Acute normovolaemic haemodilution in a Clydesdale gelding prior to partial resection of the left ventral concha under general anaesthesia

A 16‐year‐old Clydesdale gelding underwent oral extraction of tooth 210 under standing sedation with partial resection of the left ventral concha under general anaesthesia 4 days later. Due to the highly vascular nature of the surgical site, significant intraoperative haemorrhage was anticipated. A lack of compatible donor horses confirmed by crossmatching prompted an autologous donation of 6 l of blood and acute normovolaemic haemodilution using a gelatine solution immediately prior to surgery. Intraoperative haemorrhage was estimated at 5% circulating volume and autologous transfusion was commenced once haemostasis was confirmed. The horse recovered uneventfully from general anaesthesia and surgery. To our knowledge this is the first report of acute normovolaemic haemodilution used in a clinical equine case.     

Effect of postmortem storage on activity of mu- and m-calpain in five bovine muscles

An in situ system involving incubation of 60- to 80-g pieces of muscle at 4 degrees C under different conditions was used to determine the effects of time of postmortem storage, of pH, and of temperature on activities of mu- and m-calpain activity in bovine skeletal muscle. Casein zymograms were used to allow measurement of calpain activity with a minimum of sample preparation and to ensure that the calpains were not exposed to ionic strengths of 100 or greater before assay of their activities. In 4 of the 5 muscles (longissimus dorsi, lumbar; longissimus dorsi, thoracic; psoas major; semimembranosus; and triceps brachii) studied, mu-calpain activity decreased nearly to zero within 48 h postmortem. Activity of m-calpain also decreased in the in situ system used but at a much slower rate. Activities of both mu- and m-calpain decreased more slowly in the triceps brachii muscle than in the other 4 muscles during postmortem storage. Although previous studies have indicated that mu-calpain but not m-calpain is proteolytically active at pH 5.8, these studies have used calpains obtained from muscle at death. Both mu- and m-calpain are proteolytically inactive if their activities are measured at pH 5.8 and after incubating the muscle pieces for 24 h at pH 5.8. Western analysis suggested that neither the large 80-kDa subunit nor the small 28-kDa subunit of m-calpain was autolyzed during postmortem storage of the muscle pieces. As has been reported previously, the 80-kDa subunit of mu-calpain was autolyzed to 78- and then to a 76-kDa polypeptide after 7 d postmortem, but the 28-kDa small subunit was not autolyzed; hence, the autolyzed mu-calpain molecule in postmortem muscle is a 76-/28-kDa molecule and not a 76-/18-kDa molecule as previously assumed. Because both subunits were present in the postmortem calpains, loss of mu-calpain activity during postmortem storage is not due to dissociation of the 2 subunits and inactivation. Although previous studies have shown that the 76-/18-kDa mu-calpain molecule is completely active proteolytically, it is possible that the 76-/28-kDa mu-calpain molecule in postmortem muscle is proteolytically inactive and that this accounts for the loss of mu-calpain activity during postmortem storage. Because neither mu- nor m-calpain is proteolytically active at pH 5.8 after being incubated at pH 5.8 for 24 h, other proteolytic systems such as the caspases may contribute to postmortem proteolysis in addition to the calpains.     

The CHRNE 470del20 mutation causing congenital myasthenic syndrome in South African Brahman cattle: prevalence, origin, and association with performance traits

Genotyping of the South African, registered, Brahman cattle population for the 470del20 mutation in the CHRNE gene causing congenital myasthenic syndrome (CMS) was carried out in 1,453 animals. Overall prevalence of carriers was 0.97% (0.50 to 1.68%, 95% confidence interval). Carrier prevalence among breeding bulls in 2004 was 1.22% (0.65 to 2.15%, 95% confidence interval), and had not changed significantly since 2000. Using segregation analysis, CMS genotype probabilities were calculated for all 612,219 animals in the pedigree, leading to the identification of 2 founder animals as the most likely original carriers. Pedigree analysis revealed no ancestors common to all known carriers, but rather that the mutation had been introduced at least twice into the South African Brahman population, probably via animals imported from the United States. The effects of CMS genotype probability on adjusted birth, 200-d, 400-d, and 600-d BW, as well as on EBV for birth, 200-d, 400-d, and 600-d BW, and milk, were estimated, accounting for effects of sire. Heterozygosity for the CHRNE 470del20 mutation was associated with a 13.3-kg increase in adjusted 600-d BW (P = 0.03). Positive effects of CMS carrier status on all BW EBV were found, but no effect was found on milk EBV. We conclude that CMS carriers have a BW advantage at 600 d and possibly also at birth, 200 d, and 400 d. This may confer a selective advantage and tend to increase the frequency of the mutation.     

Lung function and airway cytologic profiles in horses with recurrent airway obstruction maintained in low-dust environments

BACKGROUND: The effects of long-term environmental management on airway obstruction and inflammation in horses with recurrent airway obstruction (RAO) are unknown. HYPOTHESIS: Horses with RAO maintained in low-dust environments have persistent airway obstruction and neutrophilic inflammation. ANIMALS: Study horses were treated for RAO and then maintained in low-dust environments with no medical management. Horses were classified into 3 groups by years after diagnosis: 1 year (time 1, n = 9), 2-3 years (time 2, n = 7), and 5-6 years (time 3, n = 8). The comparison groups were age-matched healthy horses. METHODS: In this cross-sectional study, a clinical examination was performed, and the clinical score was calculated. Standard lung function, forced expiratory maneuvers, and the cytology of bronchoalveolar lavage fluid (BALF) were evaluated. RESULTS: The clinical scores of the RAO horses were higher than those of the non-RAO horses at time 2 (P = .018). Standard lung function data were not different between the groups at any time point. The forced expiratory flow between 75-95% of exhaled vital capacity was lower in RAO horses than in non-RAO horses at all time points (P < .02), indicating persistent peripheral airway obstruction. Cytologic evaluation of BALF revealed no difference in total nucleated cell numbers or differential cell counts between RAO and non-RAO horses at any time point. CONCLUSIONS AND CLINICAL IMPORTANCE: The peripheral airway obstruction detected in horses with RAO maintained in low-dust environments likely is due to irreversible airway remodeling but is not associated with cytologic evidence of airway inflammation.     

Epidemiological studies of pig diseases: 2. Post-weaning diarrhoea and performance in Western Australian pigs

Objective To determine in Australian pig herds the accuracy of French protocols for risk factor assessment of post-weaning diarrhoea and illthrift.
Procedure French protocols for the collection of data on health indicators and risk factors for post-weaning diarrhoea were conducted on 54 batches of weaner pigs from 28 Western Australian pig herds during three years.
Results Large variations in post-weaning performance were found. About one-third of the batches were growing at <200 g/day during the 3 weeks after weaning, and 54% had growth rates of <250 g/day. Weaning age and weight of at least 30 days and 7.9 kg, respectively, optimised weaner performance. Other risk factors associated with little post-weaning diarrhoea and good weaner performance were high creep feed intakes, relatively little diarrhoea as suckers, and, contrary to expectations, large temperature fluctuations.
Conclusion Overall, the 'predictability' of post-weaning problems as assessed by measurement of risk status, was good. However, the model was less accurate at predicting the performance of a single batch of pigs.     

Fractionation of High-Amylose Maize Starches by Differential Alcohol Precipitation and Chromatography of the Fractions

Three high-amylose maize starches (HAS) and a common corn starch (CCS) were subjected to differential alcohol precipitation using isoamyl alcohol and 1-butanol to obtain fractions designated as amylose (AM), amylopectin (AP), and intermediate material (IM). For each starch, IM had a blue value and an iodine binding wavelength maximum (λ_max) between the λ_max of the respective AM and AP. Size-exclusion chromatography (SEC) showed similarities in the AM from CCS and HAS. HAS AP had higher blue values and iodine binding λ_max values than CCS AP. SEC of the intact HAS AP and IM both showed large proportions of material eluting after the void volume (45–85%) when compared to CCS AP and IM. Chain length (CL) distributions of debranched AP and IM indicated that these fractions from each starch were highly branched, and that AP had a shorter average chain length than IM. Consequently, the differential precipitation behavior of the HAS AP and IM appears dependent on general branching structure rather than size. We conclude that in both CCS and HAS, AP and IM are subsets of the branched molecules with AP as the predominant fraction. For HAS, AP and IM include molecules of a size typical for AM and contain a higher proportion of chains that are longer than those of CCS AP. Differential alcohol precipitation is a useful method of separating amylose, amylopectin, and intermediate material from HAS.     

Retrogradation of du wx and su2 wx Maize Starches After Different Gelatinization Heat Treatments

Retrogradation of du wx and su2 wx starches after different gelatinization heat treatments was studied by differential scanning calorimetry. Suspensions of 30% (w/w) starch were initially heated to final temperatures of 55–180°C. Gelatinized starch was cooled and stored at 4°C. Starch retrogradation in the storage period was influenced by initial heat treatments. Retrogradation of du wx starch was rapid: when initially heated to 80–105°C, retrogradation enthalpy was ≈10 J/g after one day at 4°C. The retrogradation enthalpy was ≈15 J/g after 22 days of storage, and reached a maximum of 16.2 J/g after 40 days of storage. For du wx starch, application of the Avrami equation to increases in retrogradation enthalpy suggests retrogradation kinetics vary with initial heating temperature. Furthermore, starch retrogradation may not fit simple Avrami theory for initial heating ≤140°C. Retrogradation of su2 wx starch was slow. After 30 days of storage at 4°C, the maximum retrogradation enthalpy for all initial heating temperatures tested was 7.0 J/g, for the initial heating to 80°C. This work indicates that gelatinization heat treatment in these starches is an important factor in amylopectin retrogradation, and that the effect of initial heat treatment varies according to the genotype.     

Sheep grazing and defoliation of contrasting varieties of organically grown winter wheat with and without undersowing

Field experiments in Gloucestershire, UK, in the 1990–91, 1991–92, 1993–94 and 1994–95 growing seasons explored the merits of grazing in spring a traditional tall wheat (Triticum aestivum) variety, Maris Widgeon, with more modern shorter varieties. In the first 2 years, defoliation was achieved by mowing at 7 cm in March and/or April. In the second 2 years, varieties sown at two sowing dates were grazed by sheep at a stocking rate of 42 × 50 kg sheep ha^?1 for 3 or 4 days in March. Defoliation reduced crop height and interception of photosynthetically active radiation (PAR). In 1991–92, mowing significantly reduced grain yield of some of the shorter varieties but not of Maris Widgeon. This interaction was related to the amount of PAR intercepted. In this year, mowing improved the establishment of undersown white clover (Trifolium repens) and perennial ryegrass (Lolium perenne), but in subsequent years the conditions were much drier and undersowing failed. In the last two experiments, grazing in March did not significantly reduce grain yield of any variety. The quality of the forage eaten by the sheep had a modified acid-detergent fibre (MADF) content of less than 300 g kg^?1 dry matter (DM) and a crude protein (CP) content of more than 200 g kg^?1 DM in both seasons. Yield of DM and calculated metabolizable energy (ME) of different varieties removed by the sheep interacted strongly with sowing date. September-sown Maris Widgeon provided ≈ 0·7 and 0·3 t DM ha^?1 (or 7·8 and 3·4 GJ ME ha^?1) in March 1994 and March 1995 respectively. However, the shorter wheat varieties, Hereward and Genesis, only provided 0·3 and 0·1 t DM ha^?1 when sown at the same time in the 2 years. At later sowing dates all of the varieties only provided about 0·1 t DM ha^?1 when sown in October 1993, or 0·01 t DM ha^?1 when sown in November 1994. Sheep grazing reduced total weed biomass in June, and reduced the emergence of weed seedlings from soil samples collected after the wheat harvest. Effects of defoliation on foliar infection by Septoria tritici were inconsistent.