Edilson Soares Lopes Júnior

Efeito de diferentes concentrações de melatonina em espermatozoides de carneiros sobre estresse oxidativo após criopreservação

The aim was to evaluate the effect of adding different concentrations of melatonin in ram semen diluted after cryopreservation. Ten ejaculates were collected0 from three adult ram (n=30) by means of artificial vagina for sheep. The collected samples were diluted in Tris-egg yolk, to a final concentration 200x106 sptz/mL kept in water bath at 32°C, and melatonin added as treatments: control; 100pM; 100nM; 100μM and 1mM melatonin. Then, the samples were cooled in a cold chamber at 5°C for two hours, in straws of 0.5mL and sealed. They were stored under the liquid nitrogen vapor for 15 minutes to 8cm of liquid blade and frozen with liquid nitrogen. Samples were analyzed for sperm motility, membrane integrity, acrosomal membrane, mitochondrial activity, oxidative stress and quantification of the binding capacity. The variables were subjected to analysis of variance and the means were compared by Tukey test at 5% probability. The total and progressive motility of thawed sperm were higher in samples treated with 100pM melatonin (62.99 and 45.07%, respectively; P<0.05) when compared to other treatments. The addition of different concentrations of melatonin in semen diluted with the exception of 1mM concentration, a higher percentage of cells with intact plasma membrane, as compared with the control (P<0.05). The percentage of sperm with acrosome membrane integrity was higher in the semen with 100pM melatonin (P<0.05) than the other treatments. The high mitochondrial activity was higher in spermatozoa treated with 100pM melatonin (69.30%; P<0.05). Addition of 100nM melatonin reduced the amount of TBARS after cryopreservation (2.84, P<0.05) when compared with the other treatments. After thawing, the number of sperm which bind to the perivitelline membrane was higher in the melatonin treated with 100pM (155,73; P<0.05). Therefore, melatonin addition the semen diluted can be useful to enhance the cryopreservation of sheep semen, improving fertilization rates through artificial insemination.

Retorno da atividade ovariana pós parto em cabras leiteiras suplementadas com diferentes níveis de energia

This study aimed to evaluate the return of post partum ovarian activity in dairy goats supplemented with different levels of energy during the dry period in the semi-arid region of Pernambuco. Twenty-four animals were allocated into four treatments of six animals each: Control, consisting of goats that had access to pasture and only received 4 kg of fresh palm, and three groups with isoproteic supplementation (20% Crude Protein), ranging in TDN content of 65%, 75% and 85%. The daily milk yield showed a linear growth behavior (P 0.05). We concluded that the supplementation with different levels of energy promoted a positive effect, as increased productive parameters and reduced the number of days for the reestablishment of the reproductive parameters postpartum; for instance, uterine involution, return to estrus and consequently return of ovarian activity postpartum.

Fatores meteorológicos sobre a atividade reprodutiva de cabras leiteiras na época seca do semiárido pernambucano

The heat stress conditions with reference to meteorological and individual factors were investigated, and the influence of this condition on the reproductive activity of undefined breed of goats (SPRD), calved during the dry period. In all, 24 animals were used, divided into four treatments: control group, consisting of goats that had access only to the pasture and palm in nature and 3 groups through supplementation with concentrated isoproteic 20% crude protein (CP), varying the total digestible nutrients (TDN) content of 65, 75 and 85%. Data were expressed as mean ± standard deviation. The meteorological factors were observed by index of temperature of black globe and humidity (ITGU) and the physiological through respiratory (RF) and cardiac frequencies (CF); cutaneous (CT) and rectal temperatures (RT) and analysed in factorial scheme. Statistical differences were found in the respiratory and cardiac frequencies, showed an interaction between the month and times of observation. The uterine involution, did not show differences between treatments (p > 0.05). The return to estrus tended to be faster in groups 85 and 75% than in other groups. There was no negative influence of mild heat stress, indicated by climatic factors (ITGU) and the individual factors on the reproductive activity of goats SPRD.