Influence of Veterinary Care on the Urinary Corticoid: Creatinine Ratio in Dogs

Physical and emotional stresses are known to increase the production and secretion of glucocorticoids by the adrenal cortex in both humans and experimental animals. The urinary corticoid: creatinine (C:C) ratio is increasingly used as a measure of adrenocortical function. In this study we investigated whether a visit to a veterinary practice for vaccination, a visit to a referral clinic for orthopedic examination, or hospitalization in a referral clinic for 1.5 days resulted in increases of the urinary C: C ratio in pet dogs. In experiment 1, owners collected voided urine samples from 19 healthy pet dogs at specified times before and after taking the dogs to a veterinary practice for yearly vaccination. In experiment 2, 12 pet dogs were evaluated in a similar way before and after an orthopedic examination at a referral clinic. In experiment 3, 9 healthy pet dogs were hospitalized for 1.5 days and urine samples were collected before, during, and after this stay. Basal urinary C:C ratios in all experiments ranged from 0.8 to 8.3 × 10^-6. In experiment 1, the urinary C:C ratio after the visit to the veterinary practice ranged from 0.9 to 22.0 × 10^-6. Six dogs had a significantly increased urinary C:C ratio (responders), but in 5 of these dogs the ratio was ≤10 × 10^-6 In experiment 2. 8 of 12 dogs responded significantly with urinary C:C ratios ranging from 3.1 to 27.0 × 10^-6. In experiment 3, 8 of 9 dogs had significantly increased urinary C:C ratios, ranging from 2.4 to 24.0 × 10^-6, in some or all urine samples collected during hospitalization. In 4 dogs urinary C:C ratios 12 hours after hospitalization were still significantly higher than the initial values. Thus, a visit to a veterinary practice, an orthopedic examination in a referral clinic, and hospitalization can be considered stressful conditions for dogs. A large variation occurs in response, and in individual dogs the increases in urinary C:C ratios can exceed the cutoff level for the diagnosis of hyperadrenocorticism. Therefore, urine samples for measurement of the C: C ratio in the diagnosis of hyperadrenocorticism should be collected in the dog's home environment, to avoid the influence of stress on glucocorticoid secretion.     

Yields and N uptake of barley and ryegrass from soils with added animal manure differing in straw and urine content

Four types of cattle manure were prepared by mixing faeces with different ratios of urine + straw, one manure being faeces without straw and urine. Following 3 to 6 months of storage, the manures were applied in spring or autumn to a sandy loam and a coarse sand in amounts corresponding to 120 kg N ha⁻¹. Spring barley (Hordeum vulgare L.) undersown with perennial ryegrass (Lolium perenne L.) were used as test crops. Barley was harvested at maturity and the wintering ryegrass was cut three times in the second year. Additional mineral N in the form of ¹⁵N-labelled mineral fertilizer (50 kg N ha⁻¹) was added to all barley plots at planting in spring. Non-manured plots receiving only the ¹⁵N-labelled mineral fertilizer were included. Faeces without urine + straw contained more NH₄-N than the other manures and spring incorporation of this manure gave the highest dry matter yield and N uptake of the barley. When faeces without urine + straw was applied in autumn, the yield and N uptake were increased only on the sandy loam. On the coarse sand, the NH₄-N was probably leached as NO₃-N during the winter. The three manures with urine + straw did not affect barley grain yield or total N uptake. Thus these manures did not mineralize nor immobilize measurable quantities of N in the first growth period. On the sandy loam, the patterns of N uptake in ryegrass indicated an increased availability of manure N during the second growth period. The availability of N from the ¹⁵NH₄¹⁵NO₃ was similar in all plots when manures were applied in spring. Less ¹⁵N was taken up by the spring barley when manure was added in autumn compared with crops given ¹⁵NH₄¹⁵NO₃ only. Thus short-term effects of N in cattle faeces stored with or without straw + urine are low. For soils low in mineral N such manures may potentially reduce crop N uptake.     

干奶牛阴离子盐利用效果研究初报

选用干奶后期奶牛10头，探讨干奶期奶牛应用阴离子盐产生效应所需的条件。结果表明：1、收穗后青刈玉米秸与小麦秸作为大容积性饲料，尿液pH易达到阴离子盐产生效应的状态，而萨拉秧与苜蓿干草则不易达到；2、不同大容积性饲料，阴离子盐的适宜添加量不同，收穗后青刈玉米秸、苜蓿干草的适宜添加量为每头440~500g/d，小麦秸则为440g/d；3、将添加的阴离子盐分成两部分，一部分与精料均匀混合，另一部分先溶于少量水，再均匀喷洒于大容积性饲料表面进行饲喂，可避免阴离子盐对采食量的影响。     

Effects of plant material on ammonia volatilization from simulated livestock urine applied to soil

Summary The volatilization of ammonia from simulated urine applied to small columns of soil was reduced by the presence of ryegrass growing in the soil. The ryegrass had been sown 18 weeks previously and had been cut on seven occasions to a height of 5–6 cm with the cut herbage removed. Cumulative volatilization over 8 days amounted to 39% of the urinary N from bare soil, and 23% in the presence of the ryegrass. In contrast, the volatilization of ammonia was increased by dead leaf litter placed on the soil surface, apparently due to the increase in surface area for urease activity and volatilization. Differences in the C:N ratio of the leaf litter over the range 13:1–29:1 had little effect on the extent of ammonia volatilization. When living ryegrass and dead leaf litter were examined together, the reduction in volatilization due to the ryegrass was the dominant effect.     

Increased hippuric acid content of urine can reduce soil N2O fluxes

Urine patches in grazed pastures are a major source of nitrous oxide (N₂O) emission. It is well-documented that the relative concentration of the various nitrogenous urine constituents varies significantly with diet. The effect of these variations on N₂O emissions from urine patches, however, has never been reported. The aim of this study was to test whether variations in urine composition, consistent with different diets, lead to significant differences in N₂O emission. Four varieties of artificial urine, all with similar total N concentrations, but varying in the relative contribution of the nitrogenous constituents, were applied to undisturbed cores from a sandy pasture soil. N₂O fluxes were monitored for 65 days at two moisture treatments; 92% WFPS for the entire incubation, and 70% WFPS up to day 41 and 92% afterwards. Extra replicates were included for destructive analysis on mineral N concentrations and pH. Urine composition was a significant (P<0.001) factor determining N₂O emissions. An increase in the relative hippuric acid concentration from 3 to 9% of total N resulted in a significant decline in average N₂O fluxes, from 16.4 to 8.7 μg N₂O-N h⁻¹ kg⁻¹ soil (averaged over all treatments). Cumulative emission decreased from 8.4 to 4.4% of the applied urine-N (P<0.01). Soil mineral N showed a modest but significant decrease with an increase of hippuric acid content. pH did not show any significant relationship with urine composition. Increasing the urea concentration with 12% of applied urinary N did not significantly affect N₂O emissions. Moisture content significantly affected N₂O emissions (P<0.001), but no interaction between moisture and urine composition was found. As the inhibitory effect of hippuric acid could not be linked directly to mineral N concentrations in the soil, we hypothesize that the breakdown product benzoic acid either inhibits denitrification or decreases the N₂O/N₂ ratio. We conclude that hippuric acid concentration in urine is an important factor influencing N₂O emission, with a potential for reducing emissions with 50%. We suggest alternative rationing leading to higher hippuric acid concentrations in urine as a possible strategy to mitigate N₂O emission from grazed pastures.     

液相色谱-串联质谱法测定动物尿液中糖皮质激素类药物的测定

建立了动物尿液样品中泼尼松（Prednisone）、泼尼松龙（Prednisolone）、甲基泼尼松龙（Methylprednisone）、地塞米松（Demxamethasone）、倍他米松（Betamethasone）、倍氯米松（Beclometasone）、醋酸氟氢可的松（Fludrocortisone Acetate）、醋酸可的松（Cortisone Acetate）、氢化可的松（Hydrocortisone）等9种糖皮质激素类药物的测定方法,明确规定了适用范围、确定了取样量、酶解、提取净化等方法以及液相色谱条件、串联质谱条件等。该方法具有较好的灵敏度、准确度和精密度。     

绵羊膀胱瘘与皱胃瘘手术

绵羊膀胱瘘与皱胃瘘可以方便地取材,研究尿液与胃液的分泌及理化分析,在疾病诊疗,尤其在膀胱修补及真胃手术中具有临床意义。     

Routes of water loss in South African abalone (Haliotis midae) during aerial exposure

South African abalone, Haliotis midae, were exposed to air at 12 °C for 36 h to simulate the extent and rate mass loss experienced by animals during long distance live exports. Animals lost 15.1 ± 0.94% of their mass during the 36 h air exposure, an approximation of the highest mass losses sustained by industry.The total mass loss was attributed to water loss, as the contribution of dry mass to the total mass remained constant under all conditions. Water content decreased from 64.8% of the body mass (M_b) under control conditions to 58.8% M_b after 36 h in air. In real terms, however, animals had lost 22% of the body water pool.Abalone exhibited a typically high water turnover rate when in water (125 μL g^− 1 h^− 1), which decreased markedly during air exposure (2.2 μL g^− 1 h^− 1). Haemolymph volume decreased from 43% M_b in water to 14% M_b in air. The concomitant decrease in haemolymph pressure probably limited the first step in urine formation (ultra-filtration through the pericardium). Thus we observed that while urine flow represented about 26% of the total water loss when the animals were in water, urine flow ceased during air exposure.The decrease in haemolymph volume in air represents a redistribution of water to the tissues and not a bulk loss of haemolymph. This is supported by the concentration of haemolymph ions by a factor of 1.2 during aerial exposure, which was predicted based on the 22% decrease in water content. Under the same conditions, evaporation from water containers with similar surface to volume dimensions as abalone, accounted for only an 8.25% mass loss. As all other water loss routes were accounted for, we measured pedal mucus production rates of abalone in water and air. During 36 h aerial exposure, the pedal mucus production represented a loss of 6.8% M_b. We conclude that water loss during 36 h air exposure is attributable to evaporation (8.25% M_b) and pedal mucus production (6.8% M_b). This paves the way for directed research into mitigating water loss during the live export process.