This study aimed to investigate the effect of supplementing a wheat straw-based diet with Saccharomyces cerevisiae (S.C.) on feed intake, nutrient digestibility, nitrogen balance, body weight and reproduction performance. The experiment was conducted on 14 Queue Fine de l’Ouest rams between 3 and 4 years of age (body weight (B.W.): 54.7 ± 2.03 kg; body condition score (B.C.S.): 3.5 ± 0.5), for 80 days during the breeding season. The rams were divided into two homogenous groups (n = 7), housed individually in floor pens, and allocated to two dietary treatments. The control group was offered a basal diet of 1 kg/d of wheat straw and 700 g of concentrate. The experimental group (yeast) received the same basal diet supplemented with 10 g of S.C./head/day. The results indicated that the S.C. supplementation had no significant effect on the animal’s body weight, volume and concentration of semen, dry matter intake, crude protein digestibility and nitrogen balance. Compared to the control group, the S.C. addition improved (p < 0.05) the digestibility of dry matter by 7.3%, organic matter by 11.9% and crude fiber by 24%. In addition, the mass motility score increased for the yeast group compared to the control (3.7 ± 0.24 vs. 1.9 ± 0.27, p < 0.05). The total number of dead and abnormal spermatozoa decreased for the yeast group in contrast to the control group (9.28 ± 0.95 vs. 26.8 ± 3.85% and 25.5 ± 3.33 vs. 59.2 ± 2.78%, respectively; p < 0.05). These results showed that adding S.C. to Queue Fine de l’Ouest ram’s diet during breeding season could improve nutrient digestibility and reproductive performance.

This study aims to investigate whether the variation in reproduction success, growth, and milk trajectories is associated with different adaptive strategies in the short term (response to an acute nutritional challenge), using two Alpine goat lines. A total of 382 Alpine goats (179 low longevity (low_LGV) and 203 high longevity (high_LGV)), selected for divergent functional longevity from a commercial population, were monitored for 4 years and recorded for BW, reproduction and milking performance. Every year, an average of fifty primiparous goats were exposed to a 2-d nutritional challenge in early lactation. A polynomial model was used to analyse the lifetime trajectory of lactation and BW. A piecewise model was used to analyse the individual milk yield and responses of milk components to the nutritional challenges. The statistical analysis revealed that the two lines had a similar performance for total milk yield in the first lactation, BW at birth and at first kidding, litter size and weight, kidding interval and interval from the first insemination to conception. BW trajectories revealed that low_LGV goats had a greater BW in pregnancy but then lost more weight in early lactation compared to high_LGV goats, which showed a greater BW after kidding. Milk trajectories showed that the high_LGV goats had a higher initial milk yield, an earlier but less marked lactation peak and more persistency in milk production in late lactation than low_LGV goats. Except for milk protein content, quite similar response and recovery profiles of milk yield and milk fat content were observed during the challenge for both lines. The response to the challenge was positively correlated to the initial level of milk production in early lactation but negatively correlated with milk production decline after the peak. This finding suggests that the low_LGV goats were more adapted to allocate resources to meet an expected physiological change such as gestation and lactation. However, high_LGV goats allocate more than low_LGV goats for structural mass and may better cope with an unexpected environmental change such as nutritional deficit.

This study investigated the combined effects of seminal plasma (SP) and Sonchus oleraceus L. aqueous extract on post-thaw sperm quality and fertilizing ability in rams. Semen collected from seven adult rams was pooled and divided into six experimental groups according to the presence (SP+) or absence (SP−) of SP and supplementation with 0, 0.5, or 2 g/L of Sonchus oleraceus extract. Samples were cryopreserved in a Tris–egg yolk–citric acid extender. Post-thaw sperm quality using computer-assisted sperm analysis (CASA), hypo-osmotic swelling (HOS) test, and oxidative stress biomarkers, including reactive oxygen species (ROS), malondialdehyde (MDA) and total thiols as antioxidative parameter were evaluated. Removal of SP significantly enhanced several kinematic parameters (VCL, ALH, DCL) and reduced abnormal morphology (p < 0.05), whereas its presence improved motion quality indicators such as beat cross frequency (BCF), linearity (LIN), and straightness (STR) (p < 0.05). However, SP removal induced a marked oxidative imbalance, characterized by increased ROS and MDA levels and decreased total thiols (p < 0.001). Supplementation with S. oleraceus extract improved membrane integrity and restored redox balance by increasing thiols levels (p = 0.0001) and reducing lipid peroxidation (p < 0.001), with significant SP × dose interactions. Based on these results, in vitro fertilization (IVF) was performed only using SP+ groups, as the presence of SP ensured a more physiologically relevant environment and maintained oxidative balance necessary for fertilization. No significant differences were detected in cleavage or blastocyst rates among the three S. oleraceus extract doses. These findings highlight an interaction between SP and Sonchus oleraceus aqueous extract, suggesting that combining endogenous protein-rich components with exogenous plant-derived antioxidants may enhance post-thaw sperm functionality and its oxidative status in rams.