Effect of cereal type and exogenous enzyme supplementation in pig diets on odour and ammonia emissions

A 2 × 2 factorial experiment was conducted to investigate the interaction between cereal type (wheat vs. barley) and exogenous enzyme supplementation (with or without) on odour concentration and ammonia emissions in grower–finisher pigs. The enzyme supplement used contained Endo-1, 3 (4)-β-glucanase (EC 3.2.1.6) and Endo-1, 4-β-xylanase (E.C 3.2.1.8). The diets were formulated to contain similar levels of digestible energy and lysine. The experimental treatments were as follows: (1) wheat-based diet, (2) wheat-based diet containing a β-glucanase and β-xylanase mixed enzyme supplement, (3) barley-based diet and (4) barley-based diet containing a β-glucanase and β-xylanase mixed enzyme supplement. The diets were offered to the pigs for 4 weeks and this was repeated 4 times (n = 4). Odour and ammonia emissions were measured on days 9, 11, 14, 16, 21 and 23 of each experimental period. Odour samples were collected in 20-litre Nalophan bags and analysed for odour concentration using an ECOMA Yes/No Olfactometer. Ammonia concentrations were measured using Dräger tubes. There was a cereal × enzyme interaction in odour emission rates (P < 0.05) and in ammonia emissions (P < 0.01). The addition of an enzyme supplement increased odour emissions and had no effect on ammonia emissions in the barley-based diet. The enzyme supplementation had no effect on odour but decreased ammonia emissions in the wheat based diet.     

Growth and enzyme production by Bacillus subtilis and Flavobacterium pectinovorum in Picea sitchensis

Summary When Sitka spruce (Picea sitchensis) is stored in water, an increase takes place in the permeability of the wood. This increase is due to bacterial degradation of the tori and bordered pit membranes and partial degradation of the crossfield pits. It has been demonstrated that two bacteria—Bacillus subtilis and Flavobacterium pectinovorum—isolated from this water stored wood, grow and produce amylase, xylanase and pectinase in sapwood blocks suspended in sterile pond water. Since these organisms have also been shown to increase the permeability of sapwood blocks, it has been concluded that they are primarily responsible for the permeability changes that occur when spruce poles are stored in lake water.When the two organisms are incubated together in sapwood blocks, growth of F. pectinovorum is synergistically affected, while growth of B. subtilis is antagonised. However, no antagonism of enzyme production was evident. The levels of biological activity in the sapwood in these laboratory experiments were much higher than the values observed in the natural lake system. The concentration effect obtained in the laboratory system, in contrast to the dilution effect occurring in the lake environment, is undoubtedly responsible for this variance. Results indicate that the rate at which permeability changes occur could possibly be accelerated by replacing the natural lake system with an enclosed tank system.     

RELATIONSHIP BETWEEN PELVIC DIMENSIONS, OTHER BODY MEASUREMENTS AND DYSTOCIA IN DORSET HORN EWES

Fifteen live and 16 post slaughter measurements were recorded from each of 29 mature Dorset Horn ewes in an investigation of pelvic dimensions and their association with past history of dystocia or difficult birth amongst the ewes. For comparison with a breed having a low incidence of dystocia, similar measurements were recorded from 6 mature Border Leicester ewes with no previous history of dystocia.
The range in size of the Dorset Horn pelves was considerable, with conjugate diameter being more variable than transverse diameter (P < 0.05) and a more important cause of variation in pelvic area. A higher incidence of dystocia amongst the Dorset Horn ewes tended to be associated with smaller pelvic areas (r =—0.34; P = 0.08). Pelvic area and conjugate diameter were significantly less (73.4 v 82.8 cm², P < 0.01; and 9.9 v 10.9 cm, P < 0.05, respectively) for those ewes which had dystocia at more than 65% of their lambings, suggesting that pelvic area and conjugate diameter may be factors with critcial levels in predisposition to dystocia. The Border Leicester pelves were 21 % greater in area (P < 0.01) and 17% greater in conjugate diameter (P < 0.01) than the Dorset Horn pelves, although there was no difference in their transverse diameters.
In general, measurements in the region of the pelvis were closely correlated with transverse diameter of the pelvis but not with pelvic area or conjugate diameter. Forelimb length and bodylength were the only measurements recorded in the live Dorset Horn ewes that were significantly correlated (P < 0.01) with both pelvic area (r = 0.53 and r = 0.47 respectively) and conjugate diameter (r = 0.48 and r = 0.49 respectively). However, these live measurements accounted for less than 35% of the variation in conjugate diameter and pelvic area when included in a multiple regression equation.     

Investigations on the efficacy of routinely used phenotypic methods compared to genotypic approaches for the identification of staphylococcal species isolated from companion animals in Irish veterinary hospitals

Background

Identification of Staphylococci to species level in veterinary microbiology is important to inform therapeutic intervention and management. We report on the efficacy of three routinely used commercial phenotypic methods for staphylococcal species identification, namely API Staph 32 (bioMérieux), RapID (Remel) and Staph-Zym (Rosco Diagnostica) compared to genotyping as a reference method to identify 52 staphylococcal clinical isolates (23 coagulase positive; 29 coagulase negative) from companion animals in Irish veterinary hospitals.

Results

Genotyping of a 412 bp fragment of the staphylococcal tuf gene and coagulase testing were carried out on all 52 veterinary samples along with 7 reference strains. In addition, genotyping of the staphylococcal rpoB gene, as well as PCR-RFLP of the pta gene, were performed to definitively identify members of the Staphylococcus intermedius group (SIG). The API Staph 32 correctly identified all S. aureus isolates (11/11), 83% (10/12) of the SIG species, and 66% (19/29) of the coagulase negative species. RapID and Staph-Zym correctly identified 61% (14/23) and 0% (0/23) respectively of the coagulase-positives, and 10% (3/29) and 3% (1/29) respectively of the coagulase-negative species.

Conclusions

Commercially available phenotypic species identification tests are inadequate for the correct identification of both coagulase negative and coagulase positive staphylococcal species from companion animals. Genotyping using the tuf gene sequence is superior to phenotyping for identification of staphylococcal species of animal origin. However, use of PCR-RFLP of pta gene or rpoB sequencing is recommended as a confirmatory method for discriminating between SIG isolates.     

In-Laboratory Diffraction-Enhanced X-Ray Imaging of an Equine Hoof

We describe and demonstrate the first application of a laboratory-based diffraction-enhanced X-ray imaging instrument for noninvasive equine imaging. A formalin-preserved disarticulated forelimb from a near-term aborted miniature horse fetus was imaged with diffraction-enhanced X-ray imaging. The resultant calculated images—absorption, extinction, refraction, and scattering—are presented, and soft-tissues such as the dorsal digital extensor tendon, articular cartilage, as well as various joint, tendon sheath, and bursa recesses are observed in simultaneous registration with the adjacent dense bone tissue. Radiation dose calculations were performed and a calculated surface dose of 0.6 mGy for the soft muscular tissue was determined for the imaging experiment.     

Evaluation of an air ionizer unit and its effects on cellular respiratory defense in racing thoroughbreds

A double crossover trial, consisting of two three-week periods, was conducted to evaluate an air ionizer unit and its effects on cellular respiratory defenses in racing Thoroughbreds. Each week, samples of the stable air were taken and horses were sampled for hematological and blood biochemical analyses. At the end of both three-week periods, blood neutrophil and bronchopulmonary lavage immune cellular responses were assayed and bronchopulmonary lavage samples were cultured aerobically and anaerobically. The air ionizer unit had no significant effects on the parameters assayed.     

Nutrient Movement Due to Overland Flow in Managed Native Eucalyptus Forests,Southeastern Australia

A rainfall simulator study of total nutrient movement due to overland flow on forest skid trails and general harvesting areas (GHA) in the native eucalypt forests of southeastern Australia, confirmed that the disturbed and compacted areas were the dominant sources of sediment-bound pollutants. Low runoff production and low sediment availability on the rough surfaces of the GHA reduced total nutrient yields. On the more recently disturbed and burnt sites, the solution pathway may have been more dominant due to runoff coming in contact with surface ash and charcoal. We also recorded significant reductions in the total nutrient yields as runoff from the skid trail was delivered to the adjacent hillslope via a cross bank (water bar). This was due primarily to coarse-grained sediment deposition at the base of the banks. Nutrient concentrations in the eroded sediment at the cross bank outlets, however, remained 9 times higher than the in-situ surface soils, due to the preferential delivery of fine aggregate material to the adjacent hillslope. Further reductions in total nutrient yields occurred as overland flow passed through the GHA, illustrating the effectiveness of vegetative filtering in reducing runoff volumes and sediment fluxes. Temporal trends in the data highlighted significant reductions in total nutrient movement on both areas of disturbance as sites regenerated over a period of ～ 5 years. Water pollution abatement practices in these environments should aim to locate skid trails to maximise the redistribution of runoff and sediment from highly disturbed areas to more vegetated parts of the hillslope, and by appropriate cross bank spacing, reduce the volume of overland flow carrying sediment and nutrients.     

Models of predation and fishing mortality in aquatic ecosystems

The dynamics of fish stocks are greatly influenced by predatory and fishery removals. We describe the strengths and weaknesses of a suite of approaches that assess the scope and magnitude of fishery and predatory mortality in aquatic ecosystems. We examine: (i) empirical models for pattern detection, process exploration, and model parameterization (e.g. multispecies time series and multiple regression); (ii) qualitative process-based models of species interactions (e.g. food web analyses and loop analyses); and quantitative process-based multispecies models that include: (iii) static flow models (e.g. Ecopath ); (iv) dynamic models of either numerical abundance (e.g. Lotka–Volterra) or biomass (e.g. Ecosim and multispecies biomass dynamics); and (v) spatially explicit versions of the above. Decisions concerning a specific modelling approach should be evaluated in the context of the goals of the model and empirical database. Important considerations include model use, desired output, and management context. Four important factors to consider in model selection are the spatial and temporal extent and resolution, conservation of mass or numbers, mathematical representation of predator–prey interactions, and mathematical representation of technical interactions. We conclude that the most effective modelling exercise to achieve a given set of goals should incorporate the evaluation of multiple model configurations.