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.     

Intravenous vitamin K1 normalises prothrombin time in 1 hour in dogs with anticoagulant rodenticide toxicosis

Four dogs with anticoagulant rodenticide toxicosis were treated with intravenous vitamin K₁ in lieu of plasma transfusion due to client cost constraints. Two dogs experienced a suspected anaphylactoid reaction, necessitating cessation of the treatment in one dog. Prothrombin time was rechecked 1 h after treatment in the remaining three dogs and all results were within the normal reference range. All four dogs were discharged from hospital within 48 h of presentation. Intravenous vitamin K₁ rapidly reverses the coagulopathic state in dogs with anticoagulant rodenticide toxicosis. It is a viable alternative therapy to plasma transfusion if circumstances preclude its use; however, patients must be monitored for anaphylactoid reactions.     

Postnatal Changes in Testicular Concentrations of Transforming Growth Factors‐Alpha and‐Beta 1, 2 and 3 and Serum Concentrations of Insulin Like Growth Factor I in Bulls

Based on work largely in laboratory animals, transforming growth factors (TGF) and insulin like growth factors (IGF) could be regulators of testicular development. The aim of this study was to see if TGF‐alpha and ‐beta 1, 2 and 3 are present in the bovine testis and to monitor concentrations of these factors in the testis and IGF‐I in serum during reproductive development. Separate groups of Hereford × Charolais calves (n = 6) were castrated every 4 weeks from 5 to 33 weeks of age and at 56 weeks of age. A week prior to castration, from 5 to 33 weeks of age, blood was collected every 15 min for 10 h. Serum IGF‐I concentrations increased from 8 to 12 weeks of age, decreased from 24 to 28 weeks and increased to 32 weeks of age (p < 0.05). Testicular TGF‐alpha concentrations increased from 13 to 17 weeks of age, decreased to 21 weeks and from 33 to 56 weeks of age (p < 0.05). Testicular TGF‐beta 1 concentrations decreased from 17 to 21 weeks of age, increased to 25 weeks and decreased from 25 to 33 weeks of age (p < 0.05). Testicular TGF‐beta 2 concentrations increased from 5 to 17 weeks of age, decreased to 21 weeks, increased to 25 weeks and decreased at 29 weeks of age (p < 0.05). Testicular TGF‐beta 3 concentrations increased from 13 to 17 weeks of age, decreased to 21 weeks and from 25 to 29 weeks of age (p < 0.05). We concluded that TGF‐alpha and TGF‐beta 1, 2 and 3 are present in the testis of the bull calf, and changes in concentrations with age suggest a functional role in the development of the testis.     

The Effect of Parity of the Dam on Sexual Maturation,Serum Concentrations of Metabolic Hormones and the Response to Luteinizing Hormone Releasing Hormone in Bull Calves

The objectives of this study were to determine the effect of parity of the dam on age at which a scrotal circumference (SC) ≥ 28 cm was attained and the LH response to Luteinizing Hormone Releasing Hormone (LHRH) in bull calves. We also wanted to confirm, in a large group of bull calves, that the LH response to LHRH could be used to select early maturing bulls. Body weight and SC of the bull calves were measured every other week. At 15, 20 and 25 weeks of age, calves received 4.12 nm /kg body weight of LHRH ischio‐rectally and blood samples were taken every 15 min for 4 h. Calves from primiparous and multiparous dams were separated into two sub‐groups based on age at which an SC ≥ 28 cm was attained (early or late). An SC ≥ 28 cm was attained earlier in calves born to multiparous as compared with primiparous dams (p < 0.05). At 20 and 25 weeks of age, peak serum LH concentrations (LH‐peak) and area under the LH response curve (LH‐AUC) in response to LHRH were higher (p < 0.01) in calves born to multiparous as compared with primiparous dams. In calves born to multiparous dams the LH‐peak at 15 and 25 weeks of age and the LH‐AUC at 15 weeks of age were lower (p < 0.05) in calves that attained an SC ≥ 28 cm early as compared with late. The LHRH‐challenge test sensitivity and specificity ranged from 46% to 86%. We concluded that parity of the dam affected age at which SC ≥ 28 cm was attained and the LH response to LHRH in bull calves. Serum LH responses to LHRH at 15 and 25 weeks of age, in calves born to multiparous dams, show some promise for development into a test to select early maturing bull calves.     

Post‐natal Changes in Testicular Concentrations of Interleukin‐1 Alpha and Beta and Interleukin‐6 during Sexual Maturation in Bulls

Based on observations in laboratory animals interleukins could be regulators of testicular development. The objects of this study were to see if interleukins (IL‐1 and IL‐6) are present in the developing bull testis and to establish the temporal patterns of concentrations of IL‐1 and IL‐6 in the bovine testis during development. Separate groups of six bull calves were castrated every 4 weeks from 5 to 33 weeks of age, and at 56 weeks of age. Mean testicular IL‐1 alpha concentrations decreased (p < 0.01) from 5 to 9 weeks of age and 13 to 21 weeks of age. Mean testicular IL‐1 beta concentrations decreased (p < 0.01) from 13 to 17 weeks of age and from 29 to 33 weeks of age. Mean IL‐1 bioactivity increased from 13 to 17 weeks of age, decreased to 21 weeks, increased to 25 weeks, decreased to 29 weeks and decreased from 33 to 56 weeks of age (p < 0.05). Mean testicular IL‐6 concentrations decreased (p < 0.05) from 9 to 13 weeks of age, increased (p < 0.05) to 21 weeks, decreased (p < 0.05) to 25 weeks, increased (p < 0.05) to 29 weeks and decreased (p < 0.01) to 56 weeks of age. In conclusion, testicular IL‐1 alpha, IL‐1 beta and IL‐6 were found in the bovine testis and concentrations were age dependent. Testicular IL‐1 alpha and IL‐1 beta concentrations were highest in the early post‐natal period; however, IL‐1 bioactivity and IL‐6 concentrations were greatest in the immediate pre‐pubertal period. These findings suggest a functional role for interleukins in testicular development in the bull.     

Effect of selenium and vitamin E addition to the extender on liquid stored capercaillie (Tetrao urogallus) semen quality

Captive breeding has become an important tool in species conservations programmes, maintaining genetic diversity and restoring wild, endangered populations. In order to improve the reproductive efficiency of captive kept capercaillie, the purpose of the study was to determine the effect of selenium and vitamin E addition to semen extender on sperm characteristic during short‐term storage. Ejaculates collected individually from four capercaillie were divided into two parts, diluted threefold with basic EK extender and EK enriched with 1 mg/ml of organic selenium and 8 mg/ml of vitamin E (EK+Se+E) and stored 24 hr at temp. +4°C. Spermatozoa morphology, motility and motility parameter were evaluated in net, diluted and stored semen samples. Significant (p < .05) differences between individual males were stated in relation to the majority of traits evaluated in the freshly collected semen. Comparing to the fresh semen, a significant (p < .05) decrease in percentage of live sperm in total (by 3.8% points on average) has been observed in samples diluted by EK extender, while in semen diluted with EK+Se+E extender this decrease was lower (1.5%pts on average) and not significant. Also per cent of motile sperm in EK+Se+E extender was higher (p < .05) then in EK (71.6% vs. 58.9%), but taking into account the values of individual males, both extender and male effect on liquid semen storage become apparent. Obtained data allow concluding that selenium and vitamin E addition to EK extender had positive effect on morphology and motility of capercaillie semen stored 24 hr at 4°C and can be recommended for similar studies carried out on other Galliformes species.     

Inhibition of denitrification and N2O emission by urine-derived benzoic and hippuric acid

Hippuric acid (HA) in cattle urine acts as a natural inhibitor of soil N₂O emissions. As HA concentration varies with diet, we determined critical HA levels. We also tested the hypothesis that the inhibition occurs because the HA breakdown product benzoic acid (BA) inhibits denitrification rates. During a 64-day incubation, we quantified emissions from artificial urine varying in HA, BA and glycine (Gly) concentrations, added to a sandy pasture soil. Increasing HA concentration from 0.4 to 5.6 mmol kg⁻¹ soil significantly decreased the average N₂O flux by 54%. At 3.9 mmol kg⁻¹ soil, denitrification levels were 50% reduced for BA as compared to Gly. We conclude that HA inhibits both denitrification and N₂O emission, at least partly through a BA mechanism.     

Importance and use of carbohydrate reserves in above-ground stem parts of rose cv. Motrea

Summary

The effect of deshooting of flowering stems of rose cv. Motrea as compared with normal harvesting procedure was studied with respect to carbohydrate storage and subsequent flower production after downwards pruning of shoots. Growth analyses over two periods were conducted to calculate total biomass production and partitioning. Soluble sugars and starch in samples of the stem taken at several heights in the plant were also analysed. In general, starch concentrations increased and sugar concentrations decreased from upper to lower stem parts. Deshooting increased total non-structural carbohydrates, mainly caused by starch. The stored carbohydrates were used during a subsequent flowering cycle. Total extra carbohydrate reserves due to the deshooting practice could explain the resulting increase in fresh-weight production. Biomass production was not influenced by treatments over the experimental period but deshooting greatly reduced flower production and enhanced the weight of discarded prunings. It is concluded that treatments primarily directed at redistribution of carbohydrates are probably of little use in improving the management of a rose crop.