AN EVALUATION OF AN ELECTRONIC INSTRUMENT FOR PASTURE YIELD ESTIMATION

A model of the electronic instrument described by Campbell et al . (3) was built at the Grassland Research Institute and was found to behave in a very similar way to their New Zealand model. A considerable amount of field work was undertaken with it in 1964 and this demonstrated that no general relationship of acceptable accuracy had yet been found; nor could it be sufficiently improved by the inclusion of the meteorological and botanical factors recorded. This forces one to a consideration of double-sampling techniques, which appear worth while; they will be discussed in Part 2 of this paper.     

Liquorice and canine Addison's disease

Abstract

Extract

Hypoadrenocorticism, or Addison's disease, is an uncommon en-docrinopathy of dogs (Feldman and Nelson 2004 Feldman, EC and Nelson, RW. 2004. “Hypoadrenocorticism (Addison's disease)”. In Canine and Feline Endocrinology and Reproduction, 3rd, 394–439. Philadelphia, , USA: WB Saunders.  [Google Scholar]). Long-term management of affected dogs in New Zealand involves treatment with oral fludrocortisone acetate (Florinef tablets; Bristol-Myers Squibb (NZ) Ltd, Auckland, NZ), which is a relatively expensive synthetic adrenocortical steroid. Table salt may be added to the food, in an attempt to reduce the amount of fludrocortisone required. Despite fludrocortisone therapy, many Addisonian dogs remain hyponatraemic and hyperkalaemic and the required dose of fludrocortisone may need to be increased during the first year of treatment. Increasing the dose of fludrocortisone is not only expensive, but may also have undesirable effects through its potent glucocorticoid action.     

Increased yearling weight as a proportion of 21-month weight was associated with increased milk production in dairy heifers

ABSTRACT

Aims: To examine the relationship between liveweight (LWT) at 12 months as a proportion of LWT at 21 months of age (LWT(12/21)%) and first lactation and cumulative 3-year milk production in dairy heifers in New Zealand.

Methods: Liveweight and milk production records were obtained for dairy heifers born from June to December (spring-calving season) between 2006–2007 and 2013–2014 dairy seasons; production records included first lactation (n?=?140,113) and cumulative 3-year (n?=?67,833) milksolids and energy-corrected milk (ECM) yields. Heifers were classified into five breed groups; Holstein-Friesian, Holstein-Friesian crossbred, Jersey, Jersey crossbred and Holstein-Friesian-Jersey crossbred. Within each breed group heifers were categorised into quintiles based on 21-month LWT. The LWT(12/21)% was calculated for each animal. Relationships between LWT(12/21)% and milk production within each breed group and LWT category were estimated using linear mixed effects models including the linear and quadratic effects of LWT(12/21)%.

Results: The relationship between LWT(12/21)% and milk production was predominantly curvilinear, with lower milk production at lesser LWT(12/21)% compared with greater LWT(12/21)%. For all breed groups and most LWT categories, heifers that were 55 or 65% LWT(12/21)% produced greater ECM and milksolids yields compared with heifers that were 45% LWT(12/21)%. Holstein-Friesian, Holstein-Friesian crossbred and Holstein-Friesian-Jersey crossbred heifers that were 65% LWT(12/21)% produced greater cumulative 3-year ECM and milksolids yields compared with heifers of the same breed group that were 45% LWT(12/21)%

Conclusions and clinical relevance: Heifers that were a greater proportion of their 21-month LWT at 12 months of age produced more first lactation and cumulative 3-year milk yields than heifers that were a lesser proportion of their 21-month LWT at 12 months of age. These results indicate that increased growth in early life of New Zealand dairy heifers is beneficial to future milk production.     

Characterisation of midgut digestive proteases from the maize stem borer Busseola fusca

BACKGROUND: Insect damage is a major constraint on maize production. Control of Busseola fusca (Fuller) in sub‐Saharan Africa is relatively ineffective; the major larval digestive enzymes were characterised with a view to developing future control strategies. RESULTS: Using BODIPY‐FL Casein, maximal activity was at pH 9.5, with six protease forms visualised by gelatin‐PAGE. Synthetic substrates and diagnostic inhibitors demonstrated the presence of serine proteases. Chymostatin was a potent inhibitor of general proteolysis (90%), providing strong evidence for the presence of chymotrypsin; it also caused significant inhibition (>95%) with SA₂PFpNA as substrate. The I₅₀ values for chymostatin with casein and SA₂PFpNA were 0.0075 µM and 0.06 µM respectively. Z‐Phe‐Arg‐pNA activity was inhibited by chymostatin and TLCK (50 and 30% respectively), suggesting the presence of trypsin‐like activity. BApNA hydrolysis was also strongly inhibited by chymostatin and TLCK (92 and 75%), suggesting trypsin activity, while SBBI, PMSF, pepstatin and E‐64 had no significant effect. Interestingly, SBBI (I₅₀ = 0.39 µM ) and SBTI both inhibited general proteolysis by approximately 70%, suggesting that SBBI's dual inhibitory role makes this inhibitor a potentially useful candidate for expression in maize for control of B. fusca. CONCLUSION: These results provide a basis for the rational design of insect‐resistant transgenic maize expressing protease inhibitors. Copyright © 2008 Society of Chemical Industry     

Analgesic and anti-hyperalgesic effects of epidural morphine in an equine LPS-induced acute synovitis model

Epidural morphine is widely used in veterinary medicine, but there is no information about the anti-hyperalgesic and anti-inflammatory effects in acute inflammatory joint disease in horses. The analgesic, anti-hyperalgesic and anti-inflammatory effects of epidural morphine (100mg/animal or 0.17±0.02mg/kg) were therefore investigated in horses with acute synovitis. In a cross-over study, synovitis was induced in the talocrural joint by intra-articular lipopolysaccharide (LPS). The effect of epidural morphine was evaluated using physiological, kinematic and behavioural variables. Ranges of motion (ROM) of the metatarsophalangeal and talocrural joints were measured, clinical lameness scores and mechanical nociceptive thresholds (MNTs) were assessed and synovial fluid inflammatory markers were measured. The injection of LPS induced transient synovitis, resulting in clinical lameness, decreased ranges of motion in the talocrural and metatarsophalangeal joints, decreased limb loading at rest and increased composite pain scores. Epidural morphine resulted in a significant improvement in clinical lameness, increased ROM and improved loading of the LPS-injected limb at rest, with no effects on synovial fluid inflammatory markers. Morphine prevented a decrease in MNT and, hence, inhibited the development of hyperalgesia close to the dorsal aspect of inflamed talocrural joints. This study showed that epidural morphine provides analgesic and anti-hyperalgesic effects in horses with acute synovitis, without exerting peripheral anti-inflammatory effects.     

Malignant melanoma of the pelvis as a possible cause of pelvic limb lameness in two gray mares

Two grey mares, a 12-year-old Arabian and a 13-year-old Lippizaner cross, were referred for chronic pelvic limb lameness and abduction of the limb during the non supporting phase of the stride. The clinical examination revealed melanomas under the tail and on the perineum, and oedema of the proximal lame limb. A mass in the pelvic area was detected on rectal palpation. Laparoscopy was performed and the provisional diagnosis of malignant melanoma was made. Histological examination of the biopsy taken under laparoscopic control from the mass in the pelvis confirmed the diagnosis of malignant melanoma. In the postmortem examination a large black mass in the pelvis and metastases in several organs were diagnosed. The process under the tail showed microscopically the characteristics of dermal melanomatosis. The metastases showed the appearance of a malignant melanoma. The lameness and abduction during the non supporting phase of the stride were possibly caused by a combination of pain, a mechanical limitation, and paresis/paralysis. When an older grey horse with melanomas on the predilection sites is submitted with pelvic limb lameness and abduction of the limb during the non supporting phase of the stride, a malignant melanoma in the pelvis is one of the differential diagnoses and a rectal examination should be performed. Diagnostic laparoscopy in the standing horse can be useful to confirm the provisional diagnosis.     

Quantitative electromyographic examination in myogenic disorders of 6 horses

Electromyographic needle examination (EMG), including the semiautomatic quantitative analysis of motor unit action potential (MUAP), is an important diagnostic tool for myopathy in humans. The diagnostic possibilities of this technique have not been fully explored in horses; however, recent studies have shown that MUAP analysis can be performed in conscious horses. To determine the diagnostic possibilities of EMG in horses, we compared the EMG results of the subclavian muscle, the triceps, and the lateral vastus muscle in 6 equine patients thought to have myogenic disorders with those in 7 normal control horses. The EMG results were compared with the results of the histopathologic examination of the lateral vastus muscle in patients and controls. Histopathologic examination showed muscle disease in 3 patients. In the patient group, several types of abnormal spontaneous activities were observed (mainly fibrillation potentials and positive sharp waves), and the MUAPs of the patient group had a markedly shorter duration and lower amplitude than those of the control group. In the subclavian muscle, triceps, and lateral vastus muscle of affected horses, the MUAP duration was 5.0 +/- 0.4 (mean +/- SD), 3.9 +/- 0.3, and 4.7 +/- 1.1 milliseconds, respectively. The MUAP amplitude was 217 +/- 55, 150 +/- 74, and 180 +/- 54 microV; the number of phases was 2.4 +/- 0.2, 2.5 +/- 0.3, and 2.3 +/- 0.1; and the number of turns was 2.6 +/- 0.2, 2.4 +/- 0.2, and 2.8 +/- 0.5, respectively. In conclusion, it appears that the EMG may be a more sensitive method than other techniques for examining muscle biopsies for diagnosis of early-stage myopathy in horses.