蘑菇废弃菌棒及其与猪粪混合发酵对沼气产量及质量的影响

为了研究厌氧消化过程中日产气量、累计产气量和甲烷含量随厌氧消化时间的变化规律,在中温35℃±1℃条件下,采用批式单相厌氧消化工艺,分别用香菇、杏鲍菇和平菇废弃菌棒与猪粪混合发酵。结果表明,蘑菇菌棒具有很好的产气潜力,其中香菇菌棒TS产气量最高,为142.9mL.g-1,平均产气量664.1mL.d-1,杏鲍菇菌棒所产气体甲烷含量最高,平均63.8%;添加猪粪调节蘑菇菌棒C/N至25/1,对香菇菌棒前期严重酸化现象起到了很好的缓冲作用,使香菇菌棒、杏鲍菇菌棒和平菇菌棒累计产气量较单一物料分别提高了131.5%、97.9%和79.9%。研究结论为:香菇、杏鲍菇和平菇废弃菌棒均具有良好的产气潜力;添加猪粪能显著提高蘑菇菌棒累计产气量,同时提高香菇菌棒甲烷含量,降低杏鲍菇菌棒甲烷含量,对平菇菌棒甲烷含量影响不大。     

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.     

MILK PRODUCTION OF GRAZING DAIRY COWS GIVEN MONTHLY ANTHELMINTIC TREATMENT

SUMMARY The milk and butterfat production of 226 cows treated with fenbendazole at monthly intervals throughout lactation was compared with the production of 216 untreated cows in 8 herds on the North Coast and Northern Tablelands of New South Wales. There was no significant effect of treatment on milk or butterfat production, nor did anthelmintic treatment interact significantly with herds or age of cows in influencing production.     

MILK PRODUCTION OF GRAZING DAIRY CATTLE AFTER A SINGLE ANTHELMINTIC TREATMENT

The prevalence of nematode infections in lactating dairy cattle was determined by faecal egg counts and cultures from over 350 cows selected at random from twelve herds. The mean egg count was 3 eggs per gram (epg) and 43% of the cows sampled were passing detectable concentrations of eggs (greater than 6 eggs) in their faeces. In June 1976 171 cows in 10 herds were treated with 7.5 mg/kg fenbendazole and their milk production compared over the following 2 months with that of 164 untreated cows in the same herds. Anthelmintic treatment had no significant influence on milk production in any of the herds. The contrasting results of this study and recent studies in the United States of America are discussed.     

Validation of the FACSCount AF System for Determination of Sperm Concentration in Boar Semen

A flow cytometric method has been developed for rapid determination of sperm concentration in semen from various mammalian species. * * Patent Pending, Int. Publication Number WO/00/54026.
All cells containing DNA are stained with SYBR‐14 or propidium iodide (PI) and sperm concentration is determined in relation to an internal standard of fluorescent microspheres (beads). Satisfactory staining can be achieved within 2–3 min and the following flow cytometric analysis on the FACSCount AF System rapidly provides the user with a precise and accurate assessment of the sperm concentration. In this study, the FACSCount AF System and Sperm Counting Reagent (BD Biosciences) was compared with microscopic counting using a Bürker–Türk haemocytometer. In addition, sperm concentration was determined using the Corning 254 spectrophotometer which is used routinely by Danish artificial insemination stations for boars. The results show that the agreement between flow cytometry and microscopic counting is very high. The slope for the regression line was 1.12 (SE = 0.03) with an estimated intercept with the Y‐axis of 22 × 10⁶sperm/ml (SE = 10 × 10⁶ sperm/ml) and an estimated error of the model of 10 × 10⁶ sperm/ml. For the spectrophotometer, the slope of the regression line was 1.09 (SE = 0.07) with an estimated intercept of 137 × 10⁶ sperm/ml (SE = 25 × 10⁶ sperm/ml). The average error made by the spectrophotometer was 55 × 10⁶ sperm/ml. In addition, the results obtained using flow cytometry was highly repeatable (CV = 2.7%) in comparison with the spectrophotometric method (CV = 6.3%). These results indicate that the FACSCount AF System is a valuable tool for precise and accurate assessment of sperm concentration in boar semen and that use of this system may lead to production of more uniform insemination doses containing a specific number of sperm per dose.     

The effect of autonomic manipulation on heart rate variability in dogs

Beat‐to‐beat variation of heart rate is reflective of autonomic balance and has been used to assess pain and stress in human beings. The purpose of this investigation was to pharmacologically manipulate the autonomic nervous system and to determine the effect of these manipulations on heart rate variability (HRV) in dogs. Four adult male hound dogs (27 ± 1 kg) were used in the investigation. Each dog was given five treatments: Parasympathetic blockade (glycopyrrolate; 0.01 mg kg^–1 IV and 0.01 mg kg^–1 IM), parasympathetic stimulation (phenylephrine; 0.005 mg kg^–1 IV + 0.05 mg kg^–1hour^–1), sympathetic blockade (propranolol; 0.11 mg kg^–1 IV), sympathetic stimulation propranolol; 0.01 μg kg^–1 minute^–1), and saline control. At least 48 hours were allowed between treatments. ECG recordings were obtained using an ambulatory ECG monitor. A 5‐minutes period of continuous recording obtained ~30 minutes after initiation of drug administration was used for data analysis. Changes in HRV were evaluated by time and frequency‐domain analysis. The standard deviation of normal R‐R intervals (SDNN), as well as the standard deviation of successive differences in RR intervals (SDSD) were assessed for each treatment. Low frequency (LFP; 0.05–0.15 Hz), high frequency (HFP; 0.15–0.35 Hz), and total (TP; 0.017–0.5 Hz) spectral power were also determined. The LFP:HFP ratio was also evaluated. A two‐way anova with a Tukey's test was used to detect differences (p < 0.05). Administration of glycopyrrolate or isoproterenol increased HR and decreased SDNN and SDSD below control levels. Phenylephrine or propranolol administration were without effect. LFP was diminished by glycopyrrolate and isoproterenol, but was unaffected by phenylephrine and propranolol. HFP, TP, and LFP:HFP were unaffected by treatment. Both branches of the autonomic nervous system influence SDNN and LFP. SDSD, in contrast, is altered primarily by parasympathetic activity. Thus, it appears that parasympathetic activity modulates HRV in the resting dog, as either withdrawal of parasympathetic influence or accentuated sympathetic activity led to significant changes in these measures of HRV. Conversely, augmentation of parasympathetic activity or withdrawal of sympathetic tone minimally affected HRV.     

Clinicopathological findings and results of bone marrow aspiration in dogs with cutaneous mast cell tumours: 157 cases (1999–2002)*

Bone marrow aspiration for routine staging of canine cutaneous mast cell tumour is not consistently performed, and the overall incidence of bone marrow infiltration and predictive value of the complete blood count (CBC) is unknown. This study evaluated a series of 157 dogs presented for cutaneous mast cell tumours in which a CBC and bone marrow aspiration were performed. The incidence of bone marrow infiltration at initial staging was low at 2.8%, and 4.5% overall. Factors significantly associated with bone marrow infiltration included increased age, leucocytosis, anaemia, neutrophilia, monocytosis, eosinophilia, thrombocytopenia, being purebred and staging at the time of recurrent or progressive disease. Our study suggests that a bone marrow sample is not indicated for routine staging but maybe indicated for those dogs with mast cell tumours having either an abnormal haemogram (neutrophilia, monocytosis, eosinophilia, basophilia, anaemia and thrombocytopenia) or presenting for tumour regrowth, progression or new occurrence.