Cow/calf preweaning efficiency of Nellore and Bos taurus x Bos indicus crosses

The objectives of this study were to determine if percentage Bos taurus (0 or 50%) of the cow had an effect on ME requirements and milk production, and to compare cow/calf efficiency among 3 mating systems. Metabolizable energy requirements were estimated during a feeding trial that encompassed a gestation and lactation feeding trial for each of 2 groups of cows. Cows were 0 or 50% Bos taurus (100 or 50% Nellore) breed type: Nellore cows (NL; n = 10) mated to Nellore bulls, NL cows (n = 9) mated to Angus bulls, Angus x Nellore (ANL; n = 10) and Simmental x Nellore (SNL; n = 10) cows mated to Canchim (5/8 Charolais 3/8 Zebu) bulls. Cows were individually fed a total mixed diet that contained 11.3% CP and 2.23 Mcal of ME/kg of DM. At 14-d intervals, cows and calves were weighed and the amount of DM was adjusted to keep shrunk BW and BCS of cows constant. Beginning at 38 d of age, corn silage was available to calves ad libitum. Milk production at 42, 98, 126, and 180 d postpartum was measured using the weigh-suckle-weigh technique. At 190 d of age, calves were slaughtered and body composition estimated using 9-10-11th-rib section to obtain energy deposition. Regression of BW change on daily ME intake (MEI) was used to estimate MEI at zero BW change. Increase in percentage Bos taurus had a significant effect on daily ME requirements (Mcal/d) during pregnancy (P < 0.01) and lactation (P < 0.01). Percentage Bos taurus had a positive linear effect on maintenance requirements of pregnant (P = 0.07) and lactating (P < 0.01) cows; during pregnancy, the ME requirements were 91 and 86% of those in lactation (131 +/- 3.5 vs. 145 +/- 3.4 Mcal x kg(-0.75) x d(-1)) for the 0 and 50% B. taurus groups, respectively. The 50% B. taurus cows, ANL and SNL, suckling crossbred calves had greater total MEI (4,319 +/- 61 Mcal; P < 0.01) than 0% B. taurus cows suckling NL (3,484 +/- 86 Mcal) or ANL calves (3,600 +/- 91 Mcal). The 0% B. taurus cows suckling ANL calves were more efficient (45.3 +/- 1.6 g/Mcal; P = 0.03) than straightbred NL (35.1 +/- 1.5 g/Mcal) and ANL or SNL pairs (41.0 +/- 1.0 g/Mcal). Under the conditions of this study, crossbreeding improved cow/ calf efficiency and showed an advantage for cows that have lower energy requirements.     

Concurrent sialocoele and necrotising sialadenitis in a dog

A seven-year-old male, entire rottweiler was presented to Murdoch University Veterinary Hospital with a 24 hour history of blindness, chemosis, exophthalmus, pain on opening the mouth and hypersialism. Bilateral mandibular and zygomatic salivary gland enlargement with concurrent bilateral zygomatic salivary gland sialocoeles were identified. The cause of the mandibular salivary gland enlargement was confirmed as necrotising sialadenitis, while the cause of the zygomatic gland enlargement was presumed to be because of a similar disease process. No underlying aetiology was identified. Treatment consisted of supportive management, corticosteroids and paracentesis of the sialocoeles and resulted in resolution of the salivary gland enlargement and the associated clinical signs. This is an unusual presentation of salivary gland disease in the dog with multiple gland involvement and a spectrum of disease processes occurring at the same time.     

A multiplex RT-PCR assay for the rapid and differential diagnosis of classical swine fever and other pestivirus infections

Classical swine fever is a highly contagious viral disease causing severe economic losses in pig production almost worldwide. All pestivirus species can infect pigs, therefore accurate and rapid pestivirus detection and differentiation is of great importance to assure control measures in swine farming. Here we describe the development and evaluation of a novel multiplex, highly sensitive and specific RT-PCR for the simultaneous detection and rapid differentiation between CSFV and other pestivirus infections in swine. The universal and differential detection was based on primers designed to amplify a fragment of the 5′ non-coding genome region for the detection of pestiviruses and a fragment of the NS5B gene for the detection of classical swine fever virus. The assay proved to be specific when different pestivirus strains from swine and ruminants were evaluated. The analytical sensitivity was estimated to be as little as 0.89 TCID₅₀. The assay analysis of 30 tissue homogenate samples from naturally infected and non-CSF infected animals and 40 standard serum samples evaluated as part of two European Inter-laboratory Comparison Tests conducted by the European Community Reference Laboratory, Hanover, Germany proved that the multiplex RT-PCR method provides a rapid, highly sensitive, and cost-effective laboratory diagnosis for classical swine fever and other pestivirus infections in swine.     

Detection of foot-and-mouth disease virus infected cattle using infrared thermography

In this study, infrared thermography (IRT) was assessed as a means of detecting foot-and-mouth disease virus (FMDV)-infected cattle before and after the development of clinical signs. Preliminary IRT imaging demonstrated that foot temperatures increased in FMDV-infected animals. The maximum foot temperatures of healthy (n = 53), directly inoculated (DI) (n = 12), contact (CT) (n = 6), and vaccine trial (VT) (n = 21) cattle were measured over the course of FMD infection. A cut-off value was established at 34.4 °C (sensitivity = 61.1%, specificity = 87.7%) with the aim of detecting FMDV-infected animals both before and after clinical signs were observed. Seven of 12 (58%) DI and 3/6 (50%) CT animals showed maximum foot temperatures exceeding the 34.4 °C cut-off before the development of foot vesicles. In contrast, only 5/21 (24%) VT animals displayed pre-clinical foot temperatures above this cut-off possibly indicating partial vaccine protection of this group. These results show IRT as a promising screening technology to quickly identify potentially infected animals for confirmatory diagnostic testing during FMD outbreaks. Further evaluation of this technology is needed to determine the value of IRT in detecting animals with mild clinical signs or sub-clinical infections.     

Sorption of carbofuran and diuron pesticides in 43 tropical soils of Sri Lanka

To better understand the environmental fate of pesticides in Sri Lankan soils, we studied the sorption behavior of two commonly used pesticides (carbofuran and diuron) in 43 surface soils representing a range of soil physicochemical properties from dry and wet zones of Sri Lanka. For carbofuran, the K(d) (L/kg) values varied from 0.11 to 4.1 (mean, 0.83; median, 0.62) and K(oc) ranged from 7.3 to 120.6 (mean, 41.65; median, 36.1), whereas for diuron K(d) values varied from 0.5 to 75 (mean, 9.6; median, 5.15) and K(oc) ranged from 55.3 to 962 (mean, 407; median, 328). A comparison of sorption data on these tropical soils with published studies (mostly European and north American soils) showed that the ranges of sorption coefficients from Sri Lankan soils were within the wide range of K(oc) values reported in the literature. However, these values for both pesticides in soils from dry zones of Sri Lanka were consistently higher (up to two times) than those from the wet zone. The wide range of K(oc) values in Sri Lankan soils may be due to the possible difference in the nature of soil organic carbon, which needs to be further investigated.     

Genetic structure of Fusarium pseudograminearum populations from the Australian grain belt

Crown rot, caused by the fungus Fusarium pseudograminearum (teleomorph Gibberella coronicola) is a major disease of wheat in the Australian grain belt. However, there is little information available on the population structure of this pathogen. We measured genetic diversity as assessed with amplified fragment length polymorphism (AFLP) analysis within and between populations of F. pseudograminearum from northeastern, south central, and southwestern regions of the Australian grain belt. Amongst the 217 isolates, 176 haplotypes were identified and grouped into two main clusters. One cluster contained isolates from populations in northeastern Australia, and the other cluster contained isolates from populations in south central and southwestern Australia. The southern populations were distinguished from the northeastern populations by higher levels of population differentiation (Gst) between them and genetic identity amongst the regional populations. We hypothesize that the F. pseudograminearum populations from northeastern and southern Australia are independent, which could result from different founding events or from geographic isolation and the accumulation of genetic differences due to genetic drift and/or selection.     

Epidemiological aspects of Phyllosticta citricarpa colonization and viability in Citrus sinensis

Journal of Plant Diseases and Protection - Citrus black spot (CBS) is a disease caused by the fungus Phyllosticta citricarpa that is associated with significant yield losses. The pathogen forms...