RESUMEN
The optimization of processes associated with artificial insemination (AI) is of great importance for the success of the pig industry. Over the last two decades, great reproductive performance has been achieved, making further significant progress limited. Optimizing the AI program, however, is essential to the pig industry's sustainability. Thus, the aim is not only to reduce the number of sperm cells used per estrous sow but also to improve some practical management in sow farms and boar studs to transform the high reproductive performance to a more efficient program. As productivity is mainly influenced by the number of inseminated sows, guaranteeing a constant breeding group and with healthy animals is paramount. In the AI studs, all management must ensure conditions to the health of the boars. Some strategies have been proposed and discussed to achieve these targets. A constant flow of high-quality and well-managed breeding groups, quality control of semen doses produced, more reliable technology in the laboratory routine, removal of less fertile boars, the use of intrauterine AI, the use of a single AI with control of estrus and ovulation (fixed-time AI), estrus detection based on artificial intelligence technologies, and optimization regarding the use of semen doses from high genetic-indexed boars are some strategies in which improvement is sought. In addition to these new approaches, we must revisit the processes used in boar studs, semen delivery network, and sow farm management for a more efficient AI program. This review discusses the challenges and opportunities in adopting some technologies to achieve satisfactory reproductive performance and efficiency.
RESUMEN
Hypothermic storage has been proposed as a method to reduce bacterial loads and promoting prudent use of antibiotics. Reducing temperature, however, can lead to cold shock damage and oxidative stress in boar semen. This study verified the effect of L-cysteine on the quality of semen stored at 5 °C for 120 h. Twenty-one normospermic ejaculates were diluted in Beltsville Thawing Solution into five treatments: Positive control (Pos_Cont, storage at 17 °C without L-cysteine) and groups with 0, 0.5, 1, and 2 mmol/L of L-cysteine supplementation stored at 5 °C. Variables were analyzed as repeated measures, considering treatment, storage time, and interaction as main factors. The effects of different L-cysteine concentrations were also evaluated using polynomial orthogonal contrasts. Sperm motility and pH were higher in the Pos_Cont compared to the groups stored at 5 °C (P < 0.05). In polynomial orthogonal contrast models, total motility was affected by the interaction between L-cysteine and storage time (P = 0.04), with a linear increase in motility when increasing the amount of L-cysteine at 72 and 120 h. Progressive motility increased quadratically as the L-cysteine reached 1 mmol/L (P < 0.01). In the thermoresistance test at 120 h, sperm motility increased quadratically up to an L-cysteine dose of 1 mmol/L (P < 0.05). Sulfhydryl content linearly increased with L-cysteine supplementation (P = 0.01), with no effect on intracellular ROS and sperm lipid peroxidation (P ≥ 0.06) in 5ºC-stored doses. In conclusion, L-cysteine supplementation has a positive effect on sperm motility up to 120 h of storage at 5 °C.