Epidemiological studies of pig diseases: 2. Post-weaning diarrhoea and performance in Western Australian pigs

Objective To determine in Australian pig herds the accuracy of French protocols for risk factor assessment of post-weaning diarrhoea and illthrift.
Procedure French protocols for the collection of data on health indicators and risk factors for post-weaning diarrhoea were conducted on 54 batches of weaner pigs from 28 Western Australian pig herds during three years.
Results Large variations in post-weaning performance were found. About one-third of the batches were growing at <200 g/day during the 3 weeks after weaning, and 54% had growth rates of <250 g/day. Weaning age and weight of at least 30 days and 7.9 kg, respectively, optimised weaner performance. Other risk factors associated with little post-weaning diarrhoea and good weaner performance were high creep feed intakes, relatively little diarrhoea as suckers, and, contrary to expectations, large temperature fluctuations.
Conclusion Overall, the 'predictability' of post-weaning problems as assessed by measurement of risk status, was good. However, the model was less accurate at predicting the performance of a single batch of pigs.     

The pathogenesis and treatment of osteomyelitis and laminitis in a stallion after the prolonged topical application of formalin to the distal phalanx

A 12-year-old Quarterhorse stallion was presented with a severe lameness in the left forefoot. There was a 3 cm diameter cavity in the sole that extended to the solar surface of the distal phalanx. Radiographs revealed an osteomyelitis and a sequestrum which probably developed following the prolonged topical application of 10 percent formalin. The sequestrum was removed and the infected bone curetted under general anaesthesia. The horse was shod with heart bar shoes on both front feet 7 days after the surgery. Eight months later, radiographs showed marked rotation of the distal phalanx despite continual shoeing with heart bar shoes. Surgical resection of the dorsal wall of the hoof at the toe removed the pressure applied by the laminar wedge, and combined with the stabilising and supporting action of the heart bar shoe, permitted realignment of the distal phalanx approximately 30 degrees closer to the normal skeletal axis by 26 days post-operatively. This case highlights some of the recent developments in the treatment of laminitis and suggests that effective treatment is possible if the value of the animal warrants the time and investment.     

Single crystals of single-walled carbon nanotubes formed by self-assembly

We report the self-assembly of single crystals of single-walled carbon nanotubes (SWCNTs) using thermolysis of nano-patterned precursors. The synthesis of these perfectly ordered, single crystals of SWCNTs results in extended structures with dimension on the micrometer scale. Each crystal is composed of an ordered array of tubes with identical diameters and chirality, although these properties vary between crystals. The results show that SWCNTs can be produced as a perfect bulk material on the micrometer scale and point toward the synthesis of bulk macroscopic crystalline material.     

Testing newly introduced ornamental plants to the arid climate of Kuwait

Thirty five ornamental plants were introduced into the Ahmadi Bioremediated Soil Park to screen and closely monitor the growth performance of these new introductions under the local environmental conditions. Out of these 35 plant species, 15 were planted in both bioremediated and agricultural soils to assess their suitability for growing in bioremediated soils. Data on vegetative growth was recorded to assess the performance of newly-introduced plants, whereas, the heat stress was documented of Bauhinia blakeana, where no visible effects of petroleum pollutants on plant growth were observed. Performance of each plant group is discussed separately in the text. Overall, plant survival was 72.73% for all plant groups. Generally, plants that failed to grow in bioremediated soil also did not survive in the agricultural soil, indicating that they were sensitive to heat stress more than the presence of petroleum contaminants in the soil. New plant species that were able to establish and perform satisfactorily will be used in greenery projects after they are fully naturalized to the prevailing climatic conditions.     

Association analysis of novel polymorphisms in 2′, 5′‐oligoadenylate synthetase gene with reproductive traits in indigenous and cross‐bred cattle of Indian Origin

2′, 5′‐Oligoadenylate synthetases (OAS) are important components of an interferon‐mediated antiviral pathway. No polymorphisms in exonic regions of bovine OAS1 gene have been identified and associated with reproduction traits. The objective of the study was to detect and evaluate the effects of mutations in exonic region of bovine OAS1 gene with reproduction traits in cattle. DNA samples collected from 250 individual cows of two Indian dairy breeds (Sahiwal and Frieswal) of cattle were used in the study. The genetic variants of the OAS1 gene were identified with polymerase chain reaction–single‐strand conformation polymorphism (PCR‐SSCP) and sequence analysis using seven set of primer pairs. The PCR‐SSCP analysis revealed polymorphism in the fragments comprising of exon 2, exon 5 and first fragment of exon 6 while the fragments of exons 1, 3, 4 and second fragment of exon 6 were monomorphic in Sahiwal and Frieswal cattle. The mutations in the amplified region comprising of exon 2 were found to have significant association with age at first breeding and calving, service period, dry period and pregnancy rate. Significant associations were found between SNPs in the exon 5 and service and dry periods of the animal, whereas the genetic variants in the first fragment of the exon 6 showed significant association with age at first breeding and calving. To our knowledge, this study demonstrated for the first time that the polymorphisms in OAS1 gene were associated with reproductive traits and it can be chosen as a candidate gene for improvement of reproductive performance of cattle.     

Factors affecting the prevalence and severity of footrot in a Merino flock selected for resistance to Haemonchus contortus

SUMMARY An outbreak of virulent footrot occurred in three lines of sheep selected for different levels of resistance to Haemonchus contortus , providing an opportunity to examine the factors affecting footrot severity. The selection lines did not differ significantly in average footrot score, but various other factors were found to have an effect. In breeding ewes, the average score was 10.2 (maximum possible score 20) and the prevalence of footrot was 96%. There was a significant age effect, with average score increasing from 9.1 ± 0.8 in 2-year-old ewes, to 13.4 ± 0.9 in 7-year-old ewes. Ewes that lost their lambs tended to have higher scores than those that either failed to lamb or successfully reared their litter. Significant differences in footrot score were caused by the lambing paddock in which the ewes had been, during the period seven weeks to one week before infection. Among lambs, aged about 20 weeks, the average footrot score was lower (5.0), as was the prevalence (75%). The score increased by an average of 0.09 ± 0.03 per day of age and the prevalence increased by an average of 0.6%± 0.3% per day of age. Lambs born and reared as twins had significantly lower scores than singles, and progeny of maiden dams had lower scores than progeny of older ewes. There was no significant difference because of the sex of the lamb. The paternal half-sib estimate of heritability of footrot score was 0.20 ± 0.14 and of the genetic correlation between footrot score and worm egg count was essentially zero (0.02 ± 0.20), but these estimates were probably biased by the confounding of sires with lambing paddocks. Nevertheless, the results strongly suggest that there are no adverse genetic associations between resistance to footrot and resistance to internal parasites.     

Comparative Aspects of the Endotoxin- and Cytokine-Induced Endocrine Cascade Influencing Neuroendocrine Control of Growth and Reproduction in Farm Animals

Disease in animals is a well-known inhibitor of growth and reproduction. Earlier studies were initiated to determine the effects of endotoxin on pituitary hormone secretion. These studies found that in sheep, growth hormone (GH) concentration was elevated, whereas insulin-like growth factor-I (IGF-I) was inhibited, as was luteinizing hormone (LH). Examination of the site of action of endotoxin in sheep determined that somatotropes expressed the endotoxin receptor (CD14) and that both endotoxin and interleukin-Iβ activated GH secretion directly from the pituitary. In the face of elevated GH, there is a reduction of IGF-I in all species examined. As GH cannot activate IGF-I release during disease, there appears to be a downregulation of GH signalling at the liver, perhaps related to altered nitration of Janus kinase (JAK). In contrast to GH downregulation, LH release is inhibited at the level of the hypothalamus. New insights have been gained in determining the mechanisms by which disease perturbs growth and reproduction, particularly with regard to nitration of critical control pathways, with this perhaps serving as a novel mechanism central to lipopolysaccharide suppression of all signalling pathways. This pathway-based analysis is critical to the developing novel strategies to reverse the detrimental effect of disease on animal production.     

Quantity of IL‐2, IL‐4, IL‐10, INF‐γ, TNF‐α and KC‐Like Cytokines in Serum of Bitches With Pyometra in Different Stages of Oestrous Cycle and Pregnancy

The occurrence of the pyometra is most common in the first half of the dioestrus when there is decreased cellular immunity associated with increased serum concentration of progesterone in females. The aim of this study was to determine the immunological profile of bitches with pyometra, studying serum levels of IL‐2, IL‐4, IL‐10, IFN‐γ, KC‐like and TNF‐α and comparing them with those of healthy bitches in anoestrus, dioestrus and pregnant. Forty females were divided into four experimental groups: group 1 (G1): with pyometra (n = 10); group 2 (G2): bitches in the second week of gestation (n = 10); group 3 (G3): in anoestrus (n = 10); and group 4 (G4): in dioestrus (n = 10). The serum levels for IL‐2, KC‐like, INF‐γ and TNF‐α were similar for all experimental groups. The values obtained for IL‐10 were found increased (p < 0.001) in animals in dioestrus and pyometra compared with females in anoestrus and pregnant, and the levels of IL‐4 observed were significantly greater (p < 0.001) in bitches with pyometra when compared with others. The cytokine profile in animals with pyometra is similar to bitches in dioestrus for IL‐10 and had increase in IL‐4 for bitches with pyometra, which represents an anti‐inflammatory these cases. This suggests the presence of an immunosuppressive state in both cases, which may explain the propensity of bitches in dioestrus to be affected by pyometra and the severity of the disease on these animals.