Mammalian reproductive function is regulated by hypothalamic neurons that secrete Kisspeptin (Kp), a neuropeptide that stimulates gonadotropin-releasing hormone (GnRH) secretion, triggering pituitary gonadotrophins (LH and FSH) and gonadal steroids. This study evaluated the effect of Kisspeptin-10 (Kp10) on ovulation induction in rabbits, comparing its efficacy with that of the GnRH analogue gonadorelin. Multiparous New Zealand White × California does were assigned to three groups: control group (0.5 % saline solution, i.v.), GnRH group (20 μg gonadorelin, i.m.), and Kp10 group (250 μg Kp10, i.v.). Kp10 induced ovulation in 87.5 % of does, matching the response observed in the GnRH group, with a comparable number of corpora lutea (CL) per ovulated doe (12.9 ± 1.4 vs 14.6 ± 1.4 CL/doe, respectively). On day 7, plasma progesterone (P4) was significantly higher in ovulated GnRH-treated does than in Kp10-treated ones (25.12 ± 4.17 vs 9.47 ± 4.17 ng/mL; p < 0.0211), while non-ovulated controls exhibited minimal P4 concentrations (0.86 ± 0.12 ng/mL). Plasma estradiol (E2) levels showed no significant differences across days or groups, with mean values of 32.74 ± 4.33 pg/mL on day 0 and 37.27 ± 5.49 pg/mL on day 7, respectively. Histological analysis confirmed that Kp10 promoted preovulatory follicle development and CL formation, mirroring GnRH effects. Additionally, Kp10 enhanced angiogenesis, indicated by increased vascular endothelial growth factor (VEGF) expression in more developed follicles and CL. These results suggest that Kp10 could be an alternative to GnRH for ovulation induction in rabbits, although further studies are needed to explore optimal analogues, doses, and administration routes.

EU regulations on organic rabbit farming are relatively recent, and scientific evidence on key technical aspects remains limited. Outdoor systems may improve health and welfare by allowing natural behaviours, but their effectiveness depends on management practices, environmental conditions, and breed. The objective of this study was to explore breed-related differences in rabbit behaviour under outdoor rearing conditions. A total of 15 Leprino di Viterbo (LV) and 15 New Zealand White (NZW) rabbits were weaned at 29 days of age and reared under outdoor conditions until 84 days of age, during October and November. All animals had ad libitum access to a commercial pelleted diet and pasture, and the intake of both was measured weekly. Animal behaviour was monitored by video recording, and eight one-minute sample intervals per day were analysed using focal sampling and continuous recording methods. Grass intake and estimated digestible energy (DE) were assessed on a weekly basis. Data were analysed using Generalized Estimating Equations to evaluate the effects of time, time of day, and breed. Behavioural patterns varied depending on genetic strain and time of day. Notably, LV rabbits exhibited a higher frequency of grazing and active behaviours compared to NZW rabbits, whereas NZW rabbits showed a higher frequency of resting behaviours and social contact. Breed-related differences in other behaviors and in grass intake patterns were not statistically robust. In conclusion, LV rabbits appear to be better adapted to outdoor conditions, exhibiting a greater pasture utilization, but further studies are recommended to confirm these findings and to evaluate their robustness across different seasonal and environmental conditions.

The aim of this study was to analyze how recombinant rabbit NGF (Nerve Growth Factor) encapsulated in chitosan (rrβNGFch) affects sperm viability, motility, capacitation, acrosome reaction (AR), kinetic traits, and apoptosis after 30 min and 2 h of storage. Specific intracellular signaling pathways associated with either cell survival, such as protein kinase B (AKT) and extracellular signal-regulated kinases 1/2 (ERK1/2), or programmed cell death, such as c-Jun N-terminal kinase (JNK), were also analyzed. The results confirmed the effect of rrβNGFch on capacitation and AR, whereas a longer storage time (2 h) decreased all qualitative sperm traits. AKT and JNK did not show treatment-dependent activation and lacked a correlation with functional traits, as shown by ERK1/2. These findings suggest that rrβNGFch may promote the functional activation of sperm cells, particularly during early incubation. The increase in capacitation and AR was not linked to significant changes in pathways related to cell survival or death, indicating a specific action of the treatment. In contrast, prolonged storage negatively affected all sperm parameters. ERK1/2 activation correlated with capacitation, AR, and apoptosis, supporting its role as an NGF downstream mediator. Further studies should analyze other molecular mechanisms of sperm and the potential applications of NGF in assisted reproduction.

The research aimed to evaluate the effectiveness of adding linseed oil to an alfalfa-based diet for fattening rabbits. At 30 days, 360 hybrid rabbits were divided into three homogeneous groups and fed: Control feed composed of 15% wheat, 17% alfalfa hay, and 8% dehydrated alfalfa; experimental feed composed of 40% alfalfa hay and 30% dehydrated alfalfa (Alfalfa); another experimental feed composed of 38% alfalfa hay, 30% dehydrated alfalfa, and 2% linseed oil (Alfalfa+Linseed). The alfalfa-based diet showed higher crude fiber, but lower lipid, protein, and digestible energy content. Regarding performance, a reduction in slaughter weight was observed only in the Alfalfa group, while the addition of linseed oil eliminated the gap with the Control group. The lipid content of the meat was significantly lower in the Alfalfa group. Significant changes were observed in the fatty acid composition, with higher levels of n-3 precursors and derivatives of the n-3 series in the Alfalfa+Linseed group, followed by Alfalfa and Control. Furthermore, the addition of linseed oil worsened lipid oxidative stability. In conclusion, the proposed dietary treatment represents a promising strategy for producing rabbit meat with a high nutritional profile, without compromising productive performance.