Effects of Exogenous Tumour Necrosis Factor-α on the Secretory Function of the Bovine Reproductive Tract Depend on Tumour Necrosis Factor-α Concentrations

The aim of study was to correlate tumour necrosis factor-α (TNF) infused doses used with the TNF concentrations achieved and with the secretory function of both the ovary and the uterus in cows. We evaluated the concentrations of progesterone (P4), prostaglandin (PG)F_2α, PGE₂ nitric oxide (NO) and TNF in the jugular vein and vena cava caudalis as parameters of exogenous TNF action on the female reproductive tract. Aortae abdominalis of cows (n = 18) were infused with saline or two doses of TNF (luteolytic – 1 μg or luteotrophic – 10 μg). In the peripheral blood, 1 μg TNF concentrations achieved within the range of 30–45 pg/ml, and 10 μg TNF provoked a sharp increase in achieved concentrations at a range of 250–450 pg/mL). The TNF concentrations achieved in vena cava caudalis were five to six times higher than that in peripheral blood (p < 0.001). One microgram TNF increased PGF_2α and NO (p < 0.001) and decreased P4 (p < 0.05). The higher TNF dose stimulated P4 and PGE₂ (p < 0.01). TNF infusion at luteolytic dose achieved its concentrations at the physiological range previously observed in cows. Luteotrophic TNF dose achieved the concentrations in vena cava caudalis that are much higher than physiological level and were previously noted in pathological circumstances (i.e. mastitis , metritis ).     

Integrating practical, regulatory and ethical strategies for enhancing farm animal welfare

OBJECTIVE: To provide an integrated view of relationships between assessment of animal welfare. societal expectations regarding animal welfare standards, the need for regulation, and two ethical strategies for promoting animal welfare, emphasising farm animals. APPROACH: Ideas in relevant papers and key insights were outlined and illustrated, where appropriate, by New Zealand experience with different facets of the welfare management of farm animals. CONCLUSIONS: An animal's welfare is good when its nutritional, environmental, health, behavioural and mental needs are met. Compromise may occur in one or more of these areas and is assessed by scientifically-informed best judgement using parameters validated by directed research and objective analysis in clinical and practical settings. There is a wide range of perceptions of what constitutes good and bad welfare in society, so that animal welfare standards cannot be left to individual preferences to determine. Rather, the promotion of animal welfare is seen as requiring central regulation, but managed in a way that allows for adjustments based on new scientific knowledge of animals' needs and changing societal perceptions of what is acceptable and unacceptable treatment of animals. Concepts of 'minimal welfare', representing the threshold of cruelty, and 'acceptable welfare', representing higher, more acceptable standards than those that merely avoid cruelty, are outlined. They are relevant to economic analyses, which deal with determinants of animal welfare standards based on financial costs and the desire of the public to feel broadly comfortable about the treatment of the animals that are used to serve their needs. Ethical strategies for promoting animal welfare can be divided broadly into the 'gold standard' approach and the 'incremental improvement' approach. The first defines the ideal that is to be required in a particular situation and will accept nothing less than that ideal, whereas the second aims to improve welfare in a step-wise fashion by setting a series of achievable goals, seeing each small advance as worthwhile progress towards the same ideal. 'Incremental improvement' is preferred. This also has application in veterinary practice where the professional commitment to maintain good welfare standards may at times conflict with financial constraints experienced by clients.     

Tuberculosis in alpaca (Lama pacos) on a farm in Ireland. 2. Results of an epidemiological investigation

Tuberculosis (TB), due to infection with Mycobacterium bovis was diagnosed in a flock of alpaca in Ireland in 2004. An epidemiological investigation was conducted to identify the risk of TB for farmed alpaca where TB is endemic, the origin of the infection, the potential for alpaca-to-alpaca transmission and appropriate control measures. The investigation focused on the alpaca flock (including the farm, animal movements and breeding, feeding and flock health practice), the disease episode (including animal disease events and subsequent control measures) and TB infection risk in the locality. The TB risk to alpaca is high in areas where infection is endemic in cattle and badgers and where biosecurity is inadequate. It is most likely that the source of infection for the alpaca was a local strain of M. bovis, present in cattle in this area since at least 2001. Genotyping of isolates identified a single variable number tandem repeat (VNTR) profile in both cattle and alpaca in this region. Although a tuberculous badger was also removed from the vicinity, bacterial isolation was not attempted. On this farm, infection in alpaca was probably derived from a common source. Alpaca-to-alpaca transmission seems unlikely. Two broad control strategies were implemented, aimed at the rapid removal of infected (and potentially infectious) animals and the implementation of measures to limit transmission. Tests that proved useful in detecting potentially-infected animals included measurement of the albumin-to-globulin ratio and regular body condition scoring. Skin testing was time consuming and unproductive, and early detection of infected animals remains a challenge. The flock was managed as a series of separate groupings, based on perceived infection risk. No further TB cases have been detected.     

The first reported outbreak of equine herpesvirus myeloencephalopathy in New Zealand

CASE HISTORY AND CLINICAL FINDINGS: On 9 January 2014 (Day 0) a mare from a stud farm in the Waikato region presented with urinary incontinence without pyrexia. Over the following 33 days 15 mares were clinically affected with neurological signs. All but one mare had a foal at foot. The most commonly observed clinical signs were hind limb paresis and ataxia. In some cases recumbency occurred very early in the course of disease and seven mares were subject to euthanasia for humane reasons.

LABORATORY FINDINGS: Equid herpesvirus (EHV) type 1 was detected using PCR in various tissues collected post mortem from two mares with neurological signs. DNA sequencing data from the DNA polymerase gene of the virus showed a nucleotide transition at position 2254, a mutation encoding amino acid D₇₅₂ that is highly associated with the neuropathogenic genotype of EHV-1. In total 12/15 mares were confirmed positive for EHV-1 on PCR. Results from a virus neutralisation test and ELISA on paired serum samples, and PCR on whole blood and nasal swabs, indicated that of four paddocks in a high-risk area where a cluster of cases had occurred, 20/21 (95%) horses were likely to have been exposed or were confirmed infected with EHV-1. Subsequent to the outbreak two mares aborted, one at 9 months and one at 10 months of gestation. The cause of abortion was confirmed as EHV-1 with the same genotype as that involved in the outbreak.

DIAGNOSIS: Equine herpesvirus myeloencephalopathy.

CLINICAL RELEVANCE: The outbreak described shows the considerable impact that can occur in outbreaks of equine herpesvirus myeloencephalopathy in New Zealand. Early biosecurity controls not only reduced the effect on the farm but mitigated the potential for the virus to spread to other horse enterprises.     

Antimicrobial susceptibility testing of Serpulina hyodysenteriae

Summary The macrobroth dilution technique was used to test the in-vitro effectiveness of 4 commonly used antimicrobial agents against 23 Australian isolates and 7 overseas strains of Serpulina hyodysenteriae. Minimum inhibitory concentrations and minimum bactericidal concentrations were determined. The growth of 90% of isolates was inhibited by dimetridazole at a concentration of 4 μg/mL, and by tiamulin at 8 μg/mL Australian isolates resistant to both antimicrobial agents were identified. Lincomycin was less effective than these antimicrobial agents, with 90% of isolates requiring a concentration of 128 μg/mL for inhibition of growth, and 54% being susceptible at 64 μg/mL. Tylosin did not prevent the growth of the majority of S hyodysenteriae isolates tested, and 90% were resistant to concentrations of 128 μg/mL. Resistant isolates came from different geographical areas. Resistance was not related to overall genetic background of the spirochaetes, and was not correlated with the presence of plasmids or the serogroup of the isolates.     

Elasticity of single-crystal MgO to 8 gigapascals and 1600 kelvin

The cross pressure (P) and temperature (T) dependence of the elastic moduli (Cij) of single-crystal samples of periclase (MgO) from acoustic wave travel times was measured with ultrasonic interferometry: partial differential2C11/ partial differentialP partial differentialT = (-1.3 +/- 0.4) x 10(-3) per kelvin; partial differential2C110/ partial differentialP partial differentialT = (1. 7 +/- 0.7) x 10(-3) per kelvin; and partial differential2C44/ partial differentialP partial differentialT = (-0.2 +/- 0.3) x 10(-3) per kelvin. The elastic anisotropy of MgO decreases with increasing pressure at ambient temperature, but then increases as temperature is increased at high pressure. An assumption of zero cross pressure and temperature derivatives for the elastic moduli underestimates the elastic anisotropy and overestimates the acoustic velocities of MgO at the extrapolated high-pressure and high-temperature conditions of Earth's mantle.     

Emerging technologies for identifying superior dairy cows in New Zealand

The performance of animals is determined by the interaction of their genes with environmental circumstances. Accordingly, animals exhibiting superior performance are not necessarily the animals with the best genes nor are they the best choice of parents. Statistical analyses of production records for repeated traits, e.g. lactation yields and reproductive performance, show that part of the variation in performance among animals in the same herd and year is due to genetic differences, and the remainder is due to so-called residual or environmental factors that are not passed on to offspring. These within-herd environmental factors can be partitioned into a component that affects performance throughout an animal's lifetime, and a part that is unique to each observation. The process of animal evaluation from pedigree and performance records partitions the superiority of each cow into these three components. Reliable assessment of the genetic merit of bulls has required progeny testing, and for cows has required observation of their own individual performance. Selection on the genetic or breeding value component has systematically improved animal performance over recent decades, but has been limited by the age at which assessments of genetic merit are available.

Emerging molecular technologies can read DNA sequences or measure RNA expression and have allowed the identification of a number of chromosome regions, and a few specific genes in those regions, that influence economic performance. This information allows better characterisation of the relationships between animals and more accurate predictions of genetic merit in bulls without progeny information and in cows that have yet to produce their own performance record. At some stage, enough genes responsible for variation in performance will be identified to allow faster genetic progress through selection of animals at young ages and therefore more rapid turnover of the generations. Mechanisms that modify gene expression have been identified and these may ultimately allow animals to be selected at an early age for lifetime productivity, accounting for processes that modify gene expression and lead to differences in performance that are not reflected by DNA sequence information. This review describes the status of these emerging technologies and their likely role in the improvement of dairy cattle.     

Spinal dermoid sinus in a Burmese cat with paraparesis

A 2-year-old, male, Burmese cat was evaluated for chronic progressive hindlimb weakness, ataxia and urinary incontinence. Radiographic examination, myelography and magnetic resonance imaging defined congenital vertebral anomalies and a space-occupying intradural, extramedullary mass. A dermoid sinus was subsequently identified dorsal to the affected spine. Surgical excision of the tract necessitated a dorsal laminectomy and removal of a 1-cm diameter intradural dermoid sinus 'cyst' that contained hair and sebaceous debris. The cat recovered hindlimb function after surgery and remains asymptomatic 50 months after surgery except for a persistent inability to urinate voluntarily.