The effects of every-other-day feeding on the growth performance of yearling stellate sturgeon,Acipenser stellatus

The purpose of this study was to evaluate the effect of a skip-a-day feeding regime on the growth of one-year-old sturgeon, Acipenser stellatus. Sturgeons possess a spiral valve intestine, which slows down the passage of food to longer than 24 hours, providing a scientific justification for the experiment. The experiment had a duration of 12 weeks and consisted of two treatments groups with four replicates each. One group of sturgeons (n = 120) was offered feed every day, on a continuous basis, at 2% of their body weight daily; while a second group of sturgeons (n = 120) were fed every other day, also at 2% of their body weight daily. The sturgeons had an average initial body weight of 178 ± 32 g and measured 44.6 ± 2.9 cm in total length. At the end of the experimental period, all sturgeons were alive, in good health, and no statistically significant differences (P > 0.05) on growth performance indices were detected between sturgeons fed every day and every other day. The average weights and lengths of sturgeons at the end of the trial were 406 ± 96 g and 55.4 ± 4.4 cm. The results of this study suggest that yearling sturgeon may be fed every other day rather than daily. A skip-a-day feeding regime can result in feed savings for a commercial operation, help protect the natural resources such as those for making fish meal, and lessen the impact of excess nutrients in natural bodies of water.     

Intramural jejunal leiomyoma as a cause of colic

A 15-year-old Thoroughbred gelding showjumper presented with colic after a history of chronic mild, intermittent colic. He was refractory to medical management. At surgery, he was found to have a 15-cm intramural mass in the distal jejunum, approximately 3 m orad to the ileum. Histopathology post-operatively revealed a leiomyoma. Leiomyomas in horses are rare. They have been reported most commonly in the reproductive tract, with other rare reports in the oesophagus and omentum. To the knowledge of the authors, there are no reports of identification and treatment of non-strangulating obstruction of the jejunum caused by a leiomyoma. The horse recovered from his surgery and went on to compete at the same level of showjumping as previous to the surgery with no further episodes of colic. Based on this report, leiomyoma should be a differential for small intestinal obstruction in the future.     

The effect of environmental factors on infection of blueberry fruit by Colletotrichum acutatum

Anthracnose fruit rot of blueberries caused by Colletotrichum acutatum is a serious problem in humid blueberry‐growing regions of North America. In order to develop a disease prediction model, environmental factors that affect mycelial growth, conidial germination, appressorium formation and fruit infection by C. acutatum were investigated. Variables included temperature, wetness duration, wetness interruption and relative humidity. The optimal temperature for mycelial growth was 26°C, and little or no growth was observed at 5 and 35°C. The development of melanized appressoria was studied on Parafilm‐covered glass slides and infection was evaluated in immature and mature blueberry fruits. In all three assays, the optimal temperature for infection was identified as 25°C, and infections increased up to a wetness duration of 48 h. Three‐dimensional Gaussian equations were used to assess the effect of temperature and wetness duration on the development of melanized appressoria (R² = 0·89) on Parafilm‐covered glass slides and on infection incidence in immature (R² = 0·86) and mature (R² = 0·90) blueberry fruits. Interrupted wetness periods of different durations were investigated and models were fitted to the response of melanized appressoria (R² = 0·95) and infection incidence in immature (R² = 0·90) and mature (R² = 0·78) blueberry fruits. Additionally, the development of melanized appressoria and fruit infection incidence were modelled in relation to relative humidity (R² = 0·99 and 0·97, respectively). Three comprehensive equations were then developed that incorporate the aforementioned variables. The results lay the groundwork for a disease prediction model for anthracnose fruit rot in blueberries.     

Nutrition of intensive pastures in the summer rainfall areas of southern Africa

Consideration is given to the current state of knowledge regarding the nutrition of cultivated pastures in the summer rainfall areas of southern Africa. Research efforts over the years have concentrated on the nitrogen (N) requirements of pastures, with relatively little significant work being undertaken on phosphorus (P), potassium (K) and lime. The numerous N response curves derived in cutting trials provide a useful basis for predicting N requirements under cutting‐and‐removal type utilization, but are of little value in predicting N requirements under grazing. The critical roles of P, K and lime in pasture productivity and persistence have been demonstrated in field trials undertaken in the Natal Midlands and south‐eastern Transvaal. Soil test calibrations, established for several important pasture species on Natal soils, have been found to provide a sound basis for predicting P, K and lime requirements of pastures. In considering the direction of future research, it is suggested that considerable potential exists for more efficient fertilizer and lime usage; research efforts should therefore be channelled in that direction.     

A simple novel measure of passive transfer of maternal immunoglobulin is predictive of preweaning mortality in piglets

Two factors that contribute to preweaning mortality in piglets are the initiation of lactation by sows and their ability to nurse their piglets. The objective of this study was to determine if the quantification of the transfer of immunoglobulins (Igs) from sow to piglet could act as a measure of these sow factors in terms of their influence on preweaning mortality. To measure passive transfer, a simple, rapid Ig immunocrit method was developed. For validation, the smallest piglets from 204 gilts were sacrificed on day 1 after birth and blood was collected.Piglet serum Ig concentrations were measured three ways: (1) by protein A sepharose precipitation, SDS–PAGE, and densitometry of the IgG heavy chain; (2) by precipitation of Ig with (NH₄)₂SO₄ followed by spectrophotometric measurement; and (3) by precipitation of Ig with (NH₄)₂SO₄ and measurement of the ratio of precipitate to sample volume using a hematocrit microcapillary (the Ig immunocrit method). Results from the (NH₄)₂SO₄ methods correlated (r = 0.86) with those obtained using SDS–PAGE. Day 1 weights and immunocrit ratios and preweaning survival data were then collected from every piglet from first (n = 90), and second (n = 145) parity sows. Bodyweight and immunocrit ratios accounted for 4.8% and 16.7% (P < 0.01) of the variation in preweaning mortality, respectively. Litter average immunocrit ratios were not correlated with preweaning mortality. In conclusion, the Ig immunocrit method is a simple, rapid measure of passive transfer from sow to piglet, and is useful in assessing the initiation of colostrum and the nursing ability of sows, and the effect of these events on preweaning piglet mortality.     

Grain and milling characteristics and their relationship with selected mixogram parameters in hard red bread wheat

Breeders in South Africa are faced with the problem that quality testing is only done in advanced phases of the bread wheat breeding programme when enough seed is available. This means that lines not meeting quality requirements of the South African industry for cultivar release are only discarded during the advanced breeding phases. The aim of this study was to determine relationships between grain and milling characteristics and mixogram parameters and to determine whether these characteristics can be used for selection of acceptable mixogram parameters and vice versa. A mixograph with Mixsmart software was used to analyse 10 bread wheat cultivars, in four replications at three different locations. Thirteen mixogram parameters were used to determine correlations with important grain and milling characteristics. Highly significant correlations were observed between mixogram parameters and grain as well as milling characteristics, although not with hectolitre mass, thousand kernel mass, vitreous kernels, falling number or flour colour. Multiple coefficient of determination was low to moderate for grain characteristics and low for milling characteristics as independent variables in explaining the variation in several mixogram parameters. In spite of the highly significant correlations, grain and milling characteristics explained little of the variation in mixogram parameters in this study.     

Screening and characterization of resistance to succinate dehydrogenase inhibitors in Alternaria solani

Field isolates of Alternaria solani, which causes early blight of potato in Idaho, USA were evaluated in vitro for their sensitivity towards the succinate dehydrogenase inhibitor (SDHI) fungicides boscalid, fluopyram and penthiopyrad. A total of 20 isolates were collected from foliar‐infected tissue in 2009, 26 in 2010 and 49 in 2011. Fungicide sensitivity was tested using the spiral‐gradient end point dilution method. The frequency of boscalid‐resistant isolates (>50% relative growth when using a spiral dilution gradient starting at 507 mg L^?1) drastically increased over the duration of this study (15% in 2009, 62% in 2010 and 80% in 2011). Increasing resistance to fluopyram and penthiopyrad was observed. However, cross‐resistance was only observed between boscalid and penthiopyrad. The target site of this fungicide class is the succinate dehydrogenase (SDH) enzyme complex, which is vital for fungal respiration. Sequence analysis of the SDH complex revealed mutations in the subunits B and D that were correlated with the emergence of boscalid resistance in potato fields in Idaho. In particular, H277R and H133R were identified in SDH subunits B and D, respectively. The presence of restriction sites in the gene sequences allowed the development of a rapid PCR‐RFLP method to assess boscalid sensitivity in A. solani populations.     

Oesophageal ectasia as a cause of dysphagia and milk regurgitation in a neonatal foal

Dysphagia and milk regurgitation are relatively infrequently observed clinical signs in neonatal foals but, when present, can commonly arise from anatomic or functional disorders of the upper airway. Less commonly, milk regurgitation can be caused by anatomic or neuromuscular disorders of the oesophagus. In the report presented here, a neonatal foal was examined for milk regurgitation at 4 days of age and was diagnosed with transient oesophageal ectasia via oesophagoscopy and contrast radiography. Aspiration pneumonia was treated with broad-spectrum antimicrobials and the owner was instructed to intermittently elevate the forelimbs to facilitate passage of milk out of the dilated oesophagus. The milk regurgitation resolved and reassessment of the foal at 6 weeks of age documented the absence of oesophageal ectasia and resolution of aspiration pneumonia. The foal was reported to be healthy and consuming food normally 6 months after initial examination and was in good body condition. This case is unique in that the oesophageal ectasia improved with time; furthermore, other potential causes of dysphagia and milk regurgitation of oesophageal origin in neonatal foals are discussed.     

Peak functions for modeling high resolution soil profile data

Parametric and non-parametric depth functions have been used to estimate continuous soil profile properties. However, some soil properties, such as those seen in weathered loess, have anisotropic peak-shaped depth distributions. These distributions are poorly handled by common parametric functions. And while nonparametric functions can handle this data they lack meaningful parameters to describe physical phenomena in the depth distribution of a property such as a peak, an inflection point, or a gradient. The objective of this work is to introduce the use of asymmetric peak functions to model complex and anisotropic soil property depth profiles. These functions have the advantages of providing parameters, which quantify or describe pedogenic processes. We demonstrate the application of the Pearson Type IV (PIV) and the logistic power peak (LPP) functions to high resolution soil property depth profiles measured by diffuse reflectance spectroscopy in a claypan soil landscape of Northeastern Missouri, USA. Both peak functions successfully fit clay, silt, and pH data for an example soil profile from a summit landscape position (R² = 0.90 for pH and 0.98 for silt and clay). The LPP function was further demonstrated to fit clay depth distribution for a shoulder, backslope, footslope, and a depositional landscape position (R² = 0.98, 0.96, 0.96, 0.91). Relationships between the fitted parameters of these profiles were useful to describe landscape trends in their morphological features and show promise to continuously describe pedogenic processes in three dimensions. Peak functions are a useful companion to high-resolution soil profile data collected by sensors and their combined use may allow more intensive mapping and better explanation of soil landscape variability.