A case-control study to identify farm factors affecting fertility of dairy herds: univariate description of factors

Objective To identify farm factors which were associated with reproductive performance in dairy herds in New South Wales.
Procedure A survey was administered by face to face interview to examine the responses of producers drawn from 757 herds, which used the New South Wales Agriculture Department Dairy Herd Improvement scheme. A case-control approach was used to select a total of 126 herds from the first (top group - cases) and fourth quartiles (low group - controls) for intercalving interval.
Results We found that the estimated interval from calving to first mating was significantly different between groups (P = 0.03) and that the groups significantly differed in both their target for interval to first mating (P = 0.02) and their perceived optimum time for first mating (P = 0.04). Other factors associated with a longer intercalving interval included, use of embryo transfer programs (P = 0.08), younger managers (P = 0.02), fewer breedings per day (P = 0.01), a greater number of people detecting heats (P = 0.07), but less hours spent detecting heats while handling the cows (P = 0.11), and a failure to vaccinate bulls for campylobacteriosis (P = 0.14).
Conclusions Managers of herds with poorer reproductive performance did not intend to mate cattle as soon after calving as managers with better reproductive performance, were not as active in seeking veterinary advice on reproduction, and were attempting to treat reproductive diseases and disorders themselves.     

Molecular heterogeneity for bovine α-mannosidosis: PCR based assays for detection of breed-specific mutations

tests, based on the polymerase chain reaction ( ), were developed for the detection of two breed-specific mutations responsible for the autosomal recessive disorder bovine α-mannosidosis. The tests involve separate amplification of two exons of the lysosomal α-mannosidase gene followed by restriction enzyme digestion of the amplicons. We demonstrate that one of the mutations, the 662G→A transition, is responsible for α-mannosidosis in Galloway cattle. The other mutation, the 961T→C transition, is uniquely associated with α-mannosidosis in Angus, Murray Grey and Brangus cattle from Australia. The 961T→C mutation was also detected in Red Angus cattle exported from Canada to Australia as embryos. All 39 animals classified as heterozygotes on the basis of biochemical assays were heterozygous for one of the two mutations. None of 102 animals classified as homozygous-normal on the basis of biochemical assays possessed the mutations. Our results indicate that the two breed-specific mutations may have arisen in Scotland and by the export of animals and germplasm disseminated to America, New Zealand and Australia.     

Uterine Activity after Induction of Hypocalcaemia in the Ovariectomized Camel (Camelus Dromedarius)

Al-Eknah, M.M., Homeida, A.M., Dafalla, E.A., Galil, A.K.A. and Al-Tahir, A.Y., 1997. Uterine activity after induction of hypocalcaemia in the ovariectomized camel (Camelus dromedarius). Veterinary Research Communications, 21 (1), 45-50.Bilateral ovariectomy was performed in three parous, non-pregnant camels. Intrauterine and intra-abdominal pressure changes were recorded using balloon-tipped catheters. Uterine contractions were induced and maintained in the ovariectomized camels by daily intramuscular injections of 5 mg oestradiol benzoate throughout the experimental period. The frequency of uterine contractions varied from 6 to 9 per minute, whereas the amplitude varied from 2 to 3 kPa in all the animals. Inducing hypocalcaemia to a level of 0.5 mmol/L by Na2EDTA reduced the amplitude of the contractions to below 1 kPa (p<0.001). The frequency of the contractions was not affected.     

CANINE BRAIN ANATOMY ON MAGNETIC RESONANCE IMAGES

Magnetic resonance (MR) images of the canine brain were acquired during investigation of dogs with neurologic disease. A paramagnetic contrast medium was used for enhancement. MR provided images with excellent contrast between grey and white matter, as well as brain tissue and cerebrospinal fluid. Good resolution and anatomic detail of the canine brain were obtained. A series of images was compiled and labelled as a reference for MR anatomy of the canine brain.     

Collective management on communal grazing lands: Its impact on vegetation attributes and soil erosion in the upper Blue Nile basin,northwestern Ethiopia

Collective action, on communal grazing land, has evolved in the highlands of northwestern Ethiopia to mitigate the problems of feed shortage and land degradation due to overgrazing. The exercise is liked by farmers for improving the availability of natural pasture during the long dry season when other feed sources get depleted. However, large portions of the communal grazing lands are still managed under free grazing throughout the year. This study was undertaken in Maynet village in the upper Blue Nile basin, northwestern Ethiopia, to assess the impacts of three different types of grazing land management (GLM) and two slope gradients (<10%; 15–25%) on aboveground herbaceous biomass yield, ground cover, species richness, runoff, soil loss and soil bulk density of grazing lands. The GLMs include (a) freely open communal GLM, (b) restricted communal GLM – collective management of communal grazing land locally named as ‘yebere sar’ and (c) private holding GLM. Stocking density was more than carrying capacity of grazing lands across all GLMs. However, the extent of overstocking problem was exceptionally severe in freely open communal GLM. The interaction between GLM and slope was significant (P<0.05) for runoff, soil loss and runoff coefficient. The average runoff coefficient was close to 50% in freely open communal GLM on steeper slopes (15–25%). Freely open communal GLM on steeper slopes resulted in consistently highest cumulative runoff and soil loss amounting to 491 mm and 32 t/ha per year, respectively. Polynomial regression analysis showed that quadratic relationship (r²=0.87) existed between soil loss and runoff. But, soil loss was close to nil when runoff did not exceed 2 mm per rainfall event. As expected, restricted communal GLM appeared to reduce surface runoff by more than 40% and curb the rate of soil erosion by more than 50% compared to freely open communal GLM. Its vegetation cover persisted above 70% throughout the year, meeting the threshold level recommended to keep surface runoff and soil loss to minimum. Reducing the problem of overstocking and pasture resting in August–November are important components to improve ground cover and aboveground herbaceous biomass yield, which in turn reduce land degradation on grazing lands.     

Comparative pharmacokinetics of acetylsalicylic acid and sodium salicylate in chickens and turkeys

1. Pharmacokinetics of acetylsalicylic acid (ASA) and sodium salicylate (SS) were assessed following single intravenous (i.v.) and oral administration at doses of 50 mg/kg body weight to chickens and turkeys. Plasma drug concentrations were determined using high-performance liquid chromatography with ultraviolet detection and pharmacokinetic variables were calculated using a non-compartmental model.

2. The mean residence time (MRT) of salicylate (SA) after i.v. administration of SS was 6.08 ± 0.59 and 3.32 ± 0.27 h and after oral administration was 6.95 ± 0.72 and 4.55 ± 0.71 h in chickens and turkeys, respectively. The elimination half-life (T _{1/2 e}) was shorter in turkeys compared with chickens. The value of body clearance (Cl_B) was higher in turkeys than in chickens, but the apparent volume of distribution (V _ss) was similarly low in both species. The bioavailability of SS was complete and the maximal plasma concentration of SA (C _max) after oral administration was 96.93 ± 8.06 and 91.76 ± 9.64 µg/ml, respectively, in chickens and turkeys.

3. The MRT of ASA after iv administration was 0.24 ± 0.08 and 0.24 ± 0.02 h and after oral administration was 0.78 ± 0.25 and 0.59 ± 0.13 h, respectively, in chickens and turkeys. In both species, T _{1/2 e} was very short, Cl_B and V _ss were similar and markedly higher than those of salicylate. The bioavailability of unchanged ASA was low and C _max after oral administration was 6.9 ± 3.6 µg/ml in chickens and 8.6 ± 1.3 µg/ml in turkeys.     

Morphometric analyses of the body and the branches of the normal third interosseous muscle (suspensory ligament) in Standardbreds

The third interosseous muscle (suspensory ligament, TIOM) is composed of connective tissue (CT) with a variable proportion of muscle (MT) and adipose tissue (AT). The aim of our study is to quantify the CT, MT and AT within the body and the branches of right thoracic and pelvic limbs TIOM in sound horses to determine whether there are differences in CT, MT and AT between age, sex, limbs and levels. Right limbs from 11 sound horses were collected. Samples from 6 levels of the TIOM were embedded in paraffin or in Tissue‐Tek^®. Most of the paraffin sections were shredded. Using the cryosection, some artefacts appeared. Cryoprotection was carried out, which produced the best results. Hematoxylin–phloxine–saffron and Hematoxylin–eosin gave a good contrast of colours between the tissues observed allowing the use of an image analysis programme to calculate percentage of each tissue within the TIOM. The percentage of MT and AT decreased significantly (P < 0.0001), whereas the percentage of CT increased significantly (P < 0.0001) with age and when descending from the proximal to the distal level of the TIOM. The percentage of MT was significantly higher (P < 0.0001) in females than males, while the percentage of CT was significantly higher (P < 0.0001) in males than females. The percentage of AT was significantly higher (P = 0.0278) in pelvic limbs than in thoracic limbs. These results confirm the variation in tissue composition within the TIOM of sound horses.     

VERTEBRAL HEART SCORES IN EIGHT DOG BREEDS

The vertebral heart score (VHS) measurement is commonly used to provide a more objective measurement of cardiomegaly in canines. However, several studies have shown significant breed variations from the value previously established by Buchanan and Bücheler (9.7 ± 0.5). This study describes VHS measurements in Pug, Pomeranian, Yorkshire Terrier, Dachshund, Bulldog, Shih Tzu, Lhasa Apso, and Boston Terrier dog breeds. Dogs with two or three view thoracic radiographs, no subjective radiographic evidence of cardiomegaly, and no physical examination findings of heart murmurs or gallop rhythms were included in the study. The Pug, Pomeranian, Bulldog, and Boston Terrier groups were found to have a VHS significantly greater than 9.7 ± 0.5 (P < 0.00001, P = 0.0014, P < 0.0001, P < 0.00001, respectively). Body condition score (BCS) was found to have a significant effect on the VHS of Lhasa Apso group. Anomalous vertebrae in the thoracic column were associated with a significant increase in VHS of the Bulldog (P = 0.028) and Boston Terrier (P = 0.0004) groups. Thoracic depth to width ratio did not have a significant effect on VHS.     

Distribution and Genotypic Characterization of Campylobacter jejuni Isolated from Poultry in Split and Dalmatia County,Croatia

Consumption of poultry contaminated with Campylobacter jejuni has been recognized worldwide as the leading cause of campylobacteriosis. Therefore, the aim of our study was to investigate the prevalence and genotype diversity of Campylobacter jejuni in poultry meat intended for consumption in Split and Dalmatia County, which is the second biggest County in Croatia. Furthermore, we also wanted to discover possibly stable clones of C. jejuni appearing in different samples and periods of time, which would indicate their ability to persist in or adapt to poultry. In the period from March 2008 until June 2010, 834 samples of poultry from various sources were examined using a surface swab technique. Isolation of C. jejuni was performed by Preston broth and Karmali agar. Identification of the isolates was carried out using biochemical tests. C. jejuni was found in 84 of 574 chicken samples (14.6%) and in nine of 260 samples of turkey (3.5%). Pulse‐field gel electrophoresis (PFGE) was used to analyse 61 obtained isolates using SmaI and KpnI. Of 22 different macrorestriction profiles (MRP) that were found, five were detected in poultry from both different locations and periods of time. Samples from 11 locations were found to be contaminated with more than two different genotypes of C. jejuni. Interestingly, the same MRP were found both in poultry declared to be of domestic origin and in the poultry imported from abroad. The prevalence of C. jejuni in poultry samples was in accordance with previously reported results. Genotypic analysis indicated that the population of C. jejuni in Split and Dalmatia County was diverse and that multiple strains of C. jejuni could be found in the same poultry samples. Furthermore, the same genotypes were identified from the samples obtained from different locations and periods of time, which could support the theory of a global existence of certain MRP that are able to persist in or adapt to poultry.