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Alter do Chão, Portugal

Guimaraes T.,Abel Salazar Biomedical Sciences Institute | Guimaraes T.,University of Porto | Lopes G.,Abel Salazar Biomedical Sciences Institute | Lopes G.,University of Porto | And 10 more authors.

Freezability of equine semen may be influenced by microorganism population of semen. The objective of this study was to verify the effect of single-layer density gradient centrifugation (SLC) of fresh semen before cryopreservation on semen's microbial load (ML) and sperm cells kinetics after freezing-thawing. For that, one ejaculate was collected from 20 healthy stallions and split into control (C) samples (cryopreserved without previous SLC) and SLC samples (subjected to SLC). Semen cryopreservation was performed according to the same protocol in both groups. Microbial load of each microorganism species and total microbial load (TML) expressed in colony-forming units (CFU/mL) as well as frozen-thawed sperm kinetics were assessed in both groups. Additional analysis of the TML was performed, subdividing thefrozen-thawed samples in "suitable" (total motility ≥ 30%) and "unsuitable" (total motility < 30%) semen for freezing programs, and comparing the C and SLC groups withinthese subpopulations. After thawing, SLC samples had less (P < 0.05) TML (88.65 × 102 ± 83.8 × 102 CFU/mL) than C samples (155.69 × 102 ± 48.85 × 102 CFU/mL), mainly due to a reduction of Enterococcus spp. and Bacillus spp. A relationship between post-thaw motility and SLC effect on ML was noted, as only in samples with more than 30% total motility was ML reduced (P < 0.05) by SLC (from 51.33 × 102 ± 33.26 × 102 CFU/mL to 26.68× 102 ± 12.39 × 102 CFU/mL in "suitable" frozen-thawed semen vs. 240.90 × 102 ± 498.20 × 102 to 139.30 × 102 ± 290.30 × 102 CFU/mL in "unsuitable" frozen-thawed semen). The effect of SLC on kinetics of frozen-thawed sperm cells was negligible. © 2015 Elsevier Inc. Source

Fradinho M.J.,CIISA | Barbosa M.,Fundacao Alter Real | Vila-Vicosa M.J.C.,University of Evora | Rosa A.,Qta. da Lagoalva de Cima | And 4 more authors.
EAAP Scientific Series

In the foal, the relationship between skeletal development and growth rate has been studied. Bone markers as osteocalcin (OC) and bone alkaline phosphatase (BAP) are known to reflect bone metabolism and, in humans and rodents, leptin was also involved in the regulation of bone mass. Quantitative ultrasonography could provide information on bone quality as it reflects mineral density and bone mechanical properties. The main objective of this study was to evaluate the relationship between growth rate and (1) bone biochemical markers; (2) leptin, and (3) ultrasound measurements of the third metacarpal bone in the young Lusitano horse, up to one year of age. Thirty three Lusitano foals from four stud farms were monitored every two months from birth to one year of age. Animals were weighed and blood samples were collected for analysis of BAP, OC and leptin. Measurements of speed of sound (SOS) on the mid section of the right third metacarpal bone (MC III) (dorsal and lateral aspects) were performed. Individual growth curves were adjusted and the derivatives as the instantaneous growth rate (IGR) were calculated for each sampling time. Pearson's correlation coefficients were used to examine the variables relationships. Effects of group and age were evaluated. Positive correlations were found between IGR and plasma leptin (0.26; P<0.001), OC (0.67; P<0.0001) and BAP (0.34; P<0.0001). The negative correlation between IGR and lateral SOS MCIII measurements (-0.47; P<0.0001), confirm its increase with age. Negative correlations were observed between SOS lateral measurements and OC (-0.38; P<0.0001) and BAP (-0.20; P<0.05). A correlation between OC and BAP was also observed (0.21; P<0.01). Differences on OC and BAP were detected between groups. This study suggests that bone markers and SOS measurements could be influenced by different growth rates in the Lusitano foal. Source

Fradinho M.J.,University of Lisbon | Correia M.J.,Fundacao Alter Real | Beja F.,Fundacao Alter Real | Perestrello F.,Companhia das Lezirias | And 3 more authors.
EAAP Scientific Series

Most Lusitano stud farms in Portugal are based in extensive grazing systems. In these systems, mares and foals are bred outdoors throughout the year, being pasture an important part of their diets. However, grass production is highly dependent on Mediterranean climatic conditions, with hot and dry summers. Therefore, a field study was conducted in order to evaluate the effects of foaling season on growth and development of the Lusitano suckling foal. One hundred and eight foals from four stud farms (A, n=39; B, n=33; C, n=12; D, n=24) were monitored from birth to six months of age, throughout three (A and B) and two (C and D) years. Monthly, foals were weighed (BW) and withers height (WH), girth (G) and cannon circumference (CC) were measured. According to birth date, two main foaling seasons were considered: February-March and April-May. A mixed linear model allowing for repeated measures on time was used to assess the effect of foaling season, stud farm, gender and their interactions on body weight, withers height, girth and cannon circumference. Quadratic effect of time was included in the model. The effect of foaling season was significant for withers height and girth (P<0.05) with higher values for foals born in February-March. Differences between stud farms were observed (P<0.001) for BW, WH, G and CC, which are probably linked with feeding options and pasture quality. The effect of gender was only significant on CC (P<0.05) with lower values registered in fillies. In the present study, foals born in February-March seem to have better development performances compared with foals born in April-May. Since pasture production and quality usually decreases from the end of May, these results suggest that April-May foaling mares may need a supplement to dry pasture, in order to support milk production and to promote an adequate foals' growth and development. Source

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