bran source contribution. Dogs consuming a DRB diet had lower (P < 0.050) plasma phospholipid total monounsaturated fatty acids compared with those consuming a SRB diet (-1.17 vs. 0.95%, respectively), whereas plasma fatty acid concentrations tended (P < 0.119) to decrease more than with SRB diets. Total concentrations of red blood cell phospholipid SFA tended (P < 0.15) to be greater in dogs consuming a beef tallow-containing diet compared with those consuming a poultry fat or poultry fat:soybean oil diet. Total concentrations of red blood cell phospholipid PUFA and n-6 PUFA tended to be greater (P < 0.097 and P < 0.083, respectively) in dogs consuming a poultry fat-containing diet than in those consuming a beef tallow-containing diet. Statistical differences and tendencies were detected in individual plasma fatty acids and plasma and red blood cell phospholipids due to rice bran source, fat source, and their interaction. Eicosanoid concentrations did not change due to treatment. Stabilized rice bran is a highly palatable ingredient when included in a dry dog diet, and did not elicit an effect on inflammatory immune mediators in healthy dogs.     

Selected animal and plant protein sources affect nutrient digestibility and fecal characteristics of ileally cannulated dogs.

The objective of this study was to compare ileal and total tract nutrient digestibilities and fecal characteristics of dogs fed selected animal and plant protein sources incorporated into grain-based diets. Four crude protein sources--soybean meal (SBM), poultry meal (PM), poultry by-product meal (PBPM), and beef and bone meal (BBM)--were fed to four ileal cannulated dogs in a 4 x 4 Latin square design. Intakes of dry matter, organic matter, crude protein, and fat by dogs were similar. Total dietary fiber (TDF) intake was highest for the SBM treatment compared to other treatments. Ileal digestibilities of DM, OM, CP, fat, and TDF were not affected by treatment. Total tract digestibility of DM was lower for the BBM and SBM diets, while OM digestibility was lower for the SBM treatment only. Total tract CP digestibility was similar for BBM, PBPM, and SBM treatments and was higher for the PM treatment. As-is fecal excretion [g/d] was greater when dogs received the SBM treatment. Fecal output on a DM basis was higher for the SBM treatment compared to the other treatments. All diets were well utilized by the dogs as assessed by ileal and total tract digestibility data and fecal characteristics.     

Ruminal and total tract digestibilities in steers fed diets containing liquefied or prilled saturated fatty acids.

We studied the effects of the addition of liquefied vs prilled mostly saturated fatty acids (FA) to the concentrate portion of total mixed diets on ruminal and total tract digestibilities. Four Holstein steers (270 +/- 23 kg) fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square design with 21-d periods. Diets contained (DM basis) 30.0% corn silage, 22.2% chopped alfalfa hay, 25.0% ground shelled corn, 12.5% soybean meal, and 5% of one of the following fat sources: 1) prilled FA (PFA), 2) choice white grease (triglycerides) added in liquid form (LTG), 3) 2.5% PFA + 2.5% LTG, or 4) 2.5% liquefied PFA (LFA) + 2.5% LTG. Ad libitum OM intake was not different (P > .10) among diets (mean 7.8 kg/d). Ruminal digestibilities of OM (35.7, 39.9, 42.2, and 37.3% for Diets 1 to 4, respectively) were greatest (P < .10) for the combination of PFA + LTG and lowest for PFA alone. Ruminal digestibilities of NDF, ADF, and starch did not differ (P > .10) among diets. Total tract digestibilities of OM, NDF, and ADF were greater (P < .10) for the diet containing LTG alone than for the diet containing LFA + LTG because of trends for greater postruminal digestibilities. The LFA + LTG diet resulted in a greater proportion of acetate and lower proportion of propionate in ruminal fluid than PFA alone (P < .10). The acetate:propionate ratio (3.53, 2.96, 3.10, and 2.89 for Diets 1 to 4, respectively) was lower (P < .05) for LFA + LTG or LTG alone than for PFA alone. Postruminal and total tract digestibilities of total FA (66.0, 76.0, 71.2, and 68.9% for Diets 1 to 4, respectively) were lower (P < .05) for PFA than for other diets. Addition of saturated FA in liquid form resulted in digestibilities and ruminal effects similar to the same saturated FA added in prilled form.     

Effect of enzymes of microbial origin on in vitro digestibilities of dry matter and crude protein in soybean meal

The effects of supplementation with cellulase, xylanase, pectinase, hemicellulase, glucanase, phytase and protease of microbial origin on digestibility of crude protein (CP) and dry matter (DM) of soybean meal in vitro were examined in the present study. Changes in viscosity during in vitro digestion were also examined as an index of carbohydrate digestibility. Hemicellulase and all enzyme combinations without protease showed significant improvement of CP digestibility. Cellulase, xylanase, phytase and glucanase tended to improve CP digestibility. Dry matter digestibility was improved significantly by pectinase and all enzyme combinations. Cellulase and phytase tended to improve DM digestibility. Crude protein and DM digestibilities were the highest when all the enzymes except protease were added. Protease, cellulase, pectinase, xylanase, glucanase and hemicellulase significantly reduced viscosity, while phytase had no effect on viscosity. Viscosity was increased unexpectedly when all the enzymes were added. These results strongly suggest that a combination of carbohydrases improves the CP and DM digestibility of soybean meal while protease inhibits the actions of these enzymes. The present study also suggests that viscosity is not always a good index of digestibility. Moreover, excluding the protease from commercial crude enzyme preparations may improve digestibility.     

Influence of enzyme supplementation of maize-soyabean meal diets on carcase composition, whole-body nutrient accretion and total tract nutrient retention of broilers

1. Carcase composition, whole body nutrient accretion rates and total tract nutrient retention of broilers in response to supplemental phytase or carbohydrase and protease from 0 to 21 d of age were investigated. 2. A total of 480 broilers were allocated to 4 slaughter groups (SG) of 30, 150, 150 and 150 broilers. Thirty broilers, in 6 replicates of 5 birds, comprised the initial SG killed at d 0; 150 broilers were allocated to each of the d 7, 14 and 21 final SG. Broilers in the final SG were allocated to 5 treatments in a randomised complete block design; each treatment had 6 replicate cages of 5 broilers per replicate cage. 3. The diets were maize-wheat-soyabean based and the treatments were: (1) positive control which met NRC (1994) energy and nutrients requirements for broiler, (2) negative control (NC) deficient in metabolisable energy (ME) and P, (3) NC plus phytase added at 1000 FTU/kg, (4) NC plus cocktail of xylanase, amylase and protease (XAP), and (5) NC plus phytase and XAP. 4. Except for ash and Ca, the treatments had no effect on carcase composition. Phytase or XAP individually or combined had variable effects on body nutrient accretion rates at various age periods of the broilers compared with the NC diet. Phytase alone or combined with XAP consistently improved body accretion rates of DM, protein, fat, ash, Ca, and P. 5. Addition of phytase alone or combined with XAP to the NC diet improved total tract N and P retention compared with the NC diet. Cocktail of XAP alone or combined with phytase improved Ca retention. Combination of phytase and XAP improved metabolisable energy (ME) and dry matter retention. 6. Overall, the results showed that the exogenous enzymes used had greater effects on the rates of nutrient accumulation in the carcase rather than on the proportion of nutrients deposited in the carcase.     

Effect of graded levels of dietary betaine on ileal and total tract nutrient digestibilities and intestinal bacterial metabolites in piglets*

The study was conducted to investigate the effects of graded dietary inclusion levels of betaine on ileal and total tract nutrient digestibilities and intestinal bacterial metabolites in piglets. A total of eight barrows with an average initial body weight of 7.9 kg were randomly allocated to one of the four assay diets with two pigs per treatment in four repeated measurement periods. The assay diets included a basal diet based on wheat, barley and soybean meal alone, or supplemented with a liquid betaine product at dietary levels of 1.5, 3.0, or 6.0 g betaine per kilogram diet (as‐fed). Ileal digestibilities of dry matter and neutral detergent fibre increased both quadratically and linearly, and ileal digestibility of glycine increased linearly as dietary betaine level increased (p < 0.05). Furthermore, total tract digestibility of crude protein increased quadratically (p < 0.05) and total tract digestibilities of most amino acids tended to increase quadratically (p = 0.06 to p = 0.11) with increasing dietary betaine level. Moreover, there were linear increases in the concentrations of most bacterial metabolites which were significant p < 0.05 for ileal d ‐lactic acid and for faecal diaminopimelic acid. The results demonstrate that dietary betaine supplementation stimulates bacterial fermentation of fibre in the small intestine and bacterial degradation of crude protein in the large intestine.     

Growth performance, carcass characteristics, nutrient digestibility and fecal odorous compounds in growing-finishing pigs fed diets containing hydrolyzed feather meal

This study was designed to determine the effects of hydrolyzed feather meal inclusion on growth performance, carcass characteristics, nutrient digestibility and fecal odorous compounds in modern lean growth genotype pigs. Two hundred forty pigs (BW = 23.2 +/- 1.3 kg) were allotted based on BW and sex to a 2 x 6 factorial arrangement of treatments (four pens per treatment; five pigs per pen) in a randomized complete block design. Factors consisted of 1) sex (barrows or gilts) and 2) dietary treatment (0, 2, 4, 6, 8, or 10% hydrolyzed feather meal). Diets were formulated to contain 1.00, 0.90, 0.75, or 0.60% apparent ileal digestible lysine for phases 1 to 4, respectively, with other amino acids provided at an ideal ratio. Available P and ME were kept constant within each phase. No significant interactions between feather meal inclusion and sex were observed for growth performance (P > 0.15). Body weight gain was reduced (P < 0.05) for pigs fed 10% feather meal compared to pigs fed 0, 4, or 8% feather meal. Feed intake of pigs fed 10% feather meal was reduced (P < 0.05) compared to pigs fed 0 or 4% feather meal. Ultrasound backfat measurements tended (P = 0.12) to increase with increasing levels of feather meal. Daily lean gain was less (P < 0.05) in pigs fed 10% feather meal than in pigs fed either 0, 2, 4, or 8% feather meal. Digestibility of N measured on wk 9 decreased quadratically (P < 0.001) with increasing levels of feather meal. Phosphorus digestibility increased in a linear fashion (P < 0.02), however, the improvement in P digestibility with increasing levels of feather meal was more pronounced in barrows compared to gilts (interaction, P < 0.05). Fecal samples obtained from pigs fed 0, 4, or 8% feather meal were analyzed for odorous compounds. Concentrations of butanoic, pentanoic, and 3-methylbutanoic acid were greater (P < 0.05) and concentrations of 3-methylphenol, 4-methylphenol, indole, and decane were less (P < 0.05) in feces from pigs fed feather meal. These results suggest that feather meal can be included in diets for growing-finishing pigs at a rate of 8%. Excretion of N in feces increased but P excretion decreased with increasing levels of feather meal. Odorous compounds in feces can be affected by the inclusion of hydrolyzed feather meal, but the exact impact of these changes on odor perception remains to be elucidated.     

Effect of extrusion on the ileal and fecal digestibilities of lysine, nitrogen, and energy in diets for young pigs.

Forty crossbred barrows (initial average BW of 20 kg) were fitted with T-cannulas in the distal ileum to determine the effects of extrusion of soybean meal on the apparent ileal and fecal digestibilities of lysine, N, and GE. A basal corn-soybean meal diet was formulated to contain .525% lysine. Nonextruded soybean meal (SM), extruded soybean meal (ESM), and L-lysine.HCl (LLH) replaced cornstarch in the basal diet to make diets containing .60, .675, and .75% total dietary lysine for each lysine source. Treatments were arranged as a 3 x 3 factorial with the basal diet as an additional treatment. Ileal and fecal digestibilities of lysine were not affected (P greater than .05) by source of lysine. However, linear increases (P less than .05) occurred in ileal lysine digestibilities with increasing concentrations of dietary lysine provided as LLH, but not when lysine was provided as SM or ESM. Apparent ileal and fecal retention of N as percentages of N absorbed or consumed were greater (P less than .05) for diets containing LLH than for diets containing SM, and diets containing ESM were intermediate. Linear increases (P less than .05) occurred in ileal and fecal N retained as percentages of N absorbed or consumed with increasing concentration of dietary lysine provided as LLH or ESM, but not when provided as SM. Fecal DE and ME (kilocalories per gram of diet) for diets containing LLH and ESM were similar and greater (P less than .05) than the values obtained for diets containing SM.(ABSTRACT TRUNCATED AT 250 WORDS)     

Apparent and standardized ileal digestibilities of amino acids for pigs fed corn- and soybean meal-based diets at varying crude protein levels

The objective of this study was to determine the effect of CP level in corn- and soybean meal-based diets on apparent (AID) and standardized ileal digestibility (SID) of AA. Six pigs (initial BW, 47.1 ± 1.0 kg) fitted with T-cannula at the distal ileum were fed 6 diets for 6 periods in a 6 × 6 Latin square design. The 6 diets consisted of a nitrogen-free diet and 5 corn- and soybean meal-based diets that contained CP of 68, 105, 141, 177, and 214 g/kg. Each period consisted of a 5-d adjustment period and 2 d of ileal digesta collection for 10 h on each of d 6 and 7. The ratio of corn:soybean meal was fixed at 3 to 2 by weight and cornstarch was added to dilute the CP concentration. Chromic oxide was added at 5 g/kg as an indigestible marker. The results showed basal endogenous loss ranged from 65 mg/kg of DMI for Met to 3,104 mg/kg of DMI for Pro. Proline and Gly (1,053 mg/kg of DMI) were the 2 most abundant AA in endogenous flow and together accounted for approximately 43% of the total endogenous AA flow. Of the basal ileal endogenous CP, total AA accounted for 82%. The AID were 80.9 to 84.7%, 85.1 to 87.4%, 72.9 to 79.5%, and 86.5 to 87.9% for Lys, Met, Thr, and Trp, respectively, with corresponding SID being 86.6 to 89.0%, 87.5 to 90.5%, 82.7 to 88.2%, and 90.2 to 94.6%, respectively, as dietary CP increased from 68 to 214 g/kg. There were linear increases in AID of N, Arg, Gly, Ile, Lys, Ser, Thr, Tyr, and Val (P ≤ 0.05) as CP increased and linear decreases in SID of N and all AA measured in this study except Lys, Met, and Pro (P ≤ 0.05). Both linear and quadratic effects were observed in AID for Pro (P < 0.05). In conclusion, the protein content of corn-soybean meal diets evaluated in the current study affected SID of most indispensable and dispensable AA, excluding Lys, Met, and Pro.     

Effect of extrusion on the ileal and fecal digestibilities of lysine in yellow corn in diets for young pigs

Forty crossbred barrows (initial avg BW of 20 kg) were fitted with T-cannulas to determine the effects of extrusion of yellow corn on lysine digestibility. A basal corn-cornstarch-soybean meal diet was formulated to contain .55% lysine. Extruded corn (EC), non-extruded corn (C) and L-Lysine-HCl (LLH) replaced cornstarch in the basal diet to provide total dietary lysine levels of .60, .65 and .70% lysine for each lysine source. Diet intake was 5.5% of BW. Treatments were arranged as a 3 x 3 factorial with the basal diet as an extra dietary treatment. Apparent ileal digestibilities of lysine, threonine, methionine and isoleucine were greater (P less than .05) for diets with added LLH than for diets containing EC or C, which were similar (P greater than .05). Apparent ileal and fecal digestibilities and retention of nitrogen (N) as a percentage of N absorbed or consumed were greater (P less than .05) for diets containing LLH than for those containing EC or C, which were not different (P greater than .05). Plasma urea N levels were also lower (P less than .05) for pigs fed diets containing LLH than for pigs fed EC or C. Fecal DE and ME as a percentage of GE were greater (P less than .05) in diets containing EC than in those containing C. In summary, extrusion improved (P less than .05) energy utilization but did not affect the utilization of lysine or N in corn by pigs. However, lysine and N utilization were greater (P less than .05) in diets supplemented with LLH compared with EC or C.     

Optimum grape pomace proportion in feedlot cattle diets: ruminal fermentation,total tract nutrient digestibility,nitrogen utilization,and blood metabolites

Because of its high content of polyphenolic compounds, the dietary inclusion of grape pomace (GP) in ruminant diets can reduce reactive nitrogen (N) and methane emissions and enhance the shelf life and beneficial fatty acids (FAs) content of meat. However, the dietary inclusion of GP beyond a threshold that is still to be determined for feedlot cattle can also compromise nutrient supply and, thus, growth performance. This study investigated the optimum proportion of GP in finishing cattle diets. Nutrient intake and apparent total tract digestion, ruminal pH and fermentation, estimated microbial protein synthesis, route of N excretion, and blood metabolites were measured. Six ruminally fistulated crossbred beef heifers (mean initial body weight ± SD: 714 ± 50.7 kg) were used in a replicated 3 × 3 Latin square with 21-d periods. Dietary treatments were 0%, 15%, and 30% of dietary dry matter (DM) as GP, with diets containing 84%, 69%, and 54% dry-rolled barley grain, respectively. There was a linear increase (P = 0.07) in DM intake and quadratic change (P ≤ 0.01) in neutral detergent fiber (NDF) intake. There was a quadratic change (P ≤ 0.04) in apparent total tract DM, NDF, and crude protein digestibility as dietary GP content increased. However, there were no treatment effects (P ≥ 0.18) on total ruminal short-chain FA concentration and duration and area pH < 6.2, 5.8, and 5.5. Although N intake did not differ (269, 262, 253 g/d; P = 0.33) across dietary treatments, feeding GP led to a tendency for a quadratic change (P ≤ 0.07) in ruminal ammonia-N and plasma urea-N concentrations. Total N excretion also changed (quadratic, P = 0.03) because of changes (quadratic, P = 0.02) in fecal N excretion as urinary excretion of N and urea-N did not differ (P ≥ 0.15) across treatments. Feeding GP led to quadratic changes (P ≤ 0.01) in fecal excretion of fiber-bound N. Microbial N flow and apparent N retention also changed (quadratic, P ≤ 0.04) as dietary GP proportion increased. In conclusion, responses to dietary GP proportion were mostly quadratic with indications that nutrient supply as reflected by changes in apparent total tract nutrient digestibility, microbial N supply, and apparent N retention could be compromised beyond a 15% dietary inclusion level.     

玉米-豆粕型日粮中添加复合酶对仔猪生长性能及养分消化率的影响

选用72头胎次一致,体重约20kg的健康的杜×长×大三元杂交断奶仔猪(公母各半),随机分为4组,每组3个重复,每个重复6头猪。处理Ⅰ为对照组,饲喂玉米-豆粕型基础日粮,处理Ⅱ、Ⅲ和Ⅳ为试验组,分别在基础日粮中添加0.1%,0.2%,0.3%植酸酶和纤维素酶的复合酶制剂,研究复合酶制剂对仔猪生长性能及养分消化率的影响。结果表明:试验组仔猪的平均日增重、饲料转化率以及营养物质的消化率均高于对照组,其中处理Ⅲ的效果最好,但各组的采食量差异不大。     

Growth performance,nutrient digestibility,and fecal microbial composition of weaned pigs fed multi-enzyme supplemented diets

A study determined the effects of supplementing corn-based diets for weaned pigs with multi-enzymes on growth performance, apparent total tract digestibility (ATTD) of nutrients, fecal score, and fecal microbial composition. A total of 132 pigs (initial body weight = 7.23 kg) that had been weaned at 21 d of age and fed a drug-free nursery diet for 7 d were housed in 33 pens of 4 barrows or gilts, blocked by body weight and gender, and fed 3 experimental diets at 11 pens per diet. The diets were corn-based diet without or with multi-enzyme A or B. Multi-enzyme A supplied 4,000 U of xylanase, 150 U of β-glucanase, 3,500 U of protease, and 1,500 U of amylase per kilogram of diet. Multi-enzyme B was the same as multi-enzyme A except that it supplied amylase at 150 U/kg, and that its source of amylase was different from that of multi-enzyme A. All diets contained phytase at 1,000 U/kg. The diets were fed for 35 d in 2 phases; phase 1 for the first 14 d and phase 2 for the last 21 d of the trial. Fecal score was determined daily during the first 7 d of the trial. Fecal samples were collected from rectum of 1 pig per pen on days 2, 7, 14, and 35 of the trial for determining bacterial composition. Also, fresh fecal samples were collected from each pen on days 41 and 42 to determine ATTD of nutrients. Multi-enzyme B increased (P < 0.05) average daily gain (ADG) for phases 1 and 2. For the overall study period, multi-enzyme B increased (P < 0.05) ADG from 262 to 313 g, and average daily feed intake (ADFI) from 419 to 504 g. Multi-enzyme A increased (P < 0.05) overall ADG from 262 to 290 g, but did not affect ADFI. Multi-enzyme A or B did not affect ATTD of gross energy, but increased (P < 0.05) the ATTD of ether extract from 30% to 36% or 37%, respectively. Multi-enzyme A did not affect fecal score; however, multi-enzyme B tended to decrease (P = 0.09) fecal score, implying that it tended to decrease diarrhea. Firmicutes were the most abundant phylum of fecal bacteria (its relative abundance ranged from 58% to 72%). Bacteroidetes and Actinobacteria were the 2nd and 3rd most abundant phyla of fecal bacteria. Neither multi-enzyme affected fecal bacterial composition. In conclusion, the addition of multi-enzyme A or B to phytase-supplemented corn-based diet for weaned pigs can improve their growth performance and fat digestibility. However, multi-enzyme B was more effective than multi-enzyme A in terms of improving the growth performance of weaned pigs fed corn-based diet.     

Effects of dietary Ca/P ratio, P level and microbial phytase supplementation on nutrient digestibilities in growing pigs: precaecal, post-ileal and total tract disappearances of OM,

Eight female pigs (26–61 kg) provided with a simple T-cannula about 10 cm proximal to the ileo-caecal valve, were used in two experiments to investigate the effects of Ca/P ratio, P level and supplementation with phytase (500 FTU/kg) on precaecal, post-ileal and total tract disappearances of organic matter (OM), phosphorus (P) and calcium (Ca). In experiment 1, two Ca/P ratios and two P levels were tested according to a 2 × 2 factorial arrangement within a Latin square design. In experiment 2, the diets of experiment 1 were supplemented with phytase (500 FTU/kg). There was a substantial absorption of OM, P and Ca in the post-ileal tract for all diets. Precaecal and total tract disappearances of OM were reduced by phytase addition (−4.4 and −0.8%, respectively). Supplementation with phytase resulted in an improvement of total tract and post-ileal P disappearances by 10.3 and 12.1%, respectively, without affecting precaecal P disappearance. Addition of feed phosphate resulted in a higher precaecal disappearance of P (+10.8%), resulting in a higher total tract disappearance of P (+5.9%). Addition of limestone had little effect on disappearances of OM, P and Ca, but reduced activity of supplemental phytase and had a negative influence on growth performance. Precaecal, post-ileal and total tract Ca disappearances were hardly affected by the examined dietary factors. The results might indicate that P from feed phosphate is absorbed primarily prececally and that P from phytate, liberated by microbial phytases, is dominantly absorbed post-illeally.