Kinetics of jump landing in agility dogs

A recent survey reported an increased risk of injury in dogs participating in agility, a competitive canine sport involving different jumping activities. The aim of this study was to quantify the kinetic parameters during jump landing for commonly used obstacle types. It was hypothesised that with increasing obstacle height, the vertical force and vertical and accelerative horizontal impulse will increase as a result of a lengthened aerial phase, a more acute landing angle and the need to convert potential into forwards kinetic energy. Simultaneous kinetic and kinematic data were recorded from 11 competition agility dogs jumping over obstacle combinations of different height and inter-obstacle distance. Speed and landing angle of the second of the two consecutive jumps were successfully controlled by obstacle height and distance between obstacles. Statistical analysis showed differences between obstacles for peak vertical force, vertical impulse and accelerative horizontal impulse (increasing values with more acute landing angles). Extremely high peak vertical force was observed in the forelimbs (4.5 times bodyweight) when landing from a hurdle jump at high speed. Further detailed studies into the consequences for internal limb structures are warranted in order to clarify how this might be related to injury.     

Milk utilisation patterns in the low-input production systems in South Africa

Understanding the utilisation patterns of milk assists in designing appropriate dairy development schemes in rural communities. The objective of the study was to determine milk utilisation patterns in different smallholder farming systems in the Eastern Cape Province of South Africa. Data were collected through the administration of recording sheets to 130 randomly selected households in Alice, Fort Beaufort and Queenstown districts. Amounts of milk produced per household ranged from 9 to 21 l per household per day. Milk consumption/household/day was similar among the three districts. Milk consumption in the early lactation doubled the amount consumed in late lactation (P < 0.05). Milk in the communal areas was largely utilised as fresh or sour milk. Fresh milk was mostly used in tea/coffee or to make porridge for children. Sour milk was consumed with thick boiled maize meal. Fort Beaufort (10.2 ± 1.37 l/day) had the highest sour milk sales whilst Queenstown had the highest fresh milk sales (9.7 ± 5.57 l/day). It was concluded that quantities of milk consumed or sold as fresh or sour were generally low and varied across smallholder farming systems.     

Enhancement of the interferon gamma assay to detect paratuberculosis using interleukin-7 and interleukin-12 potentiation

A limitation to the widespread application of interferon gamma (IFN-γ) response assays has been logistical difficulties, as they must be performed within hours of blood collection. Detection of specific IFN-γ responses to Mycobacterium avium subspecies paratuberculosis (MAP) as part of the cell-mediated immune response of ruminants with Johne's disease could aid in diagnosis and control programs. In this study, a modified protocol was developed in which cultures were supplemented with interleukin (IL)-7, a survival factor required to maintain resting T cells, alone or in combination with IL-12 to potentiate IFN-γ responses and extend blood storage time. The combination of IL-7 and IL-12 was synergistic, giving IFN-γ responses greater than with IL-12 alone, for sheep blood stored up to 2 days. In a cohort of naturally infected sheep, the same number of animals was identified as test positive using the modified assay (performed after 2 days with IL-7/IL-12 supplementation) as the standard IFN-γ assay performed on the day of blood collection. The modified assay offered greatest advantage in the detection of early stages of paratuberculosis infection, for sheep with low grade and paucibacillary lesions, and at early time points post-infection. The potentiation protocol allowed for practical shipment of blood samples from farm to laboratory, extending permissible transit times and applicability of IFN-γ testing to detect Johne's disease.     

Distribution and risk factors of bovine cysticercosis in Belgian dairy and mixed herds

Bovine cysticercosis is an important food safety issue that is of economic concern. In Belgium, in the last years an increase in the number of cases, mostly light infections, was observed. The role of contact with contaminated surface water has been hypothesized as the main route of transmission. Based on abattoir records from 2001 till 2003 the distribution and risk factors of bovine cysticercosis among dairy and mixed farms were studied in four provinces, using Geographic Information Systems (GIS) and questionnaires. The risk factors were analysed using a case-control study design. The case group consisted of herds from which homebred cattle with cysticercosis had been detected at the abattoir; the control group was composed of herds where no cases had been detected. Case herds were distributed over the study area. A logistic regression analysis revealed that the location (province), the number of slaughtered cattle, the flooding of pastures, free access of cattle to surface water and the proximity of wastewater effluent were significant explanatory variables for bovine cysticercosis to be recorded in a herd.