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The study aimed to evaluate the carcass trait, meat quality and fatty acid profile of Awassi lambs under cultivated pasture fattening with a concentrated feed (CPF) and intensive fattening (IF) system. A total of 76 male Awassi lambs (36 lambs in the CPF group and 40 in the IF group, 85 days average age) were distributed in complete random design into two experimental groups. The final body weight was lower, but the average daily gain was higher for the lambs on the CPF compared to the lambs on the IF system. There were no significant differences (p>0.05) between CPF and IF system for dressing percentage (50.31 and 51.51%) and shrinkage loss (3.45 and 2.50%), pelvic limb (34.9 and 30.3%), thoracic limb (20.8 and 18.3%), flank (9.4 and 7.6%), neck (4.4 and 5.9%), and LTL section area (15.6 and 13.0 cm2), except for ribs (25.0 and 33.7%), which were higher in the intensive system. Also, meat pH and color value were not changed by the fattening systems. The fatty acid profile of the longissimus thoracis et lumborum muscles was assessed. The significant differences between groups were noted in margaric (1.00 and 1.80), heptadecenoic (0.51 and 0.99), eicosenoic (80.14 and 0.20), and linolenic fatty acids (0.21 and 0,19). In conclusion, the results of this study imply that carcass traits and meat quality were similar between CPF and IF systems in Awassi male lambs. [ABSTRACT FROM AUTHOR]

Protein quality plays a pivotal and dynamic role in the growth, productivity, and reproduction of ruminants. Increasing the proportion of dietary protein (CP) alone cannot balance the concentration of limiting amino acids (AA) in the duodenum of high-yielding dairy cows. However, supplying rumen-protected AA is believed to improve productivity and reproduction rates. Malabsorption of CP-rich meals in the rumen leads to high nitrogen (N) excretion through urine and faeces in the form of nitric oxide, nitrous oxide, ammonia and nitrate in the environment. Research data indicate that lysine and methionine are the two most limiting AA in the ruminant ration. Supplementing these limiting AA in ruminant diets is one of the most effective strategies to improve CP usage and reduce the negative impact of CP in the diet. Several in vivo and in vitro experimental studies have demonstrated that even low-quality dietary CP, when supplemented with rumen-protected AA (Met + Lys), exhibited a greater ability to reduce N2 or NH3 losses, while also supporting a decrease in enteric fermentation gas production and minimising soil or water pollution associated with animal production. However, further research is necessary to explore the molecular and genetic mechanisms underlying the effects of AA dietary supplementation on the rumen microbiota in ruminants. [ABSTRACT FROM AUTHOR]

The article discusses the importance and role of fungal directfed microbials (DFM) and anaerobic rumen fungi (ARF) in ruminants and their metabolic pathways of plant fibre decomposition, as well as rumen fermentation processes. ARF classification, enzymatic activity, impact on rumen metabolism, as well as fungal DFM and application of their metabolites in ruminant feeding are presented. The research area concerning ARF in ruminant feeding is gaining interest as the subject is still poorly elucidated. The latest research in the field of ruminant physiology and nutrition has pointed to a significant impact of ARF and fungal DFM on nutrient degradability, fermentation profile in the rumen, and animal performance. Although, the proportion of fungi in the total rumen microorganisms is low (approximately 8% of rumen biomass), they play a crucial role in generating a series of enzymes utilising difficult-to-debase compounds, such as cellulose, hemicelluloses and xylose. Although enzymes secreted by ARF are not able to degrade lignin, they can solubilise lignocellulosic complexes and expand the surface area for enzymatic activity. This leads to a better utilisation of fibrous feeds, increased nutrient digestibility, and enhanced rumen fermentation. A comprehensive description and discussion of these issues in the review provides an in-depth look at the role of ARF and the potential use of ARF as DFM in the ruminant nutrition in a-broad perspective. [ABSTRACT FROM AUTHOR]