Influence of rearing system on sows' prolificacy during gestation.
In females reared inindividual crates until early control of gestation and in common crates (8-16heads), prolificacy did not reach values that differ depending on the rearingsystem: there is a statistically insignificant difference in t-test(p>0.05). In gestating sows reared in individual crates, the difference wassignificant during the entire gestation period compared to group rearing:11.51±0.85 compared to only 11.13±0.68 in collective rearing. Though there arebetter results from the point of view of sows’ prolificacy when reared inindividual crates during the entire gestation, this rearing system is notrecommendable because of the high financial efforts caused by technology andbecause separation has negative influences on sows’ behaviour depending on reproductionand health state of gestating females.
Effects of the photoperiodicity on the reproduction in sow. II - Effects on the estrous cycle, pregnancy length and total born piglets.
In the frame of this paper it was researched the relationship between season and some reproductive parameters (oestrus length, pregnancy length and total born piglets) in primiparous and multiparous sows in terms of the photoperiodicity climate in Romania. The research was conducted on a crossbred Yorkshire sows (♀) × Landrace (♂) sow population and consisted of monitoring the oestrus duration, the gestation period and the number of total born piglets related to astronomical seasons: fall, winter, spring and summer. They were found seasonal influences characterized by a longer gestation length in autumn and spring seasons vs. summer and winter, with a difference of about one day between the seasons, and an annual average difference of about one day between primiparous and multiparous sows. Gestation length was inversely correlated with total born piglets. The oestrus length had an annual average of about 2.16 days in primiparous and 2.98 days in multiparous sows, with peak values in seasons of growing photoperiodicity and minimum values in seasons of decreasing photoperiodicity.
A rapid on-filter immunoassay screen for dexamethasone in equine urine
A simple on-filter immunoassay screen has been developed for the detection and semi-quantification of dexamethasone in equine urine samples. The assay consists of an indirect competitive ELISA in which dexamethasone in standards or samples competes with an immobilised dexamethasone–protein conjugate for binding to a complex of sheep anti-dexamethasone antibodies complexed with alkaline phosphatase-labelled second antibody. The drug–protein conjugate is immobilised as a spot on the surface of a cellulose nitrate filter and the assay is performed with the filter retained within a filtration port. The assay involves two incubation steps, firstly a ten minute competitive step and secondly a five minute step to generate via an enzyme-catalysed reaction an insoluble coloured dye as a spot on the filter at the site of the immobilised drug–protein conjugate. Rapid washing is achieved through use of the filtration system. The assay has a limit of detection of 10–6 M (390 ng ml–1) for a visual end point in which the colour intensity of spots developed in the presence of samples is compared with those of standards. Twelve filters can be processed in a single batch consisting of two standards and ten samples. The assay has been optimised for equine samples and dexamethasone in the urine of a race horse following injection of 20 mg of drug has been detected for 23 h post administration.