Effect of a commercial anionic dietary supplement on urinary pH and concentrations of electrolytes and pH in blood of horses

ABSTRACT

Aims: To compare urine urinary pH, blood pH and concentration of electrolytes in blood of healthy horses fed an anionic salt supplement to achieve diets with a dietary cation-anion difference (DCAD) of ?40 or 0?mEq/kg DM, with horses a fed a diet with a DCAD of 85?mEq/kg DM.

Methods: Eight healthy horses received each of three diets in a randomised crossover design. Diets consisted of grass hay and concentrate feed, with a varying amount of an anionic supplement to achieve a DCAD of 85 (control), 0 or ?40?mEq/kg DM. They were fed for 14 days each with a washout period of 7 days between. Urine pH was measured daily and blood samples were collected on Days 0, 7 and 14 of each study period for the measurement of pH and concentration of electrolytes.

Results: Four horses voluntarily consumed the anionic supplement with their feed, but four horses required oral supplement administration via dose syringe. During the study period mean urine pH was lower in horses fed diets with a DCAD of 0 (6.91; SD 0.04) and ?40 (6.83; SD 0.04) mEq/kg DM compared to the control diet (7.30; SD 0.04). Compared with horses fed the control diet, mean urine pH was lower in horses fed the 0 and ?40?mEq/kg DM diets on Days 1–12 and 14 (p?<?0.05) of the study period. On Day 13 it was only lower in horses fed the ?40?mEq/kg DM diet (p?<?0.01). Urine pH was similar for horses fed the 0 and ?40?mEq/kg DM diets (p?=?0.151). The DCAD of the diet had no effect on blood pH, ionised Ca or anion gap. Mean concentrations of bicarbonate in blood were affected by diet (p?=?0.049); they were lower when horses were fed the 0?mEq/kg diet relative to the control diet on Day 14.

Conclusions and clinical relevance: The anionic supplement reduced urine pH in horses fed diets with a DCAD of 0 or ?40?mEq/kg DM compared with 85?mEq/kg DM. However as urinary pH did not fall below pH 6.5, the pH below which calcium carbonate uroliths do not form, this reduction in urine pH is unlikely to be clinically significant. The supplement was variably palatable and showed minimal promise as an effective urinary acidifier at the doses administered in this study.     

Influence of the feed base excess on urine parameters in cats

In this study the base excess (BE) was used as a method to predict the influence of the food on the urinary pH on cats. Nine cat foods (six dry and three canned) were consecutively fed to eight cats. The urine pH, volume, specific gravity and water and food intake were determined daily. The base excess [BE; mmol/kg dry matter (DM)] was calculated from the compounds in the food (BE = 49.9*Ca+82.3*Mg*+43.5*Na+25.6*K-64.6*P-13.4*Met-16.6*Cys-28.2*Cl). The BE of the tested foods was between -287.35 and 133.38 mmol/kg DM. The mean urine pH varied between 5.76 (SD = 0.13) and 7.16 (SD = 0.22). The BE correlated with the mean urine pH (pH = 6.25+0.0023*BE; r = 0.74**). The urine volume (ml/kg BW/day) correlated significantly positive with the K- (r = 0.71**) and significantly negative with the P-content (r = -0.67**), the Ca-content (r = -0.50**) followed by the Mg-content (r = -0.36**) of the food. The correlation coefficients between the anions/cations in the food and the urine pH was for K 0.36**, for P -0.61**, the Met+Cys -0.60** and Cl -0.27**. In practice the correlation between urine pH and BE would help to pre-estimate the effect of food on the urine pH and to prevent urolith formation.     

Effect of dietary cation-anion difference on acid-base status and energy digestibility in sedentary horses fed varying levels and types of starch

Six mature horses were used in a 6×6 Latin Square design experiment to study the effects of varying dietary cation-anion differences (DCAD) on the acid-base status and energy digestibility of horses fed varying levels and sources of starch. Rolled corn, whole oats, or dehydrated alfalfa meal were used to make up the concentrate portions of the diets. Three diets had a DCAD above 300 meq/kg DM, and three below 160 meq/kg DM. This trial consisted of 11-day adjustment periods followed by 72-hour experimental collection periods. During that time, venous blood samples were drawn for analysis of pH, pCO₂, HCO₃⁻, pO₂, and lactate concentrations. Total urine was collected and measured for pH and mineral content. Representative feed and fecal samples were taken to determine energy digestibility. Blood lactate concentration showed no variation among treatments. Energy digestibility showed no variation with respect to DCAD, but did vary with starch intake. Urine pH, blood pH and blood HCO₃⁻ concentrations were significantly lower for horses consuming diets with a low DCAD as compared with high DCAD diets regardless of starch source or intake. Thus, it may be possible to reverse any metabolic acidosis caused by high starch intake by increasing the DCAD of the diet.     

Acute response of urine pH following ammonium chloride administration to dogs

To test the acidifying ability of the distal portion of the nephrons in healthy dogs, 0.2 g of NH4Cl/kg of body weight was given PO. Samples for venous blood gas analysis and urine pH were taken hourly for 6 hours. Systemic acidemia developed, as evidenced by a statistically significant (P less than 0.05) decrease in blood pH 1 hour after NH4Cl administration. Four hours after administration, mean urine pH decreased to a low of 5.16 +/- 0.1 and was less than 5.5 3 hours after administration. Changes in urine pH 2 hours after administration were statistically significant (P less than 0.05). In human beings, NH4Cl loading is used to detect patients with distal renal tubular acidosis (defective hydrogen ion secretion by the distal nephrons) and normal acid/base values. Distal renal tubular acidosis is diagnosed if urine pH fails to decrease to less than 5.5 after NH4Cl administration. On the basis of the findings of this study, a similar value would be valid for dogs.     

Effects of three infusion fluids with different sodium chloride contents on steady‐state serum concentrations of bromide in dogs

Potassium bromide overdose (bromism) in the management of canine epilepsy has been known. However, a protocol to reduce bromide concentrations rapidly has not been previously established. The effects of three infusion fluids with different chloride contents on the steady‐state serum concentrations of bromide in beagles were determined. After stabilization of the serum bromide concentrations, seven dogs were infused with saline (Na⁺ 154 mmol/L; Cl^? 154 mmol/L), lactated Ringer's (Na⁺ 131 mmol/L; Cl^? 110 mmol/L), or maintenance solutions (Na⁺ 35 mmol/L; Cl^? 35 mmol/L) at a rate of 2 or 10 ml kg^?1 hr^?1 for 5 hr. Serum and urine were collected hourly, and the bromide concentrations were measured. When saline and lactated Ringer's solutions were infused at a rate of 10 ml kg^?1 hr^?1 for 5 hr, serum bromide concentrations were decreased by 14.24% and urine bromide concentrations by 17.63%, respectively. Of all compositions of infusion fluids, only sodium and chloride contents were associated with the decreased serum concentrations and the increased renal clearance of bromide. In summary, saline and lactated Ringer's solutions reduced serum bromide concentrations in a sodium chloride‐dependent manner in dogs were found when infused at 10 ml kg^?1 hr^?1 for 5 hr.     

Evaluation of sodium bisulphate and phosphoric acid as urine acidifiers for cats.

Eighteen cats were used to compare the urine acidifying properties of sodium bisulphate to phosphoric acid. Acidifying agents were added at one of three concentrations (0.4, 0.6, or 0.8%, as-is basis). Cats were offered a commercial diet to determine basal urinary pH, and then again for a 1 week period between blocks 1 and 2. Cats were acclimated to the diets for 6 days, and urine samples were collected on day 7 at 0, 4, and 8 h postfeeding to obtain pre- and postprandial urinary pH. Intakes of diets containing sodium bisulphate tended (P < 0.07) to be lower than intakes of diets containing phosphoric acid. Cats consuming the 0.8% phosphoric acid diet had higher (P < 0.05) food intakes than cats consuming either the 0.4 or 0.6% phosphoric acid-containing diets. There was significant (P = 0.01) linear and quadratic response for food intake in cats consuming the sodium bisulphate-containing diet. Cats consuming the 0.4 and 0.8% phosphoric acid-containing diets tended (P = 0.07) to have higher water intakes than cats consuming the 0.6% phosphoric acid-containing diet. There were no differences (P > 0.05) in urine pH and specific gravity between cats fed the different acidifier types. Cats consuming the 0.6% phosphoric acid-containing diet tended (P = 0.07) to have a higher urine pH 8 h post-feeding than cats consuming the 0.4 and 0.8% phosphoric acid-containing diets. Urine pH was highest at 4 h post-feeding except for cats fed the 0.4% sodium bisulphate- and the 0.6% phosphoric acid-containing diets. No differences (P > 0.05) between acidifiers were found in faecal score or in faecal dry matter and organic matter concentrations. A quadratic response was detected in faecal score for cats consuming the phosphoric acid-containing diets. Cats consuming the 0.6% phosphoric acid diet tended (P = 0.06) to have a lower faecal score than cats consuming the 0.4 and 0.8% phosphoric acid diets. For faecal dry matter, a linear trend was detected in cats consuming the sodium bisulphate (P = 0.08) and phosphoric acid-containing (P = 0.04) diets. Sodium bisulphate and phosphoric acid generally behaved in a similar fashion when incorporated in dry cat diets.     

The effects of the loop diuretics furosemide and torasemide on diuresis in dogs and cats

Torasemide is a new loop diuretic that combines the effects of furosemide and spironolactone. There are no reports on the effects of torasemide in cats and dogs. This study compared the diuretic effects of furosemide and torasemide in cats and dogs. Cats with pressure overload cardiac hypertrophy were given oral placebo, torasemide 0.3 mg/kg, or furosemide 1 mg/kg or 3 mg/kg. Control and mitral regurgitation dogs were given oral placebo, torasemide 0.2 mg/kg, and furosemide 2 mg/kg for 7 days. Urine samples were obtained at baseline and 1, 2, 3, 4, 5, 6, 8, 12, and 24 hr after each drug dose. Urine volume and urine Na(+) and K(+) were measured. Both furosemide and torasemide increased urine volume 1 hr after administration. Furosemide caused a dose-dependent increase in urine volume that peaked at 2-3 hr in cats and dogs. The diuretic effect of furosemide disappeared 6 hr after administration, while that of torasemide peaked 2-4 hr after administration and persisted for 12 hr in cats and dogs. In MR dogs, torasemide for 7 days significantly decreased urine potassium excretion. Plasma aldosterone increased with torasemide, whereas there was no change with furosemide. In conclusion, about 1/10 concentration of torasemide was as potent as furosemide and had a longer diuretic effect in cats and dogs. These data suggest that torasemide is useful for treating congestive heart failure or edema in cats and dogs.     

Fresh and preserved green fodder modify effects of urinary acidifiers on urine pH of horses

Hay stabilises urine pH in horses. It is unknown whether this is an effect of structure or of chemical composition. In this study, four ponies (230–384 kg body weight [BW]) were fed six different diets with either a structure or a composition similar to hay with and without acidifiers in a cross‐over experimental design in amounts to maintain body weight with the following main compounds: Fresh grass (GRASS), alfalfa hay (ALF), grass cobs (COBS), grass silage (SIL), straw (STR) or extruded straw (STRe) for 2 to 10 days. Urine pH was measured in all trials, blood pH, blood base excess and bicarbonate as well as mineral balance were determined in GRASS, ALF, STR and STRe. In the trials with straw and extruded straw, urine pH decreased significantly (STR control: 7.8 ± 0.23, acidifier: 5.2 ± 0.38) when acidifiers were added, whereas in all other diets that were based on fresh or preserved green fodder, pH did not decrease below 7. Blood pH was similarly affected by diet and acidifiers. Acidifiers had little effect on the pre‐prandial blood pH, only in diet STR there was a significant reduction in relation to control. Post‐prandial blood pH was significantly reduced by acidifiers in all diets. Blood bicarbonate and base excess showed corresponding effects. Faecal and renal mineral excretion and apparent mineral digestibility were not systematically affected by diet or acidifiers except for chloride. Chloride added as inorganic chloride salt had an even better apparent digestibility than chloride originating from feed. Because only green plant material stabilised acid base balance, chlorophyll and its metabolites are discussed as potential mediators of the effect of green fodder on acid base balance.     

Phenothiazine toxicity

Thirteen adult cats were each fed consecutively five test diets: firstly a complete canned diet, and then four commercially available dry cat diets (New Formula Biscats, Cat Chow, Go-Cat and Whiskettes) for 7,13, 5, 4 and 4 weeks respectively. Urine samples were tested for pH and presence of struvite crystals. Body weight was recorded weekly.

Urine pH was ranked from acid to alkaline as follows: Whiskettes (pH 5.8), canned diet (pH 5.9), Biscats (pH 6.1), Cat Chow (pH 6.45) and Go-Cat (pH 6.5). The pH of urine when cats were fed Whiskettes, Biscats and canned diet was not significantly different. Biscats produced a urine pH significantly higher than Whiskettes but, in each case, these three diets produced a significantly lower urine pH than Cat Chow and Go-Cat. Struvite crystals occurred spontaneously in 9% of urine samples from cats when fed Whiskettes and Biscats, 71% when fed Cat Chow and 38% when fed Go-Cat: spontaneous struvite was not seen in any cat fed CX9. Haematuria was seen in 2.9% (2/69) urine samples from cats fed Cat Chow. One tom cat had a blocked urethra after 24 days on Go-Cat. No abnormalities were observed in any cat when fed canned diet, Biscats or Whiskettes.

It was concluded that of the four dry cat diets tested only Biscats and Whiskettes produce urine with an acceptably low rate of spontaneous struvite crystalluria.     

Feline struvite crystalluria: a comparison of some commercially available dry cat diets in New Zealand

Thirteen adult cats were each fed consecutively five test diets: firstly a complete canned diet, and then four commercially available dry cat diets (New Formula Biscats, Cat Chow, Go-Cat and Whiskettes) for 7,13, 5, 4 and 4 weeks respectively. Urine samples were tested for pH and presence of struvite crystals. Body weight was recorded weekly. Urine pH was ranked from acid to alkaline as follows: Whiskettes (pH 5.8), canned diet (pH 5.9), Biscats (pH 6.1), Cat Chow (pH 6.45) and Go-Cat (pH 6.5). The pH of urine when cats were fed Whiskettes, Biscats and canned diet was not significantly different. Biscats produced a urine pH significantly higher than Whiskettes but, in each case, these three diets produced a significantly lower urine pH than Cat Chow and Go-Cat. Struvite crystals occurred spontaneously in 9% of urine samples from cats when fed Whiskettes and Biscats, 71% when fed Cat Chow and 38% when fed Go-Cat: spontaneous struvite was not seen in any cat fed CX9. Haematuria was seen in 2.9% (2/69) urine samples from cats fed Cat Chow. One tom cat had a blocked urethra after 24 days on Go-Cat. No abnormalities were observed in any cat when fed canned diet, Biscats or Whiskettes. It was concluded that of the four dry cat diets tested only Biscats and Whiskettes produce urine with an acceptably low rate of spontaneous struvite crystalluria.     

Effects of dietary cation-anion balance on acid-base status in horses

Four mature, sedentary geldings were used in a 4x4 Latin square design experiment to study the effects of dietary cationanion balance (DCAB), defined as meq ((Na + K) - C1)/kg of dietary dry matter, on urine pH, blood pH and blood gasses. Four diets with actual DCAB levels of +21 (Low, L), +125 (Medium Low, ML), +231 (Medium High, MH) and +350 (High, H) were fed for a 21-day adjustment period and a 72 hour collection period. Total urine output was collected every 4 hours post feeding for 72 hours, and like times across days were combined for analyses. Arterial and venous blood samples were drawn, via indwelling catheters, hourly for 12 hours beginning at feeding. All samples were analyzed immediately after collection for pH, blood gasses and blood acid-base measures. Urine pH was lower (p<.05) at all measured intervals when geldings consumed diet L than when they consumed diets MI, MH and H. Least squares means for urine pH ranges from 5.40 to 5.86 on diet L, 6.79 to 7.30 on diet ML, 7.35 to 7.63 on diet MH and 7.52 to 8.14 on diet H. Blood pH, pCO₂ and HCO₃ values were also significantly lower in both arterial and venous samples when geldings consumed diet L than when fed diets MH and H. Results of this trial indicate that horses consuming highly anionic diets may experience a nutritionally-induced metabolic acidosis.     

Use of continuous renal replacement therapy for treatment of dogs and cats with acute or acute-on-chronic renal failure: 33 cases (2002–2006)

Objective: To describe the indications, clinical features, outcomes and complications associated with use of continuous renal replacement therapy (CRRT) in 17 client-owned dogs and 16 client-owned cats with acute or acute-on-chronic renal failure refractory to aggressive medical management.
Series summary: Twenty-nine percent of dogs and 44% of cats had evidence of pre-existing chronic kidney disease (CKD). Median duration of CRRT was 16.3 hours (range 0.3–83.0 hours) in dogs and 11.5 hours (range 1.0–35.5 hours) in cats. Median canine blood urea nitrogen (BUN) improved from 41.0 mmol/L (115.0 mg/dL) to 11.8 mmol/L (33.0 mg/dL) and creatinine from 636.5 mmol/L (7.2 mg/dL) to 274 mmol/L (3.1 mg/dL). Median feline BUN improved from 46.4 mmol/L (130 mg/dL) to 13.9 mmol/L (39.0 mg/dL) and creatinine from 1069.6 mmol/L (12.1 mg/dL) to 291.7 mmol/L (3.3 mg/dL). Metabolic acidosis resolved in 80% of affected dogs and 71% of affected cats. Hyperkalemia resolved in 100% of affected dogs and 88% of affected cats. Complications noted with CRRT included iatrogenic hypokalemia, iatrogenic metabolic alkalosis, clinical hypocalcemia, total hypercalcemia, filter clotting, anemia, hypothermia, and neurologic complications. Forty-one percent of dogs and 44% of cats survived to discharge. No dogs and only 1 cat developed newly diagnosed CKD.
New or unique information provided: CRRT can be a viable option for the management of acute or acute-on-chronic renal failure in dogs and cats that are refractory to aggressive medical management. The frequency of complications associated with CRRT in this study warrants further experience with this modality before its widespread use can be recommended.     

Phyzyme XP phytase improves growth performance and nutrient utilization in wheat-based diets fed to weaned pigs

The effect of phytase (Phyzyme XP) on performance and nutrient utilization in piglets fed wheat-based diets was evaluated using 24 male pigs averaging 7 kg. Four experimental diets containing either 0 (positive control, adequate nutrients), 0 (negative control (NC), reduced nutrients), 500 or 1000 U/kg of phytase were used for each of two dietary phases (day 0 to 14 and day 14 to 33). Feed and water were provided ad libitum. Animals were weighed at weekly intervals until day 28 and feed intake (DFI) recorded daily. From day 28 to 33 pigs were fed at 3 times maintenance energy intake and DFI recorded. Total amounts of faeces and urine were recorded for each individually housed pig. Digestibilities and balance of dry matter (DM), phosphorus (P), calcium (Ca), nitrogen (N) and gross energy (GE) were calculated for feed, faeces and urine. Compared to the NC, daily live weight gain was improved (P < 0.05) for pigs receiving the highest level of supplemental phytase in phase 2. Phytase addition at 1000 FTU/kg also increased faecal digestibilities of P and Ca (P < 0.05). Contrasts comparing NC and Phytase diets showed that Ca (P < 0.02) and P (P < 0.05) balance were improved.     

Influence of altering dietary cation anion difference on milk yield and its composition by early lactating Nili Ravi buffaloes in summer

Influence of − 11, + 11, + 22 and + 33 mEq/100 g dry matter (DM) of dietary cation anion difference (DCAD) on dry matter intake (DMI), serum concentration of minerals and milk yield and its composition by early lactating Nili Ravi buffaloes was examined in a randomized complete block design during summer. Four iso-energetic and iso-nitrogenous DCAD diets were randomly allotted to four groups, five buffaloes in each group. A linear increase in DMI and water intakes was recorded with increasing the DCAD concentration. Greater nitrogen balance was noticed in buffaloes fed diets containing + 22 and + 33 mEq/100 g DM DCAD than those fed − 11 and + 11 mEq/100 g DM DCAD concentrations. Blood pH and HCO₃ concentration increased linearly with increasing DCAD concentrations. Serum chloride concentration was greater with − 11 mEq/100 g DM DCAD concentration, while serum cation anion difference increased linearly with increasing the DCAD concentration. Serum calcium concentration increased significantly with decreasing the DCAD concentration while serum magnesium and phosphorus concentrations remained unaffected. Buffaloes fed − 11 DCAD had higher calcium and chloride balance than those fed + 11, + 22 and + 33 DCAD. Phosphorus, sodium and potassium balance increased in buffaloes fed high (+ 22 and + 33) DCAD. Urine pH was increased significantly with increasing DCAD concentration. Milk yield and milk fat percentage increased linearly with DCAD concentration, whereas milk protein and lactose content were not affected. Increasing DCAD from − 11 to + 33 mEq/100 g DM increased DMI, water intake, milk yield and milk fat content in early lactating buffaloes during summer.     

DCAB对荷斯坦奶牛泌乳性能、血液酸碱平衡及血清矿物质含量的影响

试验选用荷斯坦泌乳早期奶牛15头,采用3X3复拉丁方试验设计,研究日粮DCAB水平分别为+367、+514、+663mmol/kgDM对奶牛生产性能、血液酸碱平衡和血清矿物质含量的影响。试验结果,不同DCAB水平日粮对奶牛奶产量差异不显著(P>0.05),高DCAB水平日粮可增加奶牛血液标准HCO-3含量(P<0.05),不同DCAB水平对奶牛各种血清常量矿物质含量没有影响(P>0.05)。试验表明,日粮DCAB水平超过+514mmol/kgDM可对奶牛奶产量产生不利影响。     

Selenium status in adult cats and dogs fed high levels of dietary inorganic and organic selenium

Cats (Felis catus) maintain greater blood Se concentrations compared with dogs (Canis familiaris) and, unlike dogs, show no signs of chronic Se toxicity (selenosis) when fed dietary organic Se (selenomethionine) concentrations of 10 μg/g DM. This study investigated the response of cats and dogs to high dietary concentrations of sodium selenite and organic Se to determine differences in metabolism between both species. In 2 consecutive studies, 18 adult cats and 18 adult dogs of with equal numbers of each sex were fed a control diet (0.6 μg Se/g DM) or the control diet supplemented to 8 to 10 μg Se/g DM from Na(2)SeO(3) or organic Se for 3 wk. All animals were fed the control diet 1 mo before the start of the study and blood samples were taken on d 0 and 21. The Se balance was assessed during the final week and a liver biopsy was obtained on the final day of the study. Measurements included plasma Se concentrations, plasma glutathione peroxidise (GPx) activities, plasma Se clearance, Se intake, and urinary Se excretion. No clinical signs of selenosis were observed in the cats or dogs, and apart from Se clearance, form of Se had no effect on any of the measurements. Apparent fecal Se absorption was greater in the dogs fed both forms of Se, while greater plasma Se concentrations were observed in the cats on both the control and supplemented diet (P = 0.034). Cats fed the supplemented diets had lower hepatic Se concentrations (P < 0.001) and excreted more Se in urine (P < 0.001) compared with dogs. Furthermore, cats fed the Na(2)SeO(3) supplement had greater Se clearance rates than dogs (P < 0.001). There was no effect of species on plasma GPx activity. We conclude that cats can tolerate greater dietary Se concentrations as they are more efficient at excreting excess Se in the urine and storing less Se in the liver.     

Comparison of volumetric urine collection versus single-sample urine collection in horses consuming diets varying in cation-anion balance

OBJECTIVE: To determine daily variation in urinary clearance and fractional excretion (FE) of electrolytes and minerals within and between horses and to compare volumetric and single-sample urine collection for determining FE values of diets with a range of dietary cation-anion balance (DCAB). ANIMALS: 5 Thoroughbred and 6 mixed-breed mares. PROCEDURE: 3 isocaloric diets with low, medium, and high DCAB values (85, 190, and 380 mEq/kg of dry matter, respectively) were each fed for 14 days. Daily blood samples, single urine samples collected by using a urinary catheter (5 mares), and volumetric urine collections (6 mares) were obtained during the last 72 hours of each diet. RESULTS: Urine and plasma pH values, plasma concentrations, and FE values of sodium, chloride, potassium, magnesium, phosphorus, and calcium were altered by varying the DCAB. Noticeable variation in clearance and FE values was detected within horses from day-to-day on the same diet as well as between horses. Fractional excretion values were not significantly different between single-sample and volumetric methods, except for magnesium in the high DCAB diet. Volumetric and single-sample collections revealed similar patterns of change in urinary FE values with varying DCAB, except for calcium and magnesium. CONCLUSIONS AND CLINICAL RELEVANCE: Substantial variation in clearance and FE of electrolytes and minerals are evident within horses between 24-hour periods as well as between horses fed a specific diet. Three daily urine samples provide similar information regarding dietary-induced changes in clearance and FE values (excluding calcium and magnesium) as that obtained by volumetric urine collection.     

Ornithine metabolism, but not arginine synthesis, is affected by the addition of ornithine to an arginine-deficient diet in enterally-fed piglets

In a previous study, ornithine addition to an arginine-deficient diet did not improve whole-body arginine status in enterally-fed piglets; however, the metabolic fates of the supplemental ornithine were not studied. This experiment determined the metabolic fates of the supplemental ornithine and whether ornithine metabolism was affected by the addition of -ketoglutarate. Male piglets (n = 20, 1.8 kg), fitted with gastric catheters for diet and isotope infusion, portal vein catheters for isotope infusion and femoral vein catheters for blood sampling (d 0), received 2 d of a complete diet, followed by 5 d of 1 of 4 test diets: the arginine-deficient diet (basal), or the basal diet with either -ketoglutarate [ +  - KG; 4.6 mmol/(kg d)], ornithine [ + Orn; 9.2 mmol/(kg d)] or both [ +  - KG/ + Orn; 4.6 mmol/(kg d)  - ketoglutarate + 9.2 mmol/(kg d) ornithine]. Piglets received primed, constant infusions of [1-¹⁴C]ornithine infused intragastrically (either d 5 and d 7) to determine ornithine kinetics, and [guanido-¹⁴C]arginine intragastrically to measure arginine flux (d 6). Piglets receiving the ornithine-containing diets had a higher intragastric ornithine flux (P < 0.0001) and ornithine oxidation (P < 0.05). Ornithine supplementation did not increase arginine synthesis, although the ornithine supplemented piglets had a greater conversion of ornithine to proline (P < 0.0001). The fates of supplemental ornithine in piglets fed an arginine-deficient diet appear to be oxidation and proline synthesis; this was not affected by the presence of -ketoglutarate.     

Effects of high dietary sodium chloride content on performance and sodium and potassium balance in growing pigs

Thirty castrated male Moo Lath pigs (6–8 weeks of age) were used in a 15-week growth trial to study the effect of high dietary sodium chloride (NaCl) content on feed and water intake, performance, sodium (Na) and potassium (K) balance, and plasma aldosterone concentration. The pigs were randomly allocated (ten per treatment) to diets containing 0.24 % Na (Na0.24), 0.28 % Na (Na0.28), and 0.32 % Na (Na0.32) per kg diet. Feed and water was provided ad libitum, and water consumption, feed offered, and feed residues were recorded daily. Every third week, the pigs were weighed, blood samples were collected, and a 3-day total collection of urine and feces was performed. Water intake was higher (P?=?0.001) in pigs fed with diets Na0.28 (3.7 L/day) and Na0.32 (3.9 L/day) than in pigs fed with diet Na0.24 (3.4 L/day), and dry matter (DM) intake was higher on diet Na0.32 (P?=?0.041) than on the other diets. The average daily body weight (BW) gain was higher on diet Na0.32 than on the other diets (P?=?0.031). The feed conversion ratio (in kilogram feed DM to kilogram BW gain) was 4.6, 4.6, and 4.1 on treatments Na0.24, Na0.28, and Na0.32, respectively (P?=?0.14). The highest Na balance was observed on diet Na0.32 followed by diets Na0.28 and Na0.24 (P?<?0.001), while there was no treatment-related pattern for the K balance. The Na/K ratio in feces and urine increased (P?<?0.001), and the K/Na ratio in feces (P?<?0.001) decreased with increasing Na content in the diet. Plasma aldosterone concentration decreased (P?<?0.001) with increasing dietary content of Na. These results indicate that high NaCl intake and free access to water will increase Na balance but do not negatively influence feed intake and performance of growing local pigs.     

Re‐evaluation of the regulation of omeprazole in racehorses: An evidence‐based approach

Medication control and doping control have been established in horse racing to ensure the integrity of the sport and the welfare of the horses. This ensures that horses do not compete under the influence of any drugs, including omeprazole, a therapeutic medication used to treat equine gastric ulcer syndrome. In this study, pharmacokinetic data were produced in equine plasma and urine following an oral administration of 4 mg/kg of generic buffered formulation of omeprazole to six Thoroughbred horses in five daily doses to determine an appropriate screening limit and detection time in equine plasma and to assess whether the current detection time of 72 hr in equine urine would be applicable when an alternative omeprazole product is administered. C _max of 436–2,432 ng/ml and AUC _0–tau of 1,476–4,371 ng hr ml^?1 were obtained for plasma and indicated, in conjunction with other published oral omeprazole studies, that an appropriate plasma screening limit would be 500 pg/ml with a detection time of 48 hr. Urine analysis showed that omeprazole could be detected for up to 25 hr above the previously established urine screening limit of 500 pg/ml and thus indicated that the detection time advice could be potentially reduced from 72 to 48 hr to allow more comprehensive treatment of gastric lesions.