This study aimed to evaluate the predictive ability of NIRS for the estimation of the chemical composition and organic matter digestibility (OMD) of total mixed rations (TMR) for dairy cows. Moreover, herein, empirical equations based on chemical parameters were developed for calculating the OMD. Samples were collected from Galician dairy farms and were scanned in duplicate a Foss NIRSystem 6500 monochromator (1100-2500 nm). The predictive ability of NIRS models was evaluated according to the coefficient of determination in external validation ( $r$²). High $r$² (equal to or higher than 0.90) was shown in predicting chemical composition, however, the estimation of OMD was acceptable ( $r$² = 0.83). The ability of the NIRS models for estimating the chemical composition was considered excellent, with the ratio performance deviation of external validation ( $RPD$) higher than 3.0, allowing for quantitative predictions. The estimation of the OMD value by NIRS was considered acceptable ( $RPD$ = 2.5), and led to reduction in the standard error of external validation, in comparison of the best empirical model based on the chemical composition of samples (from ± 2.06% to ± 1.89%). Therefore, this study demonstrated that the NIRS is an effective technology for the rapid and precise nutritional evaluation of TMR in Galicia.

We studied the effect of pre-natal supplementation with n-3 α-linolenic acid (ALA) combined with a tannin-rich forage on colostrum composition and immunological quality and whether these changes had advantageous effects on lambs’ survival and stress reaction to a post-weaning stressor. Forty-eight Latxa ewes were fed during the last five weeks of pregnancy with two experimental diets: a control diet based on a neutral concentrate and forage (tall fescue hay; CO-FES), and a supplemented diet based on polyunsaturated (PUFA)-rich concentrate and tanniferous forage (sainfoin; ALA-SAIN). After parturition, twenty ewes had their blood and colostrum sampled, and their lambs were monitored until post-weaning. Lambs were afterwards subjected to (i) an aversive handling period (AHP) followed by a behavioral assessment and (ii) inflammatory and lymphocyte proliferation challenge. Feeding ALA-SAIN resulted in changes in colostrum fatty acid composition, specifically higher α-linoleic acid (p < 0.001), conjugate linoleic acid (p = 0.005), vaccenic acid (p = 0.006) and long-chain n-3 PUFA (p = 0.004). Pre-partum nutrition did not affect lamb immunoglobulin (Ig) G apparent efficacy absorption, but circulating IgG tended to be higher (p = 0.054) in ALA-SAIN lambs. ALA-SAIN lambs interacted more frequently with other lambs (p = 0.002), whereas ALA-SAIN females spent more time closer to other lambs (p < 0.001). Plasma cortisol was higher (p = 0.047) and plasma interleukin (IL)-2 lower (p = 0.003) in CO-FES lambs. This research highlights the importance of prenatal nutrition on the immune system stimulation and lambs’ behavior as a strategy to improve lambs’ health and welfare during early life.

This study analyzes 174 tank milk samples taken from 89 commercial farms located all along the Cantabrian Coast (Green Spain). Sampling was performed in two periods: autumn 2016 and spring 2017. A survey was carried out for every day of sampling to record the average lactating dairy cow production and its diet composition. For each sample, the fatty acid (FA) profile (49 FA plus its main relationships) and nine fat-soluble antioxidant (FSA) profiles (retinol (vitamin A), α- and Υ-tocopherol (vitamin E), all-trans-β-carotene, 9-cis-β-carotene, 13-cis-β-carotene, lutein, zeaxanthin, and β-cryptoxanthin) were determined. The milk production varied between 7.3 and 45.9 liters per cow per day, highlighting the diversity found among production systems. The milk fat content ranged from 2.64% to 4.38% and the protein content from 2.87% to 3.56%. Regarding the fatty acids profile, the percentage of saturated fat varied between 59.95% and 75.99%. The linolenic acid content fluctuated between 0.21 and 1.31 and rumenic acid ranged from 0.20 to 2.47 (g 100 g⁻¹ total FA). The most important correlations between diet and milk FA were always related to the content of fresh grass and total forage (which is defined by both fresh and conserved forage derived from fresh grass (GCF)) in the diet. The content of vaccenic acid, linolenic acid, total omega-3, rumenic acid, and total CLA isomers showed the highest correlation with the proportion of fresh grass in the diet. The antioxidant contents were also highly variable, although correlations with dietary components were lower. The highest correlations were between total forage content (fresh grass (FG) plus GCF) and lutein, all-trans-β-carotene, and 13-cis-β-carotene. Diets without fresh grass had lower omega-3 content, CLA, vaccenic acid, lutein, all-trans-β-carotene, and 13-cis-β-carotene.

In the present work it is studied the predictive ability of NIRS for the estimation of chemical composition (n=171) and organic matter digestibility (n=71) of whole plants forage sorghum and morphological components, being developed empirical equations based on chemical parameters to estimate the organic matter digestibility (OMD) values and compared the predictive ability of empirical models vs. NIRS equations. The predictive ability of NIRS models for estimating the OMD and chemical composition showed high reliability, according to the coefficient of determination in external validation (r²≥0.90), whilst the ratio of the standard deviation of the original data to standard error of external validation (RPD) values were higher than 3.0 for all parameters studied. Applying NIRS models to the prediction of OMD of whole plants and morphological components of forage sorghum led to the reduction in the standard error of external validation, in comparison of the best empirical model based on the chemical composition of samples (from ±3.9 to ±1.9%). It is concluded that the NIRS equations developed in the present work are valuable tools for the fast and accurate assessment of the nutritive value of the whole plant and components of forage sorghum.

Context: A common strategy to try and improve the fatty acid (FA) composition of meat and fat from cattle has been to feed protected oil or oilseeds. Aims: Concentrate containing 4.5% fat from vegetable oil, extruded linseed or extruded soybean were fed free-choice with hay to Rubia Gallega heifers to examine the effects on meat (Longissimus thoracis (LT)) and subcutaneous fat (SCF) FAcompositions, and effects on meat and carcass quality. A secondary aim was to assess treatment effects on levels of specific desirable FAs in meat and fat. Methods: Twenty-four 7-month-old Rubia Gallega heifers were assigned to three experimental diets: control concentrate (with palm oil) or concentrates containing either extruded linseed (LS) or extruded soybeans. Concentrates and hay were fed for 90 days before slaughter at an average age and weight of 300 days and 350 kg, respectively. Key results: Minor treatment effects on animal performance, carcass traits and meat quality were noted. Relative to the control concentrate diet, feeding the linseed diet led to a slight increase in a-linolenic acid (18:3n-3) in SCF (P < 0.001), no change in 18:3n-3 in LT, reduced n-6/n-3 ratios in both LT and SCF (LT, P < 0.01; SCF, P < 0.001), and avoided ?(t6- to t10-)18:1 accumulation in either tissue (LT, P = 0.017; SCF, P < 0.05). Conclusions: Although FA improvements when feeding linseed could be viewed as positive for human health, quantitatively, feeding extruded oilseeds and hay free-choice were ineffective at creating rumen conditions needed to substantially enrich n-3 polyunsaturated FAs (PUFA) or desirable biohydrogenation intermediates in LT. Implications: To produce high-quality Rubia Gallega meat with meaningful and consistent enrichments of polyunsaturated FAs and beneficial biohydrogenation products will require more efficient methods for ruminal protection of PUFA, and further investigations into the timing and amounts of PUFA-enriched concentrate feeding.

This study evaluated the nutritional value and different methods of conservation of two willow materials—the hybrid clone Terra Nova (HTN) from a short‑rotation coppice (SRC) system and the native Salix atrocinerea (SAT) from riparian stand—representing contrasting willow resources available in the study region. The leaf fraction (LE)—although representing < 50% of total stem biomass—, showed the highest nutritional value versus stems, leaf crude protein (CP) reached 23.7% dry matter (DM) in HTN and 17.7% DM in SAT, with in vitro organic matter digestibility (IVDMO) 52.75% in HTN and 38.8% in SAT; by contrast, edible stems showed much lower CP (3.3–5.8% DM) and IVDMO (11.8–31.2%). Leaf Relative Forage Value (RFV) was “Good” in HTN (110–115) and “Poor–Fair” in SAT (82). Sun‑drying proved most effective at preserving nutritional quality, followed by formic acid‑assisted ensiling. Both materials showed poor suitability for ensiling because of low water‑soluble carbohydrate levels, requiring additive application to reach target pH (4.5 vs. > 5.0 in untreated silages). Willow leaf silages achieved CP levels of 18–22% DM (up to 27.8% in HTN with additive), while fermentation intensity remained low; SAT leaves showed a higher fermentability coefficient (44 vs. 28), consistent with better acidification. The HTN material proved suitable as a protein supplement for moderate‑energy diets, whereas SAT was limited to maintenance‑level feeding. Willow forage shows notable potential as a supplemental fodder resource for ruminant systems, although effective preservation requires additive use to maintain nutritional quality during storage. Graphical abstract