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M Piagentini DC Silva CPF Dell'Aqua CF Moya‐Araujo VM Codognoto AA Ramos E Oba 《Reproduction in domestic animals》2017,52(3):355-358
The aim of this study was to investigate the effects of different concentrations of oral supplementation with selenium (Se) upon ram sperm parameters. Thirty rams managed in stall under intensive system were used and divided into five groups (six animals per group) as follows: control group (G1) mineral mixture supplementation without Se, group 2 (G2) mineral mixture supplemented with 5 mg/kg Se, group 3 (G3) supplemented with 10 mg/kg Se, group 4 (G4) supplemented with 15 mg/kg Se and group 5 (G5) supplemented with 20 mg/kg Se. For each group, there was an adjustment period of 14 days. The experimental period was 350 days. Every 56 days, the animals were weighed and semen samples were collected by electroejaculation. Semen analysis included volume, mass moviment, total motility, vigour, concentration and morphology. For plasmatic and acrosomal membrane integrity evaluation and mitochondrial membrane potential were used a combination of fluorescent probes. Differences between means values obtained by analysis of variance were verified by Tukey test with 5% probability. There was no statistical difference between treatment groups in relation to volume, mass moviment, total motility, vigour, concentration, plasma and acrosomal membrane integrity (p > .05). Sperm morphology was different between treatment groups, the G1 (0 mg of selenium) had the highest percentage of major defects (11.11 ± 1.11a; p < .05). It was concluded that selenium decrease the percentage of sperm defects and did not directly influence on ram sperm volume, mass moviment, total motility, vigour, concentration and membrane integrity. 相似文献
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CA Meza‐Herrera A Gonzalez‐Bulnes RT Kridli M Mellado CF Arechiga‐Flores H Salinas JM Luginbuhl 《Reproduction in domestic animals》2010,45(6):e495-e502
Puberty is the result of a dynamic interaction between genetic factors and environmental cues, all of which lead to the attainment of reproductive capacity. Thus, significant changes in hormone secretion occur from the pre‐pubertal to the pubertal stage. The objective of this review is to provide an update of some endocrine, physiological, metabolic and genetic concepts involved in the establishment of the hypothalamic‐hypophyseal‐gonadal axis function promoting the onset of the reproductive function during puberty. To achieve this purpose, basic aspects of the function of the hypothalamic‐hypophyseal‐gonadal axis, the control of the axis by neurotransmitters and the interaction between reproductive function and metabolic status will be considered. Finally, the role of the novel kisspeptin system and the GPR54 receptor as modulators of puberty will be considered, in addition to the hierarchical expression of the main genes acting as regulators of the onset of puberty. 相似文献
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RA Satrapa EM Razza ACS Castilho RAL Simões CF Silva T Nabhan MF Pegorer CM Barros 《Reproduction in domestic animals》2013,48(6):1043-1048
The IGF system is related to embryo quality. We aim to determine the effect of the heat stress on the mRNA expression of IGF1 and IGF2, IGFR1 and IGFR2, IGFBP2 and IGFBP4, and PAPPA in in vitro production (IVP) blastocysts from Nelore and Holstein after ovum pick up (OPU) to better understand the differences between these breeds. Oocytes from four Nelore and seven Holstein were collected in six OPU sessions. Following in vitro maturation and fertilization using six Nelore or Holstein sires, embryos were divided into control (cultured at 39°C) and heat stress (HS; exposed to 41°C for 9 h). Blastocysts were submitted to RNA extraction. The IGF1 expression was higher in blastocysts under HS in both breeds, and the expression of IGFBP2 and IGFBP4 was higher in Holstein blastocysts under HS. The high PAPPA expression and the low expression of IGFBP2 and IGFBP4 are associated with a more efficient degradation of IGFBPs, which results in greater IGF bioavailability in Nelore blastocysts and may contribute to the superior HS tolerance in Nelore, when compared to Holstein. 相似文献
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LCG Silva CF Lúcio GAL Veiga JA Rodrigues CI Vannucchi 《Reproduction in domestic animals》2009,44(S2):160-163
This study aimed to standardize signs and diagnostic criteria of respiratory function in newborn puppies delivered normally or after dystocia and caesarean operation. A total of 48 neonates were allocated into groups: eutocia (n = 20), dystocia (n = 8), caesarean (c)-section (n = 20). Neonatal health was assessed using the Apgar score and body temperature was determined at 0, 5 and 60 min after delivery. Venous blood gases (pO2 and SO2 ) was measured immediately and 60 min after delivery, and a thoracic radiograph was made between 0 and 5 min of life. The c-section group had significantly lower Apgar scores at birth and 5 min. Hypothermia was present at 5 min in the eutocia and c-section groups, and at 60 min in all groups. The eutocia group had an irregular respiratory pattern in 78% of puppies at birth, 27.7% at 5 min and 21% at 60 min compared with 87.5%, 62.5% and 12.5% of the pups in the dystocia group where there was irregular respiratory rhythm, moderate to intense respiratory sounds with agonic episodes. The c-section group had respiratory alterations in 70%, 45% and 16% of puppies at 0, 5 and 60 min, respectively. Radiographic abnormalities were present in 17% of the pups in the eutocia group, 25% of the pups in the dystocia group and 30% of the pups in the c-section group, respectively. The c-section group had significantly lower SO2 values at 60 min than at birth. All puppies had hypoxaemia, but a significant decrease was observed in the c-section group. Newborn puppies had tissue hypoxia and irregular respiratory pattern at birth. Caesarean-section puppies had lower vitality; however, all developed satisfactory Apgar scores at 5 min of life, regardless of the obstetric condition. 相似文献
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JC Monteiro JSA Gonçalves JA Rodrigues CF Lúcio LCG Silva MEOA Assumpção CI Vannucchi 《Reproduction in domestic animals》2009,44(S2):359-362
Poor sperm viability post-thaw has resulted in constant research into methods of cryopreservation of canine semen. One factor that may be involved in poor viability is sperm oxidative stress caused by excessive formation of reactive oxygen species. The present study was performed in order to evaluate the effect of different concentrations of ascorbic acid (AA) and glutathione (Glu) added to an extender for the freeze-thawing of dog sperm. Semen from five mature dogs was collected and frozen in two studies. Prior to and after freezing, sperm motility, morphology and membrane status were examined. In addition, sperm motility was examined up to 120 min after thawing to evaluate thermo-resistance. In study I, semen was collected twice from each dog. On both occasions, semen was divided into three aliquots: control, Glu 1 m m and Glu 5 m m . In study II, semen was collected twice and divided into three aliquots; control, AA 50 μ m and AA 250 μ m . Initial sperm motility was significantly higher in sperm diluted with AA 50 μ m ; sperm longevity, however, measured by a thermal-resistance test (TRT), was higher for Glu treatments. Higher concentration of Glu produced significant improvement in TRT and membrane status, whereas higher concentration of AA had a negative impact in sperm longevity. Antioxidant supplementation to semen freezing extenders improved semen quality post-thaw. Moreover, Glu had the most beneficial effect when supplemented at 5 m m . 相似文献