Disease,production and culling in Holstein-Friesian cows II. Age,season and sire effects

Effects of age, season and sire on the occurrence of common diseases of Holstein-Friesian cows were evaluated in a two and a half year study. The data were from 2875 lactation records from 2008 cows in 32 commercial dairy herds within a 50 mile radius of Guelph, Ontario.Age patterns for all disease conditions were determined using χ² or quadratic regression analyses. Linear increases with age were observed for milk fever, mastitis requiring local therapy only, cystic ovaries and foot and leg problems. Quadratic relationships with age were observed for ketosis (clinical and subclinical), mastitis requiring systemic therapy, subclinical mastitis, dystocia, respiratory diseases and traumatic reticulo-peritonitis. No consistent age patterns were found for retained placentas, reproductive tract infections, abomasal displacements, teat injuries, digestive disorders and abortions.Seasonal patterns were evaluated using a formal statistical test for the seasonality of events. Significant peaks were found in the risk of ketosis and cystic ovaries during the winter, and in the risk of teat injuries in the late winter or early spring. Seasonal patterns, more complex than a simple unimodal pattern, were observed for mastitis requiring local therapy only, traumatic reticulo-peritonitis and abortions.Heritabilities were determined for 9 disease conditions. All heritabilities were low or 0 with the exception of clinical ketosis (h² = 0.31).     

Cost-benefit analysis and investment appraisal in relation to pest control measures

A distinction is drawn between cost-benefit analysis and investment appraisal. Both are methods for evaluating projects, with cost-benefit analysis looking at proposals from the angle of the larger community in contrast to investment appraisal which looks at them from the individual, or firm, point of view. The time value of money is examined and also the treatment by cost-benefit analysis of social values and other elements outside the purview of investment appraisal, the so-called externalities or spillovers. Cost-benefit analysis of pest control measures is shown to depend heavily on analysis of the complexities and interactions of the biological/biochemical systems involved. This leads to the conclusion that the main thrust of cost-benefit studies in the pesticide field is to improve our understanding of pest problems and thereby to improve the efficiency of pest control measures, to the benefit of both the industry and the public.     

Comparative Cytology of the Neuro-Intermediate Lobe of the Reptilian Pituitary

In many reptiles the pars nervosa bears a striking resemblance to the mammalian median eminence. The structure of the ependymal cells lining the infundibular recess and the fact that many of them are in synaptic contact with nerve fibres suggests that they subserve more than a mere structural role and that they may be involed in secretory or transport functions forming functional units with neuronal elements of the hypothalamus. All species possess large numbers of typical peptidergic fibres although some have in addition a second, rarer type; aminergic fibres are also present but their numbers vary in different species. The pars intermedia contains nerve fibres only in snakes and Caiman but even in these species the innervation is sparse. This observation coupled with the organisation of the pars nervosa leads to the conclusion that the latter may act, in part at least, as the “median eminence” of the pars intermedia. A more extensive survey, particularly amongst the families of lizards thought to be related to the ancestors of snakes, might throw further light upon the course of evolution of control mechanisms within the pars intermedia of reptiles.     

Depletion of residues of benzoylprop-ethyl in soil

The depletion of residues of benzolyprop-ethyl ( I ) and its hydrolysis product N-benzoyl-N-(3,4-dichlorophenyl)-DL -alanine ( II ) in soils is reported from various trials following applications of I to soil and crops at up to 3 kg ha^?1. Quite rapid hydrolysis of I to II occurred in most soils and depletion of II followed. The total residue of I and II in the soil often initially increased, probably because of transfer of chemical from the crop to the soil, but the time for 50% disappearance of the total residue ( I+II ) was normally between 4 and 16 weeks. When four sites were treated for three successive years, carry-over of residues was negligible in three sites and showed no progressive increase in the fourth.     

Evaluation of outcome of otitis media after lavage of the tympanic bulla and long-term antimicrobial drug treatment in dogs: 44 cases (1998-2002)

OBJECTIVE: To evaluate the outcome of otitis media in dogs after video-otoscopic lavage of the tympanic bulla and long-term antimicrobial drug treatment. DESIGN: Retrospective study. ANIMALS: 44 dogs with otitis media treated in an academic referral practice. PROCEDURE: Medical records were reviewed for signalment, duration of ear canal disease, previous medical treatments, dermatologic diagnosis, results of cytologic examination and microbial culture of ear canal exudate, findings during video-otoscopy, medical treatment, days to resolution, and maintenance treatments prescribed. Four independent variables (age, duration of ear canal disease prior to referral, use of corticosteroids in treatment regimens, and infection with Pseudomonas aeruginosa) were evaluated statistically for potential influence on time to resolution. RESULTS: Mean +/- SD (range) duration of ear canal disease prior to referral was 24.9 +/- 21.6 (3 to 84) months. Otitis media in 36 dogs resolved after lavage of the tympanic bulla and medical management; mean +/- SD (range) time to resolution was 117 +/- 86.7 (30 to 360) days. Time to resolution was not significantly influenced by any variable evaluated. Three dogs were lost to follow-up, and 4 dogs eventually required surgical intervention. Seven of 36 dogs in which otitis had resolved relapsed; 4 required additional lavage procedures. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that lavage of the tympanic bulla combined with medical management is an effective and viable option for treatment of otitis media in dogs.