Ruminants, Volume 5, Issue 4 (December 2025) – 7 articles

Improving livestock nutrition with natural supplements can enhance productivity and meat quality. This study evaluated whether a clayey micromineral compound (CMC) in lamb diets improves feed efficiency, health, and meat traits. Twenty-four 60-day-old Dorper/Santa Inês crossbred lambs (28.41 ± 4.147 kg initial weight) were randomly assigned to four CMC doses (0%, 0.4%, 0.8%, or 1.2% of dry matter intake/day) for 90 days, following a 15-day adaptation. The lambs were individually housed, with daily feed intake monitoring, weekly weight measurements, and blood analyses at the start and end. On day 89, rumen fluid was sampled for digestion analysis, and post-mortem evaluations were used to assess meat quality and rumen health. The results showed that 0.8% CMC optimized fat and fiber digestion (p < 0.05), while higher doses linearly improved meat color intensity (p < 0.05). Blood tests indicated better liver function at intermediate doses (p < 0.05). However, the CMC did not affect overall growth, feed intake, or carcass traits. The supplement was safe but provided selective benefits. These findings suggest that CMCs could enhance feed efficiency and meat appeal, although further research is needed to refine dosing for maximum impact. Full article

A significant gap in specific nutritional guidelines for ruminants with compromised health exists. Due to their unique anatomy, physiology, and metabolic processes, further research is needed to establish accurate, evidence-based recommendations tailored to these animals. This review highlights the critical role of clinical ruminant nutrition and provides provisional recommendations based on studies in other species (e.g., changes in nutrient requirements in different morbidities available for humans and less for companion animals). These suggestions should be interpreted cautiously until more definitive, species-specific data become available. The review includes the foundational principles of clinical nutrition in ruminants, with particular emphasis on the pathophysiology of nutrient utilization. It explores the roles of energy, protein, vitamins, and minerals during illness or injury and discusses how these nutrients can be strategically applied in clinical interventions. Considerations for designing diets for compromised ruminants are also addressed, considering both physiological needs and the challenges posed by illness and injury states. Practical aspects of diet delivery during treatment are examined, including the indications, benefits, limitations, and potential side effects of route of feeding. Clinical nutrition can be administered orally, enterally (including rumen delivery) or parenteral, depending on the localization of the pathology and the integrity of the alimentary tract. Nutrients should be provided based on livestock requirements and pathophysiology and severity of the primary morbidity. Oral or ruminal provision of diet should be prioritized to maintain rumen functionality. Additionally, a list of pharmaconutrients with potential clinical applications in ruminant medicine is presented to encourage future research and integration into veterinary practice. The success of clinical nutritional interventions can be measured by improvements in appetite, behavior, and health of the compromised ruminant. Full article

Urea is one of the most widely used sources of non-protein nitrogen (NPN) in ruminant diets due to its low cost and high availability. However, its rapid solubilization in the rumen can result in abrupt ammonia release, leading to toxicity risks and low nitrogen utilization efficiency. In this context, slow-release technologies, particularly microencapsulation, have been developed to synchronize NPN release with fermentable carbohydrate availability, thereby enhancing microbial protein synthesis, improving animal performance, and reducing environmental impacts. This review compiles recent advances in urea microencapsulation, emphasizing different wall materials such as waxes, lipids, polysaccharides, and fatty acids, as well as drying techniques and formulation strategies. Slow-release urea (SRU) addition in small ruminants’ diet may increase nutrient intake and digestibility, improve N balance, and reduce urinary excretion losses. Regarding performance, positive responses are observed when nitrogen release is properly synchronized with energy availability, although the results may vary depending on the encapsulant type, forage-to-concentrate ratio, and ruminal passage rate. Additionally, effects on meat quality and environmental parameters indicate that this technology holds not only zootechnical but also socio-environmental potential. It is concluded that urea microencapsulation can represent a promising alternative to optimize NPN use efficiency in ruminant production systems, though greater methodological standardization, long-term evaluations, and comparative economic analyses are required to encourage its broader adoption. Full article

The objective of this study was to develop a stochastic simulation model to evaluate the impact of accelerated lambing on income over feed cost (IOFC) in Lacaune ewes managed under an intensive production system in Greece. The economic comparison of two lambing intervals (LI) was performed by varying the voluntary waiting period to allow for an 8-month LI (3 lambings in 2 years) versus a 12-month LI (1 lambing per year). Milk production per year was greater (p < 0.01) for the 8-month compared to the 12-month LI (777.4 ± 2.8 kg vs. 661.9 ± 2.1 kg, respectively), and the income from the sale of milk was greater for the 8-month compared to the 12-month LI (EUR 1166.0 ± 4.1 vs. EUR 992.9 ± 3.1, respectively). Feed cost per year was greater for the 8-month compared to the 12-month LI (EUR 255.9 ± 0.5 vs. EUR 227.8 ± 0.5, respectively). Therefore, IOFC per year was greater for the 8-month compared to the 12-month LI (EUR 989.4 ± 3.2 vs. EUR 817.1 ± 2.1, respectively). The cost per additional day open in the 12-month LI was estimated at EUR 1.08 ± 0.06 and demonstrates the importance of reproductive performance in the profitability of dairy sheep production. Therefore, reproductive management strategies that result in reduced LI are expected to increase IOFC in Lacaune dairy ewes. Future research is needed to develop practical strategies to successfully reduce the lambing interval in Lacaune ewes. Full article

We aimed to assess the seroprevalence of anti-Neospora caninum and anti-Toxoplasma gondii antibodies in cattle intended for human consumption in Paraíba, Brazil, and the associated risk factors. A total of 110 serum samples from slaughtered cattle were analyzed using the Indirect Fluorescence Antibody Test (IFAT), with cut-off points of 1:200 for N. caninum and 1:64 for T. gondii. Seroprevalence was 8.2% (9/110) for N. caninum (titers 1:200–1:6400) and 18.2% (20/110) for T. gondii (titers 1:64–1:512). Risk factor analysis revealed that the variable female sex (cows) and the extensive farming system were statistically significantly associated with seroprevalence for N. caninum. Whereas for T. gondii, extensive farming, frequent animal purchase, and the lack of separation between calves and adult cattle were statistically significant. These findings demonstrate the circulation of these parasites in herds, with implications for animal and public health, indicating a potential risk of transmission to definitive hosts and humans through the consumption of raw or undercooked infected meat. Full article

Livestock production raises significant environmental concerns, necessitating the development of sustainable feeding strategies based on non-conventional forages, such as locally available vegetation. This study evaluated the effects of a pelleted concentrate containing 10% Acacia farnesiana leaves as a dietary supplement on in vitro ruminal fermentation. Four experimental diets were formulated with increasing levels of the concentrate (0%, 25%, 50%, and 75%). Analyses were performed in triplicate and included chemical composition, in vitro gas and methane production, fermentation kinetics, ammonia nitrogen concentration (N–NH₃), in vitro dry matter digestibility (IVDMD), and metabolizable energy (ME) estimation. The results revealed no significant differences (p > 0.05) in most gas production kinetic parameters, overall fermentation patterns, or metabolizable energy. In contrast, a significant increase (p < 0.05) in secondary metabolite concentrations was detected. While methane production remained unaltered (p > 0.05), a significant linear reduction was observed for IVDMD, the lag phase (L), and N–NH₃ concentration (p = 0.0064, p = 0.0036, and p < 0.0001, respectively). These findings suggest that A. farnesiana can be incorporated into ruminant concentrates without increasing methane emissions. However, in vivo trials and mechanistic studies are required to validate and further elucidate these results. Full article

No studies have induced maternal behavior in goats through hormonal treatment. We evaluated whether ovariectomized goats treated with estradiol benzoate (EB2; n = 7 nulliparous and 10 multiparous goats) or progesterone + estradiol benzoate (P4 + EB2; n = 7 nulliparous and 7 multiparous goats), before or after vagino-cervical stimulation (VCS), displayed maternal behavior. When all goats were measured within treatments, in the EB2 group, low-pitch bleats were more frequent, and the time spent cleaning the kids was longer after VCS (p < 0.01), while location changes were more frequent before VCS. In nulliparous goats, those in the EB2 group emitted more low-pitch bleats after VCS than before (p = 0.04). The frequency of location changes was higher before VCS than after (p = 0.05). In multiparous goats, the frequency of smelling the kids and aggression toward the kids before VCS was higher in the EB2 group than in the P4 + EB2 group (p < 0.01). Within treatments, the EB2 group emitted more low-pitch bleats after VCS than before (p = 0.01), and the duration of cleaning the kids was longer after VCS than before (p = 0.028). Within the P4 + EB2 group, the kids were smelled more frequently after VCS than before (p = 0.03). The maternal index after vagino-cervical stimulation was higher in goats with EB2 (p = 0.002). Nulliparous goats treated with P4 + EB2 had a higher maternal index compared with those treated with EB2 alone (p = 0.04). In conclusion, regardless of parity, maternal behavior induced with the EB2 treatment was better when VCS was applied. Likewise, maternal experience altered the response. In multiparous females, any of the treatments were better after VCS, while in nulliparous females, this was only evident with the EB2 treatment. Full article