The aim of this study was to identify Longissimus lumborum (LL) muscle from lambs with high IMF content (≥3%) using wool FA. The FA composition was characterized in two sections of wool from Suffolk Down lambs, and its relationship with IMF content assessed. One hundred and forty lambs of similar body weight, body condition score, and age were selected. IMF content from LL muscle, and the wool fat and FA composition of the wool were determined. The proportions of FAs in the wool of lambs with low IMF were 51.96 ± 7.3% of saturated, 31.96 ± 7.7% polyunsaturated, and 16.08 ± 2.3% monounsaturated. Similar proportions of FAs were observed in wool samples of lambs with high IMF. Significant differences were found only in the SFA proportion between groups (p < 0.05). The predominant FAs in the wool samples were C16:0, C17:0, C18:0, C18:1n9c and C18:2n6c, representing over 60% of total FA methyl esters. Correlations were found between the wool FAs C16:1, C17:0, C18:0, C18:1n9c, C24:0, and C22:6n3 in wool samples divided into two sections. Discriminant analysis identified SFAs, particularly FAs C22:0 and C24:0, as potential candidate for predicting lambs with high IMF content with an accuracy of over 92%. These results provide to our knowledge evidence that IMF content could potentially be determined using wool FAs as a non-invasive method.

Under the predicted conditions of climate change, the productivity of temperate grasslands may be affected by drought stress, especially in spring and summer. In this scenario, water-deficit-tolerant species such as plantain and chicory are interesting alternatives for use in sheep production systems. In this study, we compared a mixture of plantain and chicory herbage (PCH) with a grass-based permanent sward (GBS) on the weight gain and meat quality of lambs finished on these grasslands. Fifteen weaned lambs (31.3 kg and 4 months of age) were assigned to each treatment for seven weeks in late spring and live weight gain (LWG), carcass and meat quality were evaluated. There was a tendency (p = 0.09) in final weight (40.3 ± 0.8 kg) and live weight gain (173 ± 10 g/d) to be higher in PCH compared to GBS. Carcass weight, dressing percentage and meat quality in terms of pH, color and tenderness did not differ (p > 0.05) and were considered to be of good quality. We concluded that both swards result in comparable lamb performance and good meat quality.

Summer turnips (Brassica rapa L.) have become one of the main supplementary crops in ruminant livestock systems in southern Chile because of accelerated forage growth as well as greater forage yield and nutritive value in the dry season. This study investigated the effects of forage turnip supplementation on the physicochemical and sensory quality of beef from steers. Twenty-seven Holstein–Friesian steers were allocated to one of three dietary treatments: pasture plus concentrate (Control), 50% turnip with a basal diet of pasture hay and rolled corn (T50), and 70% turnip with the same basal diet (T70). Carcass yields and physicochemical and sensory beef attributes, including fatty acid composition of intramuscular fat (IMF) in lean tissue, were measured. Compared to the Control diet, finishing steers on 50% or 70% turnips increased meat redness (a* > 25.9 vs. 22.9 in Control), IMF (1.79% in T50 vs. 1.12% in Control), polyunsaturated fatty acids (PUFAs) (especially n-3), cholesterol, and specific minerals (sodium, manganese and iron); this resulted in a reduction in the subcutaneous fat thickness (0.29 cm in T50, 0.25 cm in T70 vs. 0.51 cm in Control) and shear force of cooked meat (p < 0.05). However, no differences were found between diets in beef juiciness, flavor, and tenderness assessed by trained panelists (p > 0.05). Increasing forage turnip inclusion to 70% resulted in similar beef quality to the 50% inclusion level. Foraged turnips present a promising strategy for producing high-quality beef during periods of limited pasture growth.

The fatty acid (FA) profile of beef is a key indicator of nutritional quality. This study assessed the ability of Near Infrared Spectroscopy (NIRS) to predict the FA profile in beef samples from southern Chile. A total of 81 FAs were analyzed, and 38% of the calibration models achieved RPD ≥ 2.5 (Ratio of Performance to Deviation). Strong predictive performance was observed for major FAs, particularly SFA and MUFA, with R²p > 0.90 (Coefficient of Determination) for palmitic (16:0). Although PUFA and some CLA isomers showed lower predictive accuracy—likely due to low concentrations and spectral overlap—minor FA such as 9c,11t-18:2 (CLA, rumenic acid) was accurately predicted. External validation confirmed that 77% of FAs showed no significant differences from gas chromatography, highlighting the robustness of NIRS for most compounds analyzed here. NIRS effectively captured FAs related to grass-based diets, such as trans-vaccenic acid and specific CLA isomers. NIRS works as a practical, rapid, and non-destructive tool for FA profiling, with potential uses in nutritional labeling and quality control; however, its application depends on the prior development of robust calibration models, which must be tailored to the specific matrix and analytical objectives.

La producción de carne bovina se concentra principalmente en el sur de Chile, donde predominan los sistemas pastoriles con variaciones en razas y dietas entre las regiones. El objetivo de este estudio fue evaluar y comparar la calidad nutricional y el perfil de ácidos grasos de carne bovina de las regiones de La Araucanía, Los Ríos, Los Lagos y Aysén. Se analizaron 480 muestras del músculo Longuissimus thoracis et lumborum obtenidas de 70 carnicerías y tiendas de carne representativas de dichas regiones. Los resultados indican que la carne proveniente de La Araucanía obtuvo el mayor contenido de grasa intramuscular (3,34 %), seguida de Los Lagos (3,01 %), mientras que Aysén (2,71 %) y Los Ríos (2,75 %) presentaron los valores más bajos. Asimismo, la región de Aysén se destacó por presentar los mayores niveles de ácidos grasos poliinsaturados totales, así como de ácidos grasos n-3 y n-6, y la relación Poliinsaturados:Saturados más elevada. En contraste, la carne de La Araucanía presentó la mayor cantidad de ácidos grasos monoinsaturados y la menor cantidad de ácidos grasos n-3. Las regiones de Los Ríos y Los Lagos mostraron un perfil de ácidos grasos similar, con diferencias menores respecto a la carne de Aysén. En general, la carne de las cuatro regiones se caracterizó por un bajo contenido de grasa intramuscular (< 4%) y presentar una relación n-6:n-3 menor a < 4.0, lo que sugiere que la carne bovina producida en el sur de Chile podría recomendarse como fuente de carne magra adecuada para una dieta saludable.

Alternative forages, such as plantain (Plantago lanceolata) and chicory (Cichorium intybus), show potential to improve ruminant nutrition while reducing environmental impacts; however, their influence on rumen function remains insufficiently defined. Using eight RUSITEC fermenters (two vessels per treatment per run, across two independent runs; n = 4 fermenter replicates per treatment overall), plantain (PL), chicory (CHI), a plantain–chicory mixture (PCH), and a grass-based sward (GBS) were incubated for a 10-day adaptation period followed by a 5-day sampling period to assess nutrient digestibility, fermentation, methane (CH₄) production, and microbial composition. PL resulted in the lowest CH₄ emissions (4.13%) and ammonia nitrogen (NH₃–N; 5.92 mg/day), whereas CHI achieved the highest dry matter digestibility (77.2%) but also the highest CH₄ emissions (5.55%). PCH presented intermediate CH₄ levels (4.52%), showing efficient nutrient use, while GBS and CHI achieved the highest NDF disappearance (NDFomd: 49.0% and 50.9%, respectively). Bacterial diversity (Shannon index) was lower in PL (1.71) than in CHI (4.25) and GBS (4.23), with PCH being intermediate (3.47). These findings support PL and PCH as promising dietary options to enhance rumen efficiency and reduce methane and nitrogen emissions. In vivo validation is recommended.