1,721,102 research outputs found
THE EFFECTS OF ALFAPROSTOL (PGF2a analogue) AND eCG ON REPRODUCTIVE PERFORMANCES IN POSTPARTUM RABBITS
No full text[EN] The aim of this study was to verify the effectiveness of post partum pharmacological oestrus synchronisation with alfaprostol or eCG in improving rabbit doe reproductive performances and to evaluate the incidence of pseudopregnancy in this species. One hundred and eighty commercial hybrid rabbit does, multiparous and lactating, were randomly divided into three groups (n=60) and treated on day 8 post partum (pp) as follows: Group A, 1 mL s.c. vitaminic solution with 200 mg alfaprostol, a synthetic analogue of PGF2a; Group B, 1 mL sc vitaminic solution with 20 I.U eCG; Group C (Control) 1 mL sc vitaminic solution. On day 11 pp (3 days after treatment), all the rabbits were artificially inseminated (AI), and injected with 0.8 mg of buserelin i.m. to induce ovulation. Concurrently, blood samples were taken for progesterone (P4) analysis by RIA with the following schedule: day 8 pp (before treatment), day 11 pp (before AI and the induction of ovulation) and day 16 pp (5 days after AI). Fertility was not influenced by hormonal treatments (71.7% and 71.2% respectively) compared to control (66.1%). Conversely, both PGF2a and eCG hormonal synchronisation treatments increased (P1 ng/mL). On day 5 after insemination 95.5% had P4 values, which attest to the presence of functional corpora lutea (CL) (P4>2 ng/mL). The results of this study show that as long as rabbitry is properly managed zootechnically and sanitarily, drugs such as alfaprostol and eCG, while not ameliorating fertility rate when used for post partum oestrus sychronisation, can increase litter size.Mollo, A.; Veronesi, M.; Battocchio, M.; Cairoli, F.; Brecchia, G.; Boiti, C. (2003). THE EFFECTS OF ALFAPROSTOL (PGF2a analogue) AND eCG ON REPRODUCTIVE PERFORMANCES IN POSTPARTUM RABBITS. World Rabbit Science. 11(2):63-74. https://doi.org/10.4995/wrs.2003.498SWORD637411
Metabolic adaptations in neonatal mother-deprived rabbits
No full textIn order to study the metabolic adaptation in response to 48 h transient doe-litter separation (DLS) in young rabbits (5 rabbits/d group) between postnatal 9 and 11 d, plasma concentrations of thyroid hormones T3 and T4, insulin, leptin, glucose, triglycerides (TG), and free fatty acids (FFA) were examined before (6-8 d), during (9-11 d), and after separation (12-16 d). T3 concentrations in newborn control rabbits gradually increased from 0.6 ng/mL at postnatal 6 d to 1.0 ng/mL at postnatal 16 d, whereas those of T4 remained fairly constant (25 ng/mL) up to postnatal 14 d, when T4 gradually declined to 8 ng/mL. T3 values of DLS newborn rabbits did not differ from those of controls at postnatal 10 and 11 d, but were lower (P<0.05) at postnatal 12 d, while T4 concentrations in DLS animals increased, although not significantly, between postnatal 10 and 12 d compared to controls. Insulin concentrations in young control rabbits ranged between 0.6 and 1.0 mg/L in the early postnatal days, whereas those for leptin averaged 2-3 ng/mL. Insulin and leptin values in DLS newborn rabbits were lower (P<0.05) at postnatal 10 and 11 d, but thereafter rebounded to levels close to those of controls. Glycaemia showed a comparable trend in both groups, ranging between 170 and 190 mg/dL up to postnatal 14 d, but thereafter decreased (P<0.05) to values of 120-130 mg/dL independently of treatment. Concentrations of TG varied greatly from day to day around a mean value of 300 mg/dL, whereas those of FFA remained at approximately the same steady-state levels from postnatal 6 to 16 d, averaging 0.8 mM without any significant differences between groups. In conclusion, these findings confirm that newborn rabbits can cope with the metabolic stress of starvation associated with DLS by lowering insulin and leptin concentrations while maintaining those of thyroid hormones, an overall endocrine response which, together with temporary increase of glucorticoids, successfully maintains an adequate energy balance
Effects of aglepristone administration during the luteal phase on progesterone and LH concentrations of non-pregnant bitches
No full textIn the bitch, the mechanisms that regulate luteal function are still unclear. To investigate the role of progesterone on the gonadal axis the antiprogestinic aglepristone (Alizine Virbac, France) was administered to non-pregnant bitches during their luteal phase. Bitches were assigned to either control or treated groups. The first day of cytological diestrus was designed as day 0. On both days 21 and 22 of diestrus, control bitches (n = 4) received s.c. saline solution (0.3 ml/kg body weight) and treated ones
(n = 4) aglepristone (10 mg/kg body weight). From day 0 to day 70 of diestrus, blood samples were collected from each bitch twice a week to evaluate luteal function through plasma progesterone (P4) concentrations. On day 23, blood samples were obtained every 20 min for 4 h to evaluate the hypothalamic-pituitary function through plasma LH concentrations. The administration of aglepristone affected progesterone secretion
and shortened luteal phase of non-pregnant bitches. In fact,
treated bitches had a shorter luteal phase than controls and
complete luteolysis, arbitrarily defined as the failure of CL to
secrete progesterone so that blood levels fell below the 2.0 ng/ml, was observed on days 46.6 ± 11.4 and 66.3 ± 2.9
(p < 0.05), respectively. In treated bitches, the mean plasma LH concentrations under the curve were lower (p < 0.01) than in controls (0.29 and 0.42 ng/min, respectively). The antiluteotrophic action of aglepristone is likely because of the block of P4 receptors at hypothalmo–pituitary and/or ovarian levels
A study on the reproductive performance and physiological response of rabbit bucks fed on diets with two different mineral contents
No full textInfluence of different eCG doses on sexual receptivity and productivity of rabbit does
Full text link[EN] The aim of this study was to examine sexual receptivity and productivity of does injected 48 h before insemination with 8 or 25 IU of eCG (groups 8 and 25, respectively) in comparison with a control group (no injection, group 0). One hundred twenty four does were inseminated during 11 consecutive cycles (reproduction rythm: 35 d; inseminations: 4 d post partum and weaning: 28 d post partum). In comparison with the control group, eCG signifi cantly improves the receptivity of does (60.3 vs 80.5 and 79.8%; P<0.001), kindling rate (70.4 vs 80.9 and 79.4%; P=0.030) and the number of weaned rabbits/insemination (5.9 vs 7.1 and 7.1; P=0.008) for group 0, 8 and 25 respectively, during the whole experiment. eCG effi ciency is not obviously demonstrated for primiparous and non-lactating does. Authors conclude that only an 8 IU dose is able to improve 62% the productivity (measured as weaned rabbits per insemination) of multiparous and lactating does inseminated 4 d post partum.Theau-Clément, M.; Lebas, F.; Boiti, C.; G. Brecchia, G.; Mercier, P. (2010). Influence of different eCG doses on sexual receptivity and productivity of rabbit does. World Rabbit Science. 16(2). https://doi.org/10.4995/wrs.2008.62816
The different effects of linseed and fish oil supplemented diets on insulin sensitivity of rabbit does during pregnancy
No full textThis study investigates the effects of linseed (rich in ɑ-linolenic acid (ALA)) and fish oil (rich in eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)) supplementation on the insulin resistance of pregnant rabbits. Two months before insemination, the rabbits (15 animals/group) were fed different diets: commercial standard (group C), supplemented with 10% extruded linseed (group L), and 3% fish oil (group FO). The L group does showed both the highest feed intake before AI (P < 0.01) and the highest body weight (BW) throughout pregnancy (P < 0.001). The L does yielded less milk than the C does (P < 0.001); however, no differences were observed in either weight or size of litter at weaning. Regardless of diet, insulin concentrations and HOMA-IR values were higher during the first half of pregnancy (P < 0.001). Nevertheless, the L does showed higher mean insulin concentrations than FO rabbits (P < 0.01) and the lowest glucose clearance (P < 0.01) during pregnancy. On the other hand, pregnant FO rabbits showed the lowest glucose concentrations (P < 0.05) and the lowest Homeostasis model assessment values for insulin resistance (HOMA-IR, P < 0.05) as well as a faster restoration of baseline glucose levels following glucose load (P < 0.001). Before and during pregnancy, the BW of the rabbits was positively related to fasting sample- and tolerance test-derived indices of insulin resistance (P < 0.05) suggesting that a high pre-pregnancy BW predisposes to gestational insulin resistance. Linseed supplementation increased BW and predisposed to insulin resistance during pregnancy; whereas, fish oil improved insulin sensitivity without significant changes in BW
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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