Milk production data from Holstein × Zebu cows in small farms (2.4 cows per farm on average) in Maharashtra, India, followed by Bharatiya Agro Industries Foundation (BAIF), an Indian non-governmental organisation, were analysed to evaluate the impact of simplified milk-recording systems. The aim was to investigate, in developing tropical areas, less-costly protocols compared with the one currently implemented at BAIF, used as a reference. The latter can be considered an 'AT2' protocol with the recording made by specialised technicians at 2-week intervals. The simplified protocols were simulated from an initial data file by sampling test days according to each protocol. Bias and accuracy on the 305-day cow milk production and on the resulting reliability of the estimated breeding value of bulls were the criteria used in the comparison with the reference protocol. One type of simplified protocol considered an increase in the interval between two tests to at least 4 and up to 8 weeks. Another alternative studied corresponded to the situation where milk yield information measured by the farmer is collected by the artificial insemination technicians themselves when visiting a farm. This could be an option in the case of very small herd sizes (two or three cows). The results suggest that simplifying the current milk-recording protocol leads to a clear decrease in accuracy of estimating 305-day cow production but it has a limited effect on the reliability of bull proofs. No economic comparison was carried out, but the results strongly suggest that properly managed simplified milk-recording schemes could permit a substantial decrease of costs of milk recording per cow without damaging the efficiency of progeny testing in tropical areas with small herd size. Moreover, with the proposed simplified milk-recording protocols, up to three to four times more bulls could be tested with the same number of records. 相似文献
To fill microelectrodes using backfilling method needs excessive time approximately 4–6 h. It is often difficult to fill microelectrodes without damage or leakage. A main problem is bubble formation in microelectrodes which has an impact on the electrical properties of the electrode and thus it influences the quality of the recording. Based on Archimede's principle there is a force within a solution which pushes insoluble material with a lower specific gravity upward and outside of the solution. Centrifugation can increase the force to eliminate the bubbles.
We designed a microelectrode holder to protect microelectrode sensitive tips from mechanical damage due to the gravity tensions; it can help to eliminate the bubbles easily and simultaneously in 10 min or less.
The tests were performed for 2000, 4000, and 8000 rpm centrifugation each one for 3, 6 and 12 min duration respectively, it was found that the bubbles were completely eliminated at 8000 rpm for 6–12 min and there were no significant differences for resistance, and the number of leaky or damaged electrodes between the two methods.
In the new design of devices, the materials used and the design of the holder are simple and the approach is applicable to many laboratories worldwide. 相似文献
Pheromone-source orientation behavior can be modified by coexisting plant volatiles. Some host plant volatiles enhance the
pheromonal responses of olfactory receptor neurons and increase the sensitivity of orientation behavior in the Lepidoptera
species. Although many electrophysiological studies have focused on the pheromonal response of olfactory interneurons, the
response to the mixture of pheromone and plant odor is not yet known. Using the silkmoth, Bombyx mori, we investigated the physiology of interneurons in the antennal lobe (AL), the primary olfactory center in the insect brain,
in response to a mixture of the primary pheromone component bombykol and cis-3-hexen-1-ol, a mulberry leaf volatile. Application of the mixture enhanced the pheromonal responses of projection neurons
innervating the macroglomerular complex in the AL. In contrast, the mixture of pheromone and cis-3-hexen-1-ol had little influence on the responses of projection neurons innervating the ordinary glomeruli whereas other
plant odors dynamically modified the response. Together this suggests moths can process plant odor information under conditions
of simultaneous exposure to sex pheromone. 相似文献
We studied the electrophysiological characteristics of Mauthner neurons (MN) in in vitro preparations of the medulla fragments of goldfish fries. The characteristics of extracellularly recorded responses of MN were found to be close to those usually recorded in vivo. It was demonstrated that in vitro intracellular microelectrode recording of MN activity in goldfish fries is, in principle, possible. The main experimental approaches for successful intracellular recording from such objects have been developed, and the possible artifacts met in the course of the experiments, as well as the parameters of stimulation, have been identified.Neirofiziologiya/Neurophysiology, Vol. 36, No. 4, pp. 288–296, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date. 相似文献
The diapriid wasp Trichopria drosophilae Perkins (Hymenoptera: Diapriidae) attacks and develops in puparia of the common fruit fly, Drosophila melanogaster Meigen (Diptera: Drosophilidae). Host recognition of T. drosophilae was studied using both a morphological and behavioural approach. Scanning and electron microscopical observations of female parasitoid antennae showed the presence of two types of sensilla, which we named MGS1 and MGS2. The former are present on the ventral side of both the apical (A11) and sub-apical (A12) antennomeres, while the latter occur only on A12. Ultrastructural features suggest a gustatory function for these sensilla. Arena bioassays using intact or antennaectomised females and intact host puparia showed that MGS2 are necessary for achieving host acceptance. Further bioassays, where the host's anterior spiracles were covered with wax, led to a very low level of host acceptance. We suggest that the secretion produced by glands associated with the anterior spiracles act as a contact kairomone, which has to be perceived by MGS2 in order to elicit host recognition. The removal of both the female apical antennomeres (A12) led to the failure of the parasitoid to recognize its host. 相似文献
In order to obtain direct information of stimulus dynamics perceived by a male moth under field conditions a portable device
was constructed which enables continuous recording of responses from individual pheromone receptors. The device is suitable
for tip recording by means of micro-knives as well as for recording with tungsten electrodes making it applicable for a wide
range of insects. A micro thermistor air velocity sensor is placed within 2 mm from the preparation to record the momentary
air flow. The signal conditioning electronic circuits are battery powered, and the signals can be stored on a portable tape
recorder. Field recordings were made from individual male antennal pheromone receptors ofAegeria myopaeformis andAdoxophyes orana. In all recordings the instantaneous firing frequency of the receptor cells was strongly modulated by the air velocity. Analysis
of the data may provide information about the average pheromone concentration and the fine structure of pheromone plumes under
various conditions. 相似文献
This paper illustrates a method for automatic data recording using the printer port of personal computer and software designed ad hoc. The system was tested by measuring circadian rhythms of activity in the subterranean rodent Ctenomys talarum. Data is recorded in a text-only comma-delimited file, and displayed on screen. 相似文献