Prostaglandin F2α and its interference on pregnancy rates in heifers

The present study aimed to evaluate the pregnancy rate of Nellore and Crossbred heifers submitted the induction of puberty with prostaglandin PGF2α. Control group (n=80), heifers were submitted to a fixed-time artificial insemination protocol (FTAI), without pre-exposure to any hormone, induction group (n=80), Nellore (n=80) and Crossbred (n=80) females were submitted to two applications of prostaglandin PGF2α prior to the FTAI protocol, 24 days before the beginning of the protocol (D-24) and twelve days before the start of the protocol (D-12). All heifers were aged between 12 and 14 months, with an average weight of 311 kg and body condition score 3. FTAI protocol, both groups were performed: on day 0 (D0), there was the application of estradiol benzoate and insertion of the intravaginal implant with progesterone. On day eight (D8), implant was removed and equine chorionic gonadotropin, prostaglandin, and estradiol cypionate were applied. On day 10, artificial insemination was performed. Thirty days after FTAI, pregnancy was diagnosed by transrectal ultrasound. The animals were individually weighed to verify the interaction between weight and pregnancy rates. For statistical analysis SAS 9.3 software was used. The results were considered different with a significance level of 5%. For animals in the Induction group, pregnancy rates at 30 days after FTAI (P˃0.05) were 57.5% (46/80) for Nellore heifers and 52.5% (42/80) for Crossbred heifers. Control group, heifers had a pregnancy rate of 60% (48/80) (P˃0.05). No interaction was observed between heifer weight and conception rate in the FTAI, regardless of the induction treatment (P=0.1897). Furthermore, there was no difference in the pregnancy rate between Nellore (P=0.5389) and Crossbred females (P=0.4425), which were submitted to application of PGF2α before starting the FTAI protocol. Thus, it could be concluded that there was no difference in the pregnancy rate with the induction of puberty using the PGF2α

Action of Cholesterol-Loaded Cyclodextrin on Viability of Ram Semen

Background: Studies report that cyclodextrins have the property of carrying cholesterol to the membrane, but in some cases can also remove this cholesterol from the plasma membrane. The mechanism of action of CLC is not well understood, however, it seems to involve sperm protection during the freezing and thawing process. Studies show that its use enhancing increased osmotic tolerance and reduced premature sperm capacitation reaction. In this sense, studies report that cyclodextrins have the property of carrying cholesterol to the membrane, but in some cases can also remove this cholesterol from the plasma membrane. Improvements were reported in the sperm parameters of buffaloes, bulls, stallions and sheep. Ram naturally present less lipids in their membrane, on average 27%, while bulls have 31%, rabbits 62%, and humans 50%. The aimed of the present study was to evaluate the use of cholesterol-loaded cyclodextrin (CLC), a commercial diluent, in the kinetics and viability of frozen and thawed ram spermatozoa. Materials, Methods & Results: Five ejaculates, from five rams of Dorper breed were collected and divided into three groups: control, 1 mg CLC and 2 mg CLC. Semen was diluted in different concentrations of CLC (0, 1, and 2 mg/120×106 spermatozoa), and incubated at room temperature (21°C) for 10 min. Samples were conditioned in 0.5 mL straws and incubated at 5°C for 4 h, exposed to LN2 vapor for 10 min and storing a cryogenic container. The parameters as spermatic kinetics, plasma membrane, acrosomal membrane (MPAI, %), and intracellular levels of superoxide anion (O2-) were evaluated. Sperm progressive motility (PM), rapid spermatozoa percentage (RAP), linearity (LIN, %), average path velocity (VAP, μm/s) and MPAI (%) were more satisfactory with the use of 1 mg compared to 2 mg (P < 0.05). In addition, 1 mg CLC showed decreased levels of superoxide anion formation (O2-), a free radical detrimental to spermatozoa (P < 0.05). The use of 2 mg of CLC reduce VAP (P < 0.05) and did not have any beneficial effect on the evaluated parameters. Discussion: Authors did not observe improvement in the parameters of progressive motility when using 1 mg of CLC in goat semen and 2 mg in bull semen with the slow freezing protocol. This differs from our work, as we found that 1 mg of CLC improved the PM parameters, but not at the concentration of 2 mg CLC. Additionally, authors verified that cyclodextrin at 3 mg concentration was effective in protecting the sperm against the deleterious effects of H2O2. They obtained superior plasma membrane motility, viability, and integrity of the CLC-treated samples compared to the control group. The superoxide anion (O2-) is a free radical formed from molecular oxygen by the addition of an electron. It is generated spontaneously, mainly in the membrane of the mitochondria, by the respiratory chain and by flavoenzimes, lipoxygenases, and cicloxygenases. In our study, we found a difference between the study group with 1 mg CLC and the control group. Thus, we suggest that CLC may have a beneficial effect in stabilizing the sperm plasma membrane. Use of CLC at a concentration of 1 mg was found to be effective for the improvement of parameters of sperm progressive motility, rapid sperm percentage, and plasma and acrosomal membrane integrity. In addition, the study group with 1 mg of CLC showed decreased levels of superoxide anion formation, a free radical detrimental to spermatozoa

Biópsias endometriais seriadas em vacas Nelore (Bos taurus indicus) durante o ciclo estra

Endometrial histologycal alterations were evaluated from repeated collection of uterine samples in Nelore (Bos taurus indicus) during the estrous cycle. Sixteen adult cows with a synchronized estrous cycle were used. The endometrial samples were collected in DO (day zero; ovulation day), D5 (day five), D9 (day nine) and D13 (day thirteen) of the estous cycle. Before the samples collections, we evaluated the ovary and the uterus by transrectal ultrasonography in all the animals. The mononuclear infiltrate was predominant, however their intensity wasn’t ranged throughout the estrous cycle, isn’t representing a direct consequence of the biopsies (P > 0.05). Intensity of polymorphonuclear infiltrate varied between harvests, being absent in the first and last sample (P 0,05). A intensidade de infiltrado polimorfonuclear variou entre as colheitas, sendo ausente na primeira e na última amostra (P < 0,05). Assim, pôde-se concluir que a biópsia endometrial em vacas é uma técnica adequada para a avaliação da higidez uterina

Mechanical properties of timber deteriorated by beetles in ancient buildings: an experimental analysis

The purpose of this study is to analyse the loss of physical-mechanical properties of pine wood from old buildings (100 to 200 years old) deteriorated by wood boring beetle (Anobium punctatum, De Geer) and aims to contribute to the safety assessment of structural elements in buildings. The effect of degradation can be considered by assuming the reduction of cross-section properties in case of Anobium punctatum degradation, since the galleries formed within the wood are usually surrounded by a considerable amount of sound wood. In this study, a new methodology was developed for qualitative estimation of degradation levels, which was promising. They were then correlated with results of compression tests parallel to the fibers in specimens with 30×30×90 mm: compressive strength, modulus of elasticity and plastic extension. It has been found that, even at relatively important levels of degradation, the loss of properties is small to moderate

Adding Motility Stimulants to Improve Freezing of Buffalo Sperm Recovered from Epididymal Cauda

The cryopreservation of epididymal sperm is important to preserve genetic material from valuable buffalo bulls. This study evaluated the viability of post-thawed sperm samples recovered from the epididymal cauda adding motility inductors. For that, were used epididymides from eight Murrah buffaloes with 18 months of age. Semen samples were submitted to three different conditions: (CT - control) without adding medium, (SPERM) adding Sperm Talp medium, and (FERT) adding Fert Talp medium. Immediately after slaughter, both testicles from each animal were collected and transported at 4 degrees C at maximum six hours interval. In laboratory, the removed epididymides was flushed to obtain sperm and diluted in the freezing extender. Each buffalo sperm were divided and fractions were submitted to all conditions (CT, SPERM and FERT). Semen doses were frozen at -196 degrees C. CT, SPERM and FERT post-thawing results were 13.63 +/- 8.91, 38.77 +/- 8.91 and 42.83 +/- 8.91 for total motility, 7.30 +/- 8.74, 24.87 +/- 8.74 and 29.70 +/- 8.74 for progressive motility, 6.04 +/- 0.92, 6.74 +/- 0.92 and 6.93 +/- 0.92 for percentage of rapid cells (P < 0.05). In conclusion, diluted semen supplementation with Sperm or Fert talp increases the motility of cauda epididymal sperm of buffalo bulls

Comparison of Botu-bov and Tris as Freezing Extenders of Buffalo Sperm Recovered from Epididymal Cauda

Valuable genetic material can be preserved by the cryopreservation of epididymal sperm. This study evaluated the viability of pre-freezing and post-thawed sperm samples recovered from the epididymal cauda of buffaloes. Epididymides from eight Murrah buffaloes with 18 months of age were used. Semen samples were diluted in two different freezing extenders: Botu-bov (BB) and Tris (TRIS). Immediately after slaughter, both testicles from each animal were collected and transported at 4 degrees C for six hours interval. In laboratory, the removed epididymides were flushed to obtain sperm and the fractions were diluted in both freezing extenders (BB and TRIS). Semen doses were analyzed before and after frozen at -196 degrees C. BB and TRIS pre-freezing results were 38.54 +/- 22.33%(b) and 14.17 +/- 12.78%(a) for total motility (TM), 25.00 +/- 16.12(a) and 9.44 +/- 9.11(a) for progressive motility (PM), 7.21 +/- 0.98(a) and 5.09 +/- 2.65(a) for percentage of rapid cells (RAP), 91.08 +/- 12.53(b) and 63.33 +/- 31.47(a) for velocity of trajectory (VAP), 73.54 +/- 20.17(b) and 49.50 +/- 9.11(a) for linear progressive velocity (VSL), 172.21 +/- 24.55(a) and 116.94 +/- 59.48(a) for curvilinear velocity (VCL), respectively (P < 0.05). BB and TRIS post-thawing results were 42.25 +/- 21.50(b) and 17.62 +/- 19.46(a) for TM, 27.25 +/- 24.86(a) and 18.00 +/- 13.68(a) for PM, 7.35 +/- 0.98(a) and 6.26 +/- 1.13(a) for RAP, 91.42 +/- 16.86(a) and 75.96 +/- 13.17(a) for VAP, 67.96 +/- 12.13(a) and 60.04 +/- 10.42(a) for VSL, 177.54 +/- 23.53(b) and 141.29 +/- 24.97a for VCL, respectively (P < 0.05). The sperm recovered from the epididymal cauda, after 6 h storage of epididymides at 5 degrees C ensures sperm preservation demonstrating that the diluent Botu-bov had higher total motility both pre-and post-freezing when compared with TRIS. Additionally, the sperm frozen with the diluent Botu-bov showed higher values of VSL at post-thawing. These findings may reflect in improvement of conception rates