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Two experiments were conducted to study the effects of inclusion of additional fiber in the Phase I diet on growth performance and nutrient digestibility in piglets reared under "optimal" or "poor" hygienic conditions. In both experiments, the design was completely randomized with a control diet that contained 2.2% crude fiber and 8 additional isonutritive diets that included 2.5 or 5.0% of sugar beet pulp (SBP), straw, oat hulls (OH), or wheat middlings (WHM). Preplanned polynomial contrasts were used to study the effects of 1) fiber inclusion (control diet vs. average of the 8 fiber-containing diets), 2) source of fiber, 3) level of fiber, and 4) interaction between source and level of fiber. In Exp. 1 (clean barn), fiber inclusion increased ( < 0.01) the incidence of postweaning diarrhea (PWD) and reduced ( < 0.05) feed efficiency and apparent total tract digestibility (ATTD) of all nutrients except that of CP, which was not affected. Piglet performance was not affected by source or level of dietary fiber. The ATTD of all nutrients decreased ( < 0.05) as the level of fiber increased and was lower in pigs fed straw or OH than in pigs fed SBP or WHM. The apparent ileal digestibility of GE and DM decreased ( < 0.05) with fiber inclusion, a reduction that was more pronounced ( < 0.05) with straw or SBP than with OH inclusion, with WHM inclusion being intermediate. Fiber inclusion did not affect villous height to crypt depth ratio of the ileum mucosa. The inclusion of 5% of a fiber source increased and counts in the cecum ( < 0.001) but the to ratio was not affected. In Exp. 2 (dirty barn), fiber inclusion did not affect piglet performance but tended to increase PWD ( = 0.07). Also, fiber inclusion reduced ( < 0.05) the ATTD of all dietary components except that of CP, which was not affected. Source and level of fiber did not affect ATTD of nutrients except for DM, which was greater for pigs fed SBP than for pigs fed straw ( < 0.05). In conclusion, in the current research, pigs reared under optimal hygienic conditions had lower incidence of PWD, better growth performance, and greater DM and GE digestibility than pigs reared under poor hygienic conditions. An excess of dietary fiber was more detrimental for all these traits in piglets reared under optimal hygienic conditions. The effects of the source and level of fiber on piglet performance was limited in the 2 experiments.

In the present study, we have hypothesized that replacing barley with high proportions of dried citrus pulp in a concentrate-based diet for lambs could increase the intake of unsaturated fatty acids and could reduce the rate of the ruminal biohydrogenation of PUFA, with a consequent improvement of the intramuscular fatty acid composition. To test this hypothesis, 26 Comisana lambs were divided into 3 groups and for 56 d were fed a barley-based concentrate diet (CON; 8 lambs) or 2 diets in which barley was replaced with 24% (CIT24; 9 lambs) or 35% (CIT35; 9 lambs) dried citrus pulp. An overall improvement of the fatty acid composition of LM from lambs fed citrus pulp-containing diets was found. The PUFA/SFA ratio was lower (P < 0.05) in the LM from lambs in the CON group compared with both the CIT24 and CIT35 groups. The thrombogenic index was lower (P < 0.05) in meat from lambs fed the CIT35 diet compared with those fed the CON diet. The CIT35 diet increased the proportion of C20:5 n-3 in the LM (P < 0.05), whereas the CIT24 diet enhanced that of C22:6 -3 (P < 0.05) compared with the CON diet. Some of these results might be explained considering that feeding the CIT24 and CIT35 diets increased the intake of total fatty acids (P < 0.05) and of C18:3 n-3 (P < 0.01) compared with feeding the CON treatment. On the other hand, phenolic compounds present in citrus pulp could have inhibited the ruminal biohydrogenation of PUFA. This is supported by the fact that regardless of the level of inclusion in the diet, citrus pulp increased the proportion of rumenic acid (P < 0.001) in LM compared with the CON diet. The plasma from lambs fed both CIT24 and CIT35 diets had a greater percentage of vaccenic acid (VA; < 0.001) compared with that from lambs fed the CON diet, and the CIT35 diet increased the proportion of rumenic acid in plasma compared with the CON treatment (P < 0.05). In the ruminal fluid, stearic acid (SA) tended to decrease, and the sum of CLA tended to increase (P = 0.09) with increasing level of citrus pulp in the diets. Furthermore, the SA/(SA + VA) ratio tended to be lower (P = 0.10) in the ruminal fluid from lambs fed the CIT35 diet compared with that of the CON group. In conclusion, our results support the hypothesis that replacing barley with citrus pulp in the diet of growing lambs improves intramuscular fatty acid composition and underline the need for specific studies to clarify the mechanisms by which feeding citrus pulp affects the fatty acid metabolism in ruminants.

The objective of this experiment was to determine the effects of in vitro fermentation of coconut endosperm fiber (CEF), chicory pulp (CHP), and selective blends of these substrates on SCFA production and changes in microbiota using canine fecal inocula. A total of 6 individual substrates, including short-chain fructooligosaccharide (scFOS; a well-established prebiotic source), pectin (PEC; used as a positive control), pelletized cellulose (PC; used as a negative control), beet pulp (BP; considered the gold standard fiber source in pet foods), CEF, and CHP, and 3 CEF:CHP blends (75:25% CEF:CHP [B1], 50:50% CEF:CHP [B2], and 25:75% CEF:CHP [B3]) were tested. Triplicate samples of each substrate were fermented for 0, 8, and 16 h after inoculation. A significant substrate × time interaction (P < 0.05) was observed for pH change and acetate, propionate, butyrate, and total SCFA concentrations. After 8 and 16 h, pH change was greatest for scFOS (-2.0 and -3.0, respectively) and smallest for PC (0.0 and -0.1, respectively). After 16 h, CEF had a greater butyrate concentration than CHP and all the CEF:CHP blends and it was not different than PEC. The substrate × time interaction was significant for bifidobacteria (P < 0.05) and lactobacilli (P < 0.05). After 8 h, bifidobacteria was greatest for BP and lowest for PC (12.7 and 10.0 log10 cfu/tube, respectively). After 16 h, PC had the lowest and scFOS had the greatest bifidobacteria (6.7 and 13.3 log10 cfu/tube, respectively). In general, CEF, CHP, and their blends had similar bifidobacteria populations after 8 and 16 h of fermentation when compared with BP and scFOS. After 16 h, lactobacilli populations were greatest for B1, B2, B3, BP, and scFOS, intermediate for PEC, and lowest for PC (P < 0.05). Overall, our data suggest that CEF had a butyrogenic effect and that CEF, CHP, and their blends had similar bifidobacteria and lactobacilli populations as popular prebiotic and fiber substrates. Future research should investigate the effects of CEF, CHP, and their blends on gastrointestinal health and fecal quality in dogs.

Research on domestic animals (cattle, swine, sheep, goats, poultry, horses, and aquatic species) at land grant institutions is integral to improving the global competitiveness of US animal agriculture and to resolving complex animal and human diseases. However, dwindling federal and state budgets, years of stagnant funding from USDA for the Competitive State Research, Education, and Extension Service National Research Initiative (CSREES-NRI) Competitive Grants Program, significant reductions in farm animal species and in numbers at land grant institutions, and declining enrollment for graduate studies in animal science are diminishing the resources necessary to conduct research on domestic species. Consequently, recruitment of scientists who use such models to conduct research relevant to animal agriculture and biomedicine at land grant institutions is in jeopardy. Concerned stakeholders have addressed this critical problem by conducting workshops, holding a series of meetings with USDA and National Institutes of Health (NIH) officials, and developing a white paper to propose solutions to obstacles impeding the use of domestic species as dual-purpose animal models for high-priority problems common to agriculture and biomedicine. In addition to shortfalls in research support and human resources, overwhelming use of mouse models in biomedicine, lack of advocacy from university administrators, long-standing cultural barriers between agriculture and human medicine, inadequate grantsmanship by animal scientists, and a scarcity of key reagents and resources are major roadblocks to progress. Solutions will require a large financial enhancement of USDA's Competitive Grants Program, educational programs geared toward explaining how research using agricultural animals benefits both animal agriculture and human health, and the development of a new mind-set in land grant institutions that fosters greater cooperation among basic and applied researchers. Recruitment of outstanding scientists dedicated to using domestic animal models for agricultural and biomedical research, strong incentives for scientists to take advantage of training opportunities to write NIH grants, and greater NIH and USDA cooperation to sponsor the use of agricultural animals as dual-purpose animal models that benefit agriculture and biomedicine will also be necessary. In conclusion, the broad diversity of animal models needed for agricultural and biomedical research is at risk unless research priorities at the land grant universities are critically evaluated and financial support for such research is dramatically increased.

Deoxynivalenol (DON) contamination of DDGS is a recurring problem. Chemical pretreatment can be used to reduce the effect of DON-contamination in complete feeds. A total of 247 growing pigs (21.5 ± 2.1 kg; n = 6 pens/treatment) were used to evaluate pretreated DON-contaminated DDGS on pig performance. Experimental diets were corn/soybean meal based containing one of 3 DDGS sources [mycotoxin-free (control, 1.0 ppm DON), DON contaminated (donDDGS, 11.6 ppm DON), and pre-treated DON DDGS (trtDDGS, 7.3 ppm DON)] at 30% diet inclusion. Diets met or exceeded nutrient requirements for growing pigs and were fed for 21 d. Data were analyzed as a repeated measure with main effects of period and diet and pen as experimental unit. Pig BW and feed disappearance were measured at d3, 7, 10, 14, and 21. Mean BW of pigs fed donDDGS was lighter (P = 0.016) than pigs fed control; pigs fed trtDDGS had intermediate BW (31.3 vs 33.0 and 32.1 kg). Weigh period and diet tended to interact (P = 0.084) on daily gain such that daily gain was not different between weigh periods for control diet-fed pigs and lower in first 3d for donDDGS- and trtDDGS-fed pigs compared to other periods. donDDGS-fed pigs tended (P = 0.071) to have lower overall intake compared to trtDDGS-fed pigs and control diet-fed pigs. Pretreatment of DDGS reduced the impact of DON contamination in the first week. [Image: see text]

The objective of the present study was to compare digestion rates (kd) of NDF for different feeds estimated with the in situ method or derived from an automated gas in vitro system. A meta-analysis was conducted to evaluate how in situ derived kd of NDF related to in vivo digestibility of NDF. Furthermore, in vitro true digestibility of the feed samples incubated within filter bags or dispersed in the medium was compared, and kd for insoluble and soluble components of those feeds were estimated. Four different concentrates and 4 forages were used in this study. Two lactating Swedish Red cows fed a diet of 60% grass silage and 40% concentrate on DM basis were used for in situ incubations and for collection of rumen fluid. The feed samples were ground through a 2.0-mm screen before the in situ incubations and a 1.0-mm screen before the in vitro gas incubations. In situ nylon bags were introduced into the rumen for determination of kd of NDF. Additional kinetic data were produced from isolated NDF and intact samples subjected to in vitro incubations in which gas production was recorded for 72 h. Samples were weighed in the bottles or within filter bags (for fiber and in vitro studies) that were placed in the bottles. The interaction between feed and method was significant (P < 0.01); kd of NDF for grass hay tended (P = 0.06) to be less whereas kd of NDF for alfalfa, barley grain, canola meal, and dried sugar beet pulp were greater (P < 0.01) when estimated with the in situ method than from gas production recordings. The meta-analysis suggested that in situ derived kd of NDF were biased and underestimated in vivo digestibility of NDF. Digestion rates of the intact samples were lower for all feeds, except for the hay, when incubated within the bags compared with dispersed in the medium (P < 0.01). Less OM and NDF were digested for all feeds when incubated within bags than dispersed in the medium (P < 0.01). It is concluded from the in vitro study that microbial activity within the bags is less than in the medium. Significant interactions between method (in situ vs. in vitro) and feed suggest that one or both methods result in biased estimates of digestion kinetics.

The objective of this experiment was to test the hypothesis that differences in the digestibility of total dietary fiber among breeds of pigs is influenced by the type of fiber fed and also by the age of the pig. Five Meishan pigs (BW: 77.2 ± 15.2 kg; 5 mo old), 5 light Yorkshire pigs (BW: 80.1 ± 11.2 kg; 4 mo old), and 5 heavy Yorkshire pigs (BW: 102.1 ± 3.5 kg, 5 mo old) were surgically prepared with a T-cannula in the distal ileum. A corn-soybean meal diet (control) was formulated with 5 g•kg(-1) of titanium dioxide as an indigestible marker. Three additional diets were formulated by replacing 30% of the control diet with 30% of distillers dried grains with solubles (DDGS), soybean hulls, or sugar beet pulp, and 1 diet was formulated by replacing 15% of the control diet with 15% pectin. Each group of pigs was allotted to a 5 × 5 Latin square design, and pigs were fed the 5 experimental diets during five 14-d periods. Fecal samples were collected on d 12, and ileal digesta were collected on d 13 and 14 of each period. The apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of GE and nutrients in each ingredient were calculated using the substitution method. Hindgut disappearance was calculated as the difference between ATTD and AID. When fed the control diet, Meishan pigs tended (P < 0.10) to have a greater AID of GE and CP (78.6 and 80.3%, respectively) than light (77.0 and 78.9%, respectively) and heavy (75.7 and 76.9%, respectively) Yorkshire pigs, and they had a greater (P < 0.05) ATTD of DM, GE, and carbohydrates (89.2, 89.5, and 95.5%, respectively) than light (86.6, 86.4, and 92.4%, respectively) and heavy (87.0, 86.6, and 93.0%, respectively) Yorkshire pigs. The ATTD of DM, GE, CP, carbohydrates, and total dietary fiber in DDGS (75.4, 76.3, 81.3, 78.0, and 75.3%, respectively) was greater (P < 0.01) in Meishan pigs than in light (55.7, 58.5, 66.7, 49.2, and 39.0%, respectively) and heavy (59.8, 62.9, 70.0, 51.1, and 55.7%, respectively) Yorkshire pigs. There were no differences among the 3 groups of pigs in the ATTD of GE or nutrients in soybean hulls, sugar beet pulp, or pectin. The hindgut disappearance of DM and carbohydrates in DDGS by Meishan pigs (26.8 and 52.9%, respectively) was greater (P < 0.05) than in the light (10.0 and 22.8%, respectively) and Heavy Yorkshire pigs (12.2 and 20.0%, respectively), but for the other ingredients, no differences in hindgut disappearance among Meishan, light Yorkshire, and heavy Yorkshire pigs were observed. In conclusion, Meishan pigs have a greater ATTD of DM, GE, and some nutrients in corn-soybean meal diets and in DDGS than Yorkshire pigs.

Dehydrated citrus pulp (DCP) contains limiting amount of nitrogen (N) and phosphorus (P), probably due to the high content of fiber components and phytic acid. The use of fibrolytic enzymatic complexes could favor the use of DCP in piglets’ diets. Thus, the objective of this work was to determine the balance of P and N in weaned piglets fed diets with increasing levels of DCP, with or without the addition of exogenous enzymes. Forty castrated male piglets with average initial weight of 7.85 ± 1.64 kg were individually distributed in metabolic cages, in a factorial scheme (2x4): with or without exogenous enzymatic complex (carbohydrases + phytase) X levels of DCP inclusion (0, 3, 6 and 9%) to the diets, with five replicates per treatment and one animal per experimental unit. Diets were formulated based on corn, soybean meal, powdered milk, powdered whey, sugar, soybean oil, amino acids, vitamins, minerals and additives. Experimental diets were provided for 12 d with the initial 7 d being the adaptation period. Ferric oxide (Fe2O3) was added as an indigestible marker on d 7 and 11, respectively. P and N in diets, feces and urine were determined for P and N balance calculation. There was no interaction (P> 0.05) between the addition of enzymes and the levels of DCP. However, there was a reduction (P= 0.067) of P excreted in the feces by the addition of enzymes, as well as a reduction (P= 0.028) of N excreted in the feces. Increasing DCP levels in diets resulted in a linear increase (P= 0.046) of N excreted in feces and a linear reduction (P= 0.038) of N absorbed. The addition of exogenous enzymes (carbohydrases and phytase) in diets for weaned piglets reduces fecal excretion of P and N, while DCP inclusion increases the N excretion in feces.

Environmental issues associated with swine production are becoming a major concern among the general public and are thus an important challenge for the swine industry. There is now a renewed interest in environmental biotechnologies that can minimize the impact of swine production and add value to livestock by-products. An anaerobic biotechnology called psychrophilic anaerobic digestion (PAD) in sequencing batch reactors (SBR) has been developed at Agriculture and Agri-Food Canada. This very stable biotechnology recovers usable energy, stabilizes and deodorizes manure, and increases the availability of plant nutrients. Experimental results indicated that PAD of swine manure slurry at 15 to 25 degrees C in intermittently fed SBR reduces the pollution potential of manure by removing up to 90% of the soluble chemical oxygen demand. The process performs well under intermittent feeding, once to 3 times a week, and without external mixing. Bioreactor feeding activities can thus be easily integrated into the routine manure removal procedures in the barn, with minimal interference with other farm operations and use of existing manure-handling equipment. Process stability was not affected by the presence of antibiotics in manure. The PAD process was efficient in eliminating populations of zoonotic pathogens and parasites present in raw livestock manure slurries. Psychrophilic anaerobic digestion in SBR could also be used for swine mortality disposal. The addition of swine carcasses, at loading rates representing up to 8 times the normal mortality rates on commercial farms, did not affect the stability of SBR. No operational problems were related to the formation of foam and scum. The biotechnology was successfully operated at semi-industrial and full commercial scales. Biogas production rate exceeded 0.20 L of methane per gram of total chemical oxygen demand fed to the SBR. The biogas was of excellent quality, with a methane concentration ranging from 70 to 80%. The recovery of green energy, the production of a value-added odorless fertilizer, the elimination of manure pathogens, and the proper disposal of swine mortalities will substantially reduce the carbon and environmental footprints on products of swine origin.

Three experiments were performed to study the nutritional characteristics of sugar beet pulp (SBP) according to the concentration of vinasse (condensed molasses solubles) added. Eighteen Merino ewes were used to study preference in Exp. 1, and 18 Merino ewes were used in Exp. 2 to study voluntary intake of SBP with different amounts of vinasse inclusion (0, 7, and 13% on a DM basis; SBP0, SBP7, and SPB13, respectively). Sheep showed a marked preference for SBP with vinasse, regardless of the amount of addition, whereas voluntary feed intake was not affected (P > 0.34). Eight ruminally cannulated Merino ewes were used in Exp. 3 to study rumen fermentation of SBP0 and SBP13. Regardless of the diet fed to the animals (SBP0 or SBP13), disappearance rates of DM, NDF, and CP were greater when SBP13, compared with SBP0, was incubated in sacco (P 0.23) in response to vinasse addition. Experiment 4 was designed to study digestibility, solid passage rate, and excretion of purine derivatives from 12 Merino ewes fed SBP0 and SBP13. Digestibility of NDF tended to be greater (P 0.11). Digesta flow kinetics and urinary excretion of purine derivatives were not significantly affected by the presence (SBP13) or absence (SBP0) of vinasse in the diet (P > 0.21). In conclusion, sheep showed a clear preference for SBP with vinasse. However, the lack of significant differences in most of the in vivo variables measured indicates that ewes can be satisfactorily fed with any of the amounts of vinasse inclusion studied.

The current investigation was under- taken to study the absorption and plasma concentration of carbohydrate-derived nutrients (glucose, short-chain fatty acids (SCFA), and lactate) and the apparent insu- lin production in sows fed diets containing contrasting types and contents of dietary fiber. Six sows were fed 3 experimental diets, low fiber (LF; 177 g of dietary fiber and 44 g of soluble fiber/kg of DM), high soluble fiber (HF-S; 429 g of dietary fiber and 111 g of soluble fiber/kg of DM), and high insoluble fiber (HF-I; 455 g of dietary fiber and 74 g of soluble fiber/kg of DM), in a repeated crossover design. Variations in dietary concentration and solubility of dietary fiber were ob- tained by substituting starch-rich wheat and barley in the LF diet with dietary fiber-rich co-products (sugar beet pulp, potato pulp, pectin residue, brewers spent grain, pea hulls, and seed residue, which have distinct physicochemical properties). The main carbohydrate component of the LF diet was starch and nonstarch polysaccharides (cellulose and noncellulosic polysaccha- rides) for the 2 high dietary fiber diets. Consumption of the LF diet resulted in increased and rapid glucose absorption at 0 to 4 h postfeeding. With the HF-I diet, the glucose absorption pattern was similar but at a decreased rate, whereas it was decreased and delayed with the HF-S diet (diet, P < 0.001; time, P < 0.001). These differences were also reflected in the insulin re- sponse. The quantitative absorption of SCFA at 0 to 10 h postfeeding was greater when feeding the HF-S diet compared with the LF diet (P < 0.001) and in- termediate when feeding the HF-I diet (P < 0.001). The study showed that feeding the high dietary fiber diets resulted in a increased and more uniform uptake of SCFA than when feeding the LF control. Moreover, the HF-S diet reduced diurnal variation in glucose and insulin concentrations.

The aim of the study was to assess the ability of a dynamic in vitro model to determine the digestibility of OM, CP, and starch compared with a validated, static, in vitro method and in vivo ileal digestibility obtained from growing pigs fitted with a T-cannula. Five experimental diets with different carbohydrate types and level were assessed: a standard corn-based diet (ST) or the same diet with coarse ground corn (CC), 8% sugar beet pulp (BP), 10% wheat bran (WB), or 8% sugar beet pulp and 10% wheat bran (HF). In the in vivo experiment, diets CC and HF reduced (P = 0.015) ileal digestibility of OM compared with the ST diet. The inclusion of sugar beet pulp reduced (P = 0.049) ileal CP digestibility of the BP diet. This reduction was not statistically significant when sugar beet pulp was combined with the wheat bran in the HF diet. No differences were shown for in vivo starch digestibility among diets. With the static in vitro method, the OM disappearance was greater than that observed in the in vivo experiment. In this static method, the BP and HF diets reduced (P = 0.004 and < 0.001, respectively) the disappearance of the OM compared with the ST diet. The coarse grinding of corn did not alter OM digestibility but decreased (P = 0.005) the starch digestibility. The R(2) between the in vivo results and the static in vitro methods for OM and starch digestibility was 0.99 when the CC diet was not considered. The dynamic in vitro model yielded OM and CP digestibility coefficients comparable with those obtained in vivo for the ST and CC diets. However, the values were considerably affected by the incorporation of the fibrous ingredients. Diets BP, WB, and HF had decreased (P = 0.009, 0.058, and 0.004, respectively) OM digestibility compared with the ST diet. Protein digestibility was also decreased (P < 0.001, P = 0.019, and P = 0.003, respectively) with the BP, WB, and HF diets compared with the ST diet. However, digestibility was decreased to a greater extent in the BP diet than in the WB and HF diets, both of which contained wheat bran. The R(2) between the dynamic in vitro model and the in vivo results for CP digestibility was 0.99 when the CC diet was not considered. No differences were detected for starch digestibility among the diets with the dynamic in vitro model. This dynamic in vitro model yielded ileal digestibility results comparable with those obtained in vivo for CP and OM with a corn-soybean diet, or with a diet including coarse corn, but it underestimated digestibility when fibrous ingredients were included in the diet.

The objective of this digestibility assessment was to determine whether there are significant differences in the digestibility of Roundup Ready (glyphosate-tolerant) and conventional sugar beet, fodder beet, and beet pulp produced from sugar beet varieties when fed to sheep (seven wethers per treatment group). Three experiments were conducted in this assessment. Experiment 1 (35 wethers) compared one glyphosate-tolerant fodder beet variety with four conventional varieties, Exp. 2 (42 wethers) compared one glyphosate-tolerant sugar beet variety with five conventional varieties, and Exp. 3 (42 wethers) compared beet pulp derived from glyphosate-tolerant sugar beet with beet pulp from five European locations. The experimental phase consisted of a 2-wk preliminary period followed by a 1-wk collection period for Exp. 1 and 2, and a 1-wk preliminary period followed by a 1-wk digestibility collection period for Exp. 3. Diets were comprised of grass hay at 30, 30, and 20% of DM for Exp. 1, 2, and 3, respectively, with the balance being beet components. Urea and sodium sulfate were supplemented (8 and 2.9 g, respectively, for Exp. 1 and 2; and 6 g and 2.16 g, respectively, for Exp. 3) to supply sufficient dietary N and S. Each diet was fed to sheep (96 +/- 0.9 kg) in the three experiments to at or near maintenance energy levels. Treatment differences were considered significant at P < 0.05. Apparent digestibilities of DM, OM, CP, NDF, ADF, and DE for glyphosate-tolerant fodder and sugar beets did not differ from those for commercial fodder and sugar beets in Exp. 1 and 2. There were differences (P < 0.05) in DM, OM, CP, NDF, ADF, and DE digestibilities influenced by the different varieties of beet pulp in Exp. 3, but these were not unique to just the Roundup Ready sugar beet variety. Digestibilities and feeding values of Roundup Ready fodder beet, sugar beet, and beet pulp produced from Roundup Ready sugar beet varieties were not influenced by the introduction of the Roundup Ready trait compared with conventional varieties.

Eight gilts (29.9 ± 1.7 kg initial BW) were used to evaluate effects of dietary (crude) fiber on N excretion via feces and urine at 2 levels of dietary CP. Pigs were fed 4 dietary treatments according to a double 4 × 4 Latin square. Treatments were low (14%) CP and low (3.25%) (crude) fiber (LPAA), low CP and high (4.46%) fiber (LPAABP), high (18.8%) CP and low fiber (HP), and high CP and high fiber (HPBP). Diets were based on soybean (Glycine max) meal, wheat (Triticum aestivum), and maize (Zea mays) and were supplemented with crystalline AA. High fiber diets contained 15% dried beet (Beta vulgaris) pulp. Pigs were housed in metabolic cages and fed 2 equal meals at 0700 and 1700 h at a daily rate of 90 g/kg BW(0.75). Water was offered ad libitum. Each experimental period consisted of a 6-d adaptation followed by a 4-d collection of feces and urine (bladder catheters). Data were analyzed using ANOVA. Differences between means (P < 0.05) were assessed using Fisher's LSD procedure. The N intake, fecal N excretion and absorption, and N retention increased (P < 0.05) in pigs fed high-CP diets with added fiber (HP vs. HPBR). With added fiber, urinary N excretion (g/d) was reduced (P < 0.02) only for the low-CP diet. Urinary N as a percentage of N intake was reduced (P < 0.01) in both groups fed high-fiber diets irrespective of dietary CP content. Dietary fiber level did not affect DMI. Fecal DM excretion (g/d) was higher (P < 0.02) in pigs fed diets with high CP and high fiber content than in pigs fed diets with high CP and low fiber content. In conclusion, beet pulp fiber added to diets increased fecal N and reduced urinary N and in diets with higher CP content increased overall N retention.

The effect of dietary fiber source on molecular weight (MW) distribution of soluble fiber fractions and short chain fatty acids (SCFA) in ileal digesta of 7 post valve T-cecum (PVTC) cannulated growing pigs was studied. Pigs were fed semisynthetic diets with sugar beet (Beta vulgaris) pulp (SBP) or chicory (Cichorium intybus) forage (CFO) as fiber sources of which the soluble nonstarch polysaccharide (NSP) fraction originated mainly from pectin. Three MW intervals were selected-large MW (MWL): 10,000,000 to 1,000,000 g/mol, medium MW (MWM): 1,000,000 to 200,000 g/mol, and small MW (MWS): 200,000 to 10,000 g/mol-and the relative distribution (% of total) of molecules in each interval was calculated. The MWM fraction was higher (P < 0.05) in ileal digesta of pigs fed diet SBP and the MWS fraction was higher (P < 0.05) in ileal digesta of pigs fed diet CFO. The mole/100 mole of propionic acid (HPr) was higher (P < 0.010) in pigs fed diet SBP whereas pigs fed diet CFO had higher (P < 0.010) mole/100 mole of acetic acid (HAc). The proportion of the MWL and MWM fractions in ileal digesta were negatively correlated to HAc (r = -0.52, P = 0.05, and r = -0.62, P = 0.02, respectively). The proportion of MWM in ileal digesta was positively correlated to HPr (r = 0.83; P = 0.001) whereas MWS and HPr were negatively correlated (r = -0.76; P = 0.002). In conclusion, the bacterial degradation of the soluble NSP fraction is selective and MW distribution may explain differences in SCFA production.

Two in vitro fermentation experi- ments were conducted to evaluate the influence of source of dietary fiber fed to dogs and cats on fermentative activity of their fecal microflora. In Exp. 1, six English Pointer dogs were fed a diet containing either a non-fermentable fiber (Solka Floc@) or a fermentable fiber (citrus pulp). A fecal sample from each dog was used as the inoculum source to determine in vitro OM disappearance (OMD 1 and short-chain fatty acid (SCFA) production from selected fibrous substrates. When data were pooled across substrates and fermentation times, a lower (P = .02) OMD (24.8 vs 29.4%) and a higher (P = .01; 3.8 vs 2.2) acetate to propionate ratio (A:P) occurred for the Solka Floc than for the citrus pulp diet. In Exp. 2, six short-hair cats were fed a diet containing no supplemental fiber (NF) or a diet containing beet pulp (BP). When data were pooled across substrates and fermentation times, NF resulted in a greater (P < .01) A:P than the BP diet (3.4 vs 1.5). The BP treatment resulted in a slightly higher (P = ,071 OMD (42.0 vs 39.3%) and a higher (P = .07) propionate production (.74 vs .47 mmoVg of OM) than the NF diet. In summary, in vitro substrate OMD increased and A:P decreased when fecal inoculum from dogs and cats fed diets containing a supplemental source of fermentable fiber was used. In vitro fermentation of fibrous substrates by fecal microflora from dogs and cats increased with inclusion of fermentable fiber in the diet.

Two experiments were conducted to evaluate single sources and blends of dietary fiber in dog food. In Exp. 1, 14 fibrous substrates were fermented in vitro using dog feces as the source of inoculum. Organic matter disappearance was lowest (P.05;10%) for Solka Floc and oat fiber and greatest (P.05;80%) for fructooligosaccharides (FOS) and lactulose. Solka Floc, oat fiber, gum karaya, and xanthan gum produced the least (P.05;1 mmol/g of substrate OM) total short-chain fatty acids (SCFA). Lactulose, citrus pectin, and guar gum produced the greatest (P.05;6.8 mmol/g of substrate OM) total SCFA. In Exp. 2, six diets were formulated based on results obtained in Exp. 1. Treatments included 1) beet pulp (BP), 2) Solka Floc (SF), 3) citrus pulp (CP), 4) stool blend (SB), 5) SCFA blend (SC), and 6) combination blend (CB). Digestibility of DM and total dietary fiber (TDF) was greatest (P.05; 87.3 and 60.8%, respectively) for dogs consuming the SC diet. Feces from dogs fed SC were scored as more unformed and liquid in consistency than feces from dogs fed the other diets. Dogs consuming the SF and SB diets had the lowest (P.05; 11.0 and 4.1%, respectively) TDF digestibilities. Organic matter disappearance values derived from substrates fermented in vitro reasonably predicted the fiber digestibility of diets fed to dogs. Moderately fermentable dietary fiber sources, such as BP, promote excellent stool characteristics without compromising nutrient digestibility, and may promote gastrointestinal tract health by optimizing SCFA production.

Eight ruminally cannulated steers (average initial weight 196 & 13 kg) were arranged in a replicated 4 x 4 Latin square. Steers had ad libitum access to chopped brome hay (Bromus inermus L. 9.9% CP) and one of four supplements. Supplements were fed to provide 195 g of CP.steer-l.d-l (equalized with soybean meal), and supplemental energy intake was similar among energy supplements. Supplemental treatments were control (CTRL; primarily soybean meal), barley (BAR), beet pulp (PULP), and corn (CORN). Amounts fed were 481, 1,285, 1,335, and 1,289 g of DM.steer-l.d-l for CTRL, BAR, PULP, and CORN, respectively. Individually stanchioned steers were allowed a 13-d adaptation period followed by an 8-d collection period. Chromic oxide was used as the indigestible flow marker. Forage intake was less (P < .lo) for steers fed BAR, PULP, and CORN than for CTRL steers, but total intake (forage + supplement) did not differ among treatments. Total tract DM and OM digestibilities were greater (P < .lo) for PULP- and CORN- than for CTRL- and BAR-supplemented steers. Digestibility of NDF was least (P < .lo) for BAR, intermediate for CORN, and greatest for CTRL and PULP (44.0, 47.2, 50.1, and 52.1%, respectively). Apparent CP digestibility was least ( P < .lo) in BAR- (60.81, greatest in CTRL- (69.71, and intermediate in PULP- and CTRL- (64.0 and 64.4) supplemented steers. Ruminal DM fill was less (P < .lo) in steers fed BAR and PULP than in CTRL steers. No differences ( P < .lo) were noted in DM and NDF rate of in situ degradation. Rate of forage CP in situ degradation was faster ( P < .lo) in CTRL- and PULP- than in CORN- and BAR-supplemented steers. Steers fed BAR and PULP supplements exhibited a lower overall pH response curve (P < .005) than did steers fed CTRL and CORN; this finding corresponded to increased (P < .005) response curves in PULP-fed steers for total VFA, acetate, and propionate compared with other treatments. These data indicate that energy supplementation decreased forage intake, al- tered ruminal fill, shifted VFA patterns, and changed in situ rate of forage CP degradation. Moreover, PULP maintained NDF digestibilities equal to CTRL levels, whereas CORN and BAR did not.

Blends of fermentable oligosaccharides in combination with nonfermentable fiber, cellulose, were evaluated for their ability to serve as dietary fibers in dog foods. Using a 6 x 6 Latin square design, 6 diets were evaluated that contained either no supplemental fiber, beet pulp, cellulose, or blends of cellulose, fructooligosaccharides, and yeast cell wall added at 2.5% of the diet. Six ileal-cannulated dogs were fed 175 g of their assigned diet twice daily. Chromic oxide served as a digestibility marker. Nutrient digestibility, fecal microbial populations, fermentative end products, and immunological indices were measured. Total tract DM and OM digestibilities were lowest (P < 0.05) for the cellulose treatment. Crude protein digestibility was lower (P < 0.05) for the treatments containing carbohydrate blends. The cellulose treatment had the lowest (P < 0.05) concentration of bacteria, and all diets containing fermentable fiber had greater (P < 0.05) fecal bifidobacteria concentrations compared with the diets without supplemental fermentable fiber. Lactobacilli concentrations tended to be greater (P < 0.08) in treatments containing fermentable fiber compared with the cellulose treatment. Bifidobacteria and lactobacilli concentrations were similar for the beet pulp treatment compared with the fermentable oligosaccharide blends. Total fecal short-chain fatty acid concentration was greater for the beet pulp treatment (P < 0.05) compared with the control and cellulose treatments. The treatments containing fermentable fiber had greater (P < 0.05) fecal butyrate concentrations compared with cellulose and control treatments. Immune indices were not affected by treatment. Our results suggest that dog foods containing blends of fermentable and nonfermentable carbohydrates produce similar physiological results as dog food containing beet pulp as a fiber source. Therefore, blends of these carbohydrates could be useful substitutes for beet pulp in dog foods.

We conducted an experiment to evaluate the effects that a diet containing condensed tannins with and without polyethylene glycol (PEG) has on lamb growth and meat quality. Twenty-three male Comisana lambs were introduced to the three experimental diets between 45 and 50 d of age. Eight were given a diet containing 56% of Ceratonia siliqua (carob) pulp (tannin group), another eight received the same diet with a supplement of 40 g of PEG for each kilogram of diet (PEG group), and the remaining seven lambs were given a conventional maize-based diet (maize group). Voluntary feed intake and live weights were measured until slaughter at 105 d of age, and digestibility measurements were undertaken toward the end of the feeding trial. Carcass yield, meat quality characteristics, and a taste panel evaluation were conducted. The tannin-based diet contained 2.5% condensed tannins (DM basis), and lambs given this diet had lower growth rates and poorer feed efficiencies (P < .01) compared with the other treatment groups. Daily gain was similar between the maize and PEG lambs, although the efficiency of feed conversion was highest in the maize group. The digestibility of DM, N, and fiber was reduced (P < .05) by the condensed tannins. Lambs fed the tannin diet had a lower carcass yield (P < .05) and had less fat (P < .05), and the meat had a higher ultimate pH (P < .01) than those given the PEG or maize diets. Condensed tannins affected meat color, which was lighter (L*) than meat from lambs given the PEG-containing diet (P < .01). Sensory evaluation showed that panelists preferred meat from lambs receiving PEG and maize treatments compared with those receiving the tannin diet, and this could be related to differences in meat ultimate pH and carcass fatness. These results show that condensed tannins from carob pulp are very detrimental to feed digestibility and lamb performance. Inclusion of 40 g of PEG/kg diet eliminated the effects of condensed tannins so that lamb performance and meat quality were similar to lambs given a maize-based diet.