Genetic resistance to Salmonella typhimurium in two lines of chickens selected as resistant and sensitive on the basis of heterophil/lymphocyte ratio

1. A study was conducted to test for the validity of the heterophil/lymphocyte (H/L) ratio as a criterion for selection for resistance to Salmonella typhimurium in chickens. 2. An infective dose of S. typhimurium was given, directly in the crop, to two groups of chicken selected as Resistant (R) and Sensitive (S) on the bases of H/L ratio. The 99% lower confidence limit was used as a borderline; individuals below the limit were considered R and those above S. Many aspects of immune response were compared, namely: H/L ratio, antibody titre, cellular immunity, phagocytic activity, cortisol concentration, bursa and body weight. 3. The R group exceeded the S in all the studied variables of the immune response, indicating the possibility of using the H/L ratio and its confidence limit to select for general resistance. 4. Due to the within-strain variability in resistance, it seems that immunological and genetic studies should take into consideration separation of individuals into R and S before grouping. Failing to do so might lead to erroneous conclusions as a difference may simply be due to the different numbers of R and S included in each group.     

Genetic and non-genetic factors affecting germination and vitality in spring barley seed

Germination of eight spring barley varieties, grown in two years at eight different locations in State varietal trials in the Czech republic, was analysed. All the combinations were tested under optimal conditions for germination as recommended by ISTA and also at low temperatures (5 and 10°C), and underwater stress (- 2 and - 4 bar). Germination under low temperature and water stress was considered as a character of seed vitality. Varieties in nearly all experiments were a significant source of variation and their relative contribution to the total variation was higher for vitality (5.7–38.7%) than for germination (2.0–4.3%). However, the percentage of germination were not related to the percentage of vitality. The location in nearly all the experiments caused the greatest variation and the impact was greater for germination than for vitality. Provenance effects were different for germination and for vitality; grains harvested in the lowland had the highest germination values, but not the highest vitality values. The results should encourage breeding for seed vitality and some reconsideration of provenance effects on seed vitality.     

Association between heterophil/lymphocyte ratio, a marker of 'resistance' to stress, and some production and fitness traits in chickens

1. A stock of cross-bred CD hens was divided into 'resistant' (R) and 'sensitive' (S) to stress on the basis of the heterophil/lymphocyte (H/L) ratio using the lower 99% confidence limit method for selection. A first generation was produced from these R and S females mated with similarly selected R and S local Barred males. The association between 'resistance' and some production traits was investigated. 2. The proportions of R:S among CD females and Barred males was 51.2:48.8 and 52:48, respectively. Mean H/L ratios for Barred males and females, respectively, were 0.87 +/- 0.03 and 0.83 +/- 0.03 (P > 0.05). 3. Compared with the S group in CD females, the R group had greater egg production (59% vs 51%), egg weight (65.5 g vs 62.6 g) and body weight at 39 weeks (115 g heavier). 4. The superiority of R in terms of proportion of fertile eggs, hatchability and the proportion hatched from those set amounted to 4.8, 6.1 and 5.4%, respectively. 5. The proportion of dead embryos in the R group (5.4%) was lower than in the S group (9.3%). 6. With the F1 generation the R chicks were heavier at hatching. 7. Percentage mortality of male F1 chicks, from hatching to 4 weeks and from 4 to 8 weeks, was lower in the R group. A similar, but non-significant, trend was noted for R females. 8. The progeny of the R group was heavier than the S progeny at 4 and 8 weeks and also the percentage dressed weight of males was greater at 8 weeks. The R group was heavier than the S group at 4, 8 and 12 weeks. 9. These results suggest that selection for general 'resistance', on the basis of the H/L ratio using the 99% lower confidence limit method of selection, is positively correlated with several important production and reproduction traits. Establishing resistant lines with high production rates seems feasible.     

The Anti‐Müllerian Hormone Profile is Linked with the In Vitro Embryo Production Capacity and Embryo Viability after Transfer but Cannot Predict Pregnancy Outcome

The current study investigated the possibility of using the AMH concentration as a predictor of the ability of Korean Hanwoo cows to produce cumulus‐oocyte complexes, embryos that survive after transfer as well as the pregnancy outcome of surrogates. Eight sessions of ovum pick‐up (OPU) were performed with 19 donor cows at an interval of 3–4 days. Antral follicle count (AFC), oocyte quality and in vitro embryo development were recorded for each cow. Embryos produced from cows with different AMH profiles were transferred into recipients (n = 96). Cows in the high (≥0.25 ng/ml) and intermediate (0.1≥ to <0.25 ng/ml) AMH groups had a significantly higher AFC per OPU session (20.40 ± 1.36 and 16.91 ± 1.52, respectively; mean ± standard deviation) than cows in the low AMH group (<0.1 ng/ml; 12.19 ± 2.14). In addition, more cumulus‐oocyte complexes per donor were recovered in the high (11.46 ± 1.22) and intermediate (7.38 ± 0.83) AMH groups than in the low AMH group (4.77 ± 0.44). The percentage of oocytes reached blastocyst stage was significantly higher in the intermediate (47.0%) and high (38.5%) AMH groups than in the low AMH group (32.3%). The number of embryos produced per cow was higher in the high (3.9 ± 0.2) and intermediate (6.9 ± 0.6) AMH groups than in the low AMH group (2.2 ± 0.3). The percentage of embryos that gave birth to viable calves when transferred into recipients was higher for those derived from cows in the intermediate AMH group (50.7%) than for those derived from cows in the low (35.7%) and high (36.4%) AMH groups. In conclusion, a single measurement of AMH concentration predicted the in vitro embryo production potential of donor Korean native cows before OPU and is linked with embryo viability after transfer into recipients.     

Effects of different doses of dexmedetomidine on anaesthetic induction with alfaxalone – a clinical trial

ObjectiveTo document the effects of two doses of dexmedetomidine on the induction characteristics and dose requirements of alfaxalone.Study designRandomized controlled clinical trial.AnimalsSixty one client owned dogs, status ASA I-II.MethodsDogs were allocated randomly into three groups, receiving as pre-anaesthetic medication, no dexmedetomidine (D₀), 1 μg kg^?1 dexmedetomidine (D₁) intramuscularly (IM) or 3 μg kg^?1 dexmedetomidine IM (D₃). All dogs also received 0.2 mg kg^?1 methadone IM. Level of sedation was assessed prior to induction of anaesthesia. Induction of general anaesthesia was performed with alfaxalone administered intravenously to effect at a rate of 1 mg kg^?1 minute^?1; the required dose to achieve tracheal intubation was recorded. Anaesthesia was maintained with isoflurane in oxygen. Cardiopulmonary parameters were recorded throughout the anaesthetic period. Quality of intubation, induction and recovery of anaesthesia were recorded. Quantitative data were compared with one-way anova or Kruskal-Wallis test. Repeated measures were log-transformed and analysed with repeated measures anova (p < 0.05).ResultsTreatment groups were similar for categorical data, with exception of sedation level (p < 0.001). The doses (mean ± SD) of alfaxalone required for intubation were D₀ 1.68 ± 0.24, D₁ 1.60 ± 0.36 and D₃ 1.41 ± 0.43, the difference between D₀ and D₃ being statistically significant (p = 0.036). Heart and respiratory rates during the anaesthetic period were significantly different over time and between groups (p < 0.001); systolic arterial blood pressure was significantly different over time (p < 0.001) but not between groups (p = 0.833). Induction quality and recovery scores were similar between groups (p = 1.000 and p = 0.414, respectively).Conclusions and clinical relevanceThe administration of alfaxalone resulted in a good quality anaesthetic induction which was not affected by the dose of dexmedetomidine. Dexmedetomidine at 3 μg kg^?1 IM combined with methadone provides good sedation and enables a reduction of alfaxalone requirements.     

Clarity performance variables of polluted water

Clarity performance variables of polluted water at different conditions of bioflocculation were studied through a set of laboratory experiments using the shake flask technique. The study was based on the relationship between physical properties of developed bioflocs and some environmental parameters. The physical properties included floc sizes and numbers, solution turbidity and the ratio of unsettled floc numbers (ufn) to total floc numbers (tfn) and settled floc volume (sfv) to total floc volume (tfv). The environmental parameters were the application of different sources of wastewaters, using of filamentous, floc forming, and natural bacteria, mixed at different speeds. The results indicated that various sources of wastewater mixed at different speeds, in the presence of various categories of bacteria allowed the development of flocs possessing a wide range of physical properties. Clarity performance was directly proportional with the ratio of sfv/tfv and inversely proportional with ufn/tfn. These ratios, on one hand, and with the floc sizes, numbers and solution turbidity, on the other hand, were discussed from the view point of their importance in clarity performance efficiency measurement of wastewater.     

The effects of ephedrine on intramuscular blood flow and other cardiopulmonary parameters in halothane-anesthetized ponies

Objective To evaluate the effect of ephedrine on intramuscular blood flow and hemodynamic parameters during equine anesthesia. Study design Prospective experimental study. Animals Six healthy adult Welsh Mountain ponies (five males, one female, mean weight: 267 kg, range: 213–347 kg). Methods Halothane‐anesthetized ponies received an IV bolus of ephedrine (0.1 mg kg^?1), followed 30 minutes later by a second IV ephedrine injection (0.2 mg kg^?1). Changes in intramuscular blood flows (IMBF) in upper and lower triceps brachii were measured by laser Doppler flowmetry. Cardiopulmonary measurements were made at intervals for 30 minutes following each injection. Results were compared with values from a control group, similarly anesthetized but given saline in an earlier study. Results Ephedrine at either dose increased heart rate, arterial blood pressure (AP), cardiac index (CI) and intramuscular blood flow (IMBF), the effects on these parameters being significant and long‐lasting following the higher dose. Systemic vascular resistance remained unchanged, and was significantly lower than in the control saline group. PaO₂ decreased significantly immediately following the first injection of ephedrine, then remained unchanged for the remainder of the experiment. PaCO₂ increased slowly throughout the anesthetic period. One pony developed supraventricular premature complexes following the second injection. No other side effects were seen. Conclusion Ephedrine at dose rates of 0.2 mg kg^?1 IV consistently increased in CI, AP, and IMBF in both forelimbs. Clinical relevance Ephedrine may be of use to improve AP, CI and IMBF during halothane anesthesia, although the occurrence of an arrhythmia in one pony is of concern.     

A comparison of the duration and quality of recovery from isoflurane, sevoflurane and desflurane anaesthesia in dogs undergoing magnetic resonance imaging

ObjectiveTo compare the recovery after anaesthesia with isoflurane, sevoflurane and desflurane in dogs undergoing magnetic resonance imaging (MRI) of the brain.Study designProspective, randomized clinical trial.AnimalsThirty‐eight dogs weighing 23.7 ± 12.6 kg.MethodsFollowing pre‐medication with meperidine, 3 mg kg^?1 administered intramuscularly, anaesthesia was induced intravenously with propofol (mean dose 4.26 ± 1.3 mg kg^?1), the trachea was intubated, and an inhalational anaesthetic agent was administered in oxygen. The dogs were randomly allocated to one of three groups: group I (n = 13) received isoflurane, group S (n = 12) received sevoflurane and group D (n = 13) received desflurane. Parameters recorded included cardiopulmonary data, body temperature, end‐tidal anaesthetic concentration, duration of anaesthesia, and recovery times and quality. Qualitative data were compared using chi‐squared and Fisher's exact tests and quantitative data with anova and Kruskal–Wallis test. Post‐hoc comparisons for quantitative data were undertaken with the Mann–Whitney U‐test.ResultsThe duration of anaesthesia [mean and standard deviation (SD)] in group I was: 105.3 (27.48) minutes, group S: 120.67 (19.4) minutes, and group D: 113.69 (26.68) minutes (p = 0.32). Times to extubation [group I: 8 minutes, (interquartile range 6–9.5), group S: 7 minutes (IQR 5–7), group D: 5 minutes (IQR 3.5–7), p = 0.017] and to sternal recumbency [group I: 11 minutes (IQR 9.5–13.5), group S: 9.5 minutes (IQR 7.25–11.75), group D: 7 minutes (range 3.5–11.5), p = 0.048] were significantly different, as were times to standing. One dog, following sevoflurane, had an unacceptable quality of recovery, but most other recoveries were calm, with no significant difference between groups.Conclusions and clinical relevanceAll three agents appeared suitable for use. Dogs’ tracheas were extubated and the dogs recovered to sternal recumbency most rapidly after desflurane. This may be advantageous for animals with some neurological diseases and for day case procedures.     

RESEARCH PAPER: Incidence of elevation of cardiac troponin I prior to and following routine general anaesthesia in dogs

ObjectiveTo estimate the incidence of raised cTnI after general anaesthesia in dogs and to explore major risk factors influencing this.Study designProspective clinical study.AnimalsA total of 107 (ASA physical status 1?2) dogs, 63% male and 37% female, median age 5 years (range 0.3–13.4), median weight 24.4 kg (range 4.2–66.5 kg) undergoing anaesthesia for clinical purposes.MethodsVenous blood samples were taken within 24 hours prior to induction and 24 hours after the termination of anaesthesia. Serum concentrations of cardiac troponin I were measured using a chemiluminescent enzyme immunometric assay with a lower level of detection of 0.20 ng mL^?1 (below this level <0.20 ng mL^?1). Continuous data were assessed graphically for normality and paired and unpaired data compared with the Wilcoxon signed ranks and Mann–Whitney U‐tests respectively. Categorical data were compared with the Chi squared or Fisher’s exact test as appropriate (p < 0.05).ResultsOf the 107 dogs recruited, 100 had pre‐ and post‐anaesthetic cTnI measured. The median pre‐anaesthesia cTnI was ‘<0.20’ ng mL^?1 (range ‘<0.20’–0.43 ng mL^?1) and the median increase from pre‐anaesthesia level was 0.00 ng mL^?1 (range ?0.12 to 0.61 ng mL^?1). Fourteen dogs had increased cTnI after anaesthesia relative to pre‐anaesthesia (14%, 95% CI 7.2–20.8%, range of increase 0.03–0.61 ng mL^?1). Six animals had cTnI levels that decreased (range 0.02–0.12 ng mL^?1). Older dogs were more likely to have increased cTnI prior to anaesthesia (OR = 5.32, 95% CI 1.35–21.0, p = 0.007) and dogs 8 years and over were 3.6 times as likely to have an increased cTnI after anaesthesia (95% CI 1.1–12.4, p = 0.028).Conclusion and clinical relevanceIncreased cTnI after anaesthesia relative to pre‐anaesthesia levels was observed in a number of apparently healthy dogs undergoing routine anaesthesia.