Search

Objective: The objectives were to demonstrate that the nitrogen and energy in pig urine supplemented with hydrochloric acid (HCl) are not volatilized and to determine the minimum amount of HCl required for nitrogen preservation from pig urine.Methods: In Exp. 1, urine samples of 3.0 L each with 5 different nitrogen concentrations were divided into 2 groups: 1.5 L of urine added with i) 100 mL of distilled water or ii) 100 mL of 6 N HCl. The urine in open plastic containers was placed on a laboratory table at room temperature for 10 d. The weight, nitrogen concentration, and gross energy concentration of the urine samples were determined every 2 d. In Exp. 2, three urine samples with different nitrogen concentrations were added with different amounts of 6 N HCl to obtain varying pH values. All urine samples were placed on a laboratory table for 5 d followed by nitrogen analysis.Results: Nitrogen amounts in urine supplemented with distilled water decreased linearly with time, whereas those supplemented with 6 N HCl remained constant. Based on the linear broken-line analysis, nitrogen was not volatilized at a pH below 5.12 (standard error = 0.71 and pN HCl to preserve nitrogen in pig urine was developed: additional 6 N HCl (mL) to 100 mL of urine = 3.83×nitrogen in urine (g/100 mL)+0.71 with R2 = 0.96 and pN HCl should be added to the urine collection container.Conclusion: Nitrogen in pig urine is not volatilized at a pH below 5.12 at room temperature and the amount of 6 N HCl required for nitrogen preservation may be up to 240 mL per day for a 110-kg pig depending on urinary nitrogen excretion.

The objective was to investigate the hindgut disappearance of phosphorus (P) in corn-soybean meal-based diets with or without inorganic P sources in pigs. Hindgut disappearance of P was hypothesized to be greater in a diet without inorganic P than in a diet with inorganic P. Barrows (n = 5; initial body weight = 23.5 ± 3.1 kg and final body weight = 33.7 ± 5.5 kg) fitted with a T-cannula in the distal ileum were individually housed in pens equipped with a feeder and a nipple drinker. Two corn-soybean meal-based diets were formulated with or without the inclusion of inorganic P. No phytase was supplemented to the diets. All diets contained 0.5% chromic oxide as an indigestible index. The pigs were allotted to a 2-period crossover design with 2 diets. A diet was fed to 2 pigs and the other diet was fed to 3 pigs in each period. An additional period was conducted after the 2 periods to obtain 2 additional replicates for each treatment. Each period consisted of a 7-d adaptation period, a 2-d fecal collection period, and a 2-d ileal collection period. Apparent ileal (54.7 vs. 35.0%) and total tract (53.7 vs. 34.3%) P digestibility values in the inorganic P-containing diet were greater (P < 0.01) than those in the diet without inorganic P. However, apparent ileal P digestibility values were comparable (P > 0.90) with apparent total tract P digestibility values irrespective of the inclusion of inorganic P in the diets, and thus, a significant amount of hindgut disappearance of P was not observed in both diets. In conclusion, hindgut disappearance of P in a corn-soybean meal-based diet was negligible in 23-kg growing pigs regardless of the inclusion of inorganic P sources.

The objective was to determine standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in fish meal, defatted black soldier fly (BSF; Hermetia illucens) larva meal, and adult BSF fed to pigs. Eight barrows with an initial body weight of 72.6 kg (SD = 10.4) fitted with T-cannulas in the distal ileum were individually housed in pens that were equipped with a feeder and a nipple drinker. The pigs were allotted to a replicated 4 × 5 incomplete Latin square design with 4 diets and 5 periods. Three experimental diets containing fish meal (68.6% CP, 5.24% Lys, and 7.5% ether extract), defatted BSF larva meal (59.5% CP, 3.82% Lys, and 7.6% ether extract), and adult BSF (59.0% CP, 2.80% Lys, and 26.8% ether extract) as the sole source of AA were prepared. Additionally, a nitrogen-free diet was formulated to determine the basal endogenous losses of CP and AA. All diets contained 0.5% chromium oxide as an indigestible index. Each period consisted of 4 days of adaptation and 2 days of ileal digesta collection. The SID of CP in defatted BSF larva meal was less (73.8% vs. 88.3%; P < 0.05) than that in fish meal but was greater (P < 0.05) than that in adult BSF (56.1%). The SID of all indispensable AA except for Met and Phe in defatted BSF larva meal was less (P < 0.05) than that in fish meal. The SID of all AA in defatted BSF larva meal was greater (P < 0.05) than that in adult BSF. In conclusion, AA in defatted BSF larva meal are less digestible than those in fish meal when fed to pigs but are more digestible than those in in adult BSF.

The objectives were to evaluate the nutrient utilization of fish meal, black soldier fly (BSF, Hermetia illucens) larvae, and adult BSF meal and to develop equations for estimating in vitro nutrient disappearance of BSF larvae for pigs. Two-step and 3-step in vitro procedures were used to simulate the digestion and absorption of nutrients in the gastrointestinal tract of pigs. In Exp. 1, defatted BSF larva meal had less (P < 0.05) in vitro ileal disappearance (IVID) of dry matter (DM; 81.2% vs. 91.6% and 61.6%) and crude protein (CP; 81.8% vs. 92.2% and 67.2%) and in vitro total tract disappearance (IVTTD) of DM (82.6% vs. 93.6% and 65.7%) and organic matter (OM; 78.1% vs. 91.5% and 63.2%) than fish meal and greater (P < 0.05) values than adult BSF. In Exp. 2, CP concentrations in BSF larvae were negatively correlated with ether extract (r = −0.91) but positively correlated with acid detergent fiber (ADF; r = 0.98) and chitin (r = 0.95). Acid detergent fiber and chitin concentrations in BSF larvae were negatively correlated with IVID of DM (r = −0.98 and −0.88) and CP (r = −0.87 and −0.84) and IVTTD of DM (r = −1.00 and −0.94) and OM (r = −0.99 and −0.98). Equations for in vitro nutrient disappearance of BSF larvae using ADF (% DM) as an independent variable were developed: IVID of CP, % = −0.95×ADF + 95 (r2 = 0.75 and P = 0.058) and IVTTD of OM, % = −2.60×ADF + 115 (r2 = 0.98 and P < 0.01). In conclusion, in vitro nutrient utilization of defatted BSF larva meal was less compared with fish meal but was greater compared with adult flies and in vitro nutrient utilization of BSF larvae can be predicted using ADF as an independent variable.

The objective of this study was to determine the digestible energy (DE) and metabolizable energy (ME) concentrations in high-fiber ingredients fed to growing pigs. Twelve barrows with an initial body weight of 57.5 kg (SD = 5.7) were individually housed in metabolism crates. A replicated 6 × 3 incomplete Latin square design with 12 animals, 6 experimental diets and 3 periods was employed. A basal diet was composed of 75.0% corn and 22.7% soybean meal (SBM) as the sole energy sources. Four experimental diets were prepared by replacing 40% of corn and SBM with soybean hulls (SH), corn gluten feed (CGF), wheat bran (WB), or rice bran (RB). An additional diet was prepared by replacing 10% of corn and SBM with cashew nut hulls (CNH). Each period consisted of a 4-d adaptation period and a 4-d collection period, and the marker-to-marker procedure was used for total collection of feces and urine. The DE and ME values in RB (3,969 and 3,936 kcal/kg DM) were greater (P < 0.05) than those in CGF (2,654 and 2,520 kcal/kg DM) and SH (2,492 and 2,541 kcal/kg DM) and the energy values in WB (3,162 and 3,118 kcal/kg DM) were not different from those in RB, CGF, or SH. The DE and ME values in CNH (350 and 572 kcal/kg DM) were less (P < 0.05) than those in all other test ingredients. In conclusion, energy concentrations in RB were greatest among the high-fiber test ingredients, whereas CNH had the lowest values.

The objective of the present study was to develop prediction equations for digestible energy (DE) and metabolizable energy (ME) in swine diets based on chemical compositions of feces with no dietary information. A total of 262 fecal samples obtained from growing pigs fed 27 diets from 4 experiments were used. The diets were based mainly on corn, soybean meal, and other plant-originated feed ingredients. In the digestibility experiments, feces and urine were quantitatively collected using the marker-to-marker procedure. The diet and fecal samples were analyzed for dry matter (DM), crude protein, ash, and neutral detergent fiber (NDF). Digestible energy in the 27 diets ranged from 2,907 to 4,374 kcal/kg DM and ME ranged from 2,774 to 3,983 kcal/kg DM. Fecal ash was positively correlated with DE (r = 0.81, P < 0.001) and ME (r = 0.66, P < 0.001) whereas fecal NDF was negatively correlated with DE (r = –0.66, P < 0.001) and ME (r = –0.74, P < 0.001). The energy prediction equations developed using fecal chemical components were: energy digestibility = 88.1 + 0.37 × ash – 0.28 × NDF (R2 = 0.57, P < 0.001); DE (kcal/kg DM) = 3,604 + 32.8 × ash – 11.1 × NDF (R2 = 0.71, P < 0.001); and ME (kcal/kg DM) = 4,077 + 15.7 × ash – 18.1 × NDF (R2 = 0.63, P < 0.001) where chemical components are expressed as % DM. In conclusion, energy digestibility, DE values, and ME values in swine diets are correlated with fecal ash and NDF concentrations and the energy values can be predicted using fecal ash and NDF concentrations without dietary information.

The objectives were to demonstrate that nitrogen volatilization from pig urine can be inhibited by the addition of acids and to determine a minimum amount of HCl for nitrogen preservation in pig urine. In experiment 1, five urine samples were collected and had nitrogen concentrations of 0.29% to 0.68%. Each sample was divided into 2 groups that were supplemented with 100 mL of distilled water and 100 mL of 6 N HCl, respectively. The samples were placed in open containers at room temperature for 10 d. The nitrogen concentration was determined every 2 d. The amount of nitrogen in urine supplemented with distilled water decreased linearly (P < 0.001) with time, whereas that supplemented with 6 N HCl remained constant. In experiment 2, three urine samples with different nitrogen concentration (0.12%, 0.53%, and 0.94%) were added with different amounts of 6 N HCl used to make varying acidity (pH = 0.6, 1.1, 2.2, 4.7, 7.1, and 9.3). All urine samples were placed at a room temperature for 5 d followed by nitrogen analysis. Based on a linear broken-line analysis, nitrogen was not volatilized at a pH less than 5.12 (SE = 0.71), whereas nitrogen was volatilized at a pH greater than 5.12 (r2 = 0.98). An equation was developed for the minimum amount of 6 N HCl in urine to avoid nitrogen volatilization: 6 N HCl in urine (g/L) = 0.11 × nitrogen in urine (g/L) + 0.2 with r2 = 0.93 and P < 0.01. Assuming that up to 200 gram of nitrogen is excreted for 5 d, the addition of 100 mL of 6 N HCl to the urine collection container can inhibit nitrogen volatilization. Taken together, a minimum of 100 mL of 6 N HCl is recommended for 5 day-total collection of pig urine.

The objectives of this study were to assess the accuracy of previously published equations for predicting effects of deoxynivalenol (DON) on the growth performance of pigs and to update the equations based on the recently published data. A total of 55 data from 22 experiments published between 2013 and 2020 reporting the effects of DON on the performance of pigs were employed for the validation of the previously published equations and these data were used to update the equations. The REG procedure of SAS was used to validate and develop equations and the CORR procedure was used to determine correlation coefficients among variables. The validation of the previously published equations showed that the slope (0.33 ± 0.08, P < 0.05) representing the linear bias and intercept (-3.55 ± 1.60, P < 0.05) representing the mean bias of weight gain changes (ΔWG, %) were different from 0. The slope (0.55 ± 0.07, P < 0.05) and intercept (-6.94 ± 1.20, P < 0.05) of feed intake changes (ΔFI, %) were also different from 0. Dietary DON concentrations had a negative correlation with ΔWG (r = -0.80; P < 0.001) and ΔFI (r = -0.74; P < 0.001). Updated prediction equations for estimating ΔWG and ΔFI based on a total of 152 data from 41 experiments were: ΔWG = -5.76 × DON with r2 = 0.77 and ΔFI = -4.65 × DON with r2 = 0.71, respectively, where dietary DON concentrations ranged from 0 to 14.6 mg/kg. In conclusion, the novel equations developed based on the large number of observations including recent ones may accurately predict effects of dietary DON on the performance of pigs.