Financial analysis of dipping strategies for indigenous cattle under ranch conditions in Uganda

A financial analysis was performed to assess the performance of three acaricide-treatment groups of indigenous breeds (Zebu and Nganda) of cattle on a ranch in Luwero District, Uganda. The treatments were based on different frequencies: twice-a-week dipping, once-a-month dipping and no tick control. The objective was to evaluate the economic justification for intensive acaricide application for tick and tick-borne disease control in Uganda. Data were collected by monitoring cattle performance over a period of 34 months. Biological data collected included the number of cows at the beginning and end of the study, net starting liveweight, number of calves born, number of animals dying due to tick-borne diseases and other causes, number of animals sold or slaughtered and milk yield. Records of variable costs (acaricides, drugs, labour, etc.) and output prices were assembled and calculated by treatment group. Gross margin and marginal analysis were used in the financial analysis. The exchange rate in 1990–1993 was one US$ to 1200 Uganda shillings. The gross benefits obtained from animal sales, herd value and milk yield were Uganda shillings 1175, 1389 and 1311 per kg of net starting liveweight for animals dipped twice-a-week, once-a-month and not dipped, respectively. The variable costs were Ug. shs. 424, 390 and 360 per kg of net starting liveweight, respectively. Consequently, the gross margins were Ug. shs. 751, 999 and 951 per kg of net starting liveweight. Furthermore, the marginal rate of return (MRR) in changing from no tick control to once-a-month dipping was 160%, while changing from no tick control to twice-a-week dipping was negative (− 313%). The above results showed that the value of increased gains in production obtained from twice-a-week dipping strategy does not offset the costs of inputs for intensive dipping. Once-a-month dipping (strategic) therefore appears to be the most-profitable tick-control strategy for the farmer. The need to conduct further studies in different livestock- production systems and to rationalise future tick control policies is discussed.     

Hepatic (64)Cu excretion in Dobermanns with subclinical hepatitis

To investigate whether Dobermanns have impaired copper excretion an intravenous radioactive copper isotope ((64)Cu) was used as a tracer. Five patients and eight normal dogs (5 normal Dobermanns and 3 Beagles) were studied. The five female Dobermann patients had a subclinical hepatitis and an increased hepatic copper concentration (median 822mg/kg, range 690-1380mg/kg dry matter). The normal dogs, five Dobermanns and three Beagles, had no abnormal liver histopathology and hepatic copper concentrations were considered normal (Dobermanns; median 118mg/kg, range 50-242mg/kg dry matter; Beagles; median 82mg/kg, range 50-88mg/kg dry matter). Cholestasis was excluded in all dogs by means of a (99m)Tc-Bis-IDA hepatobiliary scintigraphy. Plasma clearance of (64)Cu was comparable in all dogs with no statistically significant differences. The excretion of (64)Cu into the bile, although not statistically significant, was less for the Dobermanns with subclinical hepatitis compared to the normal dogs. The findings suggest that impaired copper excretion may play a role in the aetiology of chronic hepatitis in the Dobermann.     

Genetic diversity in blast resistance of Bhutan rice landraces

With an objective to evaluate the Bhutan rice (Oryza sativa L.) landraces for genetic diversity in blast resistance, 402 accessions viz. 352 landraces, a differential set of 32 R gene lines and 18 modern cultivars were field-evaluated in three blast ‘hotspot’ sites followed by genetic analysis of the 352 landraces with 27 microsatellite markers. Across the sites, 19 landraces (5.4%) exhibited complete resistance with zero disease score and 203 (58%) and 163 (46%) landraces showed high partial resistance for early leaf and panicle blast, respectively, with disease score of four to six. Field evaluation for leaf and panicle blast at three experimental sites in Bhutan showed best cultivar discrimination in early leaf blast at the tillering stage (heritability, h² = 0.32) and in the panicle blast at maturity (h² = 0.44). Subdivision of the genetic variation into cultivar groups revealed the most variation for blast severity within the 352 landraces with h² of 0.31 and 0.46 for early leaf and panicle blast, respectively. Cluster analysis of the landraces revealed two distinct rice cultivar groups, which separated at dissimilarity of 0.84 according to origin of the cultivars from low, mid and high altitude zones in Bhutan. All microsatellites were polymorphic with two to 21 different alleles per marker and a high polymorphic information content value of 0.61. The identified blast resistant landraces were genetically diverse originating from different rice cultivation zones. Further investigation of the resistant and partial resistant material may reveal specific blast resistance genes, which could be useful to mitigate blast incidence in rice-producing countries.     

Efficiently locating conservation boundaries: Searching for the Tasmanian devil facial tumour disease front

Conservation management actions and decisions are often defined by the location of ecological boundaries, for example, the present range of invasive or threatened species. The position of these boundaries can be cryptic, and managers must therefore directly sample sites, an expensive and time-consuming process. While accurate boundary location techniques have been considered by ecological theorists, the issue of cost-effective, or optimal boundary location has not. We propose a general framework for boundary location which incorporates both cost-efficiency and uncertainty. To illustrate its application, we use it to help locate an infectious disease front in the endangered Tasmanian devil population. The method ensures optimal spatial sampling by maximizing the expected information gained from each sample. When resources are limited, our method provides more accurate estimates of the boundary location than traditional sampling protocols. Using a formal decision theory sampling design encourages economically efficient actions, and provides defensible and transparent rationale for management actions.     

Type of kindergarten and other potential determinants of overweight in pre-school children

OBJECTIVE: The study aimed to assess the relationship of various types of kindergarten differing in length of care and food availability with the development of overweight in pre-school children. DESIGN, SETTING AND SUBJECTS: A cross-sectional study was carried out in 2002 in Stuttgart, Germany, as part of the school entrance examination. Height and weight of 2140 children (participation 70.2%) were measured and information on type of kindergarten and other potential determinants of overweight was collected by a parental questionnaire. Change in relative body mass index (BMI) position between the ages of 4 and 6 years was assessed using medical records. RESULTS: The prevalence of overweight or change in relative BMI position did not differ according to the type of kindergarten. For the prevalence of overweight in German children, adjusted odds ratios (OR) comparing institutions that open only in the morning with those opening in the morning and afternoon or for the full day were 0.86 (95% confidence interval (CI) 0.40, 1.83) and 0.63 (95% CI 0.25, 1.58), respectively. Parental BMI and duration of television watching were positively associated, and maternal educational status and duration of breast-feeding were negatively associated, with overweight and/or change in relative BMI position. The prevalence of overweight was substantially higher among non-German than among German children (adjusted OR 2.17 (95% CI 1.53, 3.07)). CONCLUSIONS: These data show no association between different types of kindergarten and the development of overweight in early childhood. Duration of television watching and breast-feeding, as well as the relatively high prevalence of overweight in ethnic minorities, deserve further attention.     

Chronic hepatitis in Doberman pinschers. A review

Summary

Chronic hepatitis in Doberman pinschers is predominantly seen in female dogs, usually between 4 and 7 years of age and was first recognized in the early eighties. The histopathological characteristics of Doberman hepatitis are those of micronodular cirrhosis with histological features of fibrosis, piece meal necrosis and progressive lymphocyte and plasma cell infiltration of the portal triads. Currently there are two hypotheses on the pathogenesis although neither of them has been elucidated. The first hypothesis is that of a copper toxicosis. The second is that of autoimmunity. Similarities and differences with other breeds and studies on both hypotheses are reviewed, as well as results of recent research of our group. Based on recent findings chronic hepatitis in Doberman pinschers is most likely to be a form of copper toxicosis. Although there are several indications that suggest autoimmunity as well, this still remains unclear.     

Effect of selenium supplementation on semen characteristics of Brazil's ram

The aim of this study was to investigate the effects of different concentrations of oral supplementation with selenium (Se) upon ram sperm parameters. Thirty rams managed in stall under intensive system were used and divided into five groups (six animals per group) as follows: control group (G1) mineral mixture supplementation without Se, group 2 (G2) mineral mixture supplemented with 5 mg/kg Se, group 3 (G3) supplemented with 10 mg/kg Se, group 4 (G4) supplemented with 15 mg/kg Se and group 5 (G5) supplemented with 20 mg/kg Se. For each group, there was an adjustment period of 14 days. The experimental period was 350 days. Every 56 days, the animals were weighed and semen samples were collected by electroejaculation. Semen analysis included volume, mass moviment, total motility, vigour, concentration and morphology. For plasmatic and acrosomal membrane integrity evaluation and mitochondrial membrane potential were used a combination of fluorescent probes. Differences between means values obtained by analysis of variance were verified by Tukey test with 5% probability. There was no statistical difference between treatment groups in relation to volume, mass moviment, total motility, vigour, concentration, plasma and acrosomal membrane integrity (p > .05). Sperm morphology was different between treatment groups, the G1 (0 mg of selenium) had the highest percentage of major defects (11.11 ± 1.11^a; p < .05). It was concluded that selenium decrease the percentage of sperm defects and did not directly influence on ram sperm volume, mass moviment, total motility, vigour, concentration and membrane integrity.     

Neuroendocrine,Metabolic and Genomic Cues Signalling the Onset of Puberty in Females

Puberty is the result of a dynamic interaction between genetic factors and environmental cues, all of which lead to the attainment of reproductive capacity. Thus, significant changes in hormone secretion occur from the pre‐pubertal to the pubertal stage. The objective of this review is to provide an update of some endocrine, physiological, metabolic and genetic concepts involved in the establishment of the hypothalamic‐hypophyseal‐gonadal axis function promoting the onset of the reproductive function during puberty. To achieve this purpose, basic aspects of the function of the hypothalamic‐hypophyseal‐gonadal axis, the control of the axis by neurotransmitters and the interaction between reproductive function and metabolic status will be considered. Finally, the role of the novel kisspeptin system and the GPR54 receptor as modulators of puberty will be considered, in addition to the hierarchical expression of the main genes acting as regulators of the onset of puberty.