Ruminants, Volume 6, Issue 1 (March 2026) – 21 articles

Grape pomace is an agri-industrial by-product rich in fatty acids with the potential to be used in diets for goats and increase the nutraceutical properties of milk. This study aimed to investigate the effect of incorporating dehydrated grape pomace (DGP) into the diets of Saanen goats on the composition, fatty acid profile, nutritional indices of fatty acids, and antioxidant capacity of their milk. Eight multiparous Saanen goats, averaging approximately four years of age and weighing 41.2 ± 15.7 kg, were used in a double Latin square (4 × 4) design. Diets were formulated with increasing levels of grape pomace (0, 90, 150, and 210 g/kg Dry Matter—DM), replacing cactus. The data underwent analysis of variance using GLM procedure and regression analysis (both linear and quadratic) using REG procedure at a significant level of 5%. The concentration of C18:2 n-6 cis and C18:3 n-3 increased (+20.1 and +15.5%, respectively) with the grape pomace inclusion. There was a reduction in the atherogenic (−24.0%) and thrombogenic (−9.9%) indices of goat milk with the increase in DGP levels. There was a reduction in de novo fatty acids (−10.5%), Δ⁻⁹ desaturase of C14 (−21.8%) and C18 (−9.5%) indexes with the highest level of DGP. There was a quadratic effect for Ferric Reducing Antioxidant Power (FRAP) and a linear effect for phenolic compounds (PC), where the highest values were observed at the estimated levels of 160 g/kg and 210 g/kg DM, respectively. Supplementing dairy goats’ diets with dehydrated grape pomace up to 210 g/kg dry matter enhances the fatty acid profile and nutritional indices of fatty acids of Saanen goat milk without altering its basic composition. As grape production is prevalent in low rainfall regions, pomace may provide an alternative feed in areas with forage production constraints. Additionally, grape residue could establish a link between the wine and dairy sectors for cheese production, expanding markets for farmers. Full article

Growth traits in goats are impacted by both genetic and non-genetic variables; as such, it is critical to separate direct and maternal effects for reliable genetic assessment. This study determined the phenotypic and genetic characteristics for birth weight (BW), weaning weight (WW), and average daily gain (ADG) in Salem Black goats. The MTDFREML software was used to evaluate data from 930 kids, the progeny of 147 bucks and 804 does, gathered between 2004 and 2019. Three models were compared: Model 1 (direct genetic effects only), Model 2 (adding permanent environmental effects), and Model 3 (adding maternal genetic effects and direct–maternal covariance). The overall mean was 2.21 kg for BW, 9.23 kg for WW, and 78.27 g/day for ADG. The direct heritability estimates for BW, WW, and ADG were 0.06–0.22, 0.13–0.40, and 0.11–0.16 across models, respectively, whereas maternal heritability ranged from 0.01 to 0.13. The study revealed maternal genetic effects on birth weight but their total contribution to growth trait variation is modest, and model parsimony suggests that maternal effects on WW and ADG be excluded. Breeding programs should therefore prioritize direct selection for growth performance, whereas management strategies such as enhanced nutrition, targeted kidding, and support for first-parity do provide more rapid and effective avenues to improve pre-weaning developmental outcomes. Hence, a pragmatic approach that combines direct genetic selection and environmental optimization would result in greater genetic gain and support long-term meat production in Salem Black goats. Full article

A multitude of factors affect the optimum calving season, requiring site-specific systems analysis. The objective of this study was to determine the effects of the calving season (S1 and S2) and the timing of calving within the season on production parameters and economics in southwest Missouri. A five-year study was conducted from 2014 to 2018 using field data recorded for 1979 Hereford cow–calf pairs. Cows were categorized by calving season and 21 d calving periods within season (Periods 1–5) in which they calved. Data were analyzed under a completely randomized design with effects of season, period, calf sex, and two and three-way interactions with the calving year as a random effect. The Cattle Value Discovery System (CVDS) beef cow model was used to estimate required cow feed and feed intake. Historical cattle market prices were used, along with total feed costs, to calculate net returns. Calving in later periods reduced the pregnancy percentage in S1 but not S2. Cows calving earlier in both seasons weaned heavier calves. Feed costs were greater in S2, but replacement heifer costs were greater in S1, especially in later calving periods. Overall, net returns were not different between S1 and S2 cows, but net returns declined in later calving periods in S1, whereas there was no difference in S2. In conclusion, at the latitude of southwest Missouri for a forage species with a bimodal growth curve, the calving period affected cow productivity and profitability in Season 1 but less so in Season 2 cows, with no difference in profitability between calving seasons. Full article

This study evaluated the effects of four macroalgae (Colaconema spp., Ulva intestinalis, Ceramium spp., Pylaiella litoralis) and two microalgae (Haematococcus pluvialis, Porphyridium purpureum), chosen due to their local cultivability in the southern Baltic Sea region and potential gas-reducing properties reported for their taxa, on rumen fermentation and methane production. Therefore, the in vitro ANKOM Rf gas production system was used; three trials were conducted and gas kinetics, gas composition after 48 h of incubation, and short-chain fatty acids (SCFAs) were analyzed. For Trial 1.1, the algae biomasses were added at 4% to a conventional dairy diet and incubated in buffered rumen fluid for 48 h, to evaluate their potential as a supplement. In Trial 1.2, the polysaccharide-enriched algae extracts were added at 2% to the base diet using the same procedure, to investigate the role of the polysaccharide content. For Trial 2, the macroalgae biomasses were evaluated solely to assess their fermentation potential. The addition of the red alga Colaconema spp. (Colaconema) altered the SCFA profile with a shift towards propionate (rate of change in propionate concentration, ΔC3 = 1.216; p < 0.001), without compromising total SCFA yield. The same could be assessed for Ulva intestinalis (U. intestinalis), limited to Trial 2 (ΔC3 = 0.516; p < 0.001). The addition of U. intestinalis led to reduced initial gas production (p = 0.003), reaching the maximum gas production rate at 5.8 h of incubation, 0.3–0.7 h later than the others (5.1–5.5 h). While there was no significant methane reduction at the chosen inclusion rates, the results indicate that both algae influence the SCFA profile and therefore fermentation pattern, with U. intestinalis warranting further investigation on gas production dynamics. Full article

The objective of this study was to evaluate the impact of summer calving on reproductive performance, milk yield, and culling risk in U.S. organic dairy herds. Data were obtained from the Dairy Herd Improvement records of 434 organic dairy herds across 31 states, comprising 287,927 calving records from 2018 to 2022. Calving months were categorized as winter, spring, summer, or fall. Mixed models were used to analyze the 305 d milk yield, 305 d energy-corrected milk yield, peak milk DIM, peak test-day milk yield and logistic regression, and survival analyseswere applied to analyze calving difficulty, abortion, pregnancy diagnosis, and culling outcomes. Cows calving during summer had fewer days to first service and fewer days open compared with cows calving in other seasons; however, their odds of being diagnosed as pregnant were significantly lower. Summer-calving cows produced lower 305 d milk and energy-corrected milk yields, reached peak milk production later, and had a lower peak test-day milk yield. Calving during summer was also associated with increased odds of calving difficulty and a higher risk of culling. These findings indicate that summer calving poses distinct challenges for organic dairy cows, with cumulative effects on fertility, milk production, and survivability, underscoring the need for season-specific management strategies in organic dairy systems. Full article

Lactation is a dynamic process characterised by a production peak at 6–8 weeks, followed by a steady decline. To understand the molecular drivers of these phases and the influence of production systems, this study aims to provide a transcriptomic characterisation of bovine milk somatic cells (BMSCs) in Holstein (HO), Simmental (SM), Simmental × Holstein crossbreed (SM × HO), and Podolica (POD) cows at 60 and 120 days in milk (DIM). Total RNA was sequenced at high coverage, and differential expression and functional enrichment analyses were performed. While a core set of milk protein and fatty acid genes was identified, breed-specific analysis showed SM × HO had the highest variation (677 differentially expressed genes, DEGs). Genes upregulated at 120 DIM involved mitochondrial metabolism and oxidative phosphorylation, while downregulated genes were associated with nuclear transcriptional regulation. At 60 DIM, SM × HO vs. HO showed 66 DEGs, with upregulated genes linked to chromatin remodelling and immune regulation. Comparing production systems, 28 DEGs between POD and HO/SM highlighted differences in mitochondrial activity and transcriptional regulation. This study bridges a knowledge gap by profiling the milk transcriptome of unexplored cattle breeds, providing novel insights into the molecular regulation of lactation. Full article

Calf rope-and-tie is a competitive rodeo event that has drawn criticism due to concerns around the potential for stress and injury of calves. While previous studies have utilised behavioural indicators to assess the welfare of rodeo calves in the arena, there are no published studies on rodeo calf behaviour during confinement in the chute prior to release into the arena. We analysed video footage of calves in the chute prior to release during two rodeo events. The footage was categorised into short duration (SD, 28–51 s, n = 17) and long duration (LD, 52–166 s, n = 14) based on the total length of the video clip of each calf in the chute. To enable comparison, the final 28 s from both SD and LD categories before calf release were reviewed, and an ethogram was developed to assess the frequency of observable calf behaviours. All calves expressed at least one behaviour indicative of a negative mental state, with ear and head movements being the most frequent. Behaviours observed in SD and LD clips were strongly correlated (Spearman’s rank correlation coefficient 0.875, p < 0.001). Longer confinement was associated with increased frequency of “red flag” behaviours indicating fear and/or stress (chi-square = 10.48, p = 0.0149), including mouth opening, tongue protrusion, rearing and escape attempts. We conclude that calves used in roping events experience fear and stress while held in the chute, especially during longer periods of confinement. Full article

The behaviour of ewes within the vicinity of a natural stream and the impact on stream water quality in New Zealand hill country in summer has not been studied previously. Adult ewes (n = 40) were managed in a 1.7 ha paddock. Ewes were given access to a reticulated water trough for one week, then the trough was covered in the second week, resulting in the stream being the only source of free water available to the ewes. Ewe behaviour was monitored by video surveillance, GPS and Accelerometers. Ewes spent more time grazing and drinking within the stream zone (3 m buffer around the stream) during the restricted vs. unrestricted period (p < 0.05). Restricting water trough access had little impact on nutrient concentrations, except for ammonium-N, which increased (p < 0.05). Increased stream loads of E. coli, ammonium-N, and TP in the outflow from the paddock were evident. The spatial distribution of ewes was influenced by the slope and location of the trough and stream crossings. Ewes were least observed near the stream at night, with the highest activity in daylight. Ewes travelled greater distances as the slope increased, except at very steep slopes. While water trough access had no effect on the time ewes spent within the stream zone, there was a high density of ewe location fixes near the trough that was not seen when access was restricted. The water quality results suggest that the presence of sheep in the paddock had some impact on ammonium-N and E. coli. Full article

This study aimed to evaluate recycled manure solids (RMSs) as an alternative to straw as dairy bedding under controlled in vitro conditions using two different conditioners. Pre-cut straw and RMSs were treated once with either 10 wt.% hydrated lime, 200 mL/m² of an acidic liquid conditioner or left untreated, and incubated for three days at room temperature. Daily, samples were inoculated with manure and Klebsiella (K.) pneumoniae. Outcomes were aesculin-positive Streptococcus spp. and coliform counts, pH, and dry matter (DM) content. Hydrated lime reduced all target bacteria by >99% in both materials. The acidic conditioner decreased K. pneumoniae and streptococcal counts by 98.62%/96.6% (straw) and 98.63%/99.58% (RMSs), respectively. It reduced Escherichia (E.) coli counts by ~67% in both materials without statistical significance (p = 0.064). RMSs showed higher bacterial loads and lower DM content than straw but could be substantially improved by lime treatment. As the conditioner were applied following different manufacturer-recommended dosing principles, these findings reflect effectiveness under practical use rather than intrinsic superiority of one conditioner. RMSs might represent an alternative bedding material when managed with appropriate hygienic measures, although straw showed more favorable microbiological and physicochemical aspects. Both materials contained substantial bacterial loads prior to treatment. Full article

The aim of this research was to evaluate the effect of agro-industrial waste from C. cajan shell, plantain peels (Musa spp.), and Zea mays cob husk on in situ ruminal degradation kinetics and in vitro gas production. Rumen degradation of DM in the soluble fraction (A) was higher (p = 0.0001) in plantain peel (37.5%). The insoluble but potentially degradable fraction (B) was higher (p = 0.0001) in C. Cajan shell (71.7%). Regarding the degradation rate in percentage per hour (c: 0.13%/h), degradation potential (A + B: 86.3%) and effective degradation at the different passage rates (k) (0.02: 79.6%, 0.05: 72.4%, and 0.08: 67.3% k, respectively), it was higher (p < 0.05) in the plantain peels. Rumen NDF degradation was higher (p < 0.05) in plantain peels for all degradation parameters (A + B: 80.8, k: 0.02: 57.1%, 0.05: 44.9%, and 0.08: 37.6%, respectively). Total gas production kinetics (D; 333.3 mLgas/0.5 g degraded DM) and gas production at 24, 48, and 96 h were lower (p = 0.0001) in plantain peels. CH₄ production was low (p = 0.0001) in plantain peels at all evaluated times (24 h: 32.7, 48 h: 37.9, and 96 h: 53.5 mL/0.5 g degraded DM). CO₂ production was lower (p < 0.05) in C. Cajan and plantain peels at all evaluated times. Under the conditions of this study, it can be concluded that the use of plantain peels (Musa spp.) can be beneficial to animals when incorporated into the diet, as it contains a similar protein content to tropical forages, as well as low fiber content, high ruminal degradation, and secondary compounds that benefit energy maximization by mitigating enteric gas production in ruminants. Full article

Small ruminants, such as newborn lambs, rely on timely colostrum intake to acquire passive immunity through the absorption of immunoglobulin (Ig). Evaluating Ig transfer is important for ensuring lamb health and survival. However, current methods such as enzyme-linked immunosorbent assay (ELISA) and radial immunodiffusion (RID) are widely used but remain costly and require specialized facilities. The immunocrit assay has been proposed as a lower-cost alternative for evaluating serum Ig concentrations. This study aimed to evaluate the immunocrit method in lambs by comparing it with ELISA, RID, and total serum protein. Serum was collected from 135 Katahdin-Easycare lambs 24–36 h after birth. Samples were analyzed using sheep immunoglobulin G ELISA, Sheep immunoglobulin G RID, serum protein, and the immunocrit method. Pearson’s correlation was used to assess linear relationships between the methods, and Receiver Operating Characteristics (ROC) analysis was used to evaluate test accuracy, with RID as the gold standard (15 mg/mL cutoff). The immunocrit showed a high correlation with RID (r = 0.870), moderate correlation with serum protein (r = 0.725), and good correlation with ELISA (r = 0.607). The ROC analysis showed that the immunocrit had a sensitivity of 100% at a cutoff of 4.34%. These results indicate that the immunocrit method provides comparable accuracy to RID and serum protein, and could serve as a reliable, practical, and inexpensive tool for on-farm evaluation of passive transfer in Katahdin-Easycare crossbred lambs between 24 and 36 h after birth. Full article

Reduced winter hair shedding in beef cows through the spring and summer months may contribute to heat stress and reduced performance in spring-calving herds. This study evaluated the relationship of hair shedding with the fertility and maternal performance of 72 Dexter cows. Hair shedding data for 20 May, 3 June, 17 June, and 1 July in 2019 were used to classify cows as high or low hair shedders. Hair shedding levels were lower (p < 0.05) for 2-year-old cows than for cows 7+ years of age for the first three dates and lower (p ≤ 0.05) for lactating cows than for dry cows on the first two dates. Concurrent and four years of historical performance records were used to assess the associations between hair shedding and cow–calf performance. Data from 230 natural matings in July and August from 2015 to 2019 were analyzed. Birth to weaning weight data were recorded from 2016 to 2019 on 124 spring-born calves. Cow fertility was higher (p < 0.05) for high-shed cows than for low-shed cows for the 1 July classification. When the records from cows that were dry in 2019 were excluded from testing, fertility was higher (p < 0.05) for high-shed cows than for low-shed cows at all four scoring dates. The associations of cow hair shedding levels with preweaning calf performance were minimal. Dexter cows exhibiting higher hair shedding levels in the spring and summer expressed higher summer fertility. Full article

The aim of the present study was to evaluate the association between seasonal variation, the temperature–humidity index (THI), and lipid indices related to human health in the milk of Simmental and Montbéliarde cows. The investigation was conducted on a dairy farm located in Central Southern Bulgaria over a 12-month period and included 100 lactating cows, with equal numbers from each breed, housed in semi-open free-stall barns and fed an unchanged total mixed ration. Monthly measurements of microclimatic parameters (temperature, relative humidity, THI, and air velocity) were conducted throughout the study, and composite milk samples were analyzed for fatty acid composition by gas chromatography. The atherogenic index (AI), thrombogenic index (TI), health-promoting index (HPI), hypo-/hypercholesterolemic index (h/H), desaturase indices (DI16 and DI18), and the UFA/SFA, PUFA/SFA, and MUFA/SFA ratios were calculated based on the fatty acid profile. The results indicate that season has a statistically significant effect on all studied lipid indices (p < 0.001). The Kruskal–Wallis H values ranged from 16.68 for AI to 27.82 for DI18, indicating that seasonal variations in microclimatic conditions significantly influence the lipid metabolism of the cows. The data for the studied lipid indices indicate that the most favorable fat profile for human health was observed in autumn, characterized by lower AI (2.24) and TI (1.26) values and higher HPI (0.45) and h/H (0.76) values. Seasonal variation also affected DI 16 and DI 18, with the most favorable values for humans observed in autumn (DI 16: 4.38; DI 18: 74.39). The ratios of unsaturated to saturated fatty acids (UFA/SFA, PUFA/SFA, and MUFA/SFA) indicate that the milk from the studied farm exhibits the most favorable functional properties in autumn. Full article

Numerous studies have suggested controversial findings regarding the impact of microalgae on dairy cows’ production parameters. This meta-analysis aimed to investigate the overall effects of microalgae on dairy cows’ performance and milk fatty acids and to highlight variation factors inducing opposite findings in the impact of microalgae on dairy cow nutrition. Following the PRISMA guidelines, articles examining the influence of microalgae on dairy cows’ performance and milk fatty acids were searched through Google Scholar, Web of Science, Science Direct, and Scopus. As a result, 10 articles were selected and categorized into 18 experiments for inclusion in our meta-analysis. The results suggested significant increasing effects (p < 0.05) of microalgae on milk yield and rumenic acid, while decreasing effects (p < 0.05) were observed in caproic acid, caprylic acid, capric acid, lauric acid, pentadecanoic acid, and myristic acid. The sub-group analysis suggested that the Aurantiochytrium limacinum microalgae strain showed more consistent effects compared with other evaluated strains. Thus, the present meta-analysis makes a valuable contribution to comprehending the beneficial effect of microalgae in dairy cow nutrition and the factors that may influence the impact of this sustainable feed additive on milk production and quality. Full article

Tannins are known for their ability to modify digestion and reduce CH₄ emissions in ruminants. Novel forages able to tolerate water deficits often contain low-to-moderate levels of dietary tannins. The aim of the study was to compare the effect of tannic acid (hydrolysable tannin, HT) and Tannivin (quebracho, condensed tannins, CTs) added to a total mixed ration at a concentration of 2.5% on rumen fermentation over time using in vitro methods. The substrates were incubated with buffered rumen fluid at 39 °C for 0, 3, 6, 12, 24, and 48 h to study dry matter (DM) degradability, tannin disappearance, utilizable protein (uCP), and rumen fermentation parameters. In parallel, gas production was measured using the ANKOM-RF Gas Production System. Gas composition was determined after 24 and 48 h of incubation. DM degradability was influenced by the incubation time (p < 0.001), reaching approximately 50% after 48 h, with a similar course of degradability for both tannin types. Tannin disappearance was significantly influenced by the type of tannins and the incubation time (both p < 0.001), reaching 50% in HTs and 39% in CTs within the first 6 h of fermentation. Production of individual and total VFA and uCP increased during incubation (p < 0.001) but were not influenced by the tannin type. However, the formation of uCP was relatively stable over time. Ammonia-N production increased during the first 12 h of fermentation with both tannin types and the increase continued with HTs (p < 0.001). Gas and methane production increased during fermentation and the increase was more substantial in HTs (p < 0.001). Our results suggest that at moderate concentrations, tannins mainly affect protein metabolism, with a minor effect on rumen fermentation. Full article

Livestock production in the high Andes is vital for rural livelihoods and food security but is limited by poor pasture quality, environmental variability, and restricted resources. Pasture improvement, achieved through management practices and particularly through fertilization, may enhance productivity and sustainability in high-Andean livestock systems. This study aimed to characterize mixed herds composed of domestic sheep (Ovis aries), alpacas (Vicugna pacos), llamas (Lama glama), and domestic cattle (Bos taurus) and to evaluate the role of pasture fertilization on herd composition and livestock size. Primary data were collected through structured questionnaires administered to 88 randomly selected livestock producers, complemented by direct field observations of grazing areas, corrals, shelters, and water sources. The survey documented herd structure, grazing management, pasture conservation, fertilization practices, and farm infrastructure. Data from multiple farms were analyzed using a clustering approach to group production units with similar characteristics, and statistical models were applied to assess the effects of fertilization, pasture area, and water sources. Three distinct clusters were identified: one dominated by alpacas, another by sheep, and a third by llamas with the most uniform stocking density. Pasture fertilization was most common in the sheep-dominated cluster and was significantly associated with higher sheep numbers, while no significant effects were detected for alpacas, llamas, or cattle. Farms without fertilization showed slightly higher overall livestock size; however, a strong negative interaction between pasture area and lack of fertilization indicated that expanding grazing land alone could not offset low forage quality. These findings suggest that targeted fertilization, when combined with sustainable grazing practices, may contribute to improved herd performance and long-term resilience in heterogeneous Andean livestock systems. Full article

Prolonged drought and resource scarcity have limited feed availability for livestock in arid and semi-arid regions, necessitating strategic resource management to sustain cattle productivity. This study evaluated the use of spineless cactus as an alternative feed ingredient for ruminants in dryland areas. The experiment assessed in vitro cumulative gas production from silages of Miúda forage cactus (Nopalea cochenillifera Salm-Dyck) combined with Tifton 85 Bermuda Grass (Cynodon sp.) hay and varying levels of urea (1%, 2%, and 3% on a dry matter basis) as a nitrogen source. Traditional supplements comprising Tifton hay, wheat bran, soybean meal, and urea served as controls. Kinetic organic matter degradation parameters exceeded 60%. Dry matter degradability was similar across all urea levels at six hours but diverged over time, with the 3% urea treatment showing lower degradability at 48 and 96 h. Organic matter degradability varied throughout incubation, with the 2% urea treatment performing best. Overall, these findings suggest that silage made from native Miúda forage cactus combined with Tifton hay and up to 2% urea can serve as an effective alternative roughage to meet the nutritional requirements of ruminants, particularly during periods of feed scarcity in arid environments. Full article

Precision livestock farming (PLF), by integrating multimodal sensor data, provides opportunities to enhance welfare monitoring and management in small ruminants. This study evaluated whether environmental, physiological, and behavioral measurements—including the temperature–humidity index (THI), carbon dioxide (CO₂) and ammonia (NH₃) concentrations measured at the barn level, body condition score (BCS), rectal and ocular temperatures, GPS-derived locomotion metrics, accelerometry data, and fixed animal traits—can serve as key predictors of welfare and productivity in dairy sheep. Data were collected from 90 ewes: all animals underwent the same repeated welfare assessments, while 30 of them were additionally equipped with GPS–accelerometer sensor collars; environmental conditions were continuously recorded for the entire flock, generating 773 complete multimodal records. All predictive models were developed using data from all 90 ewes; collar-derived behavioral variables were included only for individuals equipped with GPS–accelerometer collars. Nine regression methods (linear regression (LR), partial least square regression (PLSR), elastic net (EN), mixed-effects models, random forest (RF), extreme gradient boosting (XGBoost), support vector regression (SVR), neural networks (multilayer perceptron, MLP), and an ensemble of RF–XGBoost–EN were evaluated using a combination of nested cross-validation (CV) and leave-one-animal-out CV (LOAOCV) to ensure robustness and generalization at the individual animal level. Nonlinear models—particularly RF, XGBoost, SVR, and the ensemble—consistently delivered superior performance across traits. For behavioral (e.g., daily distance movement) and thermal indicators (e.g., medial canthus temperature), the highest predictive capacity (R² ≈ 0.60–0.70) was achieved, while moderate predictive capacity (R² ≈ 0.40–0.50 and ≈0.35–0.45), respectively, was observed for respiratory rate and milk yield, reflecting their multifactorial nature. Feature importance analyses underscored the relevance of THI, CO₂, NH₃, concentrations, and BCS across results. Overall, these findings demonstrate that multimodal sensor fusion can effectively support the prediction of welfare and productivity indicators in intensively reared dairy sheep and emphasize the need for larger and more diverse datasets to further enhance model generalizability and model transferability. Full article

The aim of this study was to evaluate the effects of oregano essential oil (OEO) as a replacement for monensin (MON) on performance, carcass characteristics and meat quality in heifers finished either in confinement or on pasture. Thirty-six Nellore heifers (252.44 kg ± 21.80 kg) were distributed in a completely randomised design in a 2 × 2 factorial scheme, with two types of additives and two finishing systems. In both systems, a concentrate at 1.5% of body weight (BW) on a dry matter (DM) basis containing MON (282.2 mg/animal/day) or OEO (300 mg/animal/day) was offered daily. The final BW (FBW) and average daily gain (ADG) were higher in confinement-finished animals than in those finished on pasture (p < 0.01). There was no effect from the finishing system (p ≥ 0.376) or additive (p ≥ 0.057) for hot-carcass weight, hot-carcass yield, subcutaneous fat thickness, or the Longissimus lumborum area. The pH and shear force of the meat did not differ between treatments (p ≥ 0.076). Finishing in confinement resulted in brighter meat than finishing on pasture (p ≤ 0.006). The use of OEO increased the redness of the meat (p ≤ 0.042). Consumer perception (n = 63) of the sensory attributes of aroma, colour, tenderness, flavour and juiciness was not affected by the treatments (p > 0.05). Heifers finished in confinement or on pasture, with the same proportion of concentrate in the diet and the addition of MON or OEO, presented similar characteristics for both the carcass and the meat. Full article

Barley is more extensively and more rapidly fermentable than maize, thus it is supposed to increase digestive disorders in ruminants. However, the effect of cereal type on animal performance and digestion may vary with processing degree. In the present experiment, the effect of dry-rolling or grinding barley and maize, as the main cereals in a concentrate containing a high proportion of starch with different rates of fermentation, on intensively reared beef cattle performance, diet digestibility, and feed intake amount and pattern, was studied. Thirty-six 3-month-old male calves were allocated to one of four diets consisting of barley straw (BS) and a concentrate with 60% cereals (barley and maize in proportions 75:25 or 25:75) presented dry-rolled or ground through a 3.5 mm sieve. The experimental period was divided into two phases of 10 weeks each: from start to 277 ± 3.6 kg live weight (LW; Growing), and from 289 ± 3.8 kg LW to slaughter (399 ± 4.6 kg; Finishing). For the Growing phase, there were no differences (p > 0.10) between the majority cereal in the concentrates, nor between their processing methods, in the daily intake of concentrate and BS, and in the animals’ final LW. With respect to Finishing, the interaction between cereal type and processing was significant (p < 0.05) for concentrate daily intake. As a result, animals consuming ground barley ate less concentrate than those fed rolled barley, whereas there were no differences between processing methods for animals fed maize-based diets. Animals consuming ground-barley concentrates consumed significantly more straw than those fed on dry-rolled-barley concentrates (p < 0.05 for Growing and p < 0.01 for Finishing) during the first four hours after feeding. No such differences appeared in animals consuming maize-based concentrates. Starch digestibility was higher in animals fed ground cereals vs. dry-rolled cereals during the Growing phase (p = 0.048), whereas NDF digestibility was also higher (p = 0.008) in animals fed ground cereals during the Finishing phase. The faeces from animals fed on rolled-maize concentrates showed a higher concentration of purine bases than the faeces of animals fed on rolled-barley concentrates (p = 0.016), although there were no differences for the ground cereals. Overall, the results reported indicated that replacing maize with barley in diets for feedlot beef cattle did not affect average daily gain, intake of straw or concentrate, or feed conversion ratios (total or considering just the concentrate); hence the inclusion of either cereal in greater proportions should be based on their market price and on the final cost of the compound feed (which may include different ingredients). The processing method of the cereals (grinding or dry-rolling) also had no influence on the above-mentioned variables, so the selection of the method should be based on their relative cost, exclusively in terms of feed efficiency. Full article