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Objective: The present study aimed to evaluate the accuracy of previous equations for estimating gross energy (GE) in feed ingredients and to develop the novel equations. Methods: A total of 2,279 ingredient samples consisted of barley (n = 58), corn (n = 319), corn distillers dried grains with solubles (n = 13), corn gluten feed (n = 583), copra expellers (n = 156), copra meal (n = 234), cottonseed meal (n = 12), palm kernel expellers (n = 504), rapeseed meal (n = 114), soybean meal (n = 138), wheat (n = 70), and wheat bran (n = 78) were analyzed for dry matter (DM), crude protein (CP), ether extract (EE), crude fiber, ash, and GE. The 2,279 ingredient samples were used for evaluating the previous equations and developing novel equations. Using data from 62 ingredients in the swine NRC (2012), the old equations and the novel equations were evaluated. Results: Based on the evaluation using 2,279 samples, the equation developed by Ewan (1989) underestimates GE by 218 kcal/kg DM (standard error = 4 and p<0.001) on average and underestimates more for low-GE ingredients (linear bias = -0.121; standard error = 0.025 and p<0.001). The equation reported by Sauvant et al. (2004) also underestimates GE by 135 kcal/kg DM (standard error = 4 and p<0.001) on average. Novel equations for estimating GE concentration (kcal/kg DM) in feeds were developed: GE = 4,299+7×CP+53×EE, with R2 = 0.342 and p<0.001; GE = 4,341+11×CP+54×EE-24×ash, with R2 = 0.372 and p<0.001, where all independent variables are in % DM. In the validation using 62 feed ingredients in the NRC publication, the equations developed in the present study were accurate whereas the previous equations were not. Conclusion: The novel equations developed in the present study fairly accurately estimate gross energy concentrations in concentrate feeds.
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Objective: The objective was to investigate the effects of dietary benzoic acid (BA) on nitrogen (N) balance, urinary pH, slurry pH, and odorous compounds in feces and slurry of pigs. Methods: Twelve barrows with an initial body weight of 56.2±2.6 kg were individually housed in metabolism crates. The animals were allocated to a replicated 6×4 incomplete Latin square design with 12 animals, 6 experimental diets, and 4 periods, resulting in 8 observations per treatment. The basal diet consisted mainly of corn, soybean meal, and rapeseed meal. Benzoic acid was supplemented to the basal diet at 0.5%, 1.0%, 1.5%, 2.0%, or 2.5% BA at the expense of corn starch. Each period consisted of a 4-day adaptation period and a 24-hour collection period for slurry, followed by a 4-day collection period for feces and urine. On day 5, feces and urine were collected for 24 hours and mixed to obtain slurry samples. Results: The daily digested N linearly increased (p<0.05) with increasing BA supplementation. Supplemental BA lowered urinary pH (p<0.001) and slurry pH (p<0.05) in a linear and quadratic manner. In the fecal samples, the concentrations of acetate, propionate, butyrate, and skatole linearly decreased (p<0.05) with supplemental BA. In the slurry samples, the concentrations of butyrate, isovalerate, and skatole linearly decreased (p<0.05) by supplemental BA. Conclusion: In conclusion, supplemental benzoic acid has the potential to improve nitrogen digestion in a dose-dependent manner for pigs. Additionally, dietary benzoic acid lowers urinary pH, slurry pH, and concentrations of odorous compounds in pig feces and slurry.
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OBJECTIVE: The present study aimed to study effects of a chronic feeding of deoxynivalenol (DON) on growth performance, organ weight, organ DON accumulation, and blood parameters in pigs. METHODS: Forty-eight castrated male pigs with a body weight of 10.4 kg (standard deviation = 1.7) were assigned to one of 2 diet groups in a randomized complete block design with 6 blocks of pens per diet and 4 pigs per pen. A corn-soybean meal-based control diet was prepared to contain a low DON concentration of 0.28 mg/kg. Corn distillers dried grains with solubles naturally contaminated with DON were used at 30.0% to prepare a contaminated diet with a high DON concentration of 1.8 mg/kg. During the 56-day experimental period, body weight and feed intake were recorded every 14 days. A pig from each pen was euthanized for the collection of organs and muscle every 14 days. RESULTS: Gain:feed in pigs fed the contaminated diet during days 14 to 28 and days 28 to 42 were less (p<0.05) compared with the control group. As increasing feeding period, the DON concentrations in fresh liver increased during days 14 to 28 and then decreased during the subsequent periods in the DON group, whereas the DON concentrations in fresh liver were constant during the experimental period in the control group (quadratic interaction p = 0.049). The DON concentration in the kidneys in the DON group was greater (p = 0.002) than that in the control group regardless of feeding period. On day 56, the granulocyte count in the DON group was less (p = 0.035) than the control group. CONCLUSION: A chronic feeding of DON for 14 to 42 days decreased gain:feed in pigs, and dietary DON naturally contaminated in corn distillers dried grains with solubles accumulated in the liver during days 14 to 28.
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The aims of this study were to determine in vitro ileal disappearance (IVID) of dry matter (DM) and crude protein (CP) in commercial dog diets and to develop equations for predicting the IVID of DM and CP in dog diets based on chemical composition. Eighteen commercial dog diets were analyzed for IVID of DM and CP using a two-step in vitro procedure for dogs. The diet samples in flasks with digestive enzymes were incubated for 2 h and 4 h to simulate digestion in the stomach and the small intestine, respectively. The contents of CP, ether extract, neutral detergent fiber (NDF), and ash in the diets ranged from 14.4 to 42.5%, 3.5 to 23.5%, 6.4 to 34.6%, and 4.9 to 10.0%, respectively, on an as-is basis. The NDF contents were negatively correlated with the IVID of DM and CP (r = -0.73 and r = -0.62, respectively; p < 0.05). The most suitable prediction equations for the IVID of DM and CP in the dog diets were: IVID of DM (%) = 81.33 + 0.46 × CP - 0.77 × NDF, R2 = 0.78; IVID of CP (%) = 81.25 + 0.33 × CP - 0.49 × NDF, R2 = 0.64, where all nutrients were in % on an as-is basis. In conclusion, dry matter and protein utilization of dog diets based on in vitro digestibility assays can be estimated fairly well using protein and fiber concentrations as independent variables.
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The objective was to evaluate the effects of benzoic acid, bromelain, adipic acid, and humic substance supplementation on nitrogen balance, urinary pH, slurry pH, and manure odorous compounds in pigs. Fifteen castrated male pigs with an initial body weight of 37.9 kg (standard deviation = 4.1) were individually housed in metabolism crates. The animals were allocated to a triplicated 5 × 2 incomplete Latin square design with 15 animals, 5 experimental diets, and 2 periods. The basal diet mainly consisted of corn, soybean meal, and rapeseed meal. Four experimental diets were prepared by supplementing each additive at a concentration of 10 g/kg at the expense of corn starch to the basal diet. Each period consisted of a 4-day adaptation period, a 24 h collection period for slurry sampling, and a 4-day collection period for feces and urine. The feces and urine collected for 24 h on day 5 were mixed at a ratio of fecal weight and urine weight to obtain slurry samples. The apparent total tract digestibility N in pigs fed the humic substance diet was the least (p < 0.05) compared to the other groups. The daily retained N and N retention as % ingested tended (p < 0.10) to be the lowest in the adipic acid group among the treatments. The urinary pH in pigs fed the adipic acid diet was less (p < 0.05) than that in other groups except the benzoic acid group. The slurry pH tended to differ among the treatment groups (p = 0.074) with the lowest value in the pigs fed the adipic acid diet. The concentrations of indole in slurry (p = 0.084) and isovalerate in feces (p = 0.062) tended to differ among the groups with the lowest values in the pigs fed the humic substance diet. In conclusion, adipic acid supplementation in pig diets can decrease urinary pH and slurry pH. Although benzoic acid and adipic acid have limited effects in reducing odorous compounds, humic substances have the potential to reduce some odorous compounds.
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The objective of this study was to investigate the effects of supplemental mycotoxin-sequestering agents on growth performance and nutrient utilization in growing pigs fed deoxynivalenol (DON)-contaminated diets. Twelve barrows with an initial body weight of 35.5 kg (standard deviation = 1.3) were assigned to six dietary treatments in a replicated 6 × 5 incomplete Latin square design. Five experimental diets consisted of an uncontaminated diet (PC), a DON-contaminated diet at 6.89 mg/kg (NC), NC + bentonite 0.5%, NC + yeast cell wall 0.5%, and NC + a mixture product 0.5% which consisted of enzymes, microorganisms, minerals, and plant extracts. Pigs had ad libitum access to the five diets. In the last group, the PC diet was restrictedly provided to pigs at the quantity of feed consumption of the NC group. Average daily gain, average daily feed intake, and gain:feed were not affected by supplemental mycotoxin-sequestering agents except for the mixed product that tended to improve (p = 0.064) gain:feed in pigs fed DON-contaminated diets. The apparent total tract digestibility (ATTD) of dry matter was not affected by DON contamination or by supplemental mycotoxin-sequestering agents, whereas the ATTD of Ca was decreased (p = 0.032) by supplemental yeast cell wall in pigs fed DON-contaminated diets. The ATTD of P was greater (p = 0.042) in pigs fed the NC diet compared with the pigs fed the restricted amount of the PC diet. In conclusion, bentonite and yeast cell wall did not affect growth performance of pigs fed DON-contaminated diets, but a supplemental mixed product consisting of enzymes, microorganisms, minerals, and plant extracts partially alleviated the negative effects of dietary DON on the gain:feed of pigs. Calcium digestibility was decreased by supplemental yeast cell wall in pigs fed DON-contaminated diets. Based on the present work, the use of a mixed product consisting of enzymes, microorganisms, minerals, and plant extracts is suggested, and the reduction of Ca digestibility by yeast cell wall needs to be considered in diet formulations.
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The objectives were to determine the effects of dietary deoxynivalenol (DON) on apparent ileal digestibility (AID) of nutrients and to evaluate the efficacy of a bentonite (BEN) and a preservative blend (PB) product for alleviating DON effects on the nutrient digestibility of pigs. Twelve crossbred barrows with an initial body weight of 69.4 kg (standard deviation = 3.5) equipped with a T-cannula in the distal ileum were allotted a triplicated 4 × 2 incomplete Latin square design with four dietary treatments and two periods. Dietary treatments were (1) an uncontaminated diet, (2) a contaminated diet (CD) mainly based on contaminated wheat with 1.6 mg/kg DON, (3) CD + 0.25% PB consisting of preservation components as major sources, antioxidants, microorganisms, and amino acids (AA), and (4) CD + 0.25% BEN. The AID and ATTD of dry matter, organic matter, crude protein, most minerals, and most AA were not affected by DON contamination. Dietary DON decreased the AID and ATTD of sodium (p < 0.05) but were restored by supplementing the PB product (p < 0.05). The AID of zinc was increased (p < 0.05) by dietary DON, but supplementing BEN decreased zinc digestibility (p < 0.05). The AID of Arg, Ile, Thr, and Asp was decreased (p < 0.05) by BEN addition. In conclusion, dietary DON affected the digestibility of some minerals but not AA in pigs. Supplemental BEN can negatively affect the nutrient digestibility of some minerals and AA in pigs. The addition of a PB product in pig diets can restore digestibility of sodium but not of other nutrients. Based on these observations, feed additives for alleviating DON effects on nutrient digestibility of pigs can be carefully selected by swine diet formulators.