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The objective of this study was to investigate whether reducing dietary CP concentration decreases fecal VFA, manure ammonia ([NH.sub.3]) emission and odor, and urinary phenolic metabolites. Six barrows were allotted to one of six dietary treatments in a Latin square design. Treatments consisted of four corn-soybean meal based diets containing 15, 12, 9, and 6% CP, a casein-based diet containing 15% CP, and a protein-free diet (0% protein). Crystalline AA were included in the 12, 9, and 6% CP diets. The casein-based and protein-free diets were used to determine basal endogenous contribution of VFA, phenolics, [NH.sub.3], and manure odor. Pigs were housed individually in metabolism cages to allow total collection of feces and urine. Feces and urine were collected and pooled within pig and period. Feces and urine were analyzed for VFA and phenolic metabolite concentrations, respectively. Feces and urine were then mixed, stored, and fermented at room temperature for 30 d. For [NH.sub.3] determination, headspace air was sampled from manure slurries at 24, 48, and 72 h after fermentation. Slurry samples were placed into vials, capped, and randomized before odor panel evaluation. Odor offensiveness was classified on severity: 1 = non-offensive; 2 = mildly offensive; 3 = moderately offensive; 4 = strongly offensive; and 5 = extremely offensive. Reducing dietary CP increased (P < 0.05) fecal VFA concentrations but did not affect phenolic concentrations in urine. Manure [NH.sub.3] emission was reduced (P < 0.05) as dietary CP concentration decreased from 15 to 0%. The 15% diet had the ]east offensive manure slurry with odor qualitative ranking of 2.58 (i.e., mild-moderately offensive). Compared with the 15% CP diet, manure from the 9 and 6% CP diets was found to be more offensive (P < 0.05), with qualitative rankings of 2.92 and 3.10, respectively. Odor qualitative rank for the 12% CP, protein-free diet, and casein-based diet did not differ from that of the 15% CP diet. These results indicate that reduction in dietary CP concentrations decreases manure [NH.sub.3] emission, but it does not diminish manure odor offensiveness and fecal VFA concentrations. Key Words: Ammonia, Manures, Odors, Phenolic Compounds, Pigs, Volatile Fatty Acids

Fifty growing pigs were used in two experiments to evaluate the effects of cannulation and hyperalimentation on performance and body composition responses. Surgical implantation of a cannula into the greater curvature of the stomach and subsequent management associated with maintenance of the cannula did not result in a reduction (P |is greater than~ .05) of voluntary feed intake. Cannulation did not negatively affect gain (P |is greater than~ .05). Over the entire trial, feed efficiency was not changed by cannulation (P |is greater than~ .05). Cannulation itself did not affect protein or fat deposition (P |is greater than~ .05) in the carcass. Hyperalimentation to approximately 120% of control intake resulted in increased daily gain (P |is less than~ .05) and similar feed efficiency (P |is greater than~ .05) compared with that of control animals. Hyperalimentation decreased protein deposition (P |is less than~ .05) and tended to increase fat deposition.

Adipic acid is only partially catabolized when it is fed to animals, and a portion of it is excreted in urine. The excreted portion may lower urinary pH and, as a result, ammonia emission. The present study tested this hypothesis. In Exp. 1, nursery pigs (n = 14) were fed (for a period of 7 d) either a standard nursery diet or the same diet supplemented with 1% adipic acid to assess effects on urinary pH (collected on d 5 or 6) and in vitro ammonia emission from the collected urine samples that were mixed with control feces. In Exp. 2, grower pigs housed 10 each in one of two chambers were fed a control diet or the same diet supplemented with 1% adipic acid. Ventilated air was quantified and analyzed for ammonia using Fourier transform infrared spectroscopy to determine the effects of feeding 1% adipic acid on ammonia emission. The results from Exp. 1 showed that adipic acid strongly reduced urinary pH (from 7.7 to 5.5, P [is less than] 0.05). In vitro ammonia emission from these urine samples was significantly reduced at all the time points evaluated (1, 3, 18, and 46 h with reductions of 94, 93, 70, and 39%, respectively, P [is less than] 0.05). Experiment 2 showed that adipic acid supplementation reduced ammonia emission by 25% (P [is less than] 0.05), which corresponded to the predicted reduction in ammonia emission based on the reduction in manure pH observed. In conclusion, feeding adipic acid lowers urinary pH and reduces ammonia emission. The reduction in ammonia emission, though, does not correspond to the reduction in urinary pH but corresponds to the reduction in fecal pH as a result of mixing the urine and feces, in which feces act as a strong buffer. Key Words: Adipic Acid, Ammonia, pH, Pigs, Urine

Adipic acid, upon catabolism, results in intermediates that bear a structural similarity to lysine degradation products. The objectives of this research were to determine whether adipic acid affects lysine concentrations in plasma and to evaluate whether adipic acid improves the efficiency of lysine utilization in pigs. In Exp. 1, nursery pigs (n = 14) were fed (for a period of 7 d) either a standard nursery diet or the same diet supplemented with 1% adipic acid to assess effects on plasma amino acid concentrations (plasma collected on d 7). In Exp. 2, nursery pigs (n = 56) were fed (for a period of 15 d) either a control diet or the same diet but deficient in either lysine, threonine, or tryptophan with or without supplemental adipic acid to assess the effects of adipic acid on the efficiency of amino acid utilization. The results from Exp. 1 showed that adipic acid increased plasma lysine (by 18%) but not [Alpha]-amino adipic acid, an intermediate in lysine degradation. Experiment 2 demonstrated that adipic acid did not increase the efficiency of utilization of lysine, threonine, or tryptophan. The lack of effects on [Alpha]-amino adipic acid in Exp. 1 and the lack of a positive effect on the efficiency of utilization of lysine, threonine, and tryptophan suggest that adipic acid does not inhibit the mitochondrial uptake of lysine and(or) its degradation in the mitochondrion. It is concluded that feeding adipic acid increases plasma lysine but does not improve the efficiency of lysine utilization. Key Words: Adipic Acid, Lysine, Pigs

A 2 x 3 factorial experiment was conducted with 24 finishing pigs (Yorkshire x [Finnish Landrace x Dutch Landrace]) to determine the effects of dietary buffering capacity (BC) and carbohydrate sources on apparent total tract digestibility (TD), N retention, and manure characteristics. Twelve of these pigs were fitted with steered ileo-cecal value cannulas to measure the apparent ileal digestibility (ID) of N. Experimental variables were two levels of BC (High = 600 mEq/kg and Low = 530 mEq/kg) and three dietary carbohydrates (tapioca [28%], soybean hulls [25%], and sugar beet pulp [25%]). The two levels of BC were achieved by adjusting the amounts of alkalogenic limestone and acidogenic Ca sulfate in the diet. Pigs were fed twice daily at 2.4 x maintenance requirement for metabolizable energy (418 kJ ME/[BW.sup.0.75]). Chromic oxide was used as an indigestible marker. Feces and urine were collected over 5 d for nutrient balance and in vitro measurements of pH and ammonia emission over 7 d. No significant interactions between BC and dietary carbohydrates on the ID, TD, N retention, or manure characteristics were observed. Lowering BC with Ca sulfate did not affect digestibility of most nutrients, except for a negative impact on the TD of Ca (P = 0.015) and Mg (P = 0.003). Although all pigs receiving Ca sulfate had more acidic urine (by 0.49 pH units; P = 0.001), ammonia emission from manure was not lowered, irrespective of the carbohydrate source. Carbohydrates affected significantly the ID and TD of most nutrients, whereas N retention remained similar (P [is greater than] 0.10). Urinary N:fecal N ratios in manure of pigs fed diets with tapioca, soybean hulls, and beet pulp were 2.09, 1.35, and 1.67, respectively. These ratios corresponded with in vitro ammonia emission (169, 125, and 148 mmol/7 d; P = 0.023). In conclusion, these results indicate that the acidification of urine in pigs fed Ca sulfate in the presence of NSP-rich carbohydrates was achieved. However, acidity of manure and ammonia emission were not affected. The addition of NSP from soybean hulls and(or) sugar beet pulp reduced ratios of urinary:fecal N, and thereby ammonia emission. Key Words: Ammonia, Balance Studies, Buffering Capacity, Carbohydrates, Digestibility, Pigs

Vitamin E is important for animal production because of its effects on health and product quality, but the amount and form required remains controversial. Our objective was to quantify the absolute bioavailability of oral all-rac-α-tocopheryl acetate (α-TAc) in swine (22 ± 1 kg and 8 wk old, fitted with jugular catheters) adapted to a diet supplemented with 75 mg/kg all-rac-α-TAc; 75 mg/kg was chosen because this level represents the nonweighted average inclusion level in piglet diets across Western key swine-producing countries. For this, a 350-g test meal (6% fat) was supplied at time 0 containing 75 mg deuterated (D9) all-rac-α-TAc to 9 animals, and 8 animals received an intravenous (i.v.) dose containing deuterated (D6) RRR-α-tocopherol (α-T) at one-eighth the oral dose and a test meal without supplemental vitamin E. Plasma samples (12 to 13 per animal) were obtained at incremental intervals over 75 h for analysis of deuterated α-T using liquid chromatography--tandem mass spectrometry. Surprisingly, the i.v. dose rapidly disappeared from plasma and then reappeared. The half-life for this first peak was only 1.7 ± 0.3 min. The second peak had an appearance rate (Ka) of 0.10 ± 0.06 d-1 and a half-life of 5.9 ± 1.2 h. Oral dosing resulted, after a lag of 56 min, in a Ka of 0.91 ± 0.21 d-1 and a half-life of 2.6 ± 0.8 h. The bioavailability for oral α-TAc was 12.5%, whereas the area under the curve was only 5.4%. This low bioavailability, small area under the curve, and short half-life are likely because of various factors, that is, the use of only 6% fat in the diet, the use of the acetate ester and all-rac, and the high dose relative to requirements. In conclusion, i.v. dosed vitamin E shows both a rapid and a very slow pool, whereas orally dosed vitamin E shows a single slow pool. The oral material has a very short half-live (44% of i.v. or 2.6 h), low bioavailability (12.5%), and a very small area under the curve (5.4%), bringing into question the efficacy of typical doses of vitamin E in swine diets for alleviating oxidative stress. [ABSTRACT FROM AUTHOR]

Three trials were conducted to evaluate the nutritional value of BG with or without Fibrozyme[R]. In Exp. 1, eight barrows (129kg) were used to study fecal digestibility of 14.5% BG supplemented to a corn-soy diet with/without 0.02% Fibrozyme. Diets were fed at 70g x [kg.sup.-0.75] x [day.sup.-1] and tested in a Latin square design. Each period consisted of 5-d adaptation and 2-d collection of freshly voided feces. BG decreased gross energy (E) digestibility 14% (P Key Words: Bermuda grass, Energy and nitrogen, Sow and finisher

Two experiments were designed to assess the feeding value and potential environmental benefits of feeding a low fiber by-product originating from the corn dry milling process (degermed, dehulled corn, DGDH) to pigs. Twelve 27-kg barrows were used in Exp. 1 to evaluate nitrogen (N) and energy digestibility of DGDH compared to regular corn. Animals were individually housed in metabolism cages in which feces and urine was collected. Two diets were formulated to contain either 96.4% of DGDH or regular corn plus supplemental vitamins and minerals. Chromic oxide was used as an indigestible marker. Digestibilities of DM, N, and energy were greater in DGDH (93.4, 89.1, and 92.9%, respectively) compared to regular corn (84.9, 67.9, and 83.5%, respectively) (P < .01). Overall, a 56 and 39% reduction in DM and N excretion, respectively, was observed. In Exp. 2, 96 nursery pigs with initial BW of 8.8 kg, blocked by weight and gender, with 4 pigs/pen, were used in a 28-d growth performance study. Two starter diets were formulated to contain either DGDH (56%) or regular corn (58%) as the major grain source. Diets were formulated on a ME and digestible lysine basis to meet NRC requirements for this weight category of pig. At the end of the study, 24 pigs (1 from each pen) were slaughtered and gastrointestinal tract measurements were taken. Daily growth rates of pigs were the same between diets (0.64 kg/d). Feeding DGDH to pigs resulted in a 4% improvement in feed efficiency over regular corn (P < .05). The full intestinal tract weight of pigs fed DGDH tended to be 6% lighter (P=.07), likely due to a trend towards 10% less gutfill and 4% less intestinal mass. Results from these trials suggest that corn processed to remove poorly digestible fiber fractions provides more digestible nutrients than regular corn. As a result, DGDH reduces fecal and N excretion, thus providing a novel approach for reducing waste production. Key Words: Nutrient excretion, Digestibility, Pigs

Discusses the abstract of the study 'RE-Cycle: Recipe for waste-free swine production,' presented at the American Society of Animal Science's Southern Section conference on January 31-February 4, 2003, in Mobile, Alabama.

Nucleotides play several key roles in metabolism. They are the building blocks of RNA and DNA, intermediates in and regulators of energy metabolism, and co-factors for enzymes. The objective of this research was to determine if supplemental nucleotides enhanced performance of nursery piglets. Piglets (n=1280) weaned at 21 d of age were blocked into weight categories of 5, 6, and 7 kg and housed 12 per pen. Pens were assigned using a RCB design to diets containing 0 (control), 0.05%, 0.1%, 0.2%, and 0.4% nucleotides (Ascogen from Chemoforma). Piglets were fed high quality high zinc diets manufactured by SCA Iberica. Data were analyzed using analysis of variance, and treatment means were used to model the dose response using quadratic regression. ADG and G/F was significantly improved in all periods at 0.20% nucleotides. ADfiwas only significantly improved in period 1 (Table). The results of the dose-response analysis showed that nucleotide supplementation improved ADG by 18.7, 6.3, and 6.3% at an optimum dose of 0.23, 0.21, and 0.21%, in period 1, 2, and 3, respectively. In line with the results of the ANOVA, the feed intake response was less consistent, with an increase in feed intake in period 1 by 7.7% at a dose of 0.23%. G/F was improved by 10.4, 10.6, and 10.4 at doses of 0.25, 0.25, and 0.21% nucleotides in periods 1, 2, and 3, respectively. Overall, these data demonstrate that the optimum dose for nucleotides in order to optimize daily gain and gain/feed is 0.20 to 0.25%. The response for feed intake was variable and less strong. [ABSTRACT FROM AUTHOR]