equine

Comparisons of commercially available NIRS-based analyte predictions of haylage quality for equid nutrition

Maintaining animal health and performance relies on the availability of an appropriate diet. For herbivores, accurate assessment of forage nutrient quality is critical for appropriate diet formulation and rationing, including potential supplementation. Near-Infrared Reflectance Spectroscopy (NIRS) is a rapid method that is used in place of traditional chemical methodologies (wet chemistry) to predict analyte contents in forage samples. The method relies on scanning a sample with near-infrared light and predicting the analyte content by comparing the reflected spectra to a model which has been developed with samples of known analyte content measured by wet chemistry. The purpose of this study was to examine the accuracy of four NIRS-based methods on haylage from seven farm holdings compared with wet chemistry (the control). We analysed 64 samples for a range of analytes (dry matter (DM), pH, ash, acid detergent fibre expressed inclusive of residual ash (ADF), neutral detergent fibre assayed with a heat stable amylase and expressed inclusive of residual ash (aNDF), crude protein and water-soluble carbohydrate (WSC)) commonly assessed for haylage quality in equid nutrition. We compared results obtained by wet chemistry to corresponding NIRS-based predictions from four commercially available NIRS services. The results revealed large discrepancies amongst all five methods. For DM, average bias (mean±SD) for three reported methods was -15.5±188.4, -10.1±50.4, 12.9±33.8 g/kg respectively and for WSC reporting positive bias from four methods of 26.9±51.3, 24.8±38.2, 26.2±50.1 and 14.5±45.2, g/Kg respectively. The extent of these discrepancies from the wet chemistry also varied by analyte where for example, predictions for DM were more reliable than those for WSC and results demonstrated that predictions obtained by NIRS could result in feeding forage outside of target nutritional values.

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Equine anaerobic fungi: Key taxa of central importance to dietary fibre degradation

Joan E. Edwards
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The hindgut microbiota of equines enables the degradation of dietary fibre, as the equine host lacks this enzymatic capability. The hindgut microbiota is comprised of five main groups of microbes: bacteria, anaerobic fungi, protozoa, archaea and viruses (Julliand & Grimm, 2016). Despite this, however, only bacteria tend to be routinely studied when analysis of the hindgut microbiota is undertaken. This is short-sighted, as anaerobic fungi play a unique role in fibre degradation. This is due to their combined invasive growth and potent enzymatic activity enabling them to disrupt plant structural barriers and access internal areas of the plant tissue that other microbes cannot (Orpin, 1975; Ho et al., 1988; Solomon et al., 2016). In addition to being the most effective fibre degraders in the herbivore gut (Lee et al., 2000), they also benefit other gut microbes by increasing the plant surface area available for them to colonise.

Hyperlipemia in a population of aged donkeys: description, prevalence and potential risk factors

Background

Hyperlipemia is a common disorder of the donkey, with mortality rates of up to 80% reported. Such a poor prognosis makes prevention of this disorder or amelioration in the early stages crucial.

Objectives

The objective of this study was to describe and determine the prevalence of hyperlipemia in a population of donkeys and to determine risk factors for development of the disease.

Animals

A total of 449 cases were investigated from a population of 3829 donkeys; donkeys were resident at The Donkey Sanctuary, a charity providing refuge for unwanted donkeys in the UK. Animals were selected on the basis of presence of clinical disease.

Methods

A retrospective case–control study design was used, and all donkeys presenting with hyperlipemia over a 4-year period were included. Each case was matched with 2 controls that had not suffered from hyperlipemia in the previous month. Multivariable analysis was carried out to determine risk factors.

Results

A total of 449 clinical cases of hyperlipemia were reported with an associated mortality rate of 48.5%. Concurrent disease was present in 72% of donkeys and was the greatest risk factor (OR = 76.98); others included cardboard bedding (OR = 3.86), movement (OR = 3.94), weight loss (OR = 6.4), dental disease (OR = 1.73), and concentrate feeding (OR = 1.87).

Conclusions

This study shows that this population of donkeys in the UK often develops hyperlipemia, particularly in response to stress or primary illness, and provides useful insights in to health and management risk factors that may be addressed to decrease the risk of hyperlipemia both in the study population and in other similar donkey populations.

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Equine cestodosis: a sero-epidemiological study of Anoplocephala perfoliata infection in Ethiopia

A 12/13 kDa antigen, tapeworm ELISA test, developed for use in horses, was used to detect parasite-specific serum antibody, IgG(T), in the serum of donkeys. In a pilot study the 12/13 kDa antigen was tested and proved to detect the antibody, IgG(T), in donkey sera. Blood samples from 797 donkeys, naturally exposed to cestode infection, from four geographical localities were collected and sera were prepared and analysed. There was substantial serological evidence that donkeys were potentially infected with A. perfoliata. A range of ELISA OD values were obtained from the serological assay. Over 26% and 7.5% of the donkeys were moderately and highly infected, respectively, showing at least a 34% sero-prevalence. The rest, 66.1%, were either with low infection intensity or negative for A. perfoliata infection. The risk of infections, both in sero-prevalence and intensity, as determined by ELISA optical density (OD), were highest in the highland areas of Ethiopia where pastures are low-lying and wet, and permanent pasture management is regularly practised. Sex, age and body condition of the donkeys had no significant effect either on prevalence of the infection or on the serum antibody level. These results indicate a risk of intestinal disorders, particularly, colic, associated with A. perfoliata infection in donkeys.

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Development of a quantitative multivariable radiographic method to evaluate anatomic changes associated with laminitis in the forefeet of donkeys

Objective

To establish and validate an objective method of radiographic diagnosis of anatomic changes in laminitic forefeet of donkeys on the basis of data from a comprehensive series of radiographic measurements.

Animals

85 donkeys with and 85 without forelimb laminitis for baseline data determination; a cohort of 44 donkeys with and 18 without forelimb laminitis was used for validation analyses.

Procedures

For each donkey, lateromedial radiographic views of 1 weight-bearing forelimb were obtained; images from 11 laminitic and 2 nonlaminitic donkeys were excluded (motion artifact) from baseline data determination. Data from an a priori selection of 19 measurements of anatomic features of laminitic and nonlaminitic donkey feet were analyzed by use of a novel application of multivariate statistical techniques. The resultant diagnostic models were validated in a blinded manner with data from the separate cohort of laminitic and nonlaminitic donkeys.

Results

Data were modeled, and robust statistical rules were established for the diagnosis of anatomic changes within laminitic donkey forefeet. Component 1 scores ≤ −3.5 were indicative of extreme anatomic change, and scores from −2.0 to 0.0 denoted modest change. Nonlaminitic donkeys with a score from 0.5 to 1.0 should be considered as at risk for laminitis.

Conclusions and clinical relevance

Results indicated that the radiographic procedures evaluated can be used for the identification, assessment, and monitoring of anatomic changes associated with laminitis. Screening assessments by use of this method may enable early detection of mild anatomic change and identification of at-risk donkeys.

Volume
73
Issue
8
Start page
1207
End page
1218
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