Entity

Time filter

Source Type

Zaragoza, Spain

Santolaria P.,University of Zaragoza | Vicente-Fiel S.,University of Zaragoza | Palacin I.,University of Zaragoza | Fantova E.,UPRA Grupo Pastores | And 3 more authors.
Animal Reproduction Science | Year: 2015

This study was designed to evaluate the relevance of several sperm quality parameters and sperm population structure on the reproductive performance after cervical artificial insemination (AI) in sheep. One hundred and thirty-nine ejaculates from 56 adult rams were collected using an artificial vagina, processed for sperm quality assessment and used to perform 1319 AI. Analyses of sperm motility by computer-assisted sperm analysis (CASA), sperm nuclear morphometry by computer-assisted sperm morphometry analysis (CASMA), membrane integrity by acridine orange-propidium iodide combination and sperm DNA fragmentation using the sperm chromatin dispersion test (SCD) were performed. Clustering procedures using the sperm kinematic and morphometric data resulted in the classification of spermatozoa into three kinematic and three morphometric sperm subpopulations. Logistic regression procedures were used, including fertility at AI as the dependent variable (measured by lambing, 0 or 1) and farm, year, month of AI, female parity, female lambing-treatment interval, ram, AI technician and sperm quality parameters (including sperm subpopulations) as independent factors. Sperm quality variables remaining in the logistic regression model were viability and VCL. Fertility increased for each one-unit increase in viability (by a factor of 1.01) and in VCL (by a factor of 1.02). Multiple linear regression analyses were also performed to analyze the factors possibly influencing ejaculate fertility (N=139). The analysis yielded a significant (P< 0.05) relationship between sperm viability and ejaculate fertility. The discriminant ability of the different semen variables to predict field fertility was analyzed using receiver operating characteristic (ROC) curve analysis. Sperm viability and VCL showed significant, albeit limited, predictive capacity on field fertility (0.57 and 0.54 Area Under Curve, respectively). The distribution of spermatozoa in the different subpopulations was not related to fertility. © 2015 Elsevier B.V. Source


Fathallah S.,French National Institute for Agricultural Research | Alabart J.L.,CSIC - Centro de Investigacion y Tecnologia Agroalimentaria | Bodin L.,French National Institute for Agricultural Research | Jimenez-Hernando M.A.,INIA | And 4 more authors.
ITEA Informacion Tecnica Economica Agraria | Year: 2016

The effects of the BMP15 gene, located on the X chromosome, on mean prolificacy and its variability, were estimated in the Rasa Aragonesa sheep population through the analysis of 918,956 lambing records from ewes of different genotypes (FecXR or ROA® heterozygous ewes; and non-carrier ewes). Threshold models including or not the gene effect were first run to determine the effect of the BMP15 genotype and its importance in the total genetic variability of prolificacy. Two other models were also run to estimate the interaction between the BMP15 genotype and the polygenic background, as well as the effect of the genotype on the variability of prolificacy. All the models were run using the ASReml software. The effect of the presence of the ROA® allele of the BMP15 gene on the mean prolificacy was 0.32 extra lambs per lambing. Due to the selection on prolificacy performed during many years in this population ignoring the presence of this major gene, animals carrying the mutation were found to have lower remaining polygenic estimated breeding values than non-carrier animals, and there was no interaction between the BMP15 genotype and the polygenic background. Although the interaction between the genotype and the set of thresholds was significant, the resulting between-genotypes difference of variance of prolificacy on the observed scale, at a similar mean litter size, was very low and not relevant. © 2016, Asociacion Interprofesional para el Desarrollo Agrario. All Rights Reserved. Source


Palacin I.,University of Zaragoza | Yaniz J.L.,University of Zaragoza | Fantova E.,UPRA Grupo Pastores | Blasco M.E.,UPRA Grupo Pastores | And 3 more authors.
Animal Reproduction Science | Year: 2012

Field results of 18,328 cervical artificial inseminations (AI) with cooled semen in Rasa Aragonesa meat sheep under field conditions in north-eastern Spain AI were analyzed. Logistic regression procedures were used including fertility at AI as the dependent variable (measured by lambing, 0 or 1) and year, month of AI, farm, hours between extraction and insemination, number of ewes inseminated in a set of AI, parity, lambing-treatment interval, total number of synchronization treatment per ewe, inseminating ram and AI technician as independent factors. Previous parturitions, lambing-AI interval, month, farm, inseminating ram and technician were factors with significant impact on AI fertility. Based on the odds ratio, the likelihood of pregnancy decreased: in ewes with more than five previous parturitions (by a factor of 0.87, 0.79 and 0.66 for the 6th, 7th and ≥8 parturitions, respectively); in ewes with lambing-AI interval higher than 240 days (by a factor of 0.8); and for inseminations performed during the spring period, (March, April, May and June, 0.70, 0.76, 0.66, and 0.76, respectively). We noted a higher fertility in seven inseminating rams (odds ratios between 1.4 and 1.7) and lower in two rams (odds ratios between 0.6 and 0.7). Of the 17 AI technicians, two were related to fertilities improved by odds ratio of 1.6, and 1.30, whereas two technicians were attributed fertility rates reduced by odds ratios of 0.68 and 0.40. These findings should be taken into account to evaluate the AI technique performance and make decisions to enhance fertility results. © 2012 Elsevier B.V. Source


Vicente-Fiel S.,University of Zaragoza | Palacin I.,University of Zaragoza | Santolaria P.,University of Zaragoza | Fantova E.,UPRA Grupo Pastores | And 3 more authors.
Animal Reproduction Science | Year: 2014

The aim of the present study was to investigate whether differences in field fertility of rams are reflected in differences in several sperm quality parameters. Ejaculates from 8 adult rams, 4 with high and 4 with low field fertility, were collected weekly using an artificial vagina over 6 consecutive weeks. Analyses of sperm motility by computer-assisted sperm analysis (CASA), membrane integrity by acridine orange-propidium iodide combination and sperm DNA fragmentation using the sperm chromatin dispersion test (SCD) were performed at 0, 3, 6 and 24. h of incubation at 37. °C. Sperm nuclear morphometry was also determined at 0. h by computer-assisted sperm morphometry-fluorescence (CASMA-F). Sperm viability and most CASA sperm motility parameters were higher at 0, 3 and 6. h in the high fertility rams. These rams had also a higher sperm nuclear area, perimeter and length (P< 0.05) determined by CASMA-F. Significant differences between high and low fertility groups were also found in the dynamics in DNA fragmentation, with significant differences at 6. h (14.42. ±. 1.40 and 20.27. ±. 1.77, respectively, P< 0.05) and at 24. h (22.32. ±. 2.03 and 31.24. ±. 2.54, respectively, P< 0.01). It was concluded that high and low fertility rams present clear differences in several sperm quality parameters. This opens up the possibility of selection of males for artificial insemination based on sperm quality data. © 2014 Elsevier B.V. Source


Santolaria P.,University of Zaragoza | Yaniz J.,University of Zaragoza | Fantova E.,UPRA Grupo Pastores | Vicente-Fiel S.,University of Zaragoza | Palacin I.,University of Zaragoza
International Journal of Biometeorology | Year: 2013

This study was carried out to examine the impact of several climate variables on the pregnancy rate after cervical artificial insemination (AI) of Rasa Aragonesa ewes. Data were derived from 8,977 inseminations in 76 well-managed flocks performed during the first month of the breeding season (July to October). The following data were recorded for each animal: farm, year, month of AI, parity, lambing-treatment interval, inseminating ram, AI technician, and climatic variables such as mean, maximum and minimum temperature, mean and maximum relative humidity, rainfall, and mean and maximum temperature-humidity index (THI) for each day from day 12 before AI to day 14 post-AI. Means were furthermore calculated for the following periods around AI (day 0): -12 to 0, -2 to 0, AI day, 0 to 2, and 0 to 14. Logistic regression analysis indicated that the likelihood of pregnancy decreased when maximum temperature in the 2 days prior to AI was higher than 30 °C (by a factor of 0.81). Fertility was also lower for primiparous ewes and in multiparous ewes with more than five previous parturitions. Other factors with significant impact on fertility were flock, technician, inseminating ram, and a lambing-AI interval longer than 240 days. It was concluded that the 2 days prior to AI seems to be the period when heat stress had the greatest impact on pregnancy rate in Rasa Aragonesa ewes. © 2013 ISB. Source

Discover hidden collaborations