Impacts of trace element supplementation on productive/reproductive postpartum performances of grazing dairy heifers from volcanic soils

This study has been designed to evaluate the effect of trace elements (TE) on the reproductive and productive performances of postpartum Holstein Friesian heifers, fed on pasture with origin on volcanic soils, poor in TE. Twenty-six heifers pregnant were divided into two groups: experimental (EG) and control (CG) groups (n=13, each group). For animals belonging to the EG, two intra-ruminal capsules with TE were administrated 60 days before partum, while in the CG, no boluses were administered. All animals' blood was collected weekly to assess progesterone levels by the ELFA technique for 11 weeks after partum. TE were evaluated on blood by AAS when the experience started, on the day of delivery, and after 60 days. Before calving, no statistical differences were observed between groups for the trace elements, although it has been noticed that heifers had deficiencies in Selenium, Copper, and Iodine. On the calving day and 60 days after, a statistical increase (p<0.05) in serum Copper and Selenium was observed in the animals belonging to the EG. For the other TE, no statistical differences were observed. Concerning reproductive characteristics, the EG, at five weeks postpartum, 70% of the cows were cyclic, while in the CG in the same period, 33% of animals showed signs of ovarian activity. At the level of productive parameters, no differences were observed between groups. The results obtained by the present study allow concluding that, under our experimental conditions, the administration of trace elements, in addition to reducing postpartum anestrus, increases the quality of the corpus luteum in the postpartum period of heifers.

Effect of trans-10, cis-12 isomer of conjugated linoleic acid on boar semen quality after cryopreservation

The use of frozen semen in pig industry is limited by problems with viability and fertility compared to cooled semen. Part of the decrease in motility and fertility, associated to cryopreservation, may be due to oxidative damage from excessive formation ofreactive oxygen species (ROS). Frozen thawed boar spermatozoa are still considered suboptimal due to the low conception rates and smaller litters after artificial insemination. The relatively low fertility of frozen thawed boar semen is associated with many factors including cytotoxicity of the cryoprotectant, osmotic stress, injuries due to ice formation during freezing and thawing, cold shock damages and even inter and intra variations present among boars. Therefore, this study was conducted to determine the impact of conjugated linoleic acid (trans-10,cis-12; CLA) supplementationin the cryopreservation extenderfrozen-thawed boar on semen quality parameters. Semen was collected from three boars (three ejaculates per boar) which were subjected to cryopreservation, without any supplementation (control) or supplemented with 50 μm CLA, and then the semen was frozen using a controlled rate freezer. Before freezing, and after thawing, the sperm motility was assessed, microscopically and viability and acrosome integrity were assessed using the flow cytometry technique. Regarding live spermatozoa, no significant differences (P > 0.05) were observed among treatments.

Effect of trans-10, cis-12 isomer of conjugated linoleic acid on boar semen quality after cryopreservation

The use of frozen semen in pig industry is limited by problems with viability and fertility compared to cooled semen. Part of the decrease in motility and fertility, associated to cryopreservation, may be due to oxidative damage from excessive formation ofreactive oxygen species (ROS). Frozen thawed boar spermatozoa are still considered suboptimal due to the low conception rates and smaller litters after artificial insemination. The relatively low fertility of frozen thawed boar semen is associated with many factors including cytotoxicity of the cryoprotectant, osmotic stress, injuries due to ice formation during freezing and thawing, cold shock damages and even inter and intra variations present among boars. Therefore, this study was conducted to determine the impact of conjugated linoleic acid (trans-10,cis-12; CLA) supplementationin the cryopreservation extenderfrozen-thawed boar on semen quality parameters. Semen was collected from three boars (three ejaculates per boar) which were subjected to cryopreservation, without any supplementation (control) or supplemented with 50 μm CLA, and then the semen was frozen using a controlled rate freezer. Before freezing, and after thawing, the sperm motility was assessed, microscopically and viability and acrosome integrity were assessed using the flow cytometry technique. Regarding live spermatozoa, no significant differences (P > 0.05) were observed among treatments.(AU)