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Cryopreservation is associated with the production of reactive oxygen species which lead to lipid peroxidation of sperm membranes. The objective was to determine an alpha-tocopherol concentration capable of improving the quality of cryopreserved porcine semen. Boar spermatozoa frozen with 200, 500 or 1000 microg/mL alpha-tocopherol were thawed and incubated at 37 degrees C for 4 h. Routine parameters of semen quality, susceptibility to lipid peroxidation 2-thiobarbituric acid (TBARS) and oxygen uptake were evaluated. Motility was higher (P<0.05) in samples treated with different concentrations of alpha-tocopherol up to 2 h of incubation. Viability and acrosome integrity significantly decreased during incubation (no significant differences between treatments). Two hundred micrograms per milliliter alpha-tocopherol protected spermatozoa against lipid peroxidation during incubation, but 1000 microg/mL failed to protect after 2 h of incubation. There was a negative association between TBARS and motility, suggesting that lipid peroxidation affected sperm motility. Both control and 200 microg/mL alpha-tocopherol samples preserved the capacity to generate oxidative energy up to 1 h of incubation. The addition of 200 microg/mL alpha-tocopherol in the semen extender could be useful to preserve boar spermatozoa against the oxidative stress generated by cryopreservation.

The incorporation of fibre in the diet of pregnant sows improves the performance during pregnancy and increases voluntary consumption during lactation. Hydroponic green forage (HGF) constitutes a method of cultivation without soil in controlled environmental conditions. The aim of this study was to evaluate the impact of the supplementation with HGF in lactating sows on productive performance and to investigate the metabolic state through the analysis of different biochemical parameters. Twelve sows of the Porcine Productive Unit of the Faculty of Veterinary Sciences were randomly assigned to 2 feeding groups: control (conventional diet) or HGF (hydroponic green forage diet, conventional diet supplemented with HGF) from 7 days prepartum until day 28 postpartum. Productive parameters in sows (weaning-to-oestrus interval and back fat thickness) and in the litter (number of piglets born and weaned, and piglet weight) were evaluated. The effect of the diet in the metabolism of the sows was evaluated by biochemical parameters (total plasma proteins, albumin, glucose, urea and creatinine). Supplementation with HGF did not significantly affect the litter size nor productive parameters but produced a higher weight of piglets at day 60. Although lactation affected some biochemical parameters, no substantial negative consequences of the HGF supplemented diet were observed. Our results suggest that the use of HGF could be an option to take into account in porcine production with economic and environmental benefits. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the participation of lactate dehydrogenase (LDH) enzyme in capacitation and acrosome reaction in porcine sperm by determining its enzymatic activity and the effect of its inhibition on these processes. Semen samples, from four crossbred boars (Pietrain x Yorkshire) of proven fertility, 1-1.5 year of age, were analysed. The enzymatic activity of LDH was determined spectrophotometrically in extracts from fresh and cryopreserved, with and without α-tocopherol, porcine sperm. Besides, sperm suspensions were incubated in the presence of bicarbonate (40 mM), a well-known capacitation inducer, follicular fluid (30%), as an acrosome reaction inducer, and different concentrations of sodium oxamate, a specific inhibitor of the enzyme. The activity of LDH in enzymatic extracts of fresh, cryopreserved without or cryopreserved with α-tocopherol porcine sperm were 3.85±0.27, 0.7±0.04 and 1.73±0.23 U/1010 sperm, respectively (p<0.05). The addition of sodium oxamate inhibited capacitation or acrosome reaction in fresh and cryopreserved with or without α-tocopherol porcine sperm, affecting (at different concentrations) motility and sperm viability (P<0.05). Obtained results demonstrate the participation of LDH in bicarbonate-induced capacitation and follicular fluid-induced acrosome reaction in fresh and cryopreserved porcine sperm. [ABSTRACT FROM AUTHOR]